JP2006014549A - Driving power supply circuit for bidirectional switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving power supply circuit of a bidirectional switch for reducing the number of insulated power supplies, the total weight of the apparatus and a cost, and miniaturizing the apparatus. <P>SOLUTION: The driving power supply circuit of the bidirectional switch supplies power to driving circuits of IGBT 1, 2 so as to drive the bidirectional switch to which the reverse blocking IGBT 1, 2 are reversely connected in parallel. The circuit comprises a DC power supply 19 for supplying power to the driving circuit 23 of the reverse blocking IGBT 1, a capacitor 22 for supplying power to the driving circuit 24 of the reverse blocking IGBT 2, and a p-channel MOSFET 20 as a semiconductor switch for the driving power supply connected between the DC power supply 19 and the capacitor 22 in series and charging the capacitor 22 by the DC power supply 19 through the reverse blocking IGBT 1 during an on-state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive power supply circuit for supplying drive power to a bidirectional switch configured by connecting power semiconductor switching elements such as IGBTs in antiparallel.

  FIG. 6 shows a bidirectional power semiconductor switch (hereinafter simply referred to as a bidirectional switch) configured by connecting IGBTs (hereinafter referred to as reverse blocking IGBTs) 1 and 2 having reverse breakdown voltages as power semiconductor switching elements in reverse parallel. Say). FIG. 7 is a circuit configuration diagram of a three-phase matrix converter configured using nine bidirectional switches shown in FIG. 6. R, S, and T are three-phase input terminals connected to a three-phase power source. , U, V, W denote three-phase output terminals connected to a three-phase load.

Conventionally, when this type of bidirectional switch is applied to a matrix converter, six insulated power supplies for driving a reverse blocking IGBT are required as described in Table 4.1 of Non-Patent Document 1 below. It is known that there is.
Taking FIG. 7 as an example, since it is necessary to provide an insulating power source for each drive power source of reverse blocking IGBTs whose emitters have the same potential, reverse blocking IGBTs 1, 3, 5, 7, 9, 11, 13, Insulated power supplies are respectively provided for the six reverse blocking IGBT groups 15, 17, 2, 8, 14, 4, 10, 16, 6, 12, 18.

Hidenori Hara and five others, “Improvement of Matrix Converter Drive Performance”, Proceedings of the Institute of Electrical Engineers of Japan, The Institute of Electrical Engineers of Japan, pp. 931-pp. 934, FIG. 4.1, Table 4.1

In general, a DC / DC converter using a transformer is used to secure an insulated power supply. In the example of the matrix converter described above, six DC / DC converters corresponding to the number of insulated power supplies are required, and transformers and the like that are components of these DC / DC converters prevent miniaturization of the entire apparatus. Moreover, it becomes a cause which raises cost.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a drive power supply circuit for a power semiconductor switch in which the number of insulated power supplies is reduced so that the entire apparatus can be reduced in size and weight and cost.

In order to solve the above-described problem, the invention described in claim 1 is directed to a first semiconductor switch for driving a bidirectional switch in which a first semiconductor switch and a second semiconductor switch are connected in antiparallel. In the drive power supply circuit of the bidirectional switch for supplying power to the drive circuit and the drive circuit of the second semiconductor switch,
A DC power source for supplying power to the drive circuit for the first semiconductor switch; a capacitor for supplying power to the drive circuit for the second semiconductor switch; and the DC power source and the capacitor connected in series; and And a driving power supply semiconductor switch for charging the capacitor with the DC power supply via the first or second semiconductor switch when the switch is turned on.

  According to a second aspect of the present invention, in the first aspect, the first semiconductor switch and the second semiconductor switch are constituted by semiconductor switching elements having a reverse breakdown voltage.

  According to a third aspect of the present invention, in the first aspect, the first semiconductor switch and the second semiconductor switch are configured by a semiconductor switching element having no reverse breakdown voltage and a diode connected in order to the semiconductor switching element. It is a thing.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the drive power supply semiconductor switch is configured by a semiconductor switching element having a reverse breakdown voltage.

  According to a fifth aspect of the present invention, in any one of the first to third aspects, the driving power supply semiconductor switch includes a semiconductor switching element having no reverse breakdown voltage, and a diode connected in order to the semiconductor switching element. It is constituted by.

  The invention described in claim 6 is characterized in that, in claim 5, the semiconductor switching element constituting the semiconductor switch for driving power supply is a P-channel MOSFET, a P-channel IGBT or a PNP transistor.

  A seventh aspect of the present invention is the device according to any one of the first to sixth aspects, wherein the first semiconductor switch, the second semiconductor switch, and the semiconductor switch for driving power supply are simultaneously turned on and off.

  The invention described in claim 8 is the driving power supply semiconductor switch according to any one of claims 1 to 6, wherein both or one of the first semiconductor switch and the second semiconductor switch is turned on. To turn on.

  According to a ninth aspect of the present invention, in any one of the first to sixth aspects, the driving power supply semiconductor switch is turned on for a certain period of time after both the first semiconductor switch and the second semiconductor switch are turned on. It will be turned on later.

In the present invention, one semiconductor switch constituting the bidirectional switch is driven by a drive circuit to which a DC power supply is connected, and the other semiconductor switch is connected to the DC power supply via the drive power supply semiconductor switch. It is driven by a drive circuit using a capacitor as a drive voltage source.
For this reason, the number of insulated power supplies having a DC / DC converter or the like can be reduced as compared with the prior art. For example, when the present invention is applied to a three-phase matrix converter, the number of insulated power supplies can be halved. It is possible to reduce the size and weight of the entire device and to reduce the price.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing a first embodiment of the present invention, and a drive power supply circuit according to the present invention is connected to a bidirectional switch configured by connecting reverse blocking IGBT 1 and reverse blocking IGBT 2 as semiconductor switching elements in antiparallel. This is an example in which 100 (a part surrounded by a dotted line) is applied. This embodiment corresponds to the inventions of claims 1 to 6.
The reverse blocking IGBTs 1 and 2 correspond to the first semiconductor switch and the second semiconductor switch in the claims, respectively.

  In FIG. 1, reference numeral 23 denotes a drive circuit for the reverse blocking IGBT 1, and 24 denotes a drive circuit for the reverse blocking IGBT 2. The output terminals of these driving circuits 23 and 24 are connected to the gates of the reverse blocking IGBTs 1 and 2, respectively. Reference numeral 19 denotes a DC power supply for driving the reverse blocking IGBT 1, the positive electrode of which is connected to one power supply terminal of the drive circuit 23 and a drive circuit 25 described later, and the negative electrode is connected to the other of the drive circuits 23 and 25. The power supply terminal and the emitter of reverse blocking IGBT 1 (the collector of reverse blocking IGBT 2) are connected. Further, reference numeral 22 denotes a capacitor serving as a drive voltage source for the reverse blocking IGBT 2, one end of which is connected to one power supply terminal of the drive circuit 24, and the other end of the other power supply terminal of the drive circuit 24 and the emitter of the reverse blocking IGBT 2 ( Reverse collector IGBT 1 collector).

Reference numeral 20 denotes a P-channel MOSFET as a driving power supply semiconductor switch, the source of which is connected to the positive electrode of a DC power supply 19 and the drain of which is connected to one end of the capacitor 22 via a diode 21.
Reference numeral 25 denotes a drive circuit for the MOSFET 20, and its output terminal is connected to the gate of the MOSFET 20. A drive signal is input to the drive circuit 25 and the drive circuits 23 and 24 from an external control circuit. It is configured.
In the above configuration, the DC power supply 19, the capacitor 22, the drive circuit 25, the P-channel MOSFET 20 and the diode 21 constitute the drive power supply circuit 100 according to the present embodiment.

The operation of this embodiment will be described below with reference to FIGS.
In the bidirectional switch shown in FIG. 1, the reverse blocking IGBT 1 and the reverse blocking IGBT 2 are basically turned on and off at the same time. In this embodiment, the P-channel MOSFET 20 is also turned on and off simultaneously with the reverse blocking IGBTs 1 and 2.
That is, the drive circuits 23 and 25 to which power is supplied from the DC power supply 19 and the drive circuit 24 using the capacitor 22 charged by the DC power supply 19 via the MOSFET 20 and the diode 21 as a drive voltage source are externally connected. Are respectively turned on, and the reverse blocking IGBT 1, the MOSFET 20, and the reverse blocking IGBT 2 are simultaneously turned on and turned off simultaneously.

  Here, it is assumed that the DC power supply 19 as a drive power supply for the reverse blocking IGBT 1 outputs a stable power supply voltage. Further, since the P-channel MOSFET 20 has a characteristic of being turned on when the potential of the gate terminal becomes lower than the source potential, the P-channel MOSFET 20 inputs a signal obtained by inverting the drive signal of the reverse blocking IGBTs 1 and 2 from the drive circuit 25. It shall drive by doing.

  FIG. 2 shows a path through which a charging current of the capacitor 22 as a drive voltage source of the reverse blocking IGBT 2 flows. When the P-channel MOSFET 20 is turned on while the reverse blocking IGBT 1 is on, the emitter of the reverse blocking IGBT 1 and the emitter of the reverse blocking IGBT 2 have the same potential, so that a current flows along the path indicated by the arrow in the figure, and the capacitor 22 is charged to a voltage substantially equal to the voltage of the DC power supply 19 with the polarity shown.

  Further, when the reverse blocking IGBTs 1 and 2 are turned off and a positive voltage is applied to the collector side with respect to the emitter of the reverse blocking IGBT 1, the diode 21 bears the voltage, and the main circuit current is the drive power supply circuit 100. Prevent flow through. Further, since the P-channel MOSFET 20 is also turned off when the reverse blocking IGBTs 1 and 2 are turned off, when a negative voltage is applied to the collector side with respect to the emitter of the reverse blocking IGBT 1, the MOSFET 20 reduces the voltage. The main circuit current is prevented from flowing through the drive power supply circuit 100.

  In the present embodiment, the capacitor 22 cannot be charged during the period when the reverse blocking IGBTs 1 and 2 are off, and the voltage of the capacitor 22 may decrease during the period, but the capacity of the capacitor 22 is required. If it is increased accordingly, there is no practical problem, and the voltage of the capacitor 22 is maintained at a constant voltage value substantially equal to the voltage of the DC power supply 19 by the ON operation of the reverse blocking IGBTs 1 and 2 and the P-channel MOSFET 20 described above. Can do.

If the P-channel MOSFET 20 as the drive power supply semiconductor switch has a reverse breakdown voltage, the diode 21 is not necessary. Further, as described in the sixth aspect, the same effect can be obtained by using a P-channel IGBT or a PNP transistor instead of the P-channel MOSFET 20.
Further, for example, an N-channel MOSFET can be used instead of the P-channel MOSFET 20, and the same operation can be performed. In this case, however, it is necessary to separately prepare a drive power source for the N-channel MOSFET.

Next, FIG. 3 shows a main part of the second embodiment of the present invention, and corresponds to the inventions of claims 7 to 9.
In the first embodiment, the reverse blocking IGBT 1 and the reverse blocking IGBT 2 are basically turned on and off at the same time, and the P-channel MOSFET 20 is also turned on and off simultaneously with the reverse blocking IGBTs 1 and 2. However, depending on the application, the on / off timing of the reverse blocking IGBT 1 and the reverse blocking IGBT 2 may be intentionally shifted.

  The P-channel MOSFET 20 may have a current rating that is much smaller than the current ratings of the reverse blocking IGBTs 1 and 2, but generally the smaller the rated current, the faster the switching speed. There is a possibility that the P-channel MOSFET 20 is turned on. For this reason, even if an ON / OFF signal having the same timing as that of either one of the reverse blocking IGBTs 1 and 2 is input to the MOSFET 20, the MOSFET 20 is turned on before the reverse blocking IGBT1 or the reverse blocking IGBT2, and reverse blocking is normally performed. As a result of the main circuit current that should flow through either one of the IGBTs 1 and 2 flowing through the MOSFET 20, the MOSFET 20 may be destroyed.

Therefore, the second embodiment is for solving the above problems, and FIG. 3 shows a drive circuit 25A that generates a drive signal for the P-channel MOSFET 20.
As shown in the figure, the drive circuit 25A includes an AND circuit 26 to which the drive signals of the reverse blocking IGBTs 1 and 2 are input, and an on-delay circuit 27 that delays the output signal to delay the timing at which the P-channel MOSFET 20 is turned on. It is configured.

FIG. 4 is a timing chart of drive signals for the reverse blocking IGBTs 1 and 2 and the P-channel MOSFET 20 in the second embodiment.
At time t1, both of the reverse blocking IGBTs 1 and 2 are turned on, and the P-channel MOSFET 20 is turned on at time t2 when a predetermined time has elapsed after the output signal of the AND circuit 26 is applied to the on-delay circuit 27.

In addition, the timing of the signal for turning off the MOSFET 20 is the same timing as the signal that is turned off first in the reverse blocking IGBTs 1 and 2, and in the illustrated example, the timing is set to coincide with the off time t3 of the reverse blocking IGBT1. As described above, since the switching speed of the P-channel MOSFET 20 is faster than that of the reverse blocking IGBT, there is no particular problem even if the timing of the off signal is the same as that of the P-channel MOSFET 20 and the reverse blocking IGBTs 1 and 2.
By turning on / off the P-channel MOSFET 20 at the above timing by the control circuit 25A of FIG. 3, it is possible to prevent the breakdown due to the inflow of the main circuit current to the MOSFET 20.

Note that the P-channel MOSFET 20 may be intentionally turned off at a time before the reverse blocking IGBTs 1 and 2 are turned off.
Further, the P-channel MOSFET 20 may be turned off when any one of the reverse blocking IGBTs 1 and 2 is turned on.

Furthermore, the first embodiment and the second embodiment are configured by using IGBTs 28 and 29 having no reverse breakdown voltage and diodes 30 and 31 respectively connected in order to each other as shown in FIG. It can also be applied to a bidirectional switch.
This configuration corresponds to the invention of claim 3.
In this case, a series circuit of the IGBT 28 and the diode 30 corresponds to the first semiconductor switch in each claim, and a series circuit of the IGBT 29 and the diode 31 corresponds to the second semiconductor switch in each claim.

  As described above, conventionally, in the matrix converter as shown in FIG. 7, six DC / DC converters are required to secure an insulated power supply, whereas in the embodiment of the present invention, for example, It is only necessary to provide an isolated power source for each of the three reverse blocking IGBT groups of reverse blocking IGBTs 1, 3, 5, 7, 9, 11, 13, 15, and 17. This contributes to the reduction in size and weight and price.

It is a block diagram which shows 1st Embodiment of this invention. It is a figure which shows the charge path | route of the capacitor | condenser in 1st Embodiment. It is a block diagram which shows the principal part of 2nd Embodiment of this invention. It is a timing chart of the drive signal of each switch in a 2nd embodiment. It is a block diagram of the bidirectional | two-way switch using IGBT and a diode. It is a block diagram of the bidirectional | two-way switch using reverse blocking IGBT. It is a circuit block diagram of a matrix converter.

Explanation of symbols

1-18: Reverse blocking IGBT
19: DC power supply 20: P-channel MOSFET
21: Diode 22: Capacitor 23-25, 25A: Drive circuit 26: AND circuit 27: On-delay circuit 28, 29: IGBT
30, 31: Diode 100: Drive power supply circuit

Claims (9)

Power is supplied to the drive circuit of the first semiconductor switch and the drive circuit of the second semiconductor switch in order to drive the bidirectional switch in which the first semiconductor switch and the second semiconductor switch are connected in antiparallel. In the drive power supply circuit of the bidirectional switch,
A DC power supply for supplying power to the drive circuit of the first semiconductor switch;
A capacitor for supplying power to the drive circuit of the second semiconductor switch;
A drive power supply semiconductor switch connected in series between the DC power supply and the capacitor and charging the capacitor with the DC power supply via the first or second semiconductor switch when turned on;
A drive power supply circuit for a bidirectional switch, comprising: In the bidirectional switch drive power supply circuit according to claim 1,
A drive power supply circuit for a bidirectional switch, wherein the first semiconductor switch and the second semiconductor switch are constituted by semiconductor switching elements having a reverse breakdown voltage. In the bidirectional switch drive power supply circuit according to claim 1,
A drive power supply circuit for a bidirectional switch, wherein the first semiconductor switch and the second semiconductor switch are configured by a semiconductor switching element having no reverse withstand voltage and a diode connected in order to the semiconductor switching element. In the bidirectional switch drive power supply circuit according to any one of claims 1 to 3,
A drive power supply circuit for a bidirectional switch, wherein the drive power supply semiconductor switch is constituted by a semiconductor switching element having a reverse breakdown voltage. In the bidirectional switch drive power supply circuit according to any one of claims 1 to 3,
A drive power supply circuit for a bidirectional switch, characterized in that the drive power supply semiconductor switch is constituted by a semiconductor switching element having no reverse breakdown voltage and a diode sequentially connected to the semiconductor switching element. In the bidirectional switch drive power supply circuit according to claim 5,
A bidirectional switching drive power supply circuit, wherein the semiconductor switching element constituting the drive power supply semiconductor switch is a P-channel MOSFET, a P-channel IGBT, or a PNP transistor. In the drive power supply circuit of the bidirectional switch according to any one of claims 1 to 6,
A bidirectional switch drive power supply circuit, wherein the first semiconductor switch, the second semiconductor switch, and the drive power supply semiconductor switch are simultaneously turned on and off. In the drive power supply circuit of the bidirectional switch according to any one of claims 1 to 6,
A drive power supply circuit for a bidirectional switch, wherein the drive power supply semiconductor switch is turned on when both or one of the first semiconductor switch and the second semiconductor switch is turned on. In the drive power supply circuit of the bidirectional switch according to any one of claims 1 to 6,
A bidirectional switch drive power supply circuit, wherein the drive power supply semiconductor switch is turned on after a lapse of a predetermined time since both the first semiconductor switch and the second semiconductor switch are turned on.

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