JPH0351138B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a gate turn-off thyristor that drives the gate turn-off thyristor from an extinguished state to a fired state or vice versa in an electronic circuit such as a converter or inverter configured using a gate turn-off thyristor. Concerning improvements in drive circuits.

As such a gate turn-off thyristor driving circuit (hereinafter simply referred to as a thyristor driving circuit for simplicity), one having the configuration described below with reference to FIG. 1 has been proposed.

That is, in an electronic circuit 2 such as a converter or inverter configured using a gate turn-off thyristor (hereinafter simply referred to as a thyristor for simplicity) 1, the thyristor 1 can be changed from an extinguished state to an on state or vice versa. For driving, a DC power supply 3 is connected between the gate G and cathode K of the thyristor 1 as a switching element.
Through the NPN transistor 4 and diode 5, a reverse bias voltage is applied.
Connect the positive side of the DC power supply 3 to the cathode K of the thyristor 1.
The anode of the diode 5 is connected to the gate G of the thyristor 1, and the collector and emitter of the transistor 4 are connected to the cathode of the diode 5 and the negative electrode side of the DC power supply 3, respectively. ing. Also, DC power supply 3
In parallel, a primary coil 6a of a transformer 7 having a primary coil 6a and a secondary coil 6b connects one end of the primary coil 6a to the positive electrode side of the DC power supply 3 via the transistor 4 and the resistor 8, Further, the other end is connected to the collector of the transistor 4 via a resistor 8.

Further, a DC power supply 3 is connected between the base and emitter of the transistor 4 through a resistor 9 and a diode 10.
The negative electrode side of the DC power supply 3 is connected to the emitter of the transistor 4, and the cathode of the diode 10 is connected to the base of the transistor 4, so that a forward bias voltage is applied between the base and emitter of the transistor 4 via the Further, both ends of the resistor 9 are connected to the anode of the diode 10 and the positive electrode side of the DC power supply 3, respectively.

Further, an NPN type transistor 11 as a switching element is connected between the base and emitter of the transistor 4 via the diode 10 described above, and the base and emitter of the transistor 4 are short-circuited by the transistor 11 via the diode 10. The emitter of the transistor 11 is connected to the emitter of the transistor 4, and the collector is connected to the midpoint of the connection between the resistor 9 and the diode 10. , and a driving signal source 12 are connected thereto.

Further, between the gate G and cathode K of the thyristor 1, the secondary coil 6b of the transistor 7 is connected to the PNP type transistor 1 as a switching element.
3, one end of the secondary coil 6b of the transformer 7 is connected to the cathode K of the thyristor 1, and the other end is connected to the emitter of the transistor 13, so that a forward current flows through the gate G of the thyristor 1. The collector of the transistor 13 is connected to the gate G of the thyristor 1 in such a manner that the base of the transistor 13 is connected to the gate G of the transformer 7 through the resistor 14 so that a forward current flows through the base of the transistor 13. It is connected to one end of the secondary coil 6b on the side opposite to the transistor 13 side.

The above is the configuration of the conventionally proposed thyristor driving circuit.

According to the thyristor drive circuit having such a configuration, the drive signal source 12 outputs signals at time points t ₁ and t _{3 .}
In between, "1" is taken on a binary display with a positive level meaning as shown in Figure 2A, and the time point is
If a driving signal S is obtained that takes "0" in a binary display with meaning at a lower level than a positive level before t ₁ and after time t ₃ , then the driving signal S is "1". Before time t ₁ , transistor 11 remains off, so transistor 4
Since a forward bias voltage is applied between the base and emitter of the thyristor 1 from the DC power source 3 through the resistor 9 and the diode 10, the transistor 4 remains on, and therefore, a DC voltage is applied between the gate G and the cathode K of the thyristor 1. From power supply 3, transistor 4
A reverse bias voltage is applied through the diode 5 and the thyristor 1, so that the thyristor 1 remains in an extinguished state.

On the other hand, since the transistor 4 remains on before time _t1 , the primary coil 6 of the transformer 7
A current flows through the transistor 4 and the resistor 8.

However, from this state, if the drive signal S becomes "1" in binary representation from time _t1 , the transistor 11 is turned on.

Therefore, the transistor 11 short-circuits the base and emitter of the transistor 4 via the diode 10, and the forward bias voltage that had been applied between the base and emitter of the transistor 4 disappears, and the transistor 4 turns off.

Therefore, the current that had been flowing through the transistor 4 to the primary coil 6a of the transformer 7 is cut off, and based on this, the electromagnetic energy that had been stored in the primary coil 6a of the transformer 7 causes A voltage with the positive side of the transistor 13 side is induced in the secondary coil 6b of the transformer 7, and a forward current flows to the base of the transistor 13.

Therefore, the transistor 13 is turned on, and based on this, the voltage induced in the secondary coil 6b of the transformer 7 is applied as a forward bias voltage between the gate G and cathode K of the thyristor 1. A forward current flows as a firing current through the gate G of the thyristor 1 at the time
From t ₁ , the ignition state starts.

However, in this case, the current flowing in the forward direction as the ignition current to the gate G of the thyristor 1 is accumulated in the secondary coil 6b of the transformer 7 before the current flowing in the primary coil 6a of the transformer 7 is cut off. Since the electromagnetic energy that was present at time t ₁
It takes the maximum value at , and from that point it decreases over time.

Therefore, the thyristor 1, which has entered the firing state from the time _t1 , transmits the firing current to the gate G between the time t1 when the drive signal S becomes " ₁ " and the time _t3 when the drive signal S becomes "0". Assuming that the directional current does not disappear, starting from the time between time t ₁ and t ₃ , thyristor 1
As long as the electronic circuit 2 is configured such that a forward current flows through the anode A _of
From then on, keep it safe.

Furthermore, if it is assumed that the forward current as the ignition current disappears in the gate G from time t ₂ between the time t ₁ when the drive signal S becomes "1" and the time t ₃ when it becomes "0", then As long as the electronic circuit 2 is configured such that a forward current flows in the anode A of the thyristor 1 from the time between t ₁ and t ₂ , the ignition condition can be changed from the time
After t ₁ , and definitely after time t ₂ .

However, if the electronic circuit 2 is configured so that a forward current flows to the anode A of the thyristor 1 from a point after the time t ₂ , even if the firing state is maintained between the times t ₁ and t ₂ , , time t ₂
After that, the arc becomes extinguished or unstable.

Further, assuming that the thyristor 1 maintains the firing state until time _t3 , if the control signal S becomes "0" in the binary display from time _t3 , then the transistor 1
1 turns off.

For this reason, a forward bias voltage is applied between the base and emitter of the transistor 4 from the DC power supply 3 via the resistor 9 and the diode 10. Therefore, the transistor 4 is turned on, and based on this, between the gate G and the cathode K of the thyristor 1,
A reverse bias voltage is applied from the DC power supply 3 through the transistor 4 and the diode 5,
A reverse current instantaneously flows to the gate of the thyristor 1 as an extinguishing current through the transistor 4 and the diode 5, so that the thyristor 1
From time t ₃ onwards, the arc is turned off, and thereafter it is maintained.

Therefore, according to the configuration of the conventional thyristor driving circuit shown in FIG. 1, the time t ₁ described above in FIG. 2A
Previously, it took "0" in the binary display, and at the time
Take "1" between t ₁ and t ₃ , and then at time t ₃
Based on the drive signal S which takes "0" from now on,
A reverse bias voltage V _GB is applied between the gate G and the cathode K of the thyristor 1 before the time t ₁ and between the times t ₁ and t ₃ as shown in FIG. 2B.
A forward bias voltage V _GF is applied between
Furthermore, after time t ₃ , the reverse bias voltage
V _GB is given, and the gate G of thyristor 1
As shown in FIG. 2C, a forward current I _D flows as an ignition current that gradually decreases from time t ₁ between time t ₁ and t ₃ , and at time t ₃ and a slightly smaller value. Due to the reverse direction current _IE flowing as an arc-extinguishing current in the interval up to time _t4 , which is delayed from , between the gate G and cathode K of thyristor
As shown in FIG. 2D, a reverse bias voltage V _GB is applied before time t ₁ , and a forward bias voltage V _GF is applied from time t ₁ to time t ₂ between time t ₁ and t ₃ . is applied, and a reverse bias voltage V _GB is applied from time t ₃ onwards, and the gate G of thyristor 1 is gradually biased from time t ₁ between time t ₁ and t ₂ as shown in FIG. 2E. The forward current ID as the ignition current takes a small value to
flows, and a reverse current I _E as an extinguishing current flows between times t ₃ and t ₄ , causing the thyristor 1 to change from the extinguished state before time t ₁ to time t ₁
It is possible to drive the ignition state from the ignition state, and from the ignition state to the extinguishing state from the time _t3 .

However, in the case of the conventional gate turn-off thyristor driving circuit shown in FIG. 1, based on the driving signal S shown in FIG. 2A, a driving signal as shown in FIG. If a forward current I _D as an ignition current is caused to flow through the interval "1" between times t ₁ and t ₃ of S, the electronic circuit 2 is connected to the anode A of the thyristor 1 at the time t ₁
Even if the forward current is configured to flow from any time between t1 and _t3 , the thyristor 1 can be reliably fired between the times _t1 and _t3 , and the electronic circuit 2 can therefore be configured easily. However, in this case, there is a drawback that the transformer 7 needs to be made large so that a large amount of electromagnetic energy can be stored in the primary coil 6a.

Furthermore, based on the driving signal S as shown in FIG. 2A, a "1" signal is applied to the gate G of the thyristor ₁ between times t1 and _t3 of the driving signal S as shown in FIG. 2E.
Only between time points t ₁ and t ₂ during the interval of
If a forward current I _D is used as the ignition current, there is no need to store a large amount of electromagnetic energy in the primary coil 6a of the transformer 7, so there is no need to make the transformer 7 large. , unless the electronic circuit 2 is configured such that a forward current flows through the anode A of the thyristor 1 only from the instants in the interval t ₁ and t ₂ between the instants t ₁ and t ₃ . It has the disadvantage that it cannot be reliably ignited between time points t ₁ and t ₃ , which limits the construction of the electronic circuit 2.

Further, based on the driving signal S as shown in FIG. 2A, one of the forward currents ID as the ignition current shown in FIG. 2C and FIG. 2E is applied to the gate G of the thyristor 1. Even if the forward current _ID is allowed to flow, the forward current ID is made to be based on the electromagnetic energy accumulated in the primary coil 6a of the transformer 7. There is a certain limit to shortening the time from the start of the arc to the time when the drive signal S becomes "1", that is, the time when the thyristor 1 starts firing, that is, the extinction period. , there is a certain limit to increasing the speed of repeatedly firing and extinguishing the thyristor 1. It has the following drawback.

Therefore, the present invention aims to propose a new thyristor driving circuit that does not have the above-mentioned drawbacks.
This will become clear from the detailed description below.

FIG. 3 shows a first embodiment of a thyristor driving circuit according to the invention.

In FIG. 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals.

The thyristor driving circuit according to the present invention shown in FIG. 3 has the following configuration.

That is, in an electronic circuit 2 such as a converter or an inverter configured using a thyristor 1, in order to drive the thyristor 1 from an extinguished state to an on state or vice versa, the gate G and cathode of the thyristor 1 are Between K, DC power supply 3
However, the positive side of the DC power supply 3 is connected to the cathode K of the thyristor 1 so as to apply a reverse bias voltage between the gate G and the cathode K of the thyristor 1 via the NPN type transistor 4 as a switching element. Further, the negative electrode side is connected to the emitter of the transistor 4, and the collector of the transistor 4 is connected to the gate G of the thyristor 1. Meanwhile, a driving signal source 20 is connected between the base and emitter of the transistor 4. is connected.

In addition, a primary coil 21a is connected in parallel with the DC power supply 3.
and 1 of the transformer 22 having the secondary coil 21b.
The secondary coil 21a acts as a switching element.
One end of the primary coil 21a is connected to the negative electrode side of the DC power supply 3 via an NPN type transistor 23,
The other end is connected to the emitter of the transistor 23, and the collector of the transistor 23 is connected to the positive side of the DC power supply 3.
On the other hand, a resistor 24 is connected in parallel with the primary coil 21a of the transformer 22, and a transistor 23
A driving signal source 25 is connected between the base and emitter of the .

Furthermore, the secondary coil 21b of the transformer 22 is connected between the gate G of the thyristor 1 and one end of the primary coil 21a of the transformer 22 on the transistor 23 side.
2 so that a forward current flows through the gate G of the thyristor 1 through the diode 26 and the resistor 27.
One end of the secondary coil 21b is connected to the cathode of the diode 26, the other end is connected to one end of the resistor 27, and the anode of the diode 26 is connected to one end of the primary coil 21a on the transistor 23 side,
Further, the other end of the resistor 27 is connected to the gate G of the thyristor 1.

The above is the configuration of the first embodiment of the thyristor driving circuit according to the present invention.

According to the thyristor drive device according to the present invention having such a configuration, the following effects can be obtained.

That is, now, from the drive signal source 20, the fourth
As shown in Figure A, "1" is taken as a binary representation with a positive level before time t ₁ and after time t ₃ , and it is lower than the positive level between time t ₁ and t ₃ . A driving signal S1 that takes "0" in a binary representation with a meaning given by level is obtained, and from the driving signal source ₂₅ , as shown in _FIG . Take "1" on the value display,
It is assumed that a driving signal S2 that takes "0" in binary display is obtained before time _t1 and after time _t3 .

In such a case, before the time _t1 when the driving signals S1 and S2 become "0" and "1", respectively,
Transistor 23 is off, but transistor 4 is on. Therefore, between the gate G and cathode K of the thyristor 1, from the DC power supply 3,
A reverse bias voltage is applied through the transistor 4, and the thyristor 1 is maintained in an extinguished state.

However, from this state, the driving signals S1 and S2 each become "0" from time _t1 .
and when it becomes "1", transistor 4 is turned off,
Also, the transistor 23 is turned on.

Therefore, the primary coil 21a of the transformer 22
Then, a current flows from the DC power source 3 through the transistor 23, and based on this, two of the transformers 22
A voltage with the resistor 27 side being positive is induced between both ends of the next coil 21b, and that voltage is applied between the gate G and cathode K of the thyristor 1 to the transistor 23,
Via the diode 26 and the resistor 27, a forward bias voltage is applied, and a forward current flows as a firing current to the gate G of the thyristor 1, so that the thyristor 1 is fired from time _t1 .

However, in this case, the transformer 22 connects the primary coil 21a to the period from time t ₁ to time t ₃ .
Even if current is passed continuously, it will not saturate. Therefore, a voltage with the resistor 27 side being positive is continuously obtained between both ends of the secondary coil 21b of the transformer 22 during the period from time t ₁ to time t ₃ . Therefore, between the gate G and cathode K of thyristor 1, there is a time point
From t ₁ , drive signals S1 and S2 each become "1"
A forward bias voltage is applied to the gate G of thyristor 1 from time t ₁ to time t 3, and a forward current as an ignition current is applied to the gate G of thyristor 1 from time t ₁ to time t ₃ . flows. Thus, the thyristor 1 can be used at the instants t ₁ and t ₃ even if the electronic circuit 2 is configured to pass a forward current to the anode A of the thyristor 1 from any instant between the instants t 1 and t ₃ .
Reliably maintains the ignition state between t and ₃ .

Furthermore, in a state where the thyristor 1 maintains the firing state until time _t3 , if the driving signals S1 and S2 become "1" and "0", respectively, from time _t3 , the transistor 23 will turn on. The transistor 4 is turned off and the transistor 4 is turned on again.

Therefore, current no longer flows through the primary coil 21a of the transformer 22, and the primary coil 21a of the transformer 22
The electromagnetic energy accumulated in the transformer 22 due to the current flowing through the transformer 1a is consumed by the resistor 24, so that no voltage can be obtained across the secondary coil 21b of the transformer 22, and the thyristor 1 The forward bias voltage between the gate G and cathode K of the thyristor 1 and the forward current as the ignition current flowing through the gate G of the thyristor 1 are eliminated.

However, between the gate G and cathode K of the thyristor 1, the transistor 4 is connected from the DC power supply 3.
A reverse bias voltage is applied through the thyristor 1, and a reverse current instantaneously flows through the gate G of the thyristor 1 as an extinguishing current.

For this reason, the thyristor 1 enters the extinguished state from time _t3 and remains there thereafter.

From the above, according to the thyristor driving circuit according to the _present invention shown in _FIG . The driving signal S1 takes "0" between t ₁ and t ₃ , and takes "1" between time t ₁ and t ₃ shown in FIG. 4B, and "1" before time t ₁ and after time t ₃ . Based on _the drive signal S2 which takes "0", _a reverse bias voltage V _GB shown in FIG.
is given, and a forward bias voltage V _GF is given between time points t ₁ and t ₃ .

Also, at the gate G of thyristor 1, at time t ₁ and
In the entire interval between t _{and 3} , as shown in Figure 4D,
A forward current I _D , which serves as an ignition current, flows at a nearly constant level, and a reverse current I _E , which serves as an extinguishing current, flows in the section between time t ₃ and time t ₄ , which is slightly later than that. .

Therefore, as in the case of _the conventional thyristor driving circuit described above in _FIG . It can be driven from the ignition state to the extinguishing state from time _t3 .

However, in the case of the circuit for driving a thyristor according to the invention shown in FIG. 3, the gate G of the thyristor 1 is controlled between times t ₁ and t ₃ based on the driving signals S1 and S2 shown in FIGS. 4A and B, respectively. Since the forward current I _D as the ignition current flows throughout the entire section, the electronic circuit 2 is connected to the anode A of the thyristor 1.
Even if the forward current is configured to flow from any point between the times t ₁ and t ₃ , the thyristor 1 can be reliably fired between the times t ₁ and t ₃ and therefore the electronic Circuit 2 can be easily configured.

Further, even with this configuration, the forward current as the ignition current flowing through the gate G of the thyristor 1 does not require a large value, so there is no need to increase the size of the transformer 22.

Furthermore, based on the driving signals S1 and S2, a forward current I _D flows as an ignition current in the gate G of the thyristor 1 in the entire interval between time points _t1 and _t3 .
is not obtained on the basis of electromagnetic energy stored in the transformer as in the case of the conventional driving circuit described above in _{FIG .} Since it is obtained based on the current with a steep rise that flows directly from the DC power supply 3 in the section, the time when the drive signals S1 and S2 become "1" and "0", respectively, that is, from the time when the thyristor 1 starts to turn off , drive signal S
1 and S2 become "0" and "1", respectively, that is, the time until thyristor 1 starts firing, that is, the extinction period, as in the case of the conventional drive circuit described above in FIG. There is no fixed limit to how short it can be.

Therefore, the repetitive firing and extinguishing of the thyristor 1 can be driven at a much higher speed than in the case of the thyristor driving circuit described above in FIG.

Next, a second embodiment of the thyristor driving circuit according to the present invention will be described with reference to FIG.

In FIG. 5, parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

The thyristor drive circuit according to the present invention shown in FIG. 5 has the same configuration as the thyristor drive circuit according to the present invention described above in FIG. 3, except for the following matters.

That is, the resistor 24 connected to both ends of the primary coil 21a of the transformer 22 is omitted, but the transformer 22 has a tertiary coil 21c in addition to the primary coil 21a and the secondary coil 21b, and, Both ends of the tertiary coil 21c are connected between both ends of the DC power supply 3 through a diode 28, so that the transistors 4 and 23 are switched from off and on states to on and off states, respectively, and the thyristor 1 is turned on and off. When the ignition state changes from the ignition state to the extinction state, the electromagnetic energy accumulated in the transformer 22 due to the current flowing from the DC power supply 3 to the primary coil 21a of the transformer 22 is transferred to the tertiary coil 21c. and diode 28
It is configured to feed back to the DC power supply 3 and reset the transformer 22 via the DC power supply 3.

The above is the configuration of the second embodiment of the thyristor driving circuit according to the present invention.

According to the thyristor driving circuit according to the present invention having such a configuration, except for the above-mentioned matters,
Since it has the same configuration as the gate turn-off thyristor driving circuit according to the present invention described above in FIG. 3, a detailed explanation will be omitted. Effects can be obtained.

However, since the transformer 22 has a secondary coil 21c and the tertiary coil 21c is connected to the DC power supply 3 through the diode 28, the transistors 4 and 23 are turned off and on, respectively. When the thyristor 1 switches from the ignition state to the extinguishing state by switching between on and off states, the current is flowing from the DC power supply 3 to the primary coil 21a of the transformer 22, The electromagnetic energy accumulated in 22 can be returned and recovered to DC power supply 3. Therefore, higher efficiency as a thyristor driving circuit can be obtained compared to the thyristor driving circuit according to the present invention described above with reference to FIG.

Next, a third embodiment of the thyristor driving circuit according to the present invention will be described with reference to FIG.

In FIG. 6, parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

The thyristor drive circuit according to the present invention shown in FIG. 6 has the same configuration as the thyristor drive circuit according to the present invention described above in FIG. 3, except for the following matters.

That is, the resistor 24 connected between both ends of the primary coil 21a of the transformer 22 is omitted, however, the transformer 22 has a tertiary coil 21c in addition to the primary coil 21a and the secondary coil 21b, and, Both ends of the tertiary coil 21c are connected to the gate G of the thyristor 1 through the diode 29.
and the cathode K, and therefore, when the transistors 4 and 23 change from the off and on states to the on and off states, respectively, and the thyristor 1 changes from the firing state to the extinguishing state, A DC power supply 3 is connected to the primary coil 21a of the transformer 22.
The current based on the electromagnetic energy accumulated in the transformer 22 due to the current flowing through the thyristor 1 is caused to flow in the opposite direction to the gate G of the thyristor 1 via the tertiary coil 21c and the diode 29. It is composed of

The above is the configuration of the third embodiment of the thyristor driving circuit according to the present invention.

According to the thyristor driving circuit according to the present invention having such a configuration, except for the above-mentioned matters,
Since it has the same configuration as the thyristor driving circuit according to the present invention described above in FIG. It will be done.

However, since the transformer 22 has a tertiary coil 21c, and the tertiary coil 21c is connected between the gate G and cathode K of the thyristor 1 through the diode 29, the transistors 4 and 23 are turned off and off, respectively. When the thyristor 1 changes from the on state to the on and off state, and from the ignition state to the extinguishing state, the current flows from the DC power supply 3 to the primary coil 21a of the transformer 22. Then, a current based on the electromagnetic energy stored in the transformer 22 is caused to flow through the gate G of the thyristor 1 as a reverse current. Therefore, when the thyristor 1 changes from the firing state to the extinguishing state, the switching speed is higher than in the case of the thyristor driving circuit according to the present invention described above in FIG. 3.

Next, a fourth embodiment of the thyristor driving circuit according to the present invention will be described with reference to FIG.

In FIG. 7, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The thyristor drive circuit according to the present invention shown in FIG. 7 has the same configuration as the thyristor drive circuit according to the present invention described above in FIG. 3, except for the following matters.

That is, the resistor 24 connected between both ends of the primary coil 21a of the transformer 22 is omitted, the driving signal source 20 is omitted, and the transistor 4 as a switching element is replaced with the thyristor 3.
0, and the transformer 22 is connected to the tertiary coil 2 in addition to the primary coil 21a and the secondary coil 21b.
1c, and its tertiary coil 21a is
connected between the gate and cathode of the thyristor 30 through a resistor 31 and a diode 32, and in parallel with the thyristor 30, that is, the thyristor 3
A resistor 33 is connected between the anode and cathode of the thyristor 30, so that the voltage induced in the tertiary coil 21c of the transformer 22 when the transistor 23 is switched from on to off is applied to the thyristor 30. A forward current as an ignition current is applied to the gate of the thyristor 30 through the resistor 31 and the diode 32 to turn the thyristor 30 from an off state to an on state. A reverse current as an arc-extinguishing current is caused to flow from the DC power supply 1 to the gate of the thyristor 1 through the thyristor 30 to switch the thyristor 1 from the firing state to the extinction state, and
When the thyristor 1 changes from the firing state to the extinguishing state, the impedance between the gate and cathode of the thyristor 1 increases, and the current flowing to the anode of the thyristor 30 becomes equal to or less than the holding current of the thyristor 30. Although the thyristor 30 naturally extinguishes, a reverse bias voltage is applied from the DC power supply 11 through the resistor 33 between the gate and cathode of the thyristor 1.
The configuration is such that the thyristor 1 will not fire erroneously during the extinguishing period.

The above is the configuration of the fourth embodiment of the gate turn-off thyristor driving circuit according to the present invention.

The gate turn-off thyristor driving circuit according to the present invention having such a configuration has the same configuration as the gate turn-off thyristor driving circuit according to the present invention described above in FIG. 3, except for the above-mentioned matters. Although the explanation is omitted, the third
The same effects as in the case of the gate turn-off thyristor driving circuit according to the present invention described above with reference to the figures can be obtained.

However, as is clear from the above,
When thyristor 1 changes from the firing state to the extinguishing state,
Since a reverse bias voltage is applied between the gate and cathode of the thyristor 1, the thyristor 1 will not fire erroneously in the extinguished state.

Note that the above description merely shows a few embodiments of the thyristor drive circuit according to the present invention, and various modifications and changes may be made without departing from the spirit of the present invention.

[Brief explanation of drawings]

FIG. 1 is a connection diagram showing a conventional thyristor driving circuit. FIGS. 2A to 2E are waveform diagrams for explaining the operation. FIG. 3 is a connection diagram showing a first embodiment of the thyristor driving circuit according to the present invention. FIGS. 4A to 4D are waveform diagrams for explaining this. FIG. 5, FIG. 6, and FIG. 7 are connection diagrams showing second, third, and fourth embodiments of the thyristor driving circuit according to the present invention, respectively. DESCRIPTION OF SYMBOLS 1...Thyristor, 2...Electronic circuit, 3...DC power supply, 4...Transistor, 20...Drive signal source, 21a...Primary coil, 21b...Secondary coil, 21c...Third Coil, 22... Transformer, 23... Transistor, 24... Resistor, 25
...Drive signal source, 26...Diode, 27...
...Resistance, 28...Diode, 29...Diode, 31...Resistance, 32...Diode, 33...
…resistance.

Claims (1)

[Claims] 1. A DC power supply is connected between the gate and cathode of the gate turn-off thyristor when the DC power is switched to 2 by a first driving signal that takes "1" and "0" in binary display.
The first control that is turned on when the value display shows "1"
The first switching element is connected in such a way that when the first switching element is turned on, a reverse current flows through the gate of the gate turn-off thyristor as an extinction current. The primary coil of a transformer having at least a coil is displayed in binary form by a second drive signal that has "1" and "0" in an inverse relationship to the first drive signal. When the second switching element is turned on, the current from the DC power supply is connected to the primary coil through a second switching element that is controlled to be turned on when the second switching element is turned on. The secondary coil of the transformer is connected between the gate of the turn-off thyristor and one end of the primary coil of the transformer on the second transistor side through a diode and a resistor, so that when the second switching element is turned on, the For driving a gate turn-off thyristor, characterized in that the gate is connected to the gate of the gate turn-off thyristor through the second switching element so that a forward current based on the voltage induced in the secondary coil flows as an ignition current. circuit. 2. In the gate turn-off thyristor driving circuit according to claim 1, the second coil is connected in parallel to the primary coil of the transformer.
When the switching element changes from an on state to an off state under the control of the second driving signal, the electromagnetic energy accumulated in the transformer when the second switching element was on is removed. A circuit for driving a gate turn-off thyristor, characterized in that a resistor is connected that consumes . 3. In the gate turn-off thyristor driving circuit according to claim 1, the transformer has a tertiary coil in addition to the primary coil and the secondary coil, and both ends of the tertiary coil are connected to the When the second switching element is connected between both ends of the DC power source and is turned off under the control of the second drive signal, the second switching element is turned on. A gate turn-off thyristor driving circuit, characterized in that the gate turn-off thyristor drive circuit is connected via another diode so that the electromagnetic energy accumulated in the transformer is returned and recovered to the DC power supply. 4. In the gate turn-off thyristor drive circuit according to claim 1, the transformer has a tertiary coil in addition to the primary coil and the secondary coil, and both ends of the tertiary coil are connected to the When the second transistor between the gate and cathode of the gate turn-off thyristor changes from an on state to an off state under control of the second driving signal,
Gate turn-off thyristor drive, characterized in that it is connected via another diode so that a current based on electromagnetic energy accumulated in the transformer flows in the opposite direction when the second transistor is turned on. circuit. 5. In the gate turn-off thyristor driving circuit according to claim 1, the first switching element is a thyristor,
Another resistor is connected between the anode and cathode of the thyristor as the first switching element, and the transformer has a tertiary coil in addition to the primary coil and the secondary coil, and the tertiary coil However, between the gate and cathode of the thyristor serving as the first switching element, the second switching element changes from an on state to an off state under control by the second driving signal. When a current based on the voltage induced in the tertiary coil is applied to the gate of the thyristor as the first switching element, the thyristor as the first switching element is turned on from an off state. A circuit for driving a gate turn-off thyristor, characterized in that the circuit is connected through another diode and another resistor so that the current flows.