阅读说明：本技术 一种晶闸管门极触发电路 (Thyristor gate trigger circuit ) 是由 雷朝煜 郝良收 熊银武 胡今朝 魏孟刚 武晓梅 闫晗 于 2021-08-26 设计创作，主要内容包括：本申请提供了一种晶闸管门极触发电路,包括触发模块和取能模块；取能模块与触发模块连接,用于为触发模块供电；触发模块包括三极管Q3和负反馈回路,三极管Q3的集电极和发射极与负反馈回路连接,三极管Q3的基极与控制系统连接,负反馈回路还与被触发晶闸管的门极连接。触发模块用于：根据三极管Q3接收的来自控制系统提供的不同电压等级的触发信号经过负反馈回路向被触发晶闸管的门极发送恒定的门极触发电流。本申请中的触发模块可以满足不同电压等级的被触发晶闸管需求,门极触发电流恒定,使用的器件少,成本低,且能够应用于高电压大电流晶闸管的串并联场景,且能够兼容各种电压等级,适用范围广。(The application provides a thyristor gate trigger circuit, which comprises a trigger module and an energy-taking module; the energy taking module is connected with the trigger module and used for supplying power to the trigger module; the triggering module comprises a triode Q3 and a negative feedback loop, wherein a collector and an emitter of the triode Q3 are connected with the negative feedback loop, a base of the triode Q3 is connected with the control system, and the negative feedback loop is also connected with a gate of the triggered thyristor. The trigger module is used for: a constant gate trigger current is sent to the gate of the triggered thyristor via a negative feedback loop in response to a trigger signal received from the transistor Q3 from a control system providing different voltage levels. The trigger module in this application can satisfy the triggered thyristor demand of different voltage grades, and gate pole trigger current is invariable, and the device that uses is few, and is with low costs, and can be applied to the series-parallel connection scene of high voltage heavy current thyristor, and can compatible various voltage grades, and application scope is wide.)

1. The thyristor gate trigger circuit is characterized by comprising a trigger module and an energy-taking module, wherein the energy-taking module is connected with the trigger module and used for supplying power to the trigger module;

the trigger module comprises a triode Q3 and a negative feedback loop, wherein a collector and an emitter of the triode Q3 are connected with the negative feedback loop, a base of the triode Q3 is connected with the control system, and the negative feedback loop is also connected with a gate of the triggered thyristor;

the trigger module is used for: and sending constant gate trigger current to the gate of the triggered thyristor through the negative feedback loop according to trigger signals of different voltage levels received by the triode Q3 and provided by the control system.

2. The thyristor gate trigger circuit of claim 1, wherein the negative feedback loop comprises a bias resistor R3, a bias resistor R5, a bias resistor R6, a bias resistor R7, a transistor Q1, and a transistor Q2;

the collector of the triode Q3 is connected with the energy-taking module through a bias resistor R3, the emitter of the triode Q3 is connected with the cathode of the triggered thyristor through a bias resistor R6, and the connection point of the bias resistor R3 and the energy-taking module is a node V;

the base of the transistor Q2 is connected with the collector of the transistor Q3, the collector of the transistor Q2 is connected with the cathode of the triggered thyristor through a bias resistor R7, and the emitter of the transistor Q2 is connected with a node V through a bias resistor R5;

the base electrode of the triode Q1 is connected with the collector electrode of the triode Q2, the collector electrode of the triode Q1 is connected with the energy taking module through a biasing resistor R5, and the emitting electrode of the triode Q1 is connected with the gate electrode of the triggered thyristor to provide constant gate-level trigger current for the triggered thyristor.

3. The thyristor gate trigger circuit of claim 2, wherein the transistor Q1 and the transistor Q3 are NPN transistors and the transistor Q2 is a PNP transistor.

4. The thyristor gate trigger circuit of claim 2, wherein the voltage at node V is within a target voltage range by adjusting the resistance of the bias resistor R3 and/or the resistance of the bias resistor R5 when the triggered thyristor is operating at a target voltage level according to a predetermined requirement;

when the voltage of the node V is within a target voltage range, the triode Q1 works under a static working point;

when the gate impedance of the triggered thyristor is reduced, the gate trigger current of the triggered thyristor is reduced, and the negative feedback loop controls the gate trigger current to be reduced, so that the gate trigger current of the triggered thyristor is kept constant in the target voltage range;

when the gate impedance of the triggered thyristor is reduced, the gate trigger current of the triggered thyristor is reduced, and the negative feedback loop controls the gate trigger current to be increased, so that the gate trigger current of the triggered thyristor is kept constant in the target voltage range.

5. The thyristor gate trigger circuit of claim 4, wherein the gate trigger current of the triggered thyristor increases when the gate impedance of the triggered thyristor decreases, and the negative feedback loop controls the gate trigger current to decrease by:

based on the increased gate trigger current of the triggered thyristor, the base current of the transistor Q1 and the collector current of the transistor Q1 both increase;

based on the increased base current of transistor Q1 and the increased collector current of transistor Q1, the current through the bias resistor R5 increases and the voltage drop across the bias resistor R5 increases;

based on the increased voltage drop of the bias resistor R5, the emitter voltage of the transistor Q2 decreases, and the collector current of the transistor Q2 decreases;

based on the reduced collector current of transistor Q2, the current of the bias resistor R7 is reduced, and the voltage of the bias resistor R7 is reduced;

based on the reduced voltage of the bias resistor R7, the base voltage of the transistor Q1 is reduced and the emitter current of the transistor Q1 is reduced;

the gate trigger current of the triggered thyristor is reduced based on the reduced emitter current of transistor Q1.

6. The thyristor gate trigger circuit of claim 4, wherein the gate trigger current of the triggered thyristor decreases when the gate impedance of the triggered thyristor increases, and the negative feedback loop controls the gate trigger current to increase by:

based on the reduced gate trigger current of the triggered thyristor, the base current of the transistor Q1 and the collector current of the transistor Q1 both decrease;

based on the reduced base current of transistor Q1 and the reduced collector current of transistor Q1, the current through the bias resistor R5 is reduced and the voltage drop across the bias resistor R5 is reduced;

reduced bias resistance R5 based voltage drop U_R5Emitter voltage U of the transistor Q2_e2Increase, and the collector current I of the transistor Q2_c2Increasing;

based on the increased collector current of the transistor Q2, the current of the bias resistor R7 is increased, and the voltage U of the bias resistor R7 is increased_R7Increasing;

based on the increased voltage of the bias resistor R7, the base voltage of the transistor Q1 increases and the emitter current of the transistor Q1 increases;

the gate trigger current of the triggered thyristor is increased based on the increased emitter current of transistor Q1.

7. The thyristor gate trigger circuit of claim 1, wherein the trigger module further comprises a current limiting resistor R4;

the base of the triode Q3 is connected with the control system through the current limiting resistor R4.

8. The thyristor gate trigger circuit of claim 2, wherein the energy extraction module comprises a voltage stabilization module, an isolation module, and an energy storage module connected in series in sequence.

9. The thyristor gate trigger circuit of claim 8, wherein the voltage regulator module comprises a voltage regulator D1, a bypass thyristor T1, a current limiting resistor R1, a current limiting resistor R2, and a reverse freewheeling diode D2;

the cathode of the voltage regulator tube D1 is connected with the anode of the triggered thyristor, and the anode of the voltage regulator tube D1 is connected with the cathode of the triggered thyristor through the current limiting resistor R1; the anode of the bypass thyristor T1 and the cathode of the reverse freewheeling diode D2 are connected with the cathode of the voltage regulator tube D1, and the cathode of the bypass thyristor T1 and the anode of the reverse freewheeling diode D2 are connected with the cathode of the triggered thyristor; one end of the current-limiting resistor R2 is connected with the anode of the voltage regulator tube D1, and the other end is connected with the gate of the bypass thyristor T1.

10. The thyristor gate trigger circuit of claim 8, wherein the energy storage module comprises a current limiting inductor L1 and an energy storage capacitor C1;

one end of the current-limiting inductor L1 is connected to the node V, and the other end is connected to the cathode of the triggered thyristor through the energy-storing capacitor C1.

11. The thyristor gate trigger circuit of claim 10, wherein the isolation module comprises a forward freewheeling diode D3;

the anode of the forward freewheeling diode D3 is connected to the anode of the triggered thyristor, and the cathode thereof is connected to the node V, so that the voltage of the node V is provided to the trigger module.

12. The thyristor gate trigger circuit of claim 1, wherein the trigger circuit further comprises a resistance-capacitance loop;

and the resistance-capacitance loop is connected in series with the energy taking module and then bridged between the anode and the cathode of the triggered thyristor.

13. The thyristor gate trigger circuit of claim 12, wherein the resistance-capacitance loop comprises a damping capacitance Ct and a damping resistance Rt;

one end of the damping capacitor Ct is connected with the anode of the triggered thyristor, the other end of the damping capacitor Ct is connected with the damping resistor Rt, and the other end of the damping resistor Rt is connected with the energy taking module.

Technical Field

The application relates to the technical field of control and protection of electronic power devices, in particular to a thyristor gate trigger circuit.

Background

The thyristor has the advantages of high voltage resistance and current capacity, small conduction loss, small volume, easy control and the like, and is widely applied to high-power application occasions such as high-voltage direct-current transmission, electromagnetic emission sources, metal smelting and other fields. The thyristor trigger circuit is used for generating a gate trigger pulse meeting the requirement of reliably triggering the thyristor and ensuring that the thyristor is switched from blocking to conducting at the required moment.

Because of the limitation of the manufacturing process of the thyristor, the rated voltage of the mainstream product of the existing thyristor is lower, a single stage cannot meet the withstand voltage requirement of a higher voltage level, and in a high-power electronic alternating current and direct current transmission system, the multistage thyristors are often required to be connected in series and parallel for use, the situation requires that the thyristors connected in series and parallel are conducted at the same time as much as possible, the steeper the leading edge of the gate trigger pulse is, the more beneficial to the simultaneous triggering of the thyristors connected in series is, and therefore, the di/dt of each element must be within an allowable range.

At present, a thyristor gate trigger circuit is most applied to a sawtooth wave trigger circuit, the sawtooth wave circuit comprises a hysteresis element capacitor, an output pulse signal is a voltage pulse, and a certain time delay exists, so that the reliability of the trigger circuit is low, and a thyristor cannot be reliably triggered.

Disclosure of Invention

In order to overcome the defect of low reliability in the prior art, the application provides a thyristor gate trigger circuit, which comprises a trigger module and an energy-taking module; the energy taking module is connected with the trigger module and used for supplying power to the trigger module;

the triggering module comprises a triode Q3 and a negative feedback loop, wherein a collector and an emitter of the triode Q3 are connected with the negative feedback loop, a base of the triode Q3 is connected with the control system, and the negative feedback loop is also connected with a gate of the triggered thyristor.

The trigger module is used for: the trigger signals from the control system at different voltage levels received from the transistor Q3 are used to deliver a constant gate trigger current to the gate of the triggered thyristor via a negative feedback loop.

The negative feedback loop comprises a biasing resistor R3, a biasing resistor R5, a biasing resistor R6, a biasing resistor R7, a triode Q1, a triode Q2 and a triode Q3;

the collector of the triode Q3 is connected with the energy-taking module through a bias resistor R3, the emitter of the triode Q3 is connected with the cathode of the triggered thyristor through a bias resistor R6, and the connection point of the bias resistor R3 and the energy-taking module is a node V;

the base electrode of the triode Q2 is connected with the collector electrode of the triode Q3, the collector electrode of the triode Q2 is connected with the cathode electrode of the triggered thyristor through a bias resistor R7, and the emitter electrode of the triode Q2 is connected to a node V through a bias resistor R5;

the base electrode of the triode Q1 is connected with the collector electrode of the triode Q2, the collector electrode of the triode Q1 is connected with the energy obtaining module through a bias resistor R5, and the emitting electrode of the triode Q1 is connected with the gate electrode of the triggered thyristor to provide constant gate-level trigger current for the triggered thyristor.

The transistor Q1 and the transistor Q3 are both NPN transistors, and the transistor Q2 is a PNP transistor.

When the triggered thyristor works under a target voltage level according to preset requirements, the voltage of the node V is in a target voltage range by adjusting the resistance value of the bias resistor R3 and/or the resistance value of the bias resistor R5;

when the voltage of the node V is within the target voltage range, the triode Q1 works under a static working point;

when the gate impedance of the triggered thyristor is reduced, the gate trigger current of the triggered thyristor is increased, and the negative feedback loop controls the gate trigger current to be reduced, so that the gate trigger current of the triggered thyristor is kept constant within the target voltage range.

When the gate impedance of the triggered thyristor is reduced, the gate trigger current of the triggered thyristor is reduced, the negative feedback loop controls the gate trigger current to be increased, and the gate trigger current of the triggered thyristor is kept constant in a target voltage range.

When the gate impedance of the triggered thyristor is reduced, the gate trigger current of the triggered thyristor is increased, and the specific process of controlling the reduction of the gate trigger current through a negative feedback loop comprises the following steps:

based on the increased gate trigger current of the triggered thyristor, both the base current of transistor Q1 and the collector current of transistor Q1 are increased;

based on the increased base current of transistor Q1 and the increased collector current of transistor Q1, the current through bias resistor R5 increases and the voltage drop across bias resistor R5 increases;

based on the increased voltage drop of the bias resistor R5, the emitter voltage of the transistor Q2 decreases, and the collector current of the transistor Q2 decreases;

based on the reduced collector current of transistor Q2, the current of bias resistor R7 is reduced, and the voltage of bias resistor R7 is reduced;

based on the reduced voltage of bias resistor R7, the base voltage of transistor Q1 is reduced and the emitter current of transistor Q1 is reduced;

based on the reduced emitter current of transistor Q1, the gate trigger current of the triggered thyristor is reduced.

When the gate impedance of the triggered thyristor is increased, the gate trigger current of the triggered thyristor is reduced, and the specific process of controlling the increase of the gate trigger current through a negative feedback loop comprises the following steps:

based on the reduced gate trigger current of the triggered thyristor, both the base current of transistor Q1 and the collector current of transistor Q1 are reduced;

based on the reduced base current of transistor Q1 and the reduced collector current of transistor Q1, the current through bias resistor R5 is reduced and the voltage drop across bias resistor R5 is reduced;

reduced bias resistance R5 based voltage drop U_R5Emitter voltage U of transistor Q2_e2Increase and collector current I of transistor Q2_c2Increasing;

based on the increased collector current of the transistor Q2, the current of the bias resistor R7 increases, and the voltage U of the bias resistor R7 increases_R7Increasing;

based on the increased voltage of the bias resistor R7, the base voltage of the transistor Q1 increases, and the emitter current of the transistor Q1 increases;

based on the increased emitter current of transistor Q1, the gate trigger current of the triggered thyristor is increased.

The trigger module further comprises a current limiting resistor R4, and the base of the triode Q3 is connected with the control system through the current limiting resistor R4.

The energy taking module comprises a voltage stabilizing module, an isolating module and an energy storage module which are sequentially connected in series.

The voltage stabilizing module comprises a voltage stabilizing tube D1, a bypass thyristor T1, a current limiting resistor R1, a current limiting resistor R2 and a reverse freewheeling diode D2;

the cathode of the voltage regulator tube D1 is connected with the anode of the triggered thyristor, and the anode of the voltage regulator tube D1 is connected with the cathode of the triggered thyristor through a current limiting resistor R1; the anode of the bypass thyristor T1 and the cathode of the reverse freewheeling diode D2 are connected with the cathode of the voltage regulator tube D1, and the cathode of the bypass thyristor T1 and the anode of the reverse freewheeling diode D2 are connected with the cathode of the triggered thyristor; one end of the current limiting resistor R2 is connected with the anode of the voltage regulator tube D1, and the other end is connected with the gate of the bypass thyristor T1.

The energy storage module comprises a current-limiting inductor L1 and an energy storage capacitor C1;

one end of the current-limiting inductor L1 is connected to the node V, and the other end is connected to the cathode of the triggered thyristor through the energy-storing capacitor C1.

The isolation module includes a forward freewheeling diode D3;

the anode of the forward freewheeling diode D3 is connected to the anode of the triggered thyristor, and the cathode is connected to the node V, which provides the voltage at the node V to the trigger module.

The trigger circuit also comprises a resistance-capacitance loop;

after being connected in series with the energy-taking module, the resistance-capacitance loop is bridged between the anode and the cathode of the triggered thyristor.

The resistance-capacitance loop comprises a damping capacitor Ct and a damping resistor Rt;

one end of the damping capacitor Ct is connected with the anode of the triggered thyristor, the other end of the damping capacitor Ct is connected with the damping resistor Rt, and the other end of the damping resistor Rt is connected with the energy taking module.

The technical scheme provided by the application has the following beneficial effects:

the thyristor gate trigger circuit comprises a trigger module and an energy obtaining module; the energy taking module is connected with the trigger module and used for supplying power to the trigger module; the trigger module comprises a triode Q3 and a negative feedback loop, a collector and an emitter of the triode Q3 are connected with the negative feedback loop, a base of the triode Q3 is connected with the control system, the negative feedback loop is also connected with a gate of the triggered thyristor, the trigger module is used for sending constant gate-level trigger current to the gate of the triggered thyristor through the negative feedback loop according to trigger signals of different voltage levels, received by the triode Q3 and provided by the control system, and the output gate-level trigger current is not delayed and has high reliability and can reliably trigger the gate of the thyristor.

After the resistance-capacitance loop and the energy taking module are connected in series, the resistance-capacitance loop is bridged between the anode and the cathode of the triggered thyristor, so that dynamic voltage balancing and static voltage balancing of the triggered thyristor are realized, phase change overshoot of the triggered thyristor is inhibited, and reliable operation of the triggered thyristor is ensured.

The trigger module in the application can meet the requirements of triggered thyristors with different voltage levels, the gate trigger current is constant, the used devices are few, the cost is low, and the trigger module can be widely applied to triggering of various triggered thyristors.

The thyristor gate trigger circuit provided by the application can realize small change of trigger current in a wider power supply range, so that energy can be directly obtained through the resistance-capacitance loop without an additional power supply.

The thyristor gate trigger circuit provided by the application can be applied to series-parallel connection scenes of high-voltage and large-current thyristors, can be compatible with various voltage levels, and is wide in application range.

Drawings

FIG. 1 is a schematic diagram of a thyristor gate trigger circuit according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a trigger module in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of an energy-obtaining module in the embodiment of the present application;

FIG. 4 is a schematic diagram of another configuration of a thyristor gate trigger circuit in an embodiment of the present application.

Detailed Description

The present application is described in further detail below with reference to the attached figures.

The embodiment of the application provides a thyristor gate trigger circuit, as shown in fig. 1, including a trigger module and an energy-taking module.

The energy taking module is connected with the trigger module and used for supplying power to the trigger module, namely outputting a voltage V_DDIs provided to the trigger module.

The triggering module comprises a triode Q3 and a negative feedback loop, wherein a collector and an emitter of the triode Q3 are connected with the negative feedback loop, a base of the triode Q3 is connected with the control system, and the negative feedback loop is also connected with a gate of the triggered thyristor.

The trigger module is used for: under the power supply of the energy-taking module (i.e. at the input V)_DDIn this case), a constant gate-level trigger current is sent to the gate level of the triggered thyristor T according to the trigger signal received from the transistor Q3 from the different voltage levels provided by the control system.

It should be noted that the anode of the triggered thyristor T in fig. 1 is connected to the node a, the cathode of the triggered thyristor T is connected to the node K, and the GATE of the triggered thyristor T (i.e., GATE in fig. 1) is connected to the triggering module. And the energy-taking module is also connected with the node A and the node K, and the triggering module is connected with the node K.

The thyristor gate trigger circuit provided by the embodiment of the application has the advantages that the output gate trigger current is not delayed, the reliability is high, the thyristor gate can be reliably triggered, and the output gate trigger current is constant, so the thyristor gate trigger circuit can be called as a constant-current controllable thyristor gate trigger circuit.

As shown in fig. 2, the negative feedback loop includes a bias resistor R3, a bias resistor R5, a bias resistor R6, a bias resistor R7, a transistor Q1, a transistor Q2, and a transistor Q3;

the collector of the triode Q3 is connected with the energy-taking module through a bias resistor R3, the emitter of the triode Q3 is connected with the cathode of the triggered thyristor T through a bias resistor R6, and the connection point of the bias resistor R3 and the energy-taking module is a node V;

the base electrode of the triode Q2 is connected with the collector electrode of the triode Q3, the collector electrode of the triode Q2 is connected with the cathode electrode of the triggered thyristor T through a bias resistor R7, and the emitter electrode of the triode Q2 is connected to a node V through a bias resistor R5;

the base electrode of the triode Q1 is connected with the collector electrode of the triode Q2, the collector electrode of the triode Q1 is connected with the energy obtaining module through a bias resistor R5, and the emitting electrode of the triode Q1 is connected with the gate electrode of the triggered thyristor T to provide constant gate-level trigger current for the triggered thyristor T.

Alternatively, the transistor Q1 and the transistor Q3 may be NPN transistors, and the transistor Q2 may be a PNP transistor.

When the triggered thyristor T works under the target voltage level according to the preset requirement, the voltage of the node V is in the target voltage range by adjusting the resistance value of the bias resistor R3 and/or the resistance value of the bias resistor R5.

When the thyristor gate-level trigger circuit needs to work in a target voltage range, the transistor Q1 works under a static working point. Thus, the gate resistance R of the thyristor T when triggered_GWhen reduced, the gate trigger current I of the triggered thyristor T_GIncreasing, controlling the gate trigger current I by means of a negative feedback loop_GReducing and realizing the gate trigger of the triggered thyristor kept in the target voltage range (such as 30V-60V)Generating current I_GIs constant. Similarly, the gate resistance R of the thyristor T when triggered_GWhen reduced, the gate trigger current I of the triggered thyristor T_GReducing, negative feedback loop controlled gate trigger current I_GIncreasing the gate trigger current I to maintain the triggered thyristor T in the target voltage range_GIs constant.

The thyristor trigger circuit provided by the embodiment of the application has the following working principle:

first, it should be noted that the transistor Q1, the transistor Q2, and the transistor Q3 all operate in a linear amplification state. Then, the current signal (i.e. trigger current I) outputted by the trigger module_G) The size is adjusted through a bias resistor R3, and the control principle is as follows: i is_R3+I_b2＝I_c3(I_R3For the current through the bias resistor R3, I_b2Is the base current, I, of transistor Q2_c3Collector current of transistor Q3), I_c3＝β₃I_b3(β₃Is the amplification factor, I, of a triode Q3_b3Base current of transistor Q3) due to I_b3The gate trigger signal has a constant amplitude, determined by the amplitude of the trigger signal, and therefore I_b3Constant, and then I_c3Constant, I can be changed by adjusting the resistance of the bias resistor R3_R3And further change I_b2Through a transistor Q1 and a transistor Q₂Amplifying, varying the trigger current I_GBy adjusting the bias resistor R3 and the bias resistor R5, the voltage V of the node V is ensured_DDWhen the voltage is changed within the range of 40-60V, the trigger current is controlled within the range of 2-5A. Then, adapt to the thyristor of different voltage grades, the impedance of thyristor gate changes, and the trigger current change is minimum, and the control principle is as follows: i is_R5＝I_e2+I_c1(I_R5For the current through the bias resistor R5, I_e2Is the emitter current, I, of transistor Q2_c1Collector current of transistor Q1), I_e2＝I_b2+I_c2(I_c2Is a triode Q₂Collector current), I_c2＝I_R7+I_b1(I_R7To pass through a bias resistor R₇Current of，I_b1Base current of transistor Q1), I_c2＝β₂I_b2(β₂Amplification of transistor Q2), I_G＝I_e1＝(1+β₁)I_b1(β₁Is the amplification factor, I, of a triode Q1_b1Base current of transistor Q1), thyristor gate voltage V_G＝I_GR_G(V_GIs the gate voltage, R, of the thyristor_GGate impedance of thyristor), V_b1＝V_be1+V_G(V_b1Is the base voltage, V, of transistor Q1_be1The base-emitter voltage drop of the transistor Q1), the trigger current ripple can be controlled within a small range based on the above formula and a negative feedback loop. The working principle of the negative feedback loop is specifically divided into the following two cases:

the first condition is as follows: gate trigger voltage U of triggered thyristor T_GIs constant and satisfies U_G＝I_GR_GGate resistance R of the thyristor T if triggered_GDecreasing the gate trigger current I of the triggered thyristor T_GIncreasing, controlling the gate trigger current I by means of a negative feedback loop_GAnd decreases.

Due to emitter current I of transistor Q1_e1With gate trigger current I of triggered thyristor T_GEqual (i.e. I)_e1＝I_G) And satisfy I_G＝I_e1＝I_b1+I_c1＝(1+β₁)I_b1Wherein, I_b1Indicating the base current, I, of transistor Q1_c1Representing collector current I of transistor Q1_c1，β₁Representing the amplification of transistor Q1. The gate trigger current I of the triggered thyristor T_GWhen the current is increased, the base current I of the triode Q1_b1And collector current I of transistor Q1_c1Are all increasing.

Further, the current I flowing through the bias resistor R5_R5Will follow the base current I of the transistor Q1_b1And collector current I of transistor Q1_c1Is increased and the voltage drop U of the bias resistor R5 is increased_R5Satisfy U_R5＝I_R5R₅Then, the voltage drop U of the bias resistor R5_R5And is increased.

Further, the emitter voltage U due to the transistor Q2_e2Satisfy U_e2＝U-U_R5Wherein U represents the voltage at node V, with a voltage drop U based on a bias resistor R5_R5Increase of (2) emitter voltage U of transistor Q2_e2Will decrease and thus the collector current I of transistor Q2_c2Will follow the emitter voltage U of transistor Q2_e2Is reduced.

Still further, the collector current I due to the transistor Q2_c2Satisfy I_c2＝I_R7+I_b1Wherein, I_R7Represents the current through the bias resistor R7, and thus the current I through the bias resistor R7_R7Will follow the collector current I of the transistor Q2_c2Is reduced. And due to the voltage U of the bias resistor R7_R7Satisfy U_R7＝I_R7R₇Then, the voltage U of the bias resistor R7_R7It is reduced.

Still further, the base voltage U due to the transistor Q1_b1Voltage U to bias resistor R7_R7Equal, so the base voltage U of transistor Q1_b1Will follow the voltage U of the bias resistor R7_R7Is reduced, and, in turn, the emitter current I of transistor Q1_b1Also follows the base voltage U of the transistor Q1_b1Is reduced.

Finally, the gate trigger current I due to the triggered thyristor T_GSatisfy I_G＝I_e1＝I_b1+I_c1＝(1+β₁) The gate trigger current I of the triggered thyristor T_GAgain with the emitter current I of the transistor Q1_b1Is reduced, finally the gate trigger current I of the triggered thyristor T is kept_GIs constant.

Case two: gate trigger voltage U of triggered thyristor T_GConstant, if triggered, gate resistance R of thyristor T_GIncreasing the gate trigger current I of the triggered thyristor T_GReducing, controlling gate contact through negative feedback loopGenerating current I_GAnd is increased.

Due to emitter current I of transistor Q1_e1With gate trigger current I of triggered thyristor_GEqual (i.e. I)_e1＝I_G) And satisfy I_G＝I_e1＝I_b1+I_c1＝(1+β₁)I_b1Wherein, I_b1Indicating the base current, I, of transistor Q1_c1Representing collector current I of transistor Q1_c1，β₁Representing the amplification of transistor Q1. The gate trigger current I of the triggered thyristor_GWhen the base current I of the transistor Q1 is reduced_b1And collector current I of transistor Q1_c1Are all reduced.

Further, the current I flowing through the bias resistor R5_R5Will follow the base current I of the transistor Q1_b1And collector current I of transistor Q1_c1And the voltage drop U of the bias resistor R5 is reduced_R5Satisfy U_R5＝I_R5R₅Then, the voltage drop U of the bias resistor R5_R5And decreases.

Further, the emitter voltage U due to the transistor Q2_e2Satisfy U_e2＝U-U_R5Wherein U represents the voltage at node V, with a voltage drop U based on a bias resistor R5_R5Of transistor Q2, the emitter voltage U of transistor Q2_e2Will increase and thus the collector current I of transistor Q2_c2Will follow the emitter voltage U of transistor Q2_e2Is increased.

Still further, the collector current I due to the transistor Q2_c2Satisfy I_c2＝I_R7+I_b1Wherein, I_R7Represents the current through the bias resistor R7, and thus the current I through the bias resistor R7_R7Will follow the collector current I of the transistor Q2_c2Is increased. And due to the voltage U of the bias resistor R7_R7Satisfy U_R7＝I_R7R₇Then, the voltage U of the bias resistor R7_R7It will increase.

Still further, the base voltage U due to the transistor Q1_b1Voltage U to bias resistor R7_R7Equal, so the base voltage U of transistor Q1_b1Will follow the voltage U of the bias resistor R7_R7Is increased, and further, the emitter current I of the transistor Q1 is increased_b1Also follows the base voltage U of the transistor Q1_b1Is increased.

Finally, the gate trigger current I due to the triggered thyristor_GSatisfy I_G＝I_e1＝I_b1+I_c1＝(1+β₁) The gate trigger current I of the triggered thyristor_GAgain with the emitter current I of the transistor Q1_b1Is increased, and finally the gate trigger current I of the triggered thyristor is kept_GIs constant.

In the embodiment of the application, the trigger module is used for providing the rising time (10% -90% I) of the gate-level trigger current (which is a pulse signal) provided by the triggered thyristor T_GM) The rising slope of the gate-level trigger current is less than or equal to 1us, the rising slope of the gate-level trigger current is greater than or equal to 2A/us, and the pulse flow width is within the range of 5-20 us, so that the triggered thyristor T is reliably triggered. The thyristor series-parallel connection is conductive at the same time, and in order to ensure that the series thyristors are simultaneously and reliably turned on, the trigger module adopts a strong trigger technology, namely, a short-time peak is arranged in front of the waveform of the gate-level trigger current provided by the trigger module, so that the thyristor series-parallel connection trigger module is particularly suitable for application occasions in which the thyristor series-parallel connection is used in a high-voltage alternating-current and direct-current power transmission system.

In addition, the trigger module can meet the voltage V of the node V_DDThe variation of the gate-level trigger current is within the range of 2A-5A within the target voltage range, so that the T trigger requirement of the triggered thyristor is met; the trigger module can meet the requirements of thyristors with different voltage levels (the gate impedance is in the range of 5-20 omega), and the gate trigger current is constant.

The energy taking module comprises a voltage stabilizing module, an isolating module and an energy storage module which are sequentially connected in series.

As shown in fig. 3, the voltage regulator module includes a voltage regulator D1, a bypass thyristor T1, a current limiting resistor R1, a current limiting resistor R2, and a reverse freewheeling diode D2. The cathode of the voltage regulator tube D1 is connected with the anode of the triggered thyristor T (since the anode of the triggered thyristor T is connected with the node a, the cathode of the voltage regulator tube D1 can also be considered to be connected with the node a), and the anode of the voltage regulator tube D1 is connected with the cathode of the triggered thyristor T through the current limiting resistor R1 (since the cathode of the triggered thyristor T is connected with the node K, the anode of the voltage regulator tube D1 can also be considered to be connected with the node K through the current limiting resistor R1); the anode of the bypass thyristor T1 and the cathode of the reverse freewheeling diode D2 are connected with the cathode of the voltage regulator tube D1, and the cathode of the bypass thyristor T1 and the anode of the reverse freewheeling diode D2 are connected with the cathode of the triggered thyristor T (i.e. connected with the node K); one end of the current limiting resistor R2 is connected with the anode of the voltage regulator tube D1, and the other end is connected with the gate of the bypass thyristor T1.

The energy storage module comprises a current-limiting inductor L1 and an energy storage capacitor C1;

one end of the current-limiting inductor L1 is connected to the node V, and the other end thereof is connected to the cathode of the triggered thyristor T (i.e., to the node K) via the energy-storage capacitor C1.

The isolation module includes a forward freewheeling diode D3;

the anode of the forward freewheeling diode D3 is connected to the anode of the triggered thyristor T, and the cathode thereof is connected to the node V, which supplies the voltage at the node V to the trigger module.

It should be noted that the energy obtaining module can provide a power supply voltage for the trigger module through the node V, obtain energy through the damping capacitor Ct and the damping resistor Rt of the resistance-capacitance loop, and when the anode voltage of the triggered thyristor T is positive, the energy storage capacitor C1 is charged through the forward freewheeling diode D3, and the current limiting inductor L1 plays a role in limiting current, so as to prevent the charging current from being too large and affecting the service life of the energy storage capacitor C1. The terminal voltage of the energy storage capacitor C1 is controlled by a voltage regulator tube D1, a current limiting resistor R1, a current limiting resistor R2 and a bypass thyristor T1, the terminal voltage of the energy storage capacitor C1 is maintained within a range of 40-60V, a forward freewheeling diode D2 reversely freewheels, and the energy storage capacitor is not charged when the triggered thyristor T bears reverse voltage.

As shown in fig. 4, the trigger circuit further includes a resistance-capacitance loop;

after being connected in series with the energy-taking module, the resistance-capacitance loop is bridged between the anode and the cathode of the triggered thyristor T.

The resistance-capacitance loop comprises a damping capacitor Ct and a damping resistor Rt;

one end of the damping capacitor Ct is connected with the anode of the triggered thyristor T, the other end of the damping capacitor Ct is connected with the damping resistor Rt, and the other end of the damping resistor Rt is connected with the energy taking module.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application and not for limiting the same, and those skilled in the art can make modifications or equivalents to the specific embodiments of the present application with reference to the above embodiments, and such modifications or equivalents without departing from the spirit and scope of the present application are within the scope of the present application as claimed in the appended claims.