US20180278141A1 - Power conversion device and power conversion system - Google Patents
Power conversion device and power conversion system Download PDFInfo
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- US20180278141A1 US20180278141A1 US15/926,278 US201815926278A US2018278141A1 US 20180278141 A1 US20180278141 A1 US 20180278141A1 US 201815926278 A US201815926278 A US 201815926278A US 2018278141 A1 US2018278141 A1 US 2018278141A1
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- power conversion
- circuit
- common mode
- current extraction
- mode current
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/12—Arrangements for reducing harmonics from ac input or output
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/08—Limitation or suppression of earth fault currents, e.g. Petersen coil
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/01—Arrangements for reducing harmonics or ripples
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
- H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
- H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
- H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/493—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode the static converters being arranged for operation in parallel
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0038—Circuits or arrangements for suppressing, e.g. by masking incorrect turn-on or turn-off signals, e.g. due to current spikes in current mode control
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/12—Arrangements for reducing harmonics from ac input or output
- H02M1/123—Suppression of common mode voltage or current
Definitions
- Embodiments of the present invention relate to a device and a system that convert power inputted from the outside and output the converted power to a load.
- a metal material included in a power conversion device such as an inverter or a load device, such as a motor
- a parasitic capacitance is formed therebetween, and a leakage current is generated via the parasitic capacitance. Since the leakage current leads to deterioration of machines or unexpected electrical shock, there is a need to approximate the leakage current to 0 A as much as possible.
- an operating frequency of a power conversion device is increased. Since an impedance of the parasitic capacitance is reduced with increase in frequency, it becomes more significant to take measures against the leakage current.
- the impedance to a common mode is increased.
- measures such as elongating a distance between the ground potential and the facing metal or inserting a common mode choke coil of high inductance into a power line.
- any of the measures has a problem leading to upsizing of a power conversion device.
- a capacitor is intentionally connected to the ground potential in some cases. In this case, if a large-capacity capacitor is selected for producing a noise suppressing effect near a low frequency, increase in the leakage current is provoked.
- FIG. 1 shows a first embodiment, and is a functional block diagram showing a power conversion device having a three-phase AC input/three-phase AC output configuration
- FIG. 2 shows a second embodiment, and is a diagram partially showing a configuration of a DC link filter circuit
- FIG. 3 shows a third embodiment, and is a diagram showing the configuration of the first embodiment in more detail
- FIG. 4 is a diagram showing a waveform of a leakage current generated when the configuration of the third embodiment is applied;
- FIG. 5 is a diagram showing a waveform of a leakage current generated when a conventional configuration is applied
- FIG, 6 shows a fourth embodiment, and is a functional block diagram showing a power conversion device applied to a power conditioner
- FIG. 7 shows a fifth embodiment, and is a functional block diagram showing a power conversion device in which a second power conversion circuit is parallelized
- FIG. 8 shows a sixth embodiment, and is a functional block diagram simply showing a configuration of a power conversion device
- FIG. 9 shows a seventh embodiment, and is a functional block diagram simply showing a configuration of a power conversion device.
- FIG. 10 shows an eighth embodiment, and is a functional block diagram simply showing a configuration of a power conversion device.
- embodiments of the present invention provide a power conversion device and a power conversion system including a function capable of suppressing the leakage current while avoiding upsizing thereof.
- a power conversion device includes: a first power conversion circuit that converts power inputted from outside and outputs the converted power; a second power conversion circuit that is connected to the first power conversion circuit via a DC link part and converts inputted power to output the converted power to a first power conversion circuit and an input part of the second power conversion circuit; a first common mode current extraction circuit provided in an input part of the first power conversion circuit; a second common mode current extraction circuit provided in an output part of the second power conversion circuit; a virtual neutral potential line that connects the first common mode current extraction circuit and the second common mode current extraction circuit; a DC link filter circuit that includes a Y-shaped capacitor connected between the DC link part and the virtual neutral potential line; a first common mode coil inserted into a route from the first common mode current extraction circuit to a connection point of the Y-shaped capacitor in the DC link filter circuit; and a second common mode coil inserted into a route from the connection point of the Y-shaped capacitor to the second common mode current extraction circuit.
- Y-shaped capacitor here means a component connecting one end of each of two capacitors in common; the one common end is connected to a virtual neutral potential line, and the other end of each of the two capacitors is connected to a line connecting between a first and second power conversion circuits in a DC link part.
- FIG. 1 shows a power conversion device having a three-phase AC input/three-phase AC output configuration.
- a power conversion device 1 includes a converter 2 disposed on an input side and corresponding to a first power conversion circuit. Three-phase input terminals of the converter are connected to respective phase terminals of a three-phase AC power supply 3 via an external impedance adjustment circuit 4 .
- the external impedance adjustment circuit 4 includes coils 4 u, 4 v and 4 w corresponding to the respective phases.
- a first common mode extraction circuit 5 is connected to the three-phase input terminals of the converter 2 .
- the first common mode extraction circuit includes, for example, not-shown capacitors corresponding to the respective phases; one ends of the three capacitors are connected to the respective corresponding phases, and the other ends are connected in common to a virtual neutral potential line 6 .
- the common mode extraction circuit extracts common mode currents flowing through three-phase AC power supply lines and transfers the currents to the virtual neutral potential line 6 .
- the common mode extraction circuit 5 may include common mode choke coils connected in series between the three-phase capacitors and the virtual neutral potential line 6 .
- the converter convert the inputted three-phase AC current into a DC current and outputs the converted current.
- Output terminals of the converter 2 are connected, via a DC link part 7 , to input terminals of an inverter 8 disposed on an output side and corresponding to a second power conversion circuit.
- a DC link filter circuit 9 is inserted into the DC link part 7 .
- the filter circuit 2 includes a series circuit of the common mode choke coils 10 and 11 ; one end of the coil 10 is connected to the output terminals of the converter 2 , and one end of the coil 11 is connected to input terminals of the inverter 8 .
- the series circuit of the coils 10 and 11 is inserted into a route from the converter 2 to the inverter 8 .
- the coils 10 and 11 correspond to first and second common mode choke coils, respectively.
- the filter circuit 9 is a so-called T-shaped common mode filter. Moreover, between the output terminals of the converter 2 and between the input terminals of the inverter 8 , smoothing capacitors 13 and 14 are connected, respectively.
- the output terminals of the respective phases of the inverter 8 are connected to stator coils of respective phases of a three-phase motor 15 serving as a load. Moreover, between the above-described output terminals of the respective phases and the virtual neutral potential line 6 , a second common mode extraction circuit 16 , which is similar to the first common mode extraction circuit 5 , is connected. A housing of a motor 15 and the power supply 3 are grounded to the earth E. Moreover, between the virtual neutral potential line 6 and the earth E, an LC filter circuit 17 is connected. The LC filter circuit 17 includes a capacitor 18 connected between the virtual neutral potential line 6 and the earth E, and a series circuit of a coil 19 and a capacitor 20 , which is connected in parallel with the capacitor 18 .
- FIG. 2 partially shows a configuration of a DC link filter circuit 21 of the second embodiment alternative to the DC link filter circuit 9 .
- a coil 22 is inserted between the common connection point of the Y-shaped capacitor 12 and the virtual neutral potential line 6 .
- a power conversion device 23 of the third embodiment shown in FIG. 3 shows each component of the power conversion device 1 of the first embodiment more specifically and changes a part of the configuration.
- the first common mode extraction circuit 5 includes, as described in the first embodiment, capacitors 5 u, 5 v and 5 w corresponding to the respective phases.
- a second common mode extraction circuit 16 includes capacitors 16 u, 16 v and 16 w corresponding to the respective phases, and common mode choke coils 16 A, 16 E and 16 C connected between these capacitors and the virtual neutral potential line 6 .
- Each of the converter 2 and the inverter 9 is configured by connecting six switching elements in a three-phase bridge configuration. To each switching element, a return diode is connected in anti-parallel, and between arms of the respective phases, capacitors are connected in parallel. Note that, as to a motor 15 , together with stator coils 15 u, 15 v and 15 w of the respective phases, wiring resistance, wiring inductance and the parasitic capacitance formed between the motor 15 and the earth E are shown. Moreover, as to the LC filter circuit 17 , as a variation, the connecting direction thereof between the virtual neutral potential line 6 and the earth E is opposite to that of the first embodiment.
- the time constant of the LC filter circuit 17 is set to show low impedance at the frequency providing the peak.
- the total capacitance of the LC filter circuit 17 is set to the extent that the leakage current component at the switching frequency causes no problem.
- FIG. 5 shows a waveform of the leakage current generated in the conventional configuration of Patent Literature 1
- FIG. 4 shows a waveform of the leakage current generated in the configuration of the third embodiment.
- the maximum amplitude of the leakage current is about one-quarter of that of the conventional configuration.
- a power conversion device 31 of the fourth embodiment shown in FIG. 6 is a case of being applied to a power raw conditioner used for, for example, a solar power generation device or other devices.
- a power supply 32 is, for example, a solar cell, and generates DC power and outputs the generated power.
- a DC-DC converter 33 corresponding to a first power conversion circuit is connected to the power supply 32 via an external impedance adjustment circuit 34 .
- the external impedance adjustment circuit 34 is configured with, for example, a common mode choke coil.
- a first common mode extraction circuit 35 is connected between input terminals of the DC-DC converter 33 and the virtual neutral potential line 6 .
- the DC-DC converter 33 converts an inputted DC voltage into a different voltage and outputs the converted voltage.
- Output terminals of the DC-DC converter 33 are connected, via the DC link part 7 , to input terminals of a DC-AC inverter 36 corresponding to the second power conversion circuit.
- Output terminals of the inverter 36 are connected to a load 38 via an external impedance adjustment circuit 37 .
- the inverter 36 converts the inputted DC power into a single-phase AC power and outputs the converted power to the load 38 .
- the load 38 is, for example, a single-phase AC cower supply line of a commercial AC power supply system.
- a second common mode extraction circuit 39 is connected between the output terminals of the inverter 36 and the virtual neutral potential line 6 .
- the common mode extraction circuits 35 and 39 may be connected when impedance adjustment is required in accordance with the state of occurrence of the leakage current or noise.
- the power conversion device 31 can be applied to the power conditioner.
- a power conversion device 41 of the fifth embodiment shown in FIG. 7 has a configuration in which the two second power conversion circuits are connected to the DC link part 7 in parallel.
- the external impedance adjustment circuit 43 includes a common mode choke coil 43 a and a capacitor 43 b connected between terminals on the load 42 side.
- a second common mode extraction circuit 39 is connected between the output terminals of the converter 44 and the virtual neutral potential line 6 .
- a current limiting circuit 45 is inserted into the virtual neutral potential line 6 .
- the current limiting circuit 45 is disposed to prevent an excessive current from flowing into the virtual neutral potential line 6 , and is configured with, for example, other than single use of resistance or single use of inductor, those considering frequency characteristics, such as an RC parallel circuit.
- a smoothing capacitor 47 , the inverter 8 and the three-phase motor 15 are connected via another DC link filter circuit 46 .
- the filter circuit 46 corresponds to a parallel DC link filter circuit.
- the respective-phase output terminals of the inverter 8 are connected to the input terminals of the common mode extraction circuit 16 , respectively.
- the common connection point of the Y-shaped capacitor constituting the DC link filter circuit 46 is connected to the virtual neutral potential line 6 via a virtual neutral potential sharing line 48 .
- another current limiting circuit 49 is connected between the common mode extraction circuit 16 and the virtual neutral potential sharing line 42 .
- connection mode of the virtual neutral potential sharing line 48 is not limited to the one shown in the figure, and the line 48 may be connected to a portion other than the power line.
- the time constant is set so that the LC filter circuit 17 shows a low impedance at the relevant frequency.
- the leakage current can be suppressed.
- the sixth to eighth embodiments show variations of positions for inserting the first and second common mode choke coils. Note that, in FIGS. 8 to 10 corresponding to these embodiments, components corresponding to those of the first embodiment are assigned with the same reference signs to schematically illustrate the embodiments, and the Y-shaped capacitor 12 in the DC link part 7 is indicated by a symbol of a single capacitor.
- the common mode choke coil 11 is inserted into a route from the inverter 8 to the common mode extraction circuit 16 .
- the common mode choke coil 10 is inserted into a route from the common mode extraction circuit 5 to the converter 2 .
- the common mode choke coil 10 is inserted into a route from the common mode extraction circuit 5 to the converter 2
- the common mode choke coil 11 is inserted into a route from the inverter 8 to the common mode extraction circuit 16 .
- the first power conversion circuit may have a configuration to perform power conversion by diode rectification.
- the current limiting circuit may be inserted into the virtual neutral potential line 6 .
- a power conversion system may be configured by connecting the virtual neutral potential lines 6 of these devices in common.
- three or more rows of the configuration including the second power conversion circuit and components subsequent thereto may be connected in parallel.
Abstract
Description
- Embodiments of the present invention relate to a device and a system that convert power inputted from the outside and output the converted power to a load.
- For example, when a metal material included in a power conversion device, such as an inverter or a load device, such as a motor, is disposed to face a ground potential, a parasitic capacitance is formed therebetween, and a leakage current is generated via the parasitic capacitance. Since the leakage current leads to deterioration of machines or unexpected electrical shock, there is a need to approximate the leakage current to 0 A as much as possible. Moreover, due to advanced performance of a semiconductor switching element, an operating frequency of a power conversion device is increased. Since an impedance of the parasitic capacitance is reduced with increase in frequency, it becomes more significant to take measures against the leakage current.
- To suppress the leakage current, for example, the impedance to a common mode is increased. Specifically, measures, such as elongating a distance between the ground potential and the facing metal or inserting a common mode choke coil of high inductance into a power line, are taken. However, any of the measures has a problem leading to upsizing of a power conversion device. Moreover, other than the measures against the leakage current, as a purpose of suppressing electromagnetic noises, a capacitor is intentionally connected to the ground potential in some cases. In this case, if a large-capacity capacitor is selected for producing a noise suppressing effect near a low frequency, increase in the leakage current is provoked.
-
FIG. 1 shows a first embodiment, and is a functional block diagram showing a power conversion device having a three-phase AC input/three-phase AC output configuration; -
FIG. 2 shows a second embodiment, and is a diagram partially showing a configuration of a DC link filter circuit; -
FIG. 3 shows a third embodiment, and is a diagram showing the configuration of the first embodiment in more detail; -
FIG. 4 is a diagram showing a waveform of a leakage current generated when the configuration of the third embodiment is applied; -
FIG. 5 is a diagram showing a waveform of a leakage current generated when a conventional configuration is applied; - FIG, 6 shows a fourth embodiment, and is a functional block diagram showing a power conversion device applied to a power conditioner;
-
FIG. 7 shows a fifth embodiment, and is a functional block diagram showing a power conversion device in which a second power conversion circuit is parallelized; -
FIG. 8 shows a sixth embodiment, and is a functional block diagram simply showing a configuration of a power conversion device; -
FIG. 9 shows a seventh embodiment, and is a functional block diagram simply showing a configuration of a power conversion device; and -
FIG. 10 shows an eighth embodiment, and is a functional block diagram simply showing a configuration of a power conversion device. - Therefore, embodiments of the present invention provide a power conversion device and a power conversion system including a function capable of suppressing the leakage current while avoiding upsizing thereof.
- A power conversion device according to an embodiment includes: a first power conversion circuit that converts power inputted from outside and outputs the converted power; a second power conversion circuit that is connected to the first power conversion circuit via a DC link part and converts inputted power to output the converted power to a first power conversion circuit and an input part of the second power conversion circuit; a first common mode current extraction circuit provided in an input part of the first power conversion circuit; a second common mode current extraction circuit provided in an output part of the second power conversion circuit; a virtual neutral potential line that connects the first common mode current extraction circuit and the second common mode current extraction circuit; a DC link filter circuit that includes a Y-shaped capacitor connected between the DC link part and the virtual neutral potential line; a first common mode coil inserted into a route from the first common mode current extraction circuit to a connection point of the Y-shaped capacitor in the DC link filter circuit; and a second common mode coil inserted into a route from the connection point of the Y-shaped capacitor to the second common mode current extraction circuit.
- Note that, the term “Y-shaped capacitor” here means a component connecting one end of each of two capacitors in common; the one common end is connected to a virtual neutral potential line, and the other end of each of the two capacitors is connected to a line connecting between a first and second power conversion circuits in a DC link part.
- Hereinafter, the first embodiment will be described with reference to
FIG. 1 .FIG. 1 shows a power conversion device having a three-phase AC input/three-phase AC output configuration. Apower conversion device 1 includes aconverter 2 disposed on an input side and corresponding to a first power conversion circuit. Three-phase input terminals of the converter are connected to respective phase terminals of a three-phaseAC power supply 3 via an externalimpedance adjustment circuit 4. The externalimpedance adjustment circuit 4 includescoils - Moreover, to the three-phase input terminals of the
converter 2, a first commonmode extraction circuit 5 is connected. The first common mode extraction circuit includes, for example, not-shown capacitors corresponding to the respective phases; one ends of the three capacitors are connected to the respective corresponding phases, and the other ends are connected in common to a virtual neutralpotential line 6. The common mode extraction circuit extracts common mode currents flowing through three-phase AC power supply lines and transfers the currents to the virtual neutralpotential line 6. Note that the commonmode extraction circuit 5 may include common mode choke coils connected in series between the three-phase capacitors and the virtualneutral potential line 6. The converter convert the inputted three-phase AC current into a DC current and outputs the converted current. - Output terminals of the
converter 2 are connected, via aDC link part 7, to input terminals of aninverter 8 disposed on an output side and corresponding to a second power conversion circuit. Into theDC link part 7, a DClink filter circuit 9 is inserted. Thefilter circuit 2 includes a series circuit of the commonmode choke coils coil 10 is connected to the output terminals of theconverter 2, and one end of thecoil 11 is connected to input terminals of theinverter 8. In other words, the series circuit of thecoils converter 2 to theinverter 8. Thecoils - To common connection points of the
colts capacitors capacitors potential line 6. Hereinafter, the twocapacitors shaped capacitor 12 in some cases. Thefilter circuit 9 is a so-called T-shaped common mode filter. Moreover, between the output terminals of theconverter 2 and between the input terminals of theinverter 8,smoothing capacitors - The output terminals of the respective phases of the
inverter 8 are connected to stator coils of respective phases of a three-phase motor 15 serving as a load. Moreover, between the above-described output terminals of the respective phases and the virtual neutralpotential line 6, a second commonmode extraction circuit 16, which is similar to the first commonmode extraction circuit 5, is connected. A housing of amotor 15 and thepower supply 3 are grounded to the earth E. Moreover, between the virtual neutralpotential line 6 and the earth E, anLC filter circuit 17 is connected. TheLC filter circuit 17 includes acapacitor 18 connected between the virtual neutralpotential line 6 and the earth E, and a series circuit of acoil 19 and acapacitor 20, which is connected in parallel with thecapacitor 18. - According to this embodiment configured as described above, as compared to the conventional configuration of
Patent Literature 1, it is possible to produce greater suppression effect of the leakage current by providing the DClink filter circuit 9 to theDC link part 7, and in addition, providing theLC filter circuit 17 between the DClink filter circuit 9 and the earth E. Moreover, by providing the externalimpedance adjustment circuit 4 to relatively reduce the impedance on the virtualneutral potential line 6 side, it is possible to further increase the suppression effect of the leakage current. - Hereinafter, same parts as those in the first embodiment are assigned with the same reference signs and descriptions thereof are omitted, while different parts will be described.
FIG. 2 partially shows a configuration of a DClink filter circuit 21 of the second embodiment alternative to the DClink filter circuit 9. In the DClink filter circuit 21, acoil 22 is inserted between the common connection point of the Y-shaped capacitor 12 and the virtual neutralpotential line 6. By use of such a DC link filter circuit is possible to increase selectivity of frequency to suppress the leakage current. - A
power conversion device 23 of the third embodiment shown inFIG. 3 shows each component of thepower conversion device 1 of the first embodiment more specifically and changes a part of the configuration. The first commonmode extraction circuit 5 includes, as described in the first embodiment,capacitors mode extraction circuit 16 includescapacitors mode choke coils potential line 6. - Each of the
converter 2 and theinverter 9 is configured by connecting six switching elements in a three-phase bridge configuration. To each switching element, a return diode is connected in anti-parallel, and between arms of the respective phases, capacitors are connected in parallel. Note that, as to amotor 15, together withstator coils motor 15 and the earth E are shown. Moreover, as to theLC filter circuit 17, as a variation, the connecting direction thereof between the virtual neutralpotential line 6 and the earth E is opposite to that of the first embodiment. - To suppress component of the leakage current in which a peak occurs at the frequency higher than the switching frequencies in the
converter 2 and theinverter 8 by the resonance phenomenon, the time constant of theLC filter circuit 17 is set to show low impedance at the frequency providing the peak. At this time, the total capacitance of theLC filter circuit 17 is set to the extent that the leakage current component at the switching frequency causes no problem. -
FIG. 5 shows a waveform of the leakage current generated in the conventional configuration ofPatent Literature 1, andFIG. 4 shows a waveform of the leakage current generated in the configuration of the third embodiment. In the configuration of the third embodiment, the maximum amplitude of the leakage current is about one-quarter of that of the conventional configuration. - A
power conversion device 31 of the fourth embodiment shown inFIG. 6 is a case of being applied to a power raw conditioner used for, for example, a solar power generation device or other devices. Apower supply 32 is, for example, a solar cell, and generates DC power and outputs the generated power. A DC-DC converter 33 corresponding to a first power conversion circuit is connected to thepower supply 32 via an externalimpedance adjustment circuit 34. The externalimpedance adjustment circuit 34 is configured with, for example, a common mode choke coil. Between input terminals of the DC-DC converter 33 and the virtual neutralpotential line 6, a first commonmode extraction circuit 35 is connected. The DC-DC converter 33 converts an inputted DC voltage into a different voltage and outputs the converted voltage. - Output terminals of the DC-
DC converter 33 are connected, via theDC link part 7, to input terminals of a DC-AC inverter 36 corresponding to the second power conversion circuit. Output terminals of theinverter 36 are connected to aload 38 via an externalimpedance adjustment circuit 37. Theinverter 36 converts the inputted DC power into a single-phase AC power and outputs the converted power to theload 38. Theload 38 is, for example, a single-phase AC cower supply line of a commercial AC power supply system. Between the output terminals of theinverter 36 and the virtual neutralpotential line 6, a second commonmode extraction circuit 39 is connected. Note that the commonmode extraction circuits - According to the fourth embodiment configured as described above, the
power conversion device 31 can be applied to the power conditioner. - A
power conversion device 41 of the fifth embodiment shown inFIG. 7 has a configuration in which the two second power conversion circuits are connected to theDC link part 7 in parallel. Aconverter 44 connected between theDC link part 7 and aload 42, via an externalimpedance adjustment circuit 43, performs DC-DC conversion. The externalimpedance adjustment circuit 43 includes a commonmode choke coil 43 a and acapacitor 43 b connected between terminals on theload 42 side. Between the output terminals of theconverter 44 and the virtual neutralpotential line 6, a second commonmode extraction circuit 39 is connected. A current limitingcircuit 45 is inserted into the virtual neutralpotential line 6. The current limitingcircuit 45 is disposed to prevent an excessive current from flowing into the virtual neutralpotential line 6, and is configured with, for example, other than single use of resistance or single use of inductor, those considering frequency characteristics, such as an RC parallel circuit. - To output terminals of the
converter 2, a smoothingcapacitor 47, theinverter 8 and the three-phase motor 15 are connected via another DClink filter circuit 46. Thefilter circuit 46 corresponds to a parallel DC link filter circuit. The respective-phase output terminals of theinverter 8 are connected to the input terminals of the commonmode extraction circuit 16, respectively. The common connection point of the Y-shaped capacitor constituting the DClink filter circuit 46 is connected to the virtual neutralpotential line 6 via a virtual neutralpotential sharing line 48. Between the commonmode extraction circuit 16 and the virtual neutralpotential sharing line 42, another current limitingcircuit 49 is connected. - Note that the connection mode of the virtual neutral
potential sharing line 48 is not limited to the one shown in the figure, and theline 48 may be connected to a portion other than the power line. When the leakage current is increased by multiple frequencies, the time constant is set so that theLC filter circuit 17 shows a low impedance at the relevant frequency. - According to the fifth embodiment configured as described above, in the configuration in which the
converter 44 and theinverter 8 that are the second power conversion circuits are connected to theDC link part 7 in parallel and are operated by sharing the virtual neutralpotential line 6 the leakage current can be suppressed. - The sixth to eighth embodiments show variations of positions for inserting the first and second common mode choke coils. Note that, in
FIGS. 8 to 10 corresponding to these embodiments, components corresponding to those of the first embodiment are assigned with the same reference signs to schematically illustrate the embodiments, and the Y-shapedcapacitor 12 in theDC link part 7 is indicated by a symbol of a single capacitor. - In the sixth embodiment shown in
FIG. 8 , the commonmode choke coil 11 is inserted into a route from theinverter 8 to the commonmode extraction circuit 16. - In the seventh embodiment shown in
FIG. 9 , the commonmode choke coil 10 is inserted into a route from the commonmode extraction circuit 5 to theconverter 2. - In the eighth embodiment shown in
FIG. 10 , the commonmode choke coil 10 is inserted into a route from the commonmode extraction circuit 5 to theconverter 2, and the commonmode choke coil 11 is inserted into a route from theinverter 8 to the commonmode extraction circuit 16. With these configurations, also, effects similar to those in the first embodiment can be obtained. - The first power conversion circuit may have a configuration to perform power conversion by diode rectification.
- In the first to fourth embodiments and the sixth to eighth embodiments, the current limiting circuit may be inserted into the virtual neutral
potential line 6. - When two or more power conversion devices of the first to fourth embodiments and the sixth to eighth embodiments are used in parallel connection, a power conversion system may be configured by connecting the virtual neutral
potential lines 6 of these devices in common. - In the fifth embodiment, three or more rows of the configuration including the second power conversion circuit and components subsequent thereto may be connected in parallel.
- While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only and are not intended to limit the scope of the present invention. These new embodiments can be practiced in various other forms, and various omissions, substitutions and changes may be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope or the gist of the invention, and the invention as recited in the claims and equivalents thereof.
Claims (15)
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JP2017054312 | 2017-03-21 | ||
JP2017-095561 | 2017-05-12 | ||
JP2017095561A JP6797748B2 (en) | 2017-03-21 | 2017-05-12 | Power converter and power conversion system |
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US20180278141A1 true US20180278141A1 (en) | 2018-09-27 |
US10090753B1 US10090753B1 (en) | 2018-10-02 |
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CN (1) | CN108631630B (en) |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11329544B2 (en) * | 2019-11-15 | 2022-05-10 | Vacon Oy | Filter arrangement |
US11374504B2 (en) * | 2018-06-20 | 2022-06-28 | Mitsubishi Electric Corporation | Electric power converter |
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CN110829598B (en) * | 2019-11-20 | 2022-07-12 | 国网宁夏电力有限公司吴忠供电公司 | Thing networking power conversion equipment |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6987372B1 (en) * | 2001-04-11 | 2006-01-17 | Rockwell Automation Technologies, Inc. | Integrated DC link choke and method for suppressing common-mode voltage in a motor drive |
US20100045108A1 (en) * | 2008-08-20 | 2010-02-25 | Hamilton Sundstrand Corporation | Power conversion architecture with zero common mode voltage |
US20110292695A1 (en) * | 2010-05-26 | 2011-12-01 | Rockwell Automation Technologies, Inc. | Power converter system and method |
US8169179B2 (en) * | 2006-08-22 | 2012-05-01 | Regents Of The University Of Minnesota | Open-ended control circuit for electrical apparatus |
US20140268933A1 (en) * | 2013-03-18 | 2014-09-18 | Delta Electronics, Inc. | Filter device, power converter and common mode noise suppression method |
US20150009727A1 (en) * | 2013-07-02 | 2015-01-08 | Delta Electronics (Shanghai) Co., Ltd. | Power converter with low common mode noise |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4351916B2 (en) * | 2004-01-16 | 2009-10-28 | 株式会社東芝 | Noise filter |
WO2009110354A1 (en) * | 2008-03-04 | 2009-09-11 | 株式会社安川電機 | Output filter and power converter using output filter |
JP2009148162A (en) * | 2009-03-30 | 2009-07-02 | Toshiba Corp | Noise filter |
JP5347688B2 (en) * | 2009-04-27 | 2013-11-20 | サンケン電気株式会社 | Active filter device and power conversion device |
JP5701631B2 (en) | 2011-02-03 | 2015-04-15 | 株式会社東芝 | Leakage current suppression circuit |
WO2013185847A1 (en) * | 2012-06-15 | 2013-12-19 | Huawei Technologies Co., Ltd. | Method and apparatus for performing power conversion |
-
2018
- 2018-03-20 US US15/926,278 patent/US10090753B1/en active Active
- 2018-03-20 DE DE102018204222.5A patent/DE102018204222A1/en not_active Ceased
- 2018-03-21 CN CN201810233192.9A patent/CN108631630B/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6987372B1 (en) * | 2001-04-11 | 2006-01-17 | Rockwell Automation Technologies, Inc. | Integrated DC link choke and method for suppressing common-mode voltage in a motor drive |
US8169179B2 (en) * | 2006-08-22 | 2012-05-01 | Regents Of The University Of Minnesota | Open-ended control circuit for electrical apparatus |
US20100045108A1 (en) * | 2008-08-20 | 2010-02-25 | Hamilton Sundstrand Corporation | Power conversion architecture with zero common mode voltage |
US20110292695A1 (en) * | 2010-05-26 | 2011-12-01 | Rockwell Automation Technologies, Inc. | Power converter system and method |
US20140268933A1 (en) * | 2013-03-18 | 2014-09-18 | Delta Electronics, Inc. | Filter device, power converter and common mode noise suppression method |
US20150009727A1 (en) * | 2013-07-02 | 2015-01-08 | Delta Electronics (Shanghai) Co., Ltd. | Power converter with low common mode noise |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11374504B2 (en) * | 2018-06-20 | 2022-06-28 | Mitsubishi Electric Corporation | Electric power converter |
US11329544B2 (en) * | 2019-11-15 | 2022-05-10 | Vacon Oy | Filter arrangement |
Also Published As
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US10090753B1 (en) | 2018-10-02 |
CN108631630B (en) | 2020-12-08 |
DE102018204222A1 (en) | 2018-09-27 |
CN108631630A (en) | 2018-10-09 |
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