JPS63268469A - Controlling circuit for self-arc-extinguishing type semiconductor element - Google Patents

Abstract

PURPOSE:To detect the breakdown of self-arc-extinguishing type semiconductor elements quickly by providing an element breakdown detecting section at every element. CONSTITUTION:An anode for a GTO 3u is connected at the positive electrode terminal of a DC power through an overcurrent protective fuse, and a cathode for a GTO 3x is also connected similarly to a negative electrode terminal. ON gate circuits 7-8 and OFF gate circuits 9-11 are juxtaposed between a cathode and a gate for the GTO 3u. A voltage sensor 12 is connected in parallel with the fuse 11. ON gate circuits 13-14 and OFF gate circuits 15-17 are also juxtaposed similarly between a gate and a cathode for the GTO 3x, and a voltage sensor 18 is connected in parallel with the fuse 17. Accordingly, when the fuses 11, 17 are fusion-cut by the breakdown of an element, etc., the fusion of the fuses is detected rapidly, thus stopping the supply of OFF gate currents to the sound GTO by a control section, then preventing the breakdown of the sound element.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control circuit for a self-extinguishing semiconductor device used as a control element of a power converter such as an inverter.

B1 Summary of the Invention The present invention relates to a control circuit for a self-extinguishing semiconductor element bridge-connected between the positive and negative pole lines of a DC power source via a current protection fuse.

Destruction of a self-arc-extinguishing semiconductor element is detected by melting of an i-use inserted in each off-gate current supply circuit of the element, and one of the self-arc-extinguishing semiconductor elements on the positive side or the negative side of the DC power supply is detected. When destruction of an element on either side is detected, it is possible to control the elements on the other side to keep them in the on state, or to turn them off reliably using large amounts of energy, thereby quickly destroying each element. In addition to making it possible to detect
This prevents element destruction accidents from spreading to healthy elements.

BACKGROUND OF THE INVENTION In recent years, self-extinguishing semiconductor devices, such as gate turn-off thyristors (hereinafter referred to as ()To), have been frequently used as control elements for power converters such as inverters. A voltage type inverter device using this GTO is configured as shown in FIG. 4, for example. That is, the overcurrent protection fuse 2 and the GT03U are connected between the positive and negative terminals of the DC power supply 1.
, 3v, 3w, 3X.

3y and 3z connected in a bridge manner, an inverse conversion unit 3;
Overcurrent protection fuses 4 are sequentially connected in series.

5 is a DC capacitor connected between the positive and negative terminals of the power supply 1, 6U* 6V# 6Wh 6XI aY, 6Z is the GTO 3Un 3Ve 3We 3X + 3Y*
3Z are feedback diodes connected in antiparallel to each other.

In the circuit configured as above, during normal power conversion operation, for example, GTO3U and 3Y are turned on and the primary IC is turned on.
Turn on GTO3y and 3z, then OT O3W and 3
It is controlled by turning on x,
GTOs on the same arm are never turned on at the same time. However, for some reason, one GTO on the same arm
For example, GT.

If the other GTO 3X is controlled to fire when 3U loses its blocking ability, both GTO 3U and 3X become conductive and an arm short circuit accident occurs.

D1 Problems to be Solved by the Invention Conventionally, as a preventive measure against short-circuit accidents as described above, after detecting an overcurrent flowing from the DC power source 1 to the inverter 3, an off-gate current is supplied to the healthy GTO 3X to turn it off. That's what I do. However, with this accident prevention measure, it takes several tens of microseconds or more from detecting an overcurrent until the off-gate signal flow is supplied to the GTO3x.
The current flowing through O3X exceeds the maximum cut-off current of GTO.

Therefore, even if an off-gate signal is supplied in this state, the overcurrent exceeding the maximum cutoff current cannot be turned off by the gate, and the GTO 3X is destroyed and the overcurrent protection fuse 2.4 is also blown.

In other words, in the above-mentioned accident countermeasure, both GTO3U and 3x on the same arm will be damaged at the same time.

The present invention has been made in view of the above-mentioned points, and its purpose is to remove one of the GTOs plowed in series on the same arm.
When O loses blocking ability, the other G due to arm short circuit
An object of the present invention is to provide a control circuit for a self-extinguishing semiconductor device that can prevent damage to a TO.

Means for Solving the E1 Problem The present invention provides a control circuit for self-extinguishing semiconductor devices bridge-connected between the positive and negative pole lines of a fil DC power supply via an overflow protection fuse, in which the plurality of self-extinguishing an element destruction detection section having fuses inserted separately in the off-gate current supply circuits of the arc-shaped semiconductor elements, each detecting destruction of the self-arc-extinguishing semiconductor element by blowing out the fuses; and a positive electrode of the DC power supply. When the breakdown of one of the self-arc-extinguishing semiconductor elements connected to the side or the negative electrode side is detected by the element breakdown detection section, a current is supplied to the off gate 1 of the element on the other side. (2) In a control circuit for a self-extinguishing semiconductor element bridge-connected between the positive and negative pole lines of a DC power supply via an excessive TIL current protection fuse. , an element destruction detection unit having a fuse inserted separately in the off-gate current supply circuit of the plurality of self-extinguishing semiconductor elements, and detecting destruction of each of the self-extinguishing semiconductor elements by blowing the fuse; , when the destruction of one of the self-arc-extinguishing semiconductor elements connected to the positive or negative side of the DC power supply is detected by the element destruction detection section, the destruction of one of the elements on the other side is detected. The present invention is characterized in that it includes a turn-off control section that supplies the device with an off-gate current that is sufficiently larger than the off-gate current during normal off-control.

During normal operation of the F1-acting self-turn-off type semiconductor device, the device is normally turned off by supplying an off-gauge (ffifi). If the element is destroyed for some reason, it becomes impossible to turn off the element and the game is off)'! i
The T-stream continues to flow. Therefore, the fuse provided in the element blows out, and the destruction of the element is quickly detected by the detection section. Then, the control section in the first invention performs control to stop the supply of off-gate current to the fB ffi self-extinguishing semiconductor element that forms the same arm as the element involved in the destruction accident. Is this causing an arm short circuit between the element where the destruction accident occurred and the healthy element? It flow protection fuse melts,
Destruction of healthy self-extinguishing semiconductor elements is prevented.

Furthermore, when the element destruction detection section detects element destruction, the RII
The turn-off control section in the second aspect of the invention supplies an off-gate current that is sufficiently larger than an off-gate current during normal off control to the healthy self-extinguishing semiconductor elements forming the same arm. In this case, since element destruction is quickly detected on each element side, the time from the occurrence of a destruction accident until the off-gate current is supplied to all n elements of the same arm is extremely short. Therefore, when the turn-off control section supplies an off-gate current, the current flowing through the healthy element is not so large, so the element is reliably turned off. This prevents the healthy self-extinguishing semiconductor element from being destroyed.

G, Example G1. Embodiment of the First Invention FIG. 1 shows a circuit in which the first invention is applied to each GTO of the inverse conversion section 3 of FIG. The anode of GTO3U is connected to the positive end of DC power supply 1 via overcurrent protection fuse 2 (not shown), and the cathode of GTO3X is connected to the positive end of DC power supply 1 via overcurrent protection fuse 4 (not shown). ). Between the gate and cathode of GTO3U.

An on-gate circuit in which a switching element, for example a transistor 7 and an on-gate power supply 8 are connected in series, and an off-gate connected to a source 9. A switching element, for example a transistor 10
and an off-gate circuit in which the fuse 1) is connected in series are connected in parallel.

A voltage sensor 12 is connected in parallel to the fuse 1). Also between the gate and cathode of GT'03X, there is an on-gate circuit in which a switching element such as a transistor 13 and an on-gate (on-gate) X source 14 are connected in series, and an off-gate power supply 15. An off-gate circuit including a transistor 16 and a fuse 17 connected in series is connected in parallel. A voltage sensor IB is connected in parallel to the fuse 17. Note that G T O3V, 3W, 3Y, and 3Z in FIG. 4 are also constructed in the same circuit as described above (not shown).

To turn on G T O3U and 3X during normal operation,
The transistors 7 and 13 are turned on by a control circuit (not shown), and off-gate circuits are supplied from the on-gate power supplies 8 and 14. Also, GTO3U.

In order to turn off the transistor 10.16, the transistor 10.16 is turned on by a control circuit (not shown), and the off-gate)t@c
+, an off-gate current is supplied from 15. G
If the TO3U is operating normally, the off-gate current flowing through the fuse 1) will have a pulse-like waveform as the blocking ability of the GTO is restored. However, for example, if an element destruction accident occurs in GTO3U and the stopping ability is lost, fuse 1) will blow because off-game) 1 current continues to flow. Therefore, the potential across the voltage sensor 12 suddenly changes (becomes high), and the voltage sensor 12 outputs an operation signal. Then, the control circuit (not shown) turns on the transistor 13 (supplies base current) based on the operational output of the voltage sensor 12 to supply on-gate current to the healthy GTO 3X, and
The transistor 16 is turned off (base ti removed) to stop supplying off-gate current. Therefore, healthy GT0
Since 3X is kept on, G T Q 3U,
A current flows through the arm short circuit through 3X, and the overcurrent protection fuse 2.4 melts. This prevents the element destruction accident of GTO3U from spreading and destroying GTO3X. If the GTO3X element breaks down, the fuse 17 will blow out and the voltage sensor 18 will operate in the same way as described above.
GT(')3U is maintained in the on state, and destruction of G'rO3U is prevented. In this way, the element destruction of 1CGTO is caused by each GTO.
Since the voltage sensor detects the blowout of the fuse inserted in each off-current supply circuit of the TO, element destruction can be detected extremely quickly, and the spread of element destruction accidents can be reliably prevented.

Also, &! during the above-mentioned element destruction detection. As shown in Fig. 2, protection of all resistors is achieved by turning on a switching element, such as a transistor 19, connected between the gate and cathode of the GTO3X, based on the output signal of the voltage sensor 12 when the fuse 1) blows. Alternatively, the off-gate current may be bypassed so that the G T r)3x is not turned off.

In FIG. 2, the same parts as in FIG. 1 are shown with the same reference numerals, and the on-gate circuit is omitted from illustration.

Similarly to the GT○3U, the off-gate current is bypassed by controlling the transistor 20 to turn on based on the output signal of the voltage sensor 18 when the fuse 17 is blown.
This prevents the GTO3U from turning off. Even in the case of the configuration as shown in Fig. 2, by prompt detection of element destruction, as in the case of Fig. 1, it is possible to reliably prevent element destruction accidents from spreading.

Although transistors are used as switching elements in FIG. m1 and FIG. 2, the present invention is not limited to this, and other elements may be used.

G2. Embodiment of the Second Invention In the first invention, the supply of off-gauge flow to a healthy element is stopped when element destruction is detected. It may be controlled to turn off.

In other words, as shown in Figure 3, the inverse transformer 30G in Figure 4
Between the gate and cathode of TO3X, off-gate) t#15
A parallel circuit consisting of a capacitor 21 capable of repeated high frequency operation, a transistor 16, and a fuse 17 are successively connected in series, and a limiting resistor 221 is connected between both ends of the capacitor 21.
Illustrated heterogeneous diode 23 and large capacitor 24
are connected in series, and a switching element such as a transistor 26 is inserted in an electric path connecting the common connection of the diode 23 and the capacitor 24]P125 and the cathode of ()TO, 3X. In FIG. 3, the on-gate circuit of the GTO3X is not shown. Also, in Figure 3, GTQ
A GTO 3U is connected to the 7th node side of 3X', and the same circuit as in the figure is also connected to the GTO 3U.

To turn on ( )T03X during normal operation, an on-gate circuit (not shown) is used. In addition, in order to turn off the GT03X during normal operation, the transistor 16 is controlled to be turned on by a control circuit (not shown), and the off-gate power supply 1
Off gate 1 from 5! This is done by supplying a flow of water. During normal operation, the capacitor 24 is charged by the off-gate power supply 15, which controls the limiting resistor 22 and the diode 23. Here, if an element breakdown occurs in the GTO3U connected to the anode side of the GT03X, the element breakdown accident will be quickly detected by the fuse 1) and the voltage sensor 12 (not shown), as in the case of Figs. 1 and 2 above. detected. At this time, the detection output of the voltage sensor 12 is supplied to the transistor 26, and the transistor 26 becomes conductive. Then, the charge accumulated in the capacitor 24 is transferred to the transistor 2.
6 between the cathode and gate of GT O3X.

This supplied energy has a large peak value and a wide off-gate current due to the large capacitance of the capacitor 24, so even if the current flowing to the GTO3X increases, the GTO3X
T (13X is definitely turned off. In addition, GT03X
Even when the device breaks down, the voltage sensor 18 is activated by blowing out the fuse 17 in the same manner as described above to protect the GTOJ connected to the anode side of the GT03X.

As described in 5 above, since the destruction of one element on the same arm is quickly detected and the other element is reliably turned off, it is possible to reliably prevent the element destruction accident from spreading.

Note that although a transistor is used as a switching element in FIG. 3, the present invention is not limited to this, and other elements may be used.

H0 Effects of the invention As described above, according to the first and second inventions, since an element destruction detection section is provided for each self-arc-extinguishing semiconductor element, element destruction can be quickly detected. Therefore, in the first invention, when an element destruction accident is detected, the healthy element connected to the same arm as the element is immediately kept in the ON state, the arm short circuit ta is caused to flow, and the overcurrent protection fuse on the DC power supply side is blown. You can force it. This prevents the healthy element from being destroyed and reliably prevents the element destruction accident from spreading. Further, in the second invention, when an element destruction accident is detected, the normal off-gate 1! for a healthy element connected to the same arm as the reading element! An off-gate that is sufficiently larger than the flow can provide instant flow. As a result, it is possible to turn off the healthy element without destroying it, and it is possible to reliably prevent an element destruction accident from spreading.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing one embodiment of WJl's invention, wJz
FIG. 3 is a circuit diagram showing another embodiment of the first invention, FIG. 3 is a circuit diagram showing an embodiment of the second invention, and FIG. 4 is a circuit diagram of an inverter to which the invention is applied. 1...DC power supply, 2.4...Overcurrent protection fuse,
3P° inverse conversion section, 313 s 3 V # 3W +
3X s 3Y, 3Z ”' Gate turn-off thyristor, ?, 10, 13, 16° 19.20.26...
Transistor, 8.14... On-gate power supply, 9.1
5... Off-gate power supply, 1)゜17... Fuse,
12.18... Voltage sensor, 24... Capacitor.

Claims (2)

[Claims] (1) In a control circuit for self-arc-extinguishing semiconductor elements bridge-connected between the positive and negative electrode lines of a DC power supply via an overcurrent protection fuse, each of the off-gate current supply circuits of the plurality of self-arc-extinguishing semiconductor elements is an element destruction detection unit having a fuse inserted therein and detecting destruction of the self-arc-extinguishing type semiconductor element by blowing of the fuse; and a self-arc-extinguishing type connected to the positive electrode side or the negative electrode side of the DC power supply. A control unit that stops supplying an off-gate current to an element on either side when destruction of an element on one side of the semiconductor elements is detected by the element destruction detection unit. Control circuit for arc-extinguishing semiconductor devices. (2) In a control circuit for self-arc-extinguishing semiconductor devices bridge-connected between the positive and negative electrode lines of a DC power supply via an overcurrent protection fuse, each of the off-gate current supply circuits of the plurality of self-arc-extinguishing semiconductor devices is an element destruction detection unit having a fuse inserted therein and detecting destruction of the self-arc-extinguishing type semiconductor element by blowing of the fuse; and a self-arc-extinguishing type connected to the positive electrode side or the negative electrode side of the DC power supply. turn-off control for supplying an off-gate current that is sufficiently larger than an off-gate current during normal off control to an element on the other side when destruction of one of the semiconductor elements is detected by the element destruction detection unit; 1. A control circuit for a self-arc-extinguishing semiconductor device, comprising: