JP2021016264A - Power converter - Google Patents

Abstract

To provide a power converter that improves harmonic and a power factor and is downsized.SOLUTION: A power converter includes: a main circuit unit 100 having a three-phase diode rectifier 2 provided so as to be connectable to an AC power source 1, and a smoothing capacitor 3 connected between a DC end on a high potential side and a DC end on a low potential side of the three-phase diode rectifier 2; and a current passing unit that is a circuit for electrically connecting an auxiliary power source 4 for outputting a high frequency voltage and an AC end and the DC end of the three-phase diode rectifier 2, and maintains a current ratio flowing from a plurality of AC ends of the three-phase diode rectifier 2 at a predetermined value to cause an auxiliary current to flow in which a current flowing from the AC end of the three-phase diode rectifier 2 is superposed by a high frequency current due to an output voltage of the auxiliary power supply 4 in the vicinity of timing when difference in a value of two phases of three-phase AC voltage output from the AC power source 1 becomes zero.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to a power converter.

The power conversion device is widely used in a configuration including a three-phase diode bridge circuit. In recent years, in order to reduce harmonics and improve the power factor, for example, a technique using a 12-pulse rectifier, a PWM converter, a Wien converter, a 24-pulse rectifier, and an electric smoothing inductor (ESI) has been used. Has been done.

Japanese Patent No. 3580809

Novel Hybrid Unidirectional Three-Phase AC-DC Converter Systems, Swiss Federal Institute of Technology (ETH) Zurich for the degree of Doctor of Sciences, 2009 Development of a new commutation method that drastically reduces commutation failures of matrix converters, Institute of Electrical Engineers of Japan D, Vol. 128, No. 8, 2007, pp829-836

A general three-phase diode bridge is often used in combination with an ACL (alternating current reactor) or a DCL (direct current reactor) for reducing harmonics and improving the power factor. However, when the required regulations on harmonics and power factor become stricter, it is difficult to meet the requirements even if ACL or DCL is used.

Further, the 12-pulse rectifier and the 24-pulse rectifier require a transformer having a commercial frequency such as a Δ-Y type or a Δ-Δ type, and it is difficult to miniaturize the power conversion device.

PWM converters and Wien converters use semiconductor switches to control current, so they are highly effective in reducing harmonics and improving power factor, but they cool the reactor for interconnection and the heat associated with energy loss when converting power. It is difficult to reduce the size because a cooling device is required.
Rectifiers using ESI can reduce DCL, but the effect of improving harmonics is not so high, and it is difficult to meet the strict regulations required for harmonics.

An embodiment of the present invention has been made in view of the above circumstances, and an object of the present invention is to realize miniaturization of a power conversion device having improved harmonics and power factor.

The power conversion device according to the embodiment is a smoothing device connected between a three-phase diode rectifier provided so as to be connectable to an AC power supply and a DC end on the high potential side and a DC end on the low potential side of the three-phase diode rectifier. A circuit that electrically connects a main circuit unit including a capacitor, an auxiliary power source that outputs a high-frequency voltage, and an AC end and a DC end of the three-phase diode rectifier, and is a plurality of the three-phase diode rectifiers. The three-phase diode rectifier is located near the timing when the difference between the two-phase values of the three-phase AC voltage output from the AC power supply becomes zero while maintaining the current ratio flowing in from the AC end of the AC power supply at a predetermined value. A current flow section for passing an auxiliary current in which a high-frequency current due to the output voltage of the auxiliary power source is superimposed on the current flowing from the AC end of the auxiliary current, and an auxiliary circuit section for charging the smoothing capacitor with the auxiliary current. , Equipped with.

FIG. 1 is a diagram schematically showing a configuration example of a power conversion device according to the first embodiment. FIG. 2 is a diagram for explaining an example of the operation of the power conversion device of the first embodiment. FIG. 3 is a diagram schematically showing a configuration example of the power conversion device of the second embodiment. FIG. 4 is a diagram schematically showing a configuration example of the power conversion device of the third embodiment. FIG. 5 is a diagram schematically showing a configuration example of the power conversion device of the fourth embodiment. FIG. 6 is a diagram schematically showing a configuration example of a first dropper and a second dropper of the power conversion device shown in FIG. FIG. 7 is a diagram schematically showing a configuration example of the power conversion device according to the fifth embodiment. FIG. 8 is a diagram schematically showing a configuration example of the power conversion device of the sixth embodiment. FIG. 9 is a diagram schematically showing a configuration example of the power conversion device according to the seventh embodiment. FIG. 10 is a diagram schematically showing a configuration example of the power conversion device of the eighth embodiment. FIG. 11 is a diagram schematically showing a configuration example of a power conversion device according to a ninth embodiment. FIG. 12 is a diagram schematically showing a configuration example of the power conversion device according to the tenth embodiment. FIG. 13 is a diagram schematically showing a configuration example of the power conversion device of the eleventh embodiment. FIG. 14 is a diagram schematically showing a configuration example of the power conversion device according to the twelfth embodiment. FIG. 15 is a diagram schematically showing a configuration example of the power conversion device according to the thirteenth embodiment.

Hereinafter, the power conversion device of the first embodiment will be described in detail with reference to the drawings.
The same or equivalent configurations in the plurality of embodiments will be described with the same reference numerals.
FIG. 1 is a diagram schematically showing a configuration example of a power conversion device according to the first embodiment.

The power conversion device of this embodiment includes a main circuit unit 100 and an auxiliary circuit unit 200. The main circuit unit 100 includes a three-phase diode rectifier 2, a DC smoothing capacitor 3, an AC end electrically connected to an AC power supply 1, and a DC end electrically connected to a DC load (not shown). , Is equipped.

The three-phase diode rectifier 2 is connected between the AC end and the DC end of the power converter, and full-wave rectifies the AC power supplied from the AC power supply 1 and outputs it to the DC main circuit. The three-phase diode rectifier 2 includes, for example, a three-phase bridge circuit including a plurality of diodes 2A.

In the plurality of diodes 2A, the direction from the DC main circuit on the low potential side to the DC main circuit on the high potential side is set as the forward direction so that the anode is arranged on the low potential side and the cathode is arranged on the high potential side. It is arranged in each of the upper arm and the lower arm of each phase of the three-phase diode rectifier 2.

The DC smoothing capacitor 3 is connected between the DC main circuit on the high potential side and the DC main circuit on the low potential side in front of the DC end of the power conversion device. The DC smoothing capacitor 3 is charged by the current output from the three-phase diode rectifier 2, suppresses fluctuations in the voltage of the DC main circuit, and smoothes the DC power output from the power converter.

The auxiliary circuit unit 200 includes a current flow unit and an auxiliary power supply.
The auxiliary power supply outputs a high frequency voltage to the current flow section.
The current flow section is a circuit that connects the AC end and the DC end of the three-phase diode rectifier 2, and maintains the current ratio flowing from the AC end of the three-phase diode rectifier 2 at a predetermined value, and the AC power supply 1 In the vicinity of the timing when the difference between the two-phase values of the three-phase AC voltage output from is zero, the high-frequency current due to the output voltage of the auxiliary power supply is superimposed on the current flowing from the AC end of the three-phase diode rectifier. An auxiliary current is passed between the AC end and the DC end of the three-phase diode rectifier 2.

The current flow section includes a first transformer section 61, a second transformer section 62, and a plurality of single-phase rectifying diode bridges 5. The auxiliary power supply includes a high frequency auxiliary power supply 4. The first transformer unit 61 includes three diversion transformers (first transformers) 6UV, 6VW, and 6WU. The diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 include a first winding and a second winding having the opposite polarity to the first winding. The ratio of the currents flowing into the first winding and the second winding is maintained at a predetermined value by the ratio of the number of turns of the first winding to the second winding of the shunt transformers 6UV, 6VW, and 6WU. In the present embodiment, the ratio of the number of windings of the first winding and the second winding of the diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 is 1: 1.

The diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 are electrically connected to one of the U-phase, V-phase, and W-phase AC lines extending from the AC power supply 1 at the start end of the first winding, and are the first. At the end of the two windings, it is electrically connected to the other one of the U-phase, V-phase, and W-phase AC lines.
The diversion transformer 6UV of the first transformer unit 61 is connected to the U-phase AC line at the start end of the first winding, and is connected to the V-phase AC line at the end of the second winding. The diversion transformer 6VW of the first transformer unit 61 is connected to the V-phase AC line at the start end of the first winding, and is connected to the W-phase AC line at the end of the second winding. The diversion transformer 6WU of the first transformer unit 61 is connected to the W-phase AC line at the start end of the first winding, and is connected to the U-phase AC line at the end of the second winding.
The end of the first winding and the start of the second winding of the diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 are connected to the AC end of the corresponding single-phase rectifying diode bridge 5.

The second transformer unit 62 includes three diversion transformers (second transformers) 6UV, 6VW, and 6WU. The diversion transformers 6UV, 6VW, and 6WU of the second transformer unit 62 include a third winding and a fourth winding having the opposite polarity to the third winding. The ratio of the currents flowing into the third winding and the fourth winding is maintained at a predetermined value by the ratio of the number of turns of the third winding to the fourth winding of the shunt transformers 6UV, 6VW, and 6WU. In this embodiment, the ratio of the number of windings of the third winding and the fourth winding of the divergence transformers 6UV, 6VW, and 6WU is 1: 1.

The diversion transformers 6UV, 6VW, and 6WU of the second transformer unit 62 are electrically connected to one of the U-phase, V-phase, and W-phase AC lines extending from the AC power supply 1 at the start end of the third winding, and the first At the end of the four windings, it is electrically connected to the other one of the U-phase, V-phase, and W-phase AC lines.
The diversion transformer 6UV of the second transformer section 62 is connected to the U-phase AC line at the start end of the third winding, and is connected to the V-phase AC line at the end of the fourth winding. The diversion transformer 6VW of the second transformer unit 62 is connected to the V-phase AC line at the start end of the third winding, and is connected to the W-phase AC line at the end of the fourth winding. The diversion transformer 6WU of the second transformer section 62 is connected to the W-phase AC line at the start end of the third winding, and is connected to the U-phase AC line at the end of the fourth winding.
The end of the third winding and the start of the fourth winding of the diversion transformers 6UV, 6VW, and 6WU of the second transformer unit 62 are connected to the AC end of the corresponding single-phase rectifying diode bridge 5. The six diversion transformers 6UV, 6VW, and 6WU are high frequency transformers having low impedance with respect to the common mode.

The power conversion device of this embodiment includes six single-phase rectifying diode bridges 5 corresponding to six diversion transformers 6UV, 6VW, and 6WU. Each of the plurality of single-phase rectifying diode bridges 5 includes two AC ends, two DC ends, and four high-speed diodes 5a.
Two high-speed diodes 5a are connected in series between the DC end on the low potential side and the DC end on the high potential side with the direction from the low potential side to the high potential side as the forward direction. The space between the two high-speed diodes 5a is the AC end of the single-phase rectifying diode bridge 5.

One of the AC ends of the single-phase rectifying diode bridge 5 is connected to the end of the first winding (or third winding) of the divergence transformer 6UV, 6VW, 6WU, and the other one of the AC ends is the divergence transformer 6UV. , 6VW, 6WU connected to the start of the second winding (or fourth winding). The two DC ends of the single-phase rectifying diode bridge 5 are connected to the high-frequency auxiliary power supply 4.

The auxiliary circuit unit 200 includes two sets of a set of DC lines (a DC line on the high potential side and a DC line on the low potential side) to which the DC ends of the three single-phase rectifying diode bridges 5 are connected. Three DC ends of each of the three single-phase rectifying diode bridges (first single-phase rectifying diode bridge) 5 electrically connected to the three divergent transformers 6UV, 6VW, and 6WU of the first transformer unit 61 are in one set. It is connected to the DC line of. Three single-phase rectifying diode bridges (second single-phase rectifying diode bridges) 5 connected to the three divergent transformers 6UV, 6VW, and 6WU of the second transformer unit 62 The two DC ends of each are the other set of DC lines. Is electrically connected to.

The high frequency auxiliary power supply 4 includes a first high frequency power supply circuit 4A and a second high frequency power supply circuit 4B. The first high-frequency power supply circuit 4A is connected to the DC main circuit on the high potential side of the main circuit unit 100 and the DC line on the high potential side of the auxiliary circuit unit 200. The second high-frequency power supply circuit 4B is connected to the DC main circuit on the low potential side of the main circuit unit 100 and the DC line on the low potential side of the auxiliary circuit unit 200.

The first high-frequency power supply circuit 4A is connected to the DC line on the high potential side of the two sets of DC lines. The first high-frequency power supply circuit 4A outputs voltages having opposite phases to the two DC lines on the high potential side. The second high-frequency power supply circuit 4B is connected to the DC line on the low potential side of the two sets of DC lines. The second high-frequency power supply circuit 4B outputs voltages having opposite phases to the two DC lines on the low potential side. Output voltages of the same phase are supplied to the pair of DC lines connected to the three common single-phase rectifying diode bridges 5.

Next, an example of the operation of the power conversion device of this embodiment will be described.
The current output from the AC power supply 1 mainly flows to the three-phase diode rectifier 2. The three-phase diode rectifier 2 converts the supplied alternating current into a direct current and outputs it to the direct current main circuit. The DC smoothing capacitor 3 is charged by the DC current output from the three-phase diode rectifier 2. Fluctuations in the direct current output from the power converter are suppressed by the direct current smoothing capacitor 3.

When the difference between the two phase voltages output from the AC power supply 1 becomes smaller, for example, when the difference between the U-phase voltage and the V-phase voltage becomes smaller, it is assisted by the voltage of the high-frequency auxiliary power supply 4. , The current flows through the shunt transformer 6UV and the single-phase rectifier diode bridge 5 connected to the shunt transformer 6UV.

When the power conversion device of this embodiment is operating, the high frequency auxiliary power supply 4 continues to output a high frequency voltage. That is, it is not necessary to control the operation of the high frequency auxiliary power supply 4 according to the output voltage of each phase of the AC power supply 1, and it is possible to avoid complicated control of the high frequency auxiliary power supply 4.

When a current flows through the split transformer 6UV and the single-phase rectifying diode bridge 5 connected to the split transformer 6UV, the current flowing through the U-phase AC line and the current flowing through the V-phase AC line due to the action of the split transformer 6UV. Is the inverse of the turns ratio between the first winding and the second winding (or the turns ratio between the third winding and the fourth winding). That is, the ratio of the U-phase current flowing into the divergence transformer 6UV from the AC end of the three-phase diode rectifier 2 to the V-phase current is set to a predetermined value by the turns ratio between the first winding and the second winding. Be maintained.

In the present embodiment, for example, the turns ratio between the first winding and the second winding (or the turns ratio between the third winding and the fourth winding) of the shunt transformer 6UV is 1: 1 and therefore the U phase. In the AC line with the V phase, the current flowing in the AC line of the W phase and the current having the opposite polarity flow in half (1/2) each. The same operation as described above is performed for the combination of AC lines of other phases (V phase and W phase, and W phase and U phase).

In the power conversion device of the present embodiment, the ratio of the currents flowing into the divergence transformer 6UV from the U-phase AC line and the V-phase AC line is maintained to be 1: 1 and the V-phase AC line and the W-phase are maintained. The ratio of the current flowing from the AC line to the split transformer 6VW is maintained at 1: 1 and the ratio of the current flowing from the W phase AC line to the U phase AC line to the split transformer 6WU is 1: 1. It is maintained to be 1. By the above operation, when the difference between the two phase voltages of the AC power supply 1 becomes small, the power of the present embodiment is provided by the current split transformer 6UV, 6VW, 6WU, the single-phase rectifying diode bridge 5, and the high-frequency auxiliary power supply 4. The output current of the converter has a current waveform equivalent to that of a 12-pulse rectifier, and the 5th and 7th harmonic components are reduced.

In the present embodiment, two diversion transformers 6UV, 6VW, and 6WU are connected between the lines of the three-phase AC line, respectively. Anti-phase voltages are output from the high-frequency auxiliary power supply 4 to the two diversion transformers 6UV, 6VW, and 6WU connected between the same lines via the single-phase rectifying diode bridge 5.

For example, if the voltage output from the high-frequency auxiliary power supply 4 has the same polarity as the voltage of the two-phase AC line to which the diversion transformers 6UV, 6VW, 6WU are connected, the circuit after the diversion transformers 6UV, 6VW, 6WU Current flows. If the voltage output from the high-frequency auxiliary power supply 4 has the opposite polarity to the two-phase voltage to which the shunt transformers 6UV, 6VW, and 6WU are connected, current will flow through the circuits after the shunt transformers 6UV, 6VW, and 6WU. Absent.

From the above, the voltage phase when one divergence transformer 6UV, 6VW, 6WU connected to the same AC end set of the three-phase diode rectifier 2 operates is the voltage phase when the other divergence transformer 6UV, 6VW, 6WU operates. The phase is opposite to the voltage phase at the time. Therefore, the two diversion transformers 6UV, 6VW, and 6WU connected between the same AC lines do not pass at the same time.

Note that FIG. 1 does not show an AC reactor connected immediately after the AC power supply 1 or a DC reactor that suppresses the current ripple flowing through the DC smoothing capacitor 3, but the same applies even if the power conversion device includes these. Operation is possible.

FIG. 2 is a diagram for explaining an example of the operation of the power conversion device of the first embodiment.
Here, an example of the result of performing a simulation assuming a power conversion device further provided with an AC reactor (not shown) arranged immediately after the AC power supply 1 will be described. FIG. 2 shows an example of waveforms of the AC power supply UVW phase voltage, the AC power supply U-phase current, and the U-phase auxiliary current in order from the top. The voltage and current of the AC power supply 1 are, for example, examples of values detected at the AC end of each phase of the three-phase diode rectifier 2.

According to FIG. 2, the U-phase voltage output from the AC power supply 1 and the U-phase current are substantially in phase. The U-phase current waveform input to the three-phase diode rectifier 2 is not a rabbit ear-shaped waveform, which is a general input current waveform of the three-phase diode rectifier 2, but each polarity like the input current waveform of a 12-pulse rectifier. The waveform has two current steps.

The U-phase auxiliary current is a current flowing through the U-phase AC line of the auxiliary circuit unit 200, and is near the timing at which the U-phase voltage waveform and the V-phase voltage waveform intersect (the timing at which the phase voltage difference becomes zero). In addition, a large value was obtained in the vicinity of the timing at which the U-phase voltage waveform and the W-phase voltage waveform intersect (the timing at which the difference in phase voltage becomes zero). According to the example shown in FIG. 2, when the difference between the voltage values of the two phases becomes small, the diversion transformer 6UV, 6VW, 6WU and the single-phase rectifying diode bridge 5 connected to the AC line of the two phases The result was that an auxiliary current with a high-frequency current superimposed was passed through.
As described above, according to the power conversion device of the present embodiment, it is possible to obtain an output waveform equivalent to the configuration including the 12-pulse rectifier, and to reduce the harmonics of the output power.

Further, since the shunt transformers 6UV, 6VW, and 6WU are excited by the frequency of the high frequency auxiliary power supply 4 and do not depend on the frequency component of the commercial power supply, the frequency of the high frequency auxiliary power supply 4 can be sufficiently increased to obtain the shunt transformers 6UV, 6VW, The 6WU can be easily miniaturized and the loss can be reduced. Among the configurations used in the power conversion device of the present embodiment, the shunt transformers 6UV, 6VW, and 6WU have larger outer shapes, but the shunt transformers 6UV, 6VW, and 6WU are formed by increasing the frequency of the high frequency auxiliary power supply 4. Can be miniaturized, and the power conversion device of the present embodiment can be miniaturized.

That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the second embodiment will be described in detail with reference to the drawings.
FIG. 3 is a diagram schematically showing a configuration example of the power conversion device of the second embodiment.
Here, a configuration example of the high frequency auxiliary power supply 4 will be described. The configuration other than the high-frequency auxiliary power supply 4 is the same as that of the power conversion device of the first embodiment described above.

The high-frequency auxiliary power supply 4 includes a high-frequency inverter 41 and a high-frequency transformer 42.
The high frequency inverter 41 has two legs. Each of the two legs includes two power semiconductor elements 41A connected in series between the DC main circuit on the high potential side and the DC main circuit on the low potential side of the main circuit unit 100. In each leg, the two power semiconductor elements 41A are AC ends of the high frequency inverter 41 and are electrically connected to the high frequency transformer 42.

The power semiconductor element 41A has, for example, a configuration in which a switching element such as a power MOSFET (metal-oxide semiconductor field-effect transistor) or an IGBT (Insulated Gate Bipolar Transistor) and a freewheeling diode are connected in parallel.

The power conversion device of the present embodiment includes a control circuit (not shown), and the control circuit may generate a gate signal of the power semiconductor element 41A of the high frequency inverter 41 to control the operation of the high frequency inverter 41. The frequency of the AC power output from the high-frequency inverter 41 can be adjusted by the gate signal generated by the control circuit. The control circuit includes, for example, at least one processor such as a CPU or MPU, and a memory in which a program executed by the processor is recorded.

The high frequency transformer 42 includes a first transformer 42A and a second transformer 42B.
The primary winding of the first transformer 42A has a start end electrically connected to one AC end of the high frequency inverter 41 and an end electrically connected to the other AC end of the high frequency inverter 41.

The secondary winding of the first transformer 42A is electrically connected to one of the DC lines on the high potential side at the end and electrically connected to the other of the DC lines on the high potential side at the beginning. The secondary winding of the first transformer 42A is electrically connected to the DC main circuit on the high potential side at the intermediate end.

The primary winding of the second transformer 42B has a start end electrically connected to one AC end of the high frequency inverter 41 and an end electrically connected to the other AC end of the high frequency inverter 41.

The secondary winding of the second transformer 42B has a start end electrically connected to one of the DC lines on the low potential side and an end electrically connected to the other DC line on the low potential side. The secondary winding of the second transformer 42B is electrically connected to the DC main circuit on the low potential side at the intermediate end.

The first transformer 42A transforms and insulates the AC power output from the high-frequency inverter 41, and generates a power supply voltage output from the first high-frequency power supply circuit 4A. The second transformer 42B transforms and insulates the AC power output from the high frequency inverter 41, and generates a power supply voltage output from the second high frequency power supply circuit 4B.

That is, the first high frequency power supply circuit 4A includes the high frequency inverter 41 and the first transformer 42A, and the second high frequency power supply circuit 4B includes the high frequency inverter 41 and the second transformer 42B. The high frequency inverter 41 is shared by the first high frequency power supply circuit 4A and the second high frequency power supply circuit 4B.

The power conversion device of this embodiment is the same as that of the first embodiment except for the configuration of the high frequency auxiliary power supply 4 described above. That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the third embodiment will be described in detail with reference to the drawings.
FIG. 4 is a diagram schematically showing a configuration example of the power conversion device of the third embodiment.
The power conversion device of the present embodiment further includes a first voltage correction diode 7A and a second voltage correction diode 7B.

In the first voltage correction diode 7A, the cathode is electrically connected to the DC end on the high potential side of the three-phase diode rectifier 2, the anode is electrically connected to the first high frequency power supply circuit 4A, and the high potential is from the low potential side. It is connected with the direction toward the side as the forward direction.

In the second voltage correction diode 7B, the anode is electrically connected to the DC end on the low potential side of the three-phase diode rectifier 2, the cathode is electrically connected to the second high frequency power supply circuit 4B, and the high potential is from the low potential side. It is connected with the direction toward the side as the forward direction.

The first voltage correction diode 7A and the second voltage correction diode 7B are used for the period other than the flow period of the divergence transformers 6UV, 6VW, 6WU and the single-phase rectifier diode bridge 5 (the period during which the current should flow only in the three-phase rectifier 2). This prevents a part of the current output from the AC power supply 1 from flowing to the shunt transformers 6UV, 6VW, and 6WU.

The power conversion device of the present embodiment has the same configuration as the power conversion devices of the first and second embodiments described above, except that the first voltage correction diode 7A and the second voltage correction diode 7B are provided.

Next, a phenomenon in which a current flows through the split transformers 6UV, 6VW, and 6WU other than the current flow period will be described.
When a current flows through the diode 2A of the three-phase diode rectifier 2, the drop voltage of the diode 2A increases. When the value of the circuit resistance based on the drop voltage of the diode 2A becomes equal to or higher than the value of the impedance of the auxiliary circuit unit 200, a part of the current output from the AC power supply 1 flows to the divergence transformers 6UV, 6VW, and 6WU.

At this time, the current flowing from the AC power supply 1 to the split transformers 6UV, 6VW, 6WU becomes the exciting current of the split transformers 6UV, 6VW, 6WU. In the power conversion device of the present embodiment, since the divergence transformers 6UV, 6VW, and 6WU are miniaturized corresponding to high frequency excitation, they are magnetically saturated by the exciting current flowing outside the current flow period and are output from the high frequency auxiliary power supply 4. When the exciting current due to the voltage increases rapidly, not only the energy loss increases, but also the power conversion device is more likely to be destroyed.

Therefore, in the power conversion device of the present embodiment, the first voltage correction diode 7A and the second voltage correction diode 7B are connected between the auxiliary circuit unit 200 and the DC main circuit, and the diode 2A of the three-phase diode rectifier 2 is connected. It suppresses the increase of the drop voltage and prevents the current from flowing to the divergence transformers 6UV, 6VW, and 6WU other than the flow period. That is, in the power conversion device of the present embodiment, it is avoided that the value of the circuit resistance due to the drop voltage of the diode 2A of the three-phase diode rectifier 2 becomes equal to or higher than the value of the impedance of the auxiliary circuit unit 200 except during the current flow period. , It suppresses the flow of current through the split transformers 6UV, 6VW, and 6WU other than the current flow period. As a result, it is possible to avoid an increase in energy loss in the power conversion device and destruction of the power conversion device.

In order to prevent the magnetic saturation of the divergence transformers 6UV, 6VW, 6WU, it is also possible to reduce the exciting inductance of the divergence transformers 6UV, 6VW, 6WU. However, the exciting current output from the high-frequency auxiliary power supply 4 always increases, which causes an increase in the loss of the power semiconductor element 41A. If the power semiconductor element 41A capable of supporting this is used, it becomes difficult to miniaturize the power conversion device. Further, if an expensive element is adopted to output a large exciting current, the manufacturing cost of the power converter will increase. On the other hand, since the first voltage correction diode 7A and the second voltage correction diode 7B do not need a recovery operation mode, a rectifier diode can be applied, and the above effect can be obtained without using expensive parts. It will be possible.

The first voltage correction diode 7A and the second voltage correction diode 7B can be applied to the power conversion device of all other embodiments, and the same effect can be obtained in either case.

As described above, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the fourth embodiment will be described in detail with reference to the drawings.
FIG. 5 is a diagram schematically showing a configuration example of the power conversion device of the fourth embodiment.
The power conversion device of the present embodiment is different from the first and second embodiments described above in that the auxiliary circuit unit 200 includes the first dropper 8A and the second dropper 8B.

The first dropper 8A and the second dropper 8B are circuits using, for example, a general low-voltage MOSFET having a characteristic having a linear region in which the voltage rises in proportion to the rise in current.

The first dropper 8A is electrically connected between the DC end on the high potential side of the three-phase diode rectifier 2 and the first high-frequency power supply circuit 4A, and is first from the DC end on the high potential side of the three-phase diode rectifier 2. The voltage is lowered toward the high frequency power supply circuit 4A.

The second dropper 8B is electrically connected between the second high frequency power supply circuit 4B and the DC end on the low potential side of the three-phase diode rectifier 2, and is connected to the low potential side of the three-phase diode rectifier 2 from the second high frequency power supply 4B. The voltage drops toward the DC end.

In the first dropper 8A and the second dropper 8B, a voltage of about several V is dropped by a minute current other than the flow period of the auxiliary circuit unit 200, and the saturation region is used in the flow period of the auxiliary circuit unit 200. , Operates to have low resistance.

In the auxiliary circuit unit 200, the current flowing through the divergence transformers 6UV, 6VW, 6WU and the single-phase rectifying diode bridge 5 and the output current of the AC power supply 1 for the first dropper 8A and the second dropper 8B to perform the above operations It is equipped with a detector (not shown) that detects the phase.

FIG. 6 is a diagram schematically showing a configuration example of a first dropper and a second dropper of the power conversion device shown in FIG.
Here, an example of a power conversion device provided with a regenerative dropper as the first dropper 8A and the second dropper 8B is shown. The corresponding configurations of the first dropper 8A and the second dropper 8B are designated by the same reference numerals.

The first dropper 8A and the second dropper 8B include a capacitor 81, power semiconductor elements 82 and 83, a high-frequency isolation transformer 84, a resonance capacitor 85, and a diode rectifier 86. The circuit composed of the power semiconductor elements 82 and 83, the high-frequency isolation transformer 84, the resonance capacitor 85, and the diode rectifier 86 is a regenerative circuit that regenerates energy into the DC smoothing capacitor 3.

In the present embodiment, the electric charge stored in the capacitor 81 is regenerated to the DC smoothing capacitor 3 via the regenerative circuit by operating the power semiconductor elements 82 and 83. Therefore, for example, in the power conversion device of the third embodiment, energy loss occurs in the first voltage correction diode 7A and the second voltage correction diode 7B, but in the power conversion device of the present embodiment, the first dropper 8A and the first dropper 8A and the second are generated. Since it is possible to regenerate a part of the energy with the 2 dropper 8B, it is possible to reduce the energy loss due to the power conversion device. Further, for example, the configuration shown in FIG. 6 can be realized without using a large-sized component, and it is possible to avoid an increase in the size of the power conversion device.

That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.
The configuration of the dropper 8 applied to the power conversion device of the present embodiment can be applied to the power conversion device of all other embodiments, and the same effect can be obtained in any case.

Next, the power conversion device of the fifth embodiment will be described in detail with reference to the drawings.
FIG. 7 is a diagram schematically showing a configuration example of the power conversion device according to the fifth embodiment.
The power conversion device of this embodiment is different from the above-described first to fourth embodiments in that it includes a first block element 9A and a second block element 9B.

The first block element 9A and the second block element 9B include, for example, a semiconductor switch element and a diode connected in parallel with the semiconductor switch element. The diode of the first block element 9A is oriented so as to be electrically connected to the DC end on the high potential side of the three-phase diode rectifier 2 at the anode. The diode of the second block element 9B is oriented to be electrically connected to the DC end on the low potential side of the three-phase diode rectifier 2 at the cathode.

The first block element 9A is provided in a path connecting the first high frequency power supply circuit 4A and the DC main circuit on the high potential side. The first block element 9A is located in front of the end of the auxiliary circuit unit 200 that is electrically connected to the DC end on the high potential side of the three-phase diode rectifier 2, and is the current flow portion and the high potential side of the three-phase diode rectifier 2. It is connected so as to be able to switch the electric connection state with the DC end of the above and block the current from the first high frequency power supply circuit 4A to the DC end on the high potential side of the three-phase diode rectifier 2.

The second block element 9B is provided in a path connecting the second high frequency power supply circuit 4B and the DC main circuit on the low potential side. The second block element 9B is in front of the end of the auxiliary circuit unit 200 that is electrically connected to the DC end on the low potential side of the three-phase diode rectifier 2, and is the current flow portion and the low potential side of the three-phase diode rectifier 2. It is connected so as to be able to switch the electric connection state with the DC end of the three-phase diode rectifier 2 and block the current from the DC end on the low potential side of the three-phase diode rectifier 2 to the second high frequency power supply circuit 4B.

The first block element 9A and the second block element 9B are turned on during the flow period of the auxiliary circuit unit 200, and are turned off except during the flow period of the auxiliary circuit unit 200. As a result, the impedance of the circuit becomes high except for the flow period of the auxiliary circuit unit 200, and it is possible to prevent the current from flowing.

In the present embodiment, the control circuit (not shown) that controls the operation of the first block element 9A and the second block element 9B is a detector that detects the phase of the output current (or output voltage) of the AC power supply 1. A gate signal for controlling the operation of the first block element 9A and the second block element 9B is generated based on the value obtained from the detector.

That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.
The first block element 9A and the second block element 9B applied to the power conversion device of the present embodiment can be applied to the power conversion device of all other embodiments, and the same applies in any case. The effect can be obtained.

Next, the power conversion device of the sixth embodiment will be described in detail with reference to the drawings.
FIG. 8 is a diagram schematically showing a configuration example of the power conversion device of the sixth embodiment.
In the power conversion device of this embodiment, the configuration of the auxiliary circuit unit 200 is different from that of the third embodiment described above.

The high frequency auxiliary power supply 4 includes a half bridge circuit including three inverter legs 10U, 10V, and 10W, and three high frequency transformers 11UV, 11VW, and 11WU.
The inverter legs 10U, 10V, and 10W are connected between the DC main circuit on the high potential side and the DC main circuit on the low potential side of the main circuit unit 100.

Each of the inverter legs 10U, 10V, and 10W is provided with two switching elements connected in series between the DC main circuits, and the corresponding high frequency transformers 11UV, 11VW, and 11WU and electricity are provided between the two switching elements (AC end). Is connected.

The high frequency transformers 11UV, 11VW, and 11WU each include a primary winding, a secondary winding, and a tertiary winding, respectively. The high frequency transformers 11UV, 11VW, 11WU primary winding, secondary winding, and tertiary winding have the same polarity.

The primary winding of the high-frequency transformer 11UV has a start end electrically connected to the AC end of the inverter leg 10U and an end end electrically connected to the AC end of the inverter leg 10V.

The secondary winding of the high frequency transformer 11UV is electrically connected to the DC end on the high potential side of one single-phase rectifying diode bridge 5UV at the beginning, and the DC on the high potential side of the other single-phase rectifying diode bridge 5UV at the end. It is electrically connected to the end, and at the intermediate end, it is electrically connected to the DC main circuit on the high potential side via the first voltage correction diode 7A.

The tertiary winding of the high frequency transformer 11UV is electrically connected to the DC end on the low potential side of the other single-phase rectifying diode bridge 5UV at the beginning and the DC end on the low potential side of the single-phase rectifying diode bridge 5UV at the end. At the intermediate end, it is electrically connected to the DC main circuit on the low potential side via the second voltage correction diode 7B.

The primary winding of the high-frequency transformer 11VW has a start end electrically connected to the AC end of the inverter leg 10V and an end end electrically connected to the AC end of the inverter leg 10W.

The secondary winding of the high-frequency transformer 11VW is electrically connected to the DC end on the high potential side of one single-phase rectifying diode bridge 5VW at the beginning and DC on the high potential side of the other single-phase rectifying diode bridge 5VW at the end. It is electrically connected to the end, and at the intermediate end, it is electrically connected to the DC main circuit on the high potential side via the first voltage correction diode 7A.

The tertiary winding of the high frequency transformer 11VW is electrically connected to the DC end on the low potential side of the other single-phase rectifying diode bridge 5VW at the beginning and the DC end on the low potential side of the one-phase rectifying diode bridge 5VW at the end. At the intermediate end, it is electrically connected to the DC main circuit on the low potential side via the second voltage correction diode 7B.

The primary winding of the high-frequency transformer 11WU has a start end electrically connected to the AC end of the inverter leg 10W and an end end electrically connected to the AC end of the inverter leg 10U.

The secondary winding of the high frequency transformer 11WU is electrically connected to the DC end on the high potential side of one single-phase rectifying diode bridge 5WU at the beginning and DC on the high potential side of the other single-phase rectifying diode bridge 5WU at the end. It is electrically connected to the end, and at the intermediate end, it is electrically connected to the DC main circuit on the high potential side via the first voltage correction diode 7A.

The tertiary winding of the high frequency transformer 11WU is electrically connected to the DC end on the low potential side of the other single-phase rectifying diode bridge 5WU at the beginning and the DC end on the low potential side of the one-phase rectifying diode bridge 5WU at the end. At the intermediate end, it is electrically connected to the DC main circuit on the low potential side via the second voltage correction diode 7B.

The two AC ends of the single-phase rectifying diode bridge 5UV are the end of the first winding (or third winding) of the split transformer 6UV and the start of the second winding (or fourth winding) of the split transformer 6UV. Is electrically connected to.
The two AC ends of the single-phase rectifying diode bridge 5VW are the end of the first winding (or third winding) of the split transformer 6VW and the start of the second winding (or fourth winding) of the split transformer 6VW. Is electrically connected to.
The two AC ends of the single-phase rectifying diode bridge 5WU are the end of the first winding (or third winding) of the shunt transformer 6WU and the start of the second winding (or fourth winding) of the shunt transformer 6WU. Is electrically connected to.

The starting end of the first winding (or third winding) of the shunt transformer 6UV is electrically connected to the U-phase AC line extending from the AC power supply 1. The end of the second winding (or fourth winding) of the shunt transformer 6UV is electrically connected to the V-phase AC line extending from the AC power supply 1.

The start end (or third winding) of the first winding of the shunt transformer 6VW is electrically connected to the V-phase AC line extending from the AC power supply 1. The end of the second winding (or fourth winding) of the shunt transformer 6VW is electrically connected to the W-phase AC line extending from the AC power supply 1.

The starting end of the first winding (or third winding) of the shunt transformer 6WU is electrically connected to the W-phase AC line extending from the AC power supply 1. The end of the second winding (or fourth winding) of the shunt transformer 6WU is electrically connected to the U-phase AC line extending from the AC power supply 1.

In the power conversion device, two inverter legs 10U, 10V, and 10W corresponding to each phase AC line are operated during the flow period of the auxiliary circuit unit 200, and a high frequency transformer corresponding to each phase AC line is used for high frequency. A power source can be generated and passed through the split transformers 6UV, 6VW, 6WU and the single-phase rectifying diode bridge 5.

The power conversion device of the present embodiment may include a control circuit (not shown) that controls the operation of the semiconductor switch elements of the inverter legs 10U, 10V, and 10W. In this case, the control circuit includes a detector that detects the phase of the current output from the AC power supply 1, and uses the corresponding inverter legs 10U, 10V, and 10W semiconductor switch elements based on the values detected by the detector. By operating it, it is possible to realize the above operation.

The power conversion device of the present embodiment has the same configuration as the power conversion device of the third embodiment except for the above configuration. That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the seventh embodiment will be described in detail with reference to the drawings.
FIG. 9 is a diagram schematically showing a configuration example of the power conversion device according to the seventh embodiment.
The power conversion device of this embodiment is different from the first to sixth embodiments described above in the configurations of the high frequency auxiliary power supply 4 and the divergence transformers 6UV, 6VW, and 6WU.

Each of the shunt transformers 6UV, 6VW, and 6WU further includes two snubber resistors 12a and two snubber capacitors 12b. A set of snubber resistor 12a and snubber capacitor 12b in each of the path connected in parallel with the first winding (or the third winding) and the path connected in parallel with the second winding (or the fourth winding). Are connected in series with each other.

By providing the shunt transformers 6UV, 6VW, and 6WU with a snubber resistor 12a and a snubber capacitor 12b, the leakage inductance of the shunt transformers 6UV, 6VW, and 6WU, which are high-frequency transformers, and the surge voltage generated by resonance due to parasitic capacitance are suppressed. be able to.

The high frequency auxiliary power supply 4 includes a high frequency inverter 41, a high frequency transformer 42, a resonance capacitor 4b, a plurality of low voltage diode rectifiers (single phase diode bridge circuits) 4d, a plurality of low voltage DC capacitors 4e, and a plurality of full bridge circuits 4f. And have.

The high frequency inverter 41 has two legs. Each of the two legs includes two power semiconductor elements 41A connected in series between the DC main circuit on the high potential side and the DC main circuit on the low potential side of the main circuit unit 100. The two power semiconductor elements 41A of each leg are AC ends of the high frequency inverter 41 and are electrically connected to the high frequency transformer 42.

The power conversion device of the present embodiment may include a controller (not shown) that generates a gate signal of the power semiconductor element 41A of the high-frequency inverter 41 to control the operation of the high-frequency inverter 41. The frequency of the AC power output from the high-frequency inverter 41 can be adjusted by the gate signal generated by the controller.

The high frequency transformer 42 includes a primary winding and a plurality of secondary windings.
The starting end of the primary winding of the high frequency transformer 42 is electrically connected to one AC end of the high frequency inverter 41 via a resonance capacitor 4b. The end of the primary winding of the high frequency transformer 42 is electrically connected to the other AC end of the high frequency inverter 41.

The plurality of secondary windings of the high frequency transformer 42 are connected to the corresponding low voltage diode rectifier 4d. Each of the plurality of secondary windings of the high frequency transformer 42 is electrically connected to one AC end of the corresponding low voltage diode rectifier 4d at the beginning and electrically to the other AC end of the corresponding low voltage diode rectifier 4d at the end. Is connected.

The low voltage diode rectifier 4d is a single phase diode bridge circuit including a plurality of low voltage diodes. The AC end of the low voltage diode rectifier 4d is electrically connected to the secondary winding of the high frequency transformer 42. The DC end of the low voltage diode rectifier 4d is electrically connected to the DC end of the corresponding full bridge circuit 4f.

The low-voltage DC capacitor 4e is connected between the high-potential side DC end and the low-potential side DC end of the full bridge circuit 4f (between the DC ends of the low-voltage diode rectifier 4d).

The full bridge circuit 4f includes four low voltage power semiconductor elements and includes two legs to which two low voltage power semiconductor elements are connected. The AC end of the full bridge circuit 4f is between the two low-voltage power semiconductor elements. One end of the leg of the full bridge circuit 4f is electrically connected to the DC end on the high potential side, and the other end of the leg of the full bridge circuit 4f is electrically connected to the DC end on the low potential side.

In the power conversion device of the present embodiment, the high frequency auxiliary power supply 4 includes four full bridge circuits 4f. In two of the four full bridge circuits 4f, one AC end is electrically connected to the DC main circuit on the high potential side via the first voltage correction diode 7A, and the other AC end is the height of the auxiliary circuit unit 200. It is electrically connected to the DC line on the potential side. In the other two of the four full bridge circuits 4f, one AC end is electrically connected to the DC main circuit on the low potential side via the second voltage correction diode 7B, and the other AC end is the auxiliary circuit unit 200. It is electrically connected to the DC line on the low potential side of.

Since the full bridge circuit 4f is composed of a low-voltage power semiconductor, it becomes easy to generate a high-frequency power supply, and it becomes easy to miniaturize the divergence transformers 6UV, 6VW, and 6WU.

Further, since the high frequency auxiliary power supply 4 includes the resonance capacitor 4b, the resonance circuit can be operated from the power semiconductor element 41A to the low voltage DC capacitor 4e, and the switching loss of the power semiconductor element 41A can be significantly reduced.

The power conversion device of the present embodiment has the same configuration as the power conversion device of the third embodiment except for the above configuration. That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

In the power conversion device of the present embodiment, an example in which the high-frequency auxiliary power supply 4 includes a resonance circuit has been described, but the present invention is not limited to the resonance circuit, and an insulation circuit other than the resonance circuit may be provided.
Further, the configurations of the diversion transformers 6UV, 6VW, and 6WU of the power conversion device of the present embodiment can be applied to all other embodiments.

Next, the power conversion device of the eighth embodiment will be described in detail with reference to the drawings.
FIG. 10 is a diagram schematically showing a configuration example of the power conversion device of the eighth embodiment.
The power conversion device of the present embodiment is described above in that the auxiliary circuit unit 200 includes a plurality of AC switches 13, two diversion transformers 6UV, 6VW, 6WU, and two single-phase rectifying diode bridges 5. It is different from the power conversion device of the first to seventh embodiments.

The AC switch 13 is a reverse series (or) of a power semiconductor element such as a power MOSFET or an IGBT (Insulated Gate Bipolar Transistor) or a power semiconductor element having a reverse withstand voltage such as an RB-IGBT (Reverse Blocking Insulated Gate Bipolar Transistor). It is a bidirectional switch circuit connected (in antiparallel).

The AC switch 13 may be, for example, a bidirectional switch circuit in which the sources of two power MOSFETs (or the emitters of IGBTs) are connected in series and connected in anti-series, and one source of the two power MOSFETs. It may be a bidirectional switch circuit in which and the other drain (or one emitter of two IGBTs and the collector of the other) are connected in antiparallel so as to be connected to each other.

The AC switch 13 is between the U-phase AC line and the start of the first winding (or third winding) of the split transformers 6UV, 6VW, 6WU, and the V-phase AC line and the split transformer 6UV, 6VW, 6WU. Between the start of the first winding (or the third winding), between the V-phase AC line and the end of the second (or fourth) winding of the divergence transformers 6UV, 6VW, 6WU, and It is connected between the W-phase AC line and the end of the second winding (or fourth winding) of the divergence transformers 6UV, 6VW, 6WU.

That is, the electrical connection between the divergence transformers 6UV, 6VW, 6WU and each phase AC line can be switched by the AC switch 13. In the present embodiment, the AC switch 13 is switched by a control circuit (not shown), and the divergence transformers 6UV, 6VW, and 6WU are connected between the lines where the difference between the two phase voltages of the AC power supply 1 is small. It can be passed through 200. A control circuit (not shown) includes a detector (not shown) that detects the phase of the output current of the AC power supply 1.

When switching the AC switch 13, a surge voltage or short-circuit current may flow, destroying the power conversion device. Therefore, in the power conversion device of the present embodiment, surge voltage and short-circuit current are suppressed by switching by combining voltage commutation and current commutation.
The operation of switching the AC switch 13 in the control circuit may be performed, for example, other than the flow period of the auxiliary circuit 200 or after the high frequency auxiliary power supply 4 is stopped. Further, the control circuit may turn off the gate of the AC switch 13 when the gate of the power semiconductor element 41A of the high-frequency inverter 41 is turned off except during the flow period of the auxiliary circuit 200. This makes it possible to prevent the diversion transformers 6UV, 6VW, and 6WU from being magnetically saturated.

The power conversion device of the first to seventh embodiments described above includes two diversion transformers 6UV, 6VW, and 6WU connected between each line to provide a total of six diversion transformers 6UV, 6VW, and 6WU. In the power conversion device of the above, it is sufficient to provide two split transformers 6UV, 6VW, and 6WU, respectively, and the mounting area can be reduced.

In the power conversion device of the present embodiment, the configuration of the auxiliary circuit 200 (the portion surrounded by the broken line) excluding the diversion transformers 6UV, 6VW, 6WU and the high frequency transformer 42 is, for example, a metal layer and a semiconductor layer having a predetermined pattern. , It can be formed by laminating an insulating layer or the like, and does not significantly affect the size of the outer shape of the power conversion device. That is, by reducing the number of shunt transformers 6UV, 6VW, and 6WU mounted, the power conversion device can be miniaturized more effectively.
That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the ninth embodiment will be described in detail with reference to the drawings.
FIG. 11 is a diagram schematically showing a configuration example of a power conversion device according to a ninth embodiment.
In the power conversion device of this embodiment, the configuration of the high frequency auxiliary power supply 4 is different from that of the eighth embodiment described above.

The high-frequency auxiliary power supply 4 is a power supply 4hp that supplies a positive voltage and a power supply 4hm that supplies a negative voltage to each of the DC end on the high potential side and the DC end on the low potential side of the three-phase diode rectifier 2. And an AC switch (bidirectional switch) 4i for an auxiliary power supply connected between each of the four power supplies 4hp and 4hm and the DC end of the single-phase rectifying diode bridge 5.

The auxiliary power supply AC switch 4i has the same configuration as the AC switch 13. Similar to the AC switch 13, the auxiliary power supply AC switch 4i can suppress surge voltage and short-circuit current by switching by combining voltage commutation and current commutation.

According to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the tenth embodiment will be described in detail with reference to the drawings.
FIG. 12 is a diagram schematically showing a configuration example of the power conversion device according to the tenth embodiment.
The power conversion device of the present embodiment is configured to include a plurality of flow paths of the auxiliary circuit unit 200 by the split transformers 6UV, 6VW, 6WU and the single-phase rectifying diode bridge 5 of the power conversion device of the second embodiment described above. is there. The auxiliary circuit unit 200 includes a high-frequency auxiliary power supply 4, 12 diversion transformers 6UV, 6VW, 6WU (4 sets of 3 diversion transformers 6UV, 6VW, 6WU), and 12 single-phase rectifying diode bridges 5. ..

The high frequency auxiliary power supply 4 includes a high frequency inverter 41 and a high frequency transformer 42.
The high-frequency inverter 41 has the same configuration as the power conversion device of the second embodiment described above.
The high frequency transformer 42 includes a first transformer 42A and a second transformer 42B.

The first transformer 42A includes a primary winding and a secondary winding having the same polarity as the primary winding.
Both ends of the primary winding of the first transformer 42A are electrically connected to the two AC ends of the high frequency inverter 41. The secondary winding of the first transformer 42A has three intermediate ends. Here, it will be referred to as a first intermediate end, a second intermediate end, and a third intermediate end from the one closest to the end of the secondary winding. The secondary winding of the first transformer 42A is electrically connected to the DC main circuit on the high potential side via the first voltage correction diode 7A at the second intermediate end.

The number of turns of the secondary winding of the first transformer 42A from the first intermediate end to the second intermediate end is N1, and the number of turns from the end to the second intermediate end is N2. Further, the number of turns of the secondary winding of the first transformer 42A from the second intermediate end to the third intermediate end is N1, and the number of turns from the second intermediate end to the start end is N2.

The end of the secondary winding of the first transformer 42A and the first intermediate end are connected to two DC ends on the high potential side (cathode side) of the six single-phase rectifying diode bridges 5, respectively. The start end and the third intermediate end of the secondary winding are connected to two DC ends on the high potential side (cathode side) of the other six single-phase rectifying diode bridges 5, respectively.

The second transformer 42B includes a primary winding and a secondary winding having the same polarity as the primary winding.
Both ends of the primary winding of the second transformer 42B are electrically connected to the two AC ends of the high frequency inverter 41. The secondary winding of the second transformer 42B has three intermediate ends. Here, it will be referred to as a first intermediate end, a second intermediate end, and a third intermediate end from the one closest to the starting end of the secondary winding. The secondary winding of the second transformer 42B is electrically connected to the DC main circuit on the low potential side via the second voltage correction diode 7B at the second intermediate end.

The number of turns of the secondary winding of the second transformer 42B from the first intermediate end to the second intermediate end is N1, and the number of turns from the start end to the second intermediate end is N2. Further, the number of turns of the secondary winding of the second transformer 42B from the second intermediate end to the third intermediate end is N1, and the number of turns from the second intermediate end to the end is N2.

The start end and the first intermediate end of the secondary winding of the second transformer 42B are connected to two DC ends on the low potential side (anode side) of the six single-phase rectifying diode bridges 5, respectively. The end of the secondary winding and the third intermediate end are connected to two DC ends on the low potential side (anode side) of the other six single-phase rectifying diode bridges 5, respectively.

In the power conversion device of the present embodiment, the first transformer unit 61 includes two diversion transformers 6UV, two diversion transformers 6VW, and two diversion transformers 6WU. The second transformer unit 62 includes two diversion transformers 6UV, two diversion transformers 6VW, and two diversion transformers 6WU. Each of the diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 includes a first winding and a second winding having the opposite polarity to the first winding. Each of the diversion transformers 6UV, 6VW, and 6WU of the second transformer unit 62 includes a third winding and a fourth winding having the opposite polarity to the third winding.

The first windings of the diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 are electrically connected to one of the AC lines at the start end and electrically connected to one AC end of the single-phase rectifying diode bridge 5 at the end. Is connected. The second winding of the diversion transformer 6UV, 6VW, 6WU of the first transformer unit 61 is electrically connected to any one of the other AC lines at the end and starts at the other AC end of the single-phase rectifying diode bridge 5. Is electrically connected to.
The turns ratio between the first winding and the second winding of the diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 is set according to the magnitude of the voltage assisted by the high frequency transformer 42 of the high frequency auxiliary power supply 4. ing.

The third windings of the diversion transformers 6UV, 6VW, and 6WU of the second transformer section 62 are electrically connected to one of the AC lines at the beginning and electrically connected to one AC end of the single-phase rectifying diode bridge 5 at the end. Is connected. The fourth winding of the diversion transformer 6UV, 6VW, 6WU of the second transformer section 62 is electrically connected to any one of the other AC lines at the end and starts at the other AC end of the single-phase rectifying diode bridge 5. Is electrically connected to.
The turns ratio between the third winding and the fourth winding of the diversion transformers 6UV, 6VW, and 6WU of the second transformer unit 62 is set according to the magnitude of the voltage assisted by the high frequency transformer 42 of the high frequency auxiliary power supply 4. ing.

For example, the leg of the single-phase rectifying diode bridge 5 to which the first windings of the set of split transformers 6UV, 6VW, and 6WU of the first transformer unit 61 are connected is the end of the secondary winding of the first transformer 42A. The leg of the single-phase rectifying diode bridge 5 connected to the start end of the secondary winding of the second transformer 42B and the second winding of the set of divergent transformers 6UV, 6VW, 6WU is the first transformer 42A. It is connected to the first intermediate end of the secondary winding of the second transformer 42B and the first intermediate end of the secondary winding of the second transformer 42B. The turns ratio of the first winding to the second winding of this set of diversion transformers 6UV, 6VW, and 6WU is N2: N1.

For example, the leg of the single-phase rectifying diode bridge 5 to which the first windings of the other set of diversion transformers 6UV, 6VW, and 6WU of the first transformer unit 61 are connected is the first winding of the secondary winding of the first transformer 42A. A single-phase rectifying diode connected to one intermediate end and the first intermediate end of the secondary winding of the second transformer 42B, and to which the second winding of the other set of divergence transformers 6UV, 6VW, 6WU is connected. The leg of the bridge 5 is connected to the end of the secondary winding of the first transformer 42A and the start of the secondary winding of the second transformer 42B. The turns ratio of the first winding to the second winding of the other set of diversion transformers 6UV, 6VW, 6WU is N1: N2.

In the power conversion device of the present embodiment, the turns ratio N1: N2 of the high frequency transformer 42 is about 1: 2, and the first winding and the second winding of a set of diversion transformers 6UV, 6VW, 6WU of the first transformer unit 61. The turns ratio with the windings is 2: 1 and the turns ratio between the first winding and the second winding of the other set of diversion transformers 6UV, 6VW, 6WU is 1: 2.
Similarly, for the second transformer section 62, the turns ratio of the third winding to the fourth winding of the set of split transformers 6UV, 6VW, 6WU is 2: 1 and the other set of split transformers 6UV, The turns ratio between the third winding and the fourth winding of 6VW and 6WU is 1: 2.

As described above, in the power conversion device shown in FIG. 12, by setting the turns ratio N1: N2 of the high frequency transformer 42 to about 1: 2, the first winding and the second winding of the divergence transformers 6UV, 6VW, and 6WU. The turns ratio with and to is 1: 2 or 2: 1, and the current ratio flowing from the AC line to the divergence transformer can be maintained at a predetermined value, and the same operation as that of an 18-pulse rectifier can be realized. As a result, the current flowing through the AC power supply 1 becomes equivalent to that of the 18-pulse rectifier, and harmonics can be reduced.

That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the eleventh embodiment will be described in detail with reference to the drawings.
FIG. 13 is a diagram schematically showing a configuration example of the power conversion device of the eleventh embodiment.
In the power conversion device of the present embodiment, the first transformer unit 61 and the second transformer unit 62 include a plurality of diversion transformers 15 including an intermediate end, and a plurality of AC switches 16 for diversion, and a high frequency. The method of connecting the auxiliary power supply 4 and the single-phase rectifying diode bridge 5 is different from that of the power conversion device of the tenth embodiment described above.

The diversion transformer 15 of the first transformer unit 61 includes a first winding including an intermediate end and a second winding including the intermediate end and having a polarity different from that of the first winding.
The first winding of the shunt transformer 15 is electrically connected to one of the AC lines at the start end, and is electrically connected to the AC end of the single-phase rectifying diode bridge 5 via the divergence AC switch 16 at the end, and is intermediate. At the end, it is electrically connected to the AC end of another single-phase rectifying diode bridge 5 via an AC switch 16 for diversion.

The second winding of the shunt transformer 15 is electrically connected to one of the other two-phase AC lines at the end and with the other AC end of the single-phase rectifying diode bridge 5 via the divergence AC switch 16 at the start. It is electrically connected and is electrically connected to the other AC end of the other single-phase rectifying diode bridge 5 via a diversion AC switch 16 at the intermediate end.

The turns ratio between the first winding and the second winding of the shunt transformer 15 is N2: N2, and the number of turns from the start end to the middle end of the first winding and the number of turns from the end to the middle end of the second winding. The ratio with is N1: N1.
The diversion transformer portion 15 of the second transformer portion 62 includes a third winding including an intermediate end and a fourth winding including the intermediate end and having a polarity different from that of the third winding, and the first transformer portion 61 includes a third winding. It has the same configuration as the diversion transformer 15.

The single-phase rectifying diode bridge 5 connected to the end of the first winding (or third winding) of the shunt transformer 15 and the start end of the second winding (or fourth winding) is on the high potential side (cathode side). ) Is electrically connected to the end of the secondary winding of the transformer 42A (or the start of the secondary winding), and at the DC end on the low potential side (anode side), the secondary winding of the high-frequency transformer 42B. It is electrically connected to the beginning of the wire (or the end of the secondary winding).

The single-phase rectifying diode bridge 5 connected to the intermediate end of the first winding (or third winding) of the shunt transformer 15 and the intermediate end of the second winding (or fourth winding) is on the high potential side ( At the DC end on the cathode side), it is electrically connected to the first intermediate end (or third intermediate end) of the secondary winding of the transformer 42A, and at the DC end on the low potential side (anode side), the high frequency transformer 42B It is electrically connected to the first intermediate end (or third intermediate end) of the secondary winding.

The AC switch 16 for diversion has the same configuration as the AC switch 13. That is, the AC switch 16 for diversion is a bidirectional switch in which semiconductor switches are connected in anti-series (or anti-parallel).

According to the power conversion device of the present embodiment, the number of the divergence transformers 15 mounted is increased by switching the divergence AC switch 16 to switch the connection between the divergence transformer 15 and the single-phase rectifier diode bridge 5. The current flowing through the AC power supply 1 is equivalent to that of the 18-pulse rectifier, and the harmonics can be reduced, while making the distribution transformers 6UV, 6VW, and 6WU of the power conversion device of the tenth embodiment half of that. Therefore, according to the present embodiment, the power conversion device can be further miniaturized.
That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Similar to the AC switch 13 described above, the AC switch 16 for diversion is switched by a control circuit (not shown) in combination with voltage commutation, current commutation, and the like.

Next, the power conversion device of the twelfth embodiment will be described in detail with reference to the drawings.
FIG. 14 is a diagram schematically showing a configuration example of the power conversion device according to the twelfth embodiment.
The power conversion device of the present embodiment has a configuration in which the electrical connection between the AC line and the divergence transformers 6UV, 6VW, and 6WU is switched by the plurality of AC switches 13 of the power conversion device of the eighth embodiment described above. This is an example applied to the power conversion device of the embodiment.

The power conversion device of this embodiment includes two diversion transformers 15 and four single-phase rectifying diode bridges 5.
The start end of the first winding (or third winding) of the shunt transformer 15 can be electrically connected to each of the U-phase AC line and the V-phase AC line via the AC switch 13. .. The end of the second winding (or fourth winding) of the shunt transformer 15 can be electrically connected to each of the V-phase AC line and the W-phase AC line via the AC switch 13. ..

The power conversion device of the present embodiment switches the plurality of AC switches 13 and the plurality of AC switches 16 for diversion by a control circuit (not shown), thereby converting the power conversion device of the eighth embodiment and the power conversion of the eleventh embodiment described above. It can perform the same operation as the device. Therefore, according to the power conversion device of the present embodiment, the current flowing through the AC power supply 1 is equivalent to that of the 18-pulse rectifier, harmonics can be reduced, and the power conversion device can be further miniaturized.
That is, according to the power conversion device of the present embodiment, it is possible to realize miniaturization of the power conversion device with improved harmonics and power factor.

Next, the power conversion device of the thirteenth embodiment will be described in detail with reference to the drawings.
FIG. 15 is a diagram schematically showing a configuration example of the power conversion device according to the thirteenth embodiment.
The power conversion device of this embodiment is configured so that the current flowing through the AC power supply 1 is equivalent to that of the 24-pulse rectifier.

The power conversion device of the present embodiment is a configuration example in which the configuration of the power conversion device of the first embodiment and the configuration of the power conversion device of the tenth embodiment are combined.
In the present embodiment, the secondary windings of the transformers 42A and 42B further include a fourth intermediate end between the end and the first intermediate end, and further provide a fifth intermediate end between the start end and the third intermediate end. I have. The number of turns of the secondary winding of the first transformer 42A from the first intermediate end to the second intermediate end is N1, the number of turns from the fourth intermediate end to the second intermediate end is N2, and the number of turns from the end to the second The number of turns to the intermediate end is N3. Further, the number of turns of the secondary winding of the first transformer 42A from the second intermediate end to the third intermediate end is N1, the number of turns from the second intermediate end to the fifth intermediate end is N2, and the second The number of turns from the intermediate end to the starting end is N3.

The first transformer unit 61 includes three sets of diversion transformers 6UV, 6VW, and 6WU. Two of the three sets of the diversion transformers 6UV, 6VW, and 6WU of the first transformer section 61 have the same configuration as the first transformer section 61 of the power conversion device of the tenth embodiment described above. In the power conversion device of the present embodiment, the first transformer unit 61 further includes a set of split transformers 6UV, 6VW, and 6WU. The leg of the single-phase rectifying diode bridge 5 to which the first winding of the set of divergence transformers 6UV, 6VW, and 6WU is connected and the leg of the single-phase rectifying diode bridge 5 to which the second winding is connected are the first. It is connected to the fourth intermediate end of the secondary winding of the first transformer 42A and the fourth intermediate end of the secondary winding of the second transformer 42B.

In the power conversion device of the present embodiment, by setting the turns ratio N3: N2: N1 of the secondary windings of the transformers 42A and 42B to 3: 2: 1, a set of split transformers 6UV of the first transformer unit 61, The turns ratio between the first winding and the second winding of 6VW, 6WU is set to 3: 1, and the first winding and the second winding of the other set of divergence transformers 6UV, 6VW, 6WU of the first transformer section 61. The turns ratio with the wire shall be 1: 3, and the turn ratio between the first winding and the second winding of the remaining set of split transformers 6UV, 6VW, 6WU of the first transformer section 61 shall be 2: 2. Can be done.

Similarly, for the second transformer section 62, by setting the turns ratio N3: N2: N1 of the secondary windings of the transformers 42A and 42B to 3: 2: 1, a set of split transformers 6UV of the second transformer section 62 , 6VW, 6WU, the winding ratio of the first winding to the second winding is set to 3: 1, and the other set of diversion transformers 6UV, 6VW, 6WU of the second transformer section 62, the first winding and the second winding. The turns ratio with the windings is 1: 3, and the turns ratio between the first winding and the second winding of the remaining set of split transformers 6UV, 6VW, 6WU of the second transformer portion 62 is 2: 2. be able to.
As a result, the power conversion device of the present embodiment can realize the same operation as the 24-pulse rectifier, and can reduce the harmonics.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... AC power supply, 2 ... Three-phase diode rectifier, 2A ... Diode, 3 ... DC smoothing capacitor, 4 ... High frequency auxiliary power supply, 4A ... First high frequency power supply circuit, 4B ... High frequency power supply circuit, 4b ... Resonant capacitor, 4d ... Low voltage Diode rectifier, 4e ... Low-voltage DC capacitor, 4f ... Full bridge circuit, 4hm ... Power supply (2nd DC auxiliary power supply, 4th DC auxiliary power supply), 4hp ... Power supply (1st DC auxiliary power supply, 3rd DC auxiliary power supply), 4i ... AC switch for auxiliary power supply, 5 ... Single-phase rectifier diode bridge, 5UV ... Single-phase rectifier diode bridge, 5VW ... Single-phase rectifier diode bridge, 5WU ... Single-phase rectifier diode bridge, 5a ... High-speed diode, 6UV ... Divided transformer, 6VW ... Divergence transformer, 6WU ... Divergence transformer, 7A ... 1st voltage correction diode, 7B ... 2nd voltage correction diode, 8 ... Dropper, 8A ... 1st dropper, 8B ... 2nd dropper, 81 ... Condenser, 82, 83 ... Power Semiconductor element, 84 ... High frequency isolated transformer, 85 ... Resonant capacitor, 86 ... Diode rectifier, 9A ... 1st block element, 9B ... 2nd block element, 10U, 10V, 10W ... Inverter leg, 11UV, 11VW, 11WU ... High frequency transformer , 12a ... Snubber resistor, 12b ... Snubber capacitor, 13 ... AC switch, 15 ... Divergence transformer, 16 ... AC switch for diversion, 41 ... High frequency inverter, 41A ... Power semiconductor element, 42 ... High frequency transformer, 42A ... First transformer, 42B ... 2nd transformer, 100 ... main circuit section, 200 ... auxiliary circuit section.

Claims (14)

A main circuit including a three-phase diode rectifier provided so as to be connectable to an AC power supply and a smoothing capacitor connected between the DC end on the high potential side and the DC end on the low potential side of the three-phase diode rectifier. Department and
A circuit that electrically connects an auxiliary power supply that outputs a high-frequency voltage and the AC end and DC end of the three-phase diode rectifier, and determines the current ratio that flows in from the plurality of AC ends of the three-phase diode rectifier. The auxiliary power supply is supplied to the current flowing from the AC end of the three-phase diode rectifier in the vicinity of the timing at which the difference between the two-phase values of the three-phase AC voltage output from the AC power supply becomes zero while maintaining the value. A power conversion unit provided with a current flow unit for passing an auxiliary current on which a high-frequency current due to the output voltage of the above is superimposed, and an auxiliary circuit unit for charging the smoothing capacitor with the auxiliary current. apparatus. The current flow section includes a first winding in which current flows in from one of the AC ends of the three-phase diode rectifier, and a second volume in which current flows in from one of the other AC ends of the three-phase diode rectifier. Equipped with a transformer with wires
The ratio of the current flowing from the AC end of the three-phase diode rectifier to the current flow portion shall be maintained at the predetermined value by the ratio of the number of turns of the first winding to the number of turns of the second winding. The power conversion device according to claim 1. The current flow portion includes a first winding and a second winding having a polarity different from that of the first winding, and is electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the first winding. A first transformer that is connectable to and electrically connectable to the other AC end of the three-phase diode rectifier at the end of the second winding.
It is provided with a third winding and a fourth winding having a polarity different from that of the third winding, and can be electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the third winding. A second transformer that can be electrically connected to the other AC end of the three-phase diode rectifier at the end of the fourth winding.
A first single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the first winding of the first transformer and the start end of the second winding.
A second single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the third winding of the second transformer and the start end of the fourth winding.
The auxiliary power supply is interposed between the DC end on the high potential side of the first single-phase rectifier bridge circuit and the DC end on the high potential side of the three-phase diode rectifier, and is the second single-phase rectifier diode bridge circuit. The first high frequency power supply circuit interposed between the DC end on the high potential side of the three-phase diode rectifier and the DC end on the high potential side of the three-phase diode rectifier, and the DC end on the low potential side of the first single-phase rectifier bridge circuit. Intervening between the DC end on the low potential side of the three-phase diode rectifier, the DC end on the low potential side of the second single-phase rectifier bridge circuit and the DC end on the low potential side of the three-phase diode rectifier. It is equipped with a second high frequency power supply circuit that intervenes between them.
The voltage output from the first high frequency power supply circuit between the DC end on the high potential side of the first single-phase rectifier bridge circuit and the DC end on the high potential side of the three-phase diode rectifier is the first high frequency. The phase is opposite to the voltage output from the power supply circuit between the DC end on the high potential side of the second single-phase rectifier bridge circuit and the DC end on the high potential side of the three-phase rectifier, and is the second high frequency. The voltage output from the power supply circuit between the DC end on the low potential side of the first single-phase rectifier bridge circuit and the DC end on the low potential side of the three-phase diode rectifier is the voltage output from the second high-frequency power supply circuit. Claim 1 is characterized in that the phase is opposite to the voltage output between the DC end on the low potential side of the second single-phase rectifier bridge circuit and the DC end on the low potential side of the three-phase rectifier. The power converter described. The current flow portion includes a first winding and a second winding having a polarity different from that of the first winding, and is electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the first winding. A first transformer that is connectable to and electrically connectable to the other AC end of the three-phase diode rectifier at the end of the second winding.
It is provided with a third winding and a fourth winding having a polarity different from that of the third winding, and can be electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the third winding. A second transformer that can be electrically connected to the other AC end of the three-phase diode rectifier at the end of the fourth winding.
A first single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the first winding of the first transformer and the start end of the second winding.
A second single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the third winding of the second transformer and the start end of the fourth winding.
The auxiliary power supply has two semiconductor switches connected in series between the DC ends of the three-phase diode rectifier, and an inverter having two legs having an AC end between the two semiconductor switches and two. The primary winding electrically connected between the AC ends of the leg, the DC end on the high potential side of the first single-phase rectifying diode bridge circuit, and the high-potential side of the second single-phase rectifying diode bridge circuit. A first isolated transformer with a secondary winding that is connected to the DC end and electrically connected to the DC end on the high potential side of the three-phase diode rectifier at the intermediate end, and an inverter. Between the primary winding connected between the two AC ends and the low potential side DC end of the first single-phase rectifying diode bridge circuit and the low potential side DC end of the second single-phase rectifying diode bridge circuit. It is characterized by having a second isolated transformer provided with a secondary winding electrically connected to the DC end on the low potential side of the three-phase diode rectifier at the intermediate end. The power conversion device according to claim 1. The auxiliary circuit unit includes a first voltage correction diode whose cathode is electrically connected to an end electrically connected to a DC end on the high potential side of the three-phase diode rectifier, and a low potential of the three-phase diode rectifier. The power conversion device according to claim 1, further comprising a second voltage correction diode having an anode electrically connected to an end electrically connected to a DC end on the side. The auxiliary circuit portion is interposed in front of the end of the current flow portion that is electrically connected to the DC end on the high potential side of the three-phase diode rectifier, and is the DC end on the high potential side of the three-phase diode rectifier. The current is interposed in front of the first dropper that drops the voltage from the current to the current flow section and the end of the current flow section that is electrically connected to the DC end on the low potential side of the three-phase diode rectifier. A second dropper that drops the voltage from the current to the three-phase diode rectifier,
The power conversion device according to claim 1, further comprising. A first capacitor connected between the DC end on the high potential side of the three-phase diode rectifier and the first high-frequency power supply circuit, and a first capacitor that regenerates the energy stored in the first capacitor into the smoothing capacitor. A first dropper with a regenerative circuit,
A second capacitor connected between the DC end on the low potential side of the three-phase diode rectifier and the second high-frequency power supply circuit, and a second capacitor that regenerates the energy stored in the second capacitor into the smoothing capacitor. It has a regenerative circuit and a second dropper with.
The power conversion device according to claim 3, wherein the power conversion device is characterized by the above. The auxiliary circuit unit includes a first semiconductor switch that switches the electrical connection state between the DC end on the high potential side of the three-phase diode rectifier and the current flow unit, and the DC end on the low potential side of the three-phase diode rectifier. The power conversion device according to claim 1, further comprising a second semiconductor switch for switching an electrical connection state between the current and the current flow unit. The current flow portion includes a first winding and a second winding having a polarity different from that of the first winding, and is electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the first winding. A first transformer that is connectable to and electrically connectable to the other AC end of the three-phase diode rectifier at the end of the second winding.
It is provided with a third winding and a fourth winding having a polarity different from that of the third winding, and can be electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the third winding. A second transformer that can be electrically connected to the other AC end of the three-phase diode rectifier at the end of the fourth winding.
A first single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the first winding of the first transformer and the start end of the second winding.
A second single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the third winding of the second transformer and the start end of the fourth winding.
The auxiliary power supply includes a semiconductor switching element connected in series between a DC end on the high potential side and a DC end on the low potential side of the three-phase diode rectifier, and a leg in which the semiconductor switching elements are AC ends. The three-phase half-bridge circuit provided for each phase, the primary winding connected between the AC ends of the leg, and the two first single phases corresponding to the phases of the leg to which the primary winding is connected. Both ends are connected between the DC ends on the high potential side of the rectifier diode bridge circuit or between the DC ends on the high potential side of the two second single-phase rectifier bridge circuits, and on the high potential side of the three-phase diode rectifier. On the low potential side of the two first single-phase rectifying diode bridge circuits corresponding to the phase of the leg to which the primary winding is connected, and a secondary winding with an intermediate end electrically connected to the DC end. Both ends are connected between the DC ends or between the DC ends on the low potential side of the two first single-phase rectifier bridge circuits, and are electrically connected to the DC ends on the low potential side of the three-phase diode rectifier. The power conversion device according to claim 1, further comprising a tertiary winding having an intermediate end and an insulated transformer including the intermediate end. The current flow portion includes a first winding and a second winding having a polarity different from that of the first winding, and is electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the first winding. A first transformer that is connectable to and electrically connectable to the other AC end of the three-phase diode rectifier at the end of the second winding.
It is provided with a third winding and a fourth winding having a polarity different from that of the third winding, and can be electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the third winding. A second transformer that can be electrically connected to the other AC end of the three-phase diode rectifier at the end of the fourth winding.
A first single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the first winding of the first transformer and the start end of the second winding.
A second single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the third winding of the second transformer and the start end of the fourth winding.
The auxiliary power supply includes a semiconductor switching element connected in series between the DC end on the high potential side and the DC end on the low potential side of the three-phase diode rectifier, and the semiconductor switching element is an AC end. An insulated transformer with an inverter with one leg, a primary winding connected between two AC ends of the leg, and four secondary windings, and a secondary winding of the isolated transformer. Four single-phase rectifying diode bridges with AC ends connected to both ends, and the four single-phase rectifying diode bridges connected between the high-potential DC end and the low-potential DC end of each. The four capacitors are connected in parallel with the capacitor at the DC end, and are electrically connected to the DC end on the high potential side of the three-phase diode rectifier and the DC end on the high potential side of the first single-phase rectifier bridge circuit. The first full bridge circuit connected to the above and the DC end on the high potential side of the three-phase diode rectifier and the DC on the high potential side of the second single-phase rectifier bridge circuit connected in parallel with the capacitor at the DC end. A second full bridge circuit electrically connected to the end and a DC end on the low potential side of the three-phase diode rectifier and the first single-phase rectifier diode bridge circuit connected in parallel with the capacitor at the DC end. A third full bridge circuit electrically connected to the DC end on the low potential side and a DC end on the low potential side of the three-phase diode rectifier and the second single phase connected in parallel with the capacitor at the DC end. The power conversion device according to claim 1, further comprising a fourth full bridge circuit electrically connected to a DC end on the low potential side of the rectifier diode bridge circuit. The current flow section is between the AC end of each phase of the three-phase diode rectifier, the start end of the first winding and the end of the second winding of the first transformer, and the three-phase diode rectifier. A bidirectional switch connected between the AC end of each phase and the start end of the third winding of the second transformer and the end of the fourth winding, and the semiconductor switches are connected in anti-series or anti-parallel. The power conversion device according to claim 3, wherein the power conversion device is characterized by the above. The current flow portion includes a first winding and a second winding having a polarity different from that of the first winding, and is electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the first winding. A first transformer that is connectable to and electrically connectable to the other AC end of the three-phase diode rectifier at the end of the second winding.
It is provided with a third winding and a fourth winding having a polarity different from that of the third winding, and can be electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the third winding. A second transformer that can be electrically connected to the other AC end of the three-phase diode rectifier at the end of the fourth winding.
A first single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the first winding of the first transformer and the start end of the second winding.
A second single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the third winding of the second transformer and the start end of the fourth winding.
The auxiliary power supply is between the DC end on the high potential side of the three-phase diode rectifier and the DC end on the high potential side of the first single-phase rectifier bridge circuit, and on the high potential side of the three-phase diode rectifier. A first DC that is connected between the DC end and the DC end on the high potential side of the second single-phase rectifier bridge circuit and applies a positive voltage to the DC end on the high potential side of the three-phase diode rectifier. Auxiliary power supply, between the DC end on the high potential side of the three-phase diode rectifier and the DC end on the high potential side of the first single-phase rectifier bridge circuit, and the DC on the high potential side of the three-phase diode rectifier. A second DC auxiliary that is connected between the end and the DC end on the high potential side of the second single-phase rectifier bridge circuit and applies a negative voltage to the DC end on the high potential side of the three-phase diode rectifier. The power supply, the DC end on the low potential side of the three-phase diode rectifier and the DC end on the low potential side of the first single-phase rectifier bridge circuit, and the DC end on the low potential side of the three-phase diode rectifier. A third DC auxiliary power supply that is connected between the second single-phase rectifier and the DC end on the low potential side of the bridge circuit and applies a positive voltage to the DC end on the low potential side of the three-phase rectifier. And between the DC end on the low potential side of the three-phase diode rectifier and the DC end on the low potential side of the first single-phase rectifier bridge circuit, and the DC end on the low potential side of the three-phase diode rectifier. A fourth DC auxiliary power supply that is connected to the low potential side DC end of the second single-phase rectifier diode bridge circuit and applies a negative voltage to the low potential side DC end of the three-phase diode rectifier. Between each of the first DC auxiliary power supply and the second DC auxiliary power supply and the DC end on the high potential side of the first single-phase rectifier diode bridge circuit and the second single-phase rectifier diode bridge circuit, and A semiconductor interposed between each of the third DC auxiliary power supply and the fourth DC auxiliary power supply and the DC end on the low potential side of the first single-phase rectifier diode bridge circuit and the second single-phase rectifier diode bridge circuit. The power conversion device according to claim 1, further comprising a bidirectional switch in which switches are connected in anti-series or anti-parallel. The current flow portion includes a first winding and a second winding having a polarity different from that of the first winding, and is electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the first winding. A first transformer that is connectable to and electrically connectable to the other AC end of the three-phase diode rectifier at the end of the second winding.
It is provided with a third winding and a fourth winding having a polarity different from that of the third winding, and can be electrically connected to one of the AC ends of the three-phase diode rectifier at the start end of the third winding. A second transformer that can be electrically connected to the other AC end of the three-phase diode rectifier at the end of the fourth winding.
A first single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the first winding of the first transformer and the start end of the second winding.
A second single-phase rectifying diode bridge circuit in which an AC end is connected to the end of the third winding of the second transformer and the start end of the fourth winding.
The auxiliary power supply includes an inverter including a plurality of legs having semiconductor switches connected in series at the DC end of the three-phase diode rectifier, and a primary winding electrically connected between the two AC ends of the inverter. The electricity of the first end electrically connected to one of the DC ends on the high potential side of the first single-phase rectifying diode bridge circuit and one of the DC ends on the high potential side of the second single-phase rectifying diode bridge circuit. Between the first end and the second intermediate end electrically connected to the high potential side DC end of the three-phase diode rectifier, the first end and the second intermediate end. The second single-phase rectification between the first intermediate end electrically connected to the other of the DC ends on the high potential side of the first single-phase rectifier diode bridge circuit and the second end and the second intermediate end. A secondary winding with a third intermediate end electrically connected to the other of the high potential side DC ends of the diode bridge circuit, and a first high frequency power supply circuit with a first isolated transformer. , The primary winding electrically connected between the two AC ends of the inverter and the third end electrically connected to one of the low potential side DC ends of the first single-phase rectifier diode bridge circuit. , The fourth end electrically connected to the low potential side DC end of the second single-phase rectifier diode bridge circuit and the fifth intermediate electrically connected to the low potential side DC end of the three-phase diode rectifier. A fourth intermediate end electrically connected to the other end, the other of the low potential side DC ends of the first single-phase rectifying diode bridge circuit between the third end and the fifth intermediate end, and the first. A secondary winding with a sixth intermediate end electrically connected to the other of the low potential side DC ends of the second single-phase rectifying diode bridge circuit between the fourth end and the fifth intermediate end. A second high frequency power supply circuit with a second isolated transformer with and
The ratio of the number of turns from the second intermediate end to the first end to the number of turns from the second intermediate end to the first intermediate end, the number of turns from the second intermediate end to the second end and the second intermediate The ratio of the number of turns from the end to the third intermediate end, the ratio of the number of turns from the fifth intermediate end to the third end to the number of turns from the fifth intermediate end to the fourth intermediate end, and the first The ratio of the number of turns from the 5 intermediate end to the 4th end to the number of turns from the 5th intermediate end to the 6th intermediate end is equal.
The winding ratio between the first winding and the second winding of the first transformer and the winding ratio between the third winding and the fourth winding of the second transformer are equal to the ratio. The power conversion device according to claim 1. With a plurality of the first single-phase rectifying diode bridge circuits,
A plurality of the second single-phase rectifying diode bridge circuits are provided.
The first winding and the second winding of the first transformer are the AC ends of the first single-phase rectifying diode bridge circuit different from the first single-phase rectifying diode bridge circuit connected to the other end. With an electrically connected intermediate end,
The third winding and the fourth winding of the second transformer are the AC ends of the second single-phase rectifying diode bridge circuit different from the second single-phase rectifying diode bridge circuit connected to the other end. With an electrically connected intermediate end,
Between each of the AC ends of the three-phase diode rectifier and the start end of the first winding of the first transformer, and between each of the AC ends of the three-phase diode rectifier and the end of the second winding of the first transformer. Between each of the AC ends of the three-phase diode rectifier and the start end of the third winding of the second transformer, each of the AC ends of the three-phase diode rectifier and the fourth winding of the second transformer. Between the first transformer and the AC end of the first single-phase rectifying diode bridge circuit, between the second transformer and the AC end of the second single-phase rectifying diode bridge circuit, the first Between the intermediate end of the first winding of the 1 transformer and the intermediate end of the second winding of the first transformer and the AC end of the first single-phase rectifying diode bridge circuit, and the said of the second transformer. A semiconductor switch is connected in anti-series or anti-parallel between the intermediate end of the third winding and the intermediate end of the fourth winding of the second transformer and the AC end of the second single-phase rectifier diode bridge circuit. The power conversion device according to claim 13, wherein the power conversion device is connected via a bidirectional switch.