Silicon controlled rectifier driving circuit, silicon controlled rectifier driving application circuit and electrical / electronic device

Abstract

The application discloses a silicon controlled rectifier driving circuit, a silicon controlled rectifier driving application circuit and an electrical / electronic device, and relates to the technical field of silicon controlled rectifier driving circuits, and particularly relates to a silicon controlled rectifier driving circuit, a silicon controlled rectifier driving application circuit and an electrical / electronic device. The silicon controlled rectifier driving circuit comprises a control signal receiving end for receiving a control signal; when the control signal receiving end receives an invalid level, a switch trigger circuit is turned off to disconnect a gate loop of a silicon controlled rectifier, so that the silicon controlled rectifier is in an off state; when the control signal receiving end receives a valid level, the switch trigger circuit is turned on, and a trigger current is provided to the gate of the silicon controlled rectifier, so that the silicon controlled rectifier is triggered to be turned on when a forward voltage is connected between an anode and a cathode of the silicon controlled rectifier; when a reverse voltage is connected between the anode and the cathode of the silicon controlled rectifier, a unidirectional conduction element is turned off to disconnect a loop in which the switch trigger circuit is located, so that the switch trigger circuit is turned off. The application improves the reliability of silicon controlled rectifier driving, and also improves the timeliness of silicon controlled rectifier protection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon controlled rectifier driving, in particular to a silicon controlled rectifier driving circuit, a silicon controlled rectifier driving application circuit and an electrical / electronic device. BACKGROUND

[0002] As a kind of switching device, silicon controlled rectifier is widely used in industrial speed regulation transmission field and household appliance consumption field.Silicon controlled rectifier usually needs to be set silicon controlled rectifier driving circuit to drive silicon controlled rectifier work.However, the reliability of the known silicon controlled rectifier driving circuit is low, and silicon controlled rectifier is easy to be damaged, and even peripheral power circuit is easy to lose control and cause safety accidents. SUMMARY

[0003] The main purpose of the present application is to provide a silicon controlled rectifier driving circuit, a silicon controlled rectifier driving application circuit and an electrical / electronic device, to improve the reliability of silicon controlled rectifier driving and improve the protection timeliness of silicon controlled rectifier.

[0004] To achieve the above purpose, the present application provides a silicon controlled rectifier driving circuit for driving silicon controlled rectifier connected in application loop, the silicon controlled rectifier driving circuit comprises: control signal receiving end, switch trigger circuit and unidirectional conduction element;

[0005] The control signal receiving end is connected to the controlled end of the switch trigger circuit, the input end of the switch trigger circuit is connected to the output end of the unidirectional conduction element, the drive signal output end of the switch trigger circuit is connected to the gate of the silicon controlled rectifier, and the input end of the unidirectional conduction element is connected to the anode of the silicon controlled rectifier;Wherein:

[0006] When the control signal receiving end receives invalid level, the switch trigger circuit is cut off to disconnect the gate loop of the silicon controlled rectifier, so that the silicon controlled rectifier is in cut-off state;

[0007] When the control signal receiving end receives valid level, the switch trigger circuit is turned on, and trigger current is provided to the gate of the silicon controlled rectifier, so that the silicon controlled rectifier is triggered to turn on when the reverse voltage is connected between the anode and the cathode of the silicon controlled rectifier;

[0008] When the reverse voltage is connected between the anode and the cathode of the silicon controlled rectifier, the unidirectional conduction element is cut off to disconnect the loop where the switch trigger circuit is located, so that the switch trigger circuit is cut off.

[0009] Optionally, it further includes a pull-down resistor, the first end of the pull-down resistor is connected to the common point of the control signal receiving end and the switch trigger circuit, and the second end of the pull-down resistor is grounded.

[0010] Optionally, the silicon controlled rectifier driving circuit further comprises:

[0011] A signal isolation circuit is arranged in series between the control signal receiving end and the switch trigger circuit, and is used for isolating and outputting the input control signal.

[0012] Optionally, the signal isolation circuit comprises a first resistor, a second resistor and an optocoupler, a first end of the first resistor is the control signal receiving end, a second end of the first resistor is connected with the second resistor and a primary side anode of the optocoupler; a second end of the second resistor and a primary side cathode of the optocoupler are grounded; a secondary side collector of the optocoupler is used for inputting a power supply, and a secondary side emitter of the optocoupler is connected with the controlled end of the switch trigger circuit.

[0013] Optionally, the switch trigger circuit comprises a drive resistor and a trigger switch, a first end of the drive resistor is the controlled end of the switch trigger circuit, and a second end of the drive resistor is connected with the controlled end of the trigger switch; an input end of the trigger switch is a power input end of the switch trigger circuit, and an output end of the trigger switch is a drive output end of the switch trigger circuit.

[0014] Optionally, the trigger switch is a thyristor or a MOS tube.

[0015] When the trigger switch is a thyristor, a gate of the thyristor is the controlled end of the trigger switch, an anode of the thyristor is the input end of the trigger switch, and a cathode of the thyristor is the output end of the trigger switch.

[0016] When the trigger switch is a MOS tube, a gate of the MOS tube is the controlled end of the trigger switch, a source of the MOS tube is the input end of the trigger switch, and a drain of the MOS tube is the output end of the trigger switch.

[0017] Optionally, the switch trigger circuit further comprises:

[0018] a first anti-mis-triggering circuit, which is arranged in parallel between the controlled end and the output end of the trigger switch.

[0019] Optionally, the switch trigger circuit further comprises:

[0020] a second anti-mis-triggering circuit, which is arranged in parallel between the gate and the cathode of the thyristor.

[0021] The application further provides a silicon controlled rectifier driving application circuit, which comprises a silicon controlled rectifier and the silicon controlled rectifier driving circuit as described above, and the silicon controlled rectifier driving circuit is used for driving the silicon controlled rectifier.

[0022] Optionally, the number of thyristors is multiple, and the multiple thyristors form a three-phase upper bridge rectifier circuit and / or a three-phase lower bridge rectifier circuit.

[0023] The number of thyristor drive circuits is multiple, and each of the thyristor drive circuits is connected to a thyristor.

[0024] Optionally, when the multiple thyristors form the three-phase upper bridge, the thyristor application circuit further comprises a first power supply, a positive electrode of the first power supply is connected to a power supply end of three thyristor drive circuits for driving the thyristors in the three-phase upper bridge, and a negative electrode of the first power supply is connected to cathodes of the three thyristors in the three-phase upper bridge; and / or,

[0025] When the multiple thyristors form the three-phase lower bridge, the thyristor application circuit further comprises three second power supplies, the three second power supplies are respectively used for supplying power to three thyristor drive circuits corresponding to the thyristors in the three-phase lower bridge, a positive electrode of each of the second power supplies is connected to a power supply end of the corresponding thyristor drive circuit, a negative electrode of each of the second power supplies is connected to a drive signal output end of the corresponding thyristor drive circuit and a gate electrode of the corresponding thyristor.

[0026] Optionally, the thyristor drive application circuit has a soft start working mode and a normal working mode.

[0027] When the multiple thyristors form the three-phase upper bridge and the thyristor drive application circuit works in the soft start working mode, each of the thyristor drive circuits drives the corresponding thyristor to turn on according to the received control signal by increasing a first preset conduction angle every first preset time.

[0028] Optionally, the thyristor drive application circuit has a soft start working mode and a normal working mode.

[0029] When the multiple thyristors form the three-phase upper bridge and the three-phase lower bridge and the thyristor drive application circuit works in the soft start working mode, two thyristor drive circuits of the same bridge arm drive the thyristors of the corresponding upper bridge and the thyristors of the corresponding lower bridge to turn on according to the received control signal by increasing a first preset conduction angle every first preset time.

[0030] Alternatively, one of the thyristor drive circuits of the same bridge arm drives the thyristors of the corresponding upper bridge to turn on according to the received control signal by increasing a first preset conduction angle every first preset time, and the other thyristor drive circuit drives the thyristors of the corresponding lower bridge to continuously turn on according to the received control signal.

[0031] The application further provides an electrical / electronic device comprising the silicon controlled rectifier driving circuit as described above; and / or the silicon controlled rectifier driving application circuit as described above.

[0032] The application sets the control signal receiving end and the switch trigger circuit, the control signal receiving end accesses the control signal and outputs to the controlled end of the switch trigger circuit, so that the switch trigger circuit is used to drive the silicon controlled rectifier according to the received control signal; the application further sets a unidirectional conduction element, which is connected in series between the anode of the silicon controlled rectifier and the input end of the switch trigger circuit, and is used to cut off when the reverse voltage is accessed between the anode and the cathode of the silicon controlled rectifier, so as to control the switch trigger circuit to stop working, thus solving the problem that the silicon controlled rectifier has large leakage current, large loss, high temperature rise and reduced service life due to the reverse voltage between the anode A and the cathode K of the silicon controlled rectifier, and being beneficial to improving the reliable shutdown of the silicon controlled rectifier. It can be understood that the application does not need to set a reverse voltage detection circuit to detect whether the reverse voltage appears between the anode A and the cathode K of the silicon controlled rectifier, and also does not need to feedback to the external controller, so as to reduce the time for the external controller to control the switch trigger circuit to stop working through software algorithm, analysis, comparison and the like, and to trigger the switch trigger circuit to be disconnected through hardware, so as to realize the reliable protection of the silicon controlled rectifier, and be beneficial to improving the timeliness of the protection of the silicon controlled rectifier. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0034] Figure 1 The functional module schematic diagram of an embodiment of the silicon controlled rectifier driving circuit of the present application;

[0035] Figure 2 The circuit structure schematic diagram of an embodiment of the silicon controlled rectifier driving circuit of the present application;

[0036] Figure 3 The circuit structure schematic diagram of another embodiment of the silicon controlled rectifier driving circuit of the present application;

[0037] Figure 4 The structure schematic diagram of an embodiment of the silicon controlled rectifier driving circuit applied to the silicon controlled rectifier driving application circuit of the present application;

[0038] Figure 5 The structure schematic diagram of an embodiment of the silicon controlled rectifier driving circuit applied to the silicon controlled rectifier driving application circuit of the present application; Figure 4 The control signal control logic timing diagram of the silicon controlled rectifier driving circuit in the application;

[0039] Figure 6 Fig. 2 is a structural schematic diagram of another embodiment of the silicon controlled rectifier driving circuit applied to a silicon controlled rectifier driving application circuit according to the present application;

[0040] Figure 7 Fig. 3 is a structural schematic diagram of another embodiment of the silicon controlled rectifier driving circuit applied to a silicon controlled rectifier driving application circuit according to the present application; Figure 6 Fig. 4 is a control logic timing diagram of an embodiment of the control signal of the silicon controlled rectifier driving circuit according to the present application;

[0041] Figure 8 Fig. 5 is a control logic timing diagram of another embodiment of the control signal of the silicon controlled rectifier driving circuit according to the present application. Figure 6

[0042] Brief Description of the Drawings:

[0043] Reference Name Reference Name 10 Switch trigger circuit R1 First resistance 20 Unidirectional conduction element R2 Pull-down resistance / second resistance 30 Signal isolation circuit R3 Drive resistance 11 Second anti-mis-triggering circuit D1 Diode 12 First anti-mis-triggering circuit T1, T2 Thyristor U1 Optocoupler

[0044] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0046] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0047] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is also not within the protection scope claimed by the present application.

[0048] ​The term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0049] The present invention provides a thyristor driving circuit for driving and triggering a thyristor to be turned on or off.

[0050] Silicon Controlled Rectifier (SCR) is also called thyristor. Figure 1 As shown, it has three electrodes: anode A and cathode K are the thyristor's power electrodes, and gate G is the thyristor's control electrode. When a positive voltage difference exists across thyristor AK, and an external drive circuit provides a triggerable current to the thyristor gate while maintaining a certain voltage, the thyristor is triggered into conduction, and power current flows from the thyristor's anode to its cathode. Thyristors are characterized by their compact size, high efficiency, long life, and the ability to control high-voltage, high-power devices using low-voltage, low-power drive circuits. They are widely used in industrial speed control and consumer appliances. According to the source of the thyristor trigger signal, the thyristor drive circuit can be divided into a strong-current hardware contact type and a weak-current software trigger type. The weak-current software trigger type thyristor drive circuit has two defects: when the thyristor AK is subjected to positive voltage, the triggering and conduction of the thyristor needs to wait for the arrival of the software drive control signal, which will cause the thyristor triggering delay, especially the high-voltage difference triggering will damage the thyristor; when the thyristor AK is subjected to reverse pressure, the thyristor drive circuit will still receive the software trigger signal, resulting in large thyristor leakage current, large loss, temperature rise, and reduced life. The specific form of the thyristor drive circuit for contact-type high-voltage hardware still uses a constant voltage drive or constant current drive type, which has two drawbacks: the thyristor drive uses a strong trigger, and the drive circuit needs to provide more than 5 times the thyristor trigger current required by the specification. Therefore, the drive power supply is high and the drive resistor power consumption is high, resulting in high drive power supply design costs and high drive circuit heat dissipation costs. At the same time, it also leads to a large size, which is not conducive to improving the power density of the driver board; the drive circuit often needs to use a triode push-pull circuit to provide sufficient drive current. The circuit is complex and has many discrete components, which is not conducive to improving the power density of the driver board and has low reliability. The transformer pulse drive thyristor drive circuit has two drawbacks: it is only suitable for isolated pulse drive and not for normally open drive; the transformer is large in size, which is not conducive to improving the power density of the driver board, and the transformer winding cannot be fully automated and mechanized. Therefore, the reliability is low and the cost is high.

[0051] In order to solve the above problems, the application provides a strong electric hardware direct trigger type thyristor drive circuit, which is characterized in that: the thyristor drive circuit is provided with a control signal receiving end and a switch trigger circuit, the control signal receiving end is connected to the control signal and outputs to the controlled end of the switch trigger circuit, so that the switch trigger circuit is used for driving the thyristor according to the received control signal; and the one-way conducting element is further provided, which is connected in series between the anode of the thyristor and the input end of the switch trigger circuit, and is used for cutting off when the reverse voltage is connected between the anode and the cathode of the thyristor, so as to control the switch trigger circuit to stop working, so that the problem that the thyristor leakage current is large, the loss is large, the temperature rise is high and the service life is reduced due to the reverse voltage of the anode A-cathode K of the thyristor, and the reliable shutdown of the thyristor is improved. It can be understood that the application does not need to set a reverse voltage detection circuit to detect whether the reverse voltage appears in the anode A-cathode K of the thyristor, and does not need to feedback to the external controller, so as to reduce the time of controlling the switch trigger circuit to stop working by the software algorithm, analysis, comparison and the like of the external controller, and the switch trigger circuit is disconnected by the hardware trigger, so as to realize the reliable protection of the thyristor, and the timeliness of the protection of the thyristor is improved.

[0052] The thyristor drive circuit provided by the embodiment of the application will be described in detail below with reference to the drawings.

[0053] Reference Figures 1 to 3 In an embodiment of the application, the thyristor drive circuit comprises a control signal receiving end SCR_C, a switch trigger circuit 10 and a one-way conducting element 20.

[0054] The control signal receiving end SCR_C is connected to the controlled end of the switch trigger circuit 10, the input end of the switch trigger circuit 10 is connected to the output end of the one-way conducting element 20, the drive signal output end of the switch trigger circuit 10 is connected to the gate of the thyristor T2, and the input end of the one-way conducting element 20 is connected to the anode of the thyristor T2.

[0055] When the control signal receiving end SCR_C receives an invalid level, the switch trigger circuit 10 is cut off to disconnect the gate loop of the thyristor T2, so that the thyristor T2 is in a cut-off state.

[0056] When the control signal receiving end SCR_C receives a valid level, the switch trigger circuit 10 is turned on and provides a trigger current to the gate of the thyristor T2, so as to trigger the thyristor T2 to be turned on when the forward voltage is connected between the anode and the cathode of the thyristor T2.

[0057] When a reverse voltage is connected between the anode and the cathode of the thyristor T2, the unidirectional conducting element 20 is turned off to disconnect the loop in which the switch trigger circuit 10 is located, so that the switch trigger circuit 10 is turned off.

[0058] In this embodiment, the control signal receiving end SCR_C can be connected with an external controller, for example, an MCU in an electrical / electronic device, to receive the control signal output by the MCU and output the control signal to the switch trigger circuit 10. The switch trigger circuit 10 can control the trigger current of the gate of the thyristor T2 according to whether the received control signal is a valid level or an invalid level. Specifically, when the received control signal is a valid level, the switch trigger circuit 10 is turned on and outputs a trigger current to the gate of the thyristor T2, and at this time, if a forward voltage is connected between the anode A and the cathode K of the thyristor T2 in the application loop, the thyristor T2 can be turned on. When the control signal receiving end SCR_C receives an invalid level, the switch trigger circuit 10 is turned off, and at this time, the gate of the thyristor T2 has no trigger current, and the thyristor T2 is in an off state. The valid level can be a high level, for example, 3.3V or 5V level, and the invalid level can be a low level, for example, 0V. Of course, in other embodiments, the valid level can be a low level, and the invalid level can be a high level.

[0059] The switch trigger circuit 10 includes a control end, a driving output end SCR_G and a power input end, and can also have a power output end SCR_K connected with the cathode of the thyristor T2. The driving output end SCR_G of the switch trigger circuit 10 is connected with the gate of the thyristor T2. The unidirectional conducting element 20 can be realized by a diode D1 or other elements having a forward conduction and a reverse blocking characteristic. In this embodiment, the unidirectional conducting element 20 can be realized by a high-voltage fast-recovery diode D1, which can accelerate the trigger opening speed of the thyristor T2 and reduce the reverse leakage current of the switch trigger circuit 10 when the anode A-cathode K of the thyristor T2 bears a reverse voltage and the switch trigger circuit 10 is closed. The input end of the unidirectional conducting element 20 is connected with the anode of the thyristor T2 to be driven and also connected with a driving power supply. The output end of the unidirectional conducting element 20 is connected with the power input end of the switch trigger circuit 10. When the unidirectional conducting element 20 is in a forward conduction state, the driving power supply is output to the power input end of the switch trigger circuit 10.

[0060] When the switch trigger circuit 10 receives a valid control signal and is closed, the driving current output by the driving power supply is output to the gate of the thyristor T2 through the unidirectional conducting element 20, the power input end and the power output end SCR_K of the switch trigger circuit 10, so as to inject a driving current into the gate of the thyristor T2 and drive the thyristor T2 to be turned on.

[0061] When the switch trigger circuit 10 receives an invalid control signal, the driving current output by the driving power source cannot form a conduction current loop, and thus cannot be output to the gate of the thyristor T2, that is, the gate drive loop of the thyristor T2 is in an open state, and the driving current cannot be injected into the gate of the thyristor T2, thereby driving the thyristor T2 to be cut off.

[0062] When the anode A-cathode K of the thyristor T2 bears a reverse voltage, that is, the voltage of the cathode is greater than the voltage of the anode, when the switch trigger circuit 10 is in a closed state, the unidirectional conduction element 20 and the switch trigger circuit 10 are connected in series, and then are connected in parallel with the thyristor T2, at this time, the unidirectional conduction element 20 will also bear a reverse voltage, according to the characteristics of the unidirectional conduction element 20, which is forward conduction and reverse cut-off. When the unidirectional conduction element 20 bears a reverse voltage, it will be cut off, so that the driving power source cannot output to the switch trigger circuit 10 through the unidirectional conduction element 20, and the driving current output by the driving power source cannot form a conduction current loop, and thus cannot be output to the gate of the thyristor T2, the gate trigger loop of the thyristor T2 is disconnected, and thus the thyristor T2 is driven to be cut off. At this time, even if the external controller still outputs a valid control signal, the thyristor T2 remains in a cut-off state.

[0063] The application sets a control signal receiving end SCR_C and a switch trigger circuit 10, the control signal receiving end SCR_C inputs a control signal and outputs it to the controlled end of the switch trigger circuit 10, so that the switch trigger circuit 10 is used to drive the thyristor T2 to be turned on / cut off according to the received control signal. The application also sets a unidirectional conduction element 20 which is connected in series between the driving power source and the power input end of the switch trigger circuit 10. The unidirectional conduction element 20 is cut off when the thyristor T2 inputs a reverse voltage, so as to control the switch trigger circuit 10 to stop working. In this way, the problem that the thyristor T2 has a large leakage current, large loss, high temperature rise and reduced service life due to the fact that the anode A-cathode K of the thyristor T2 bears a reverse voltage and the thyristor drive circuit still receives a control signal is solved. It can be understood that the application does not need to set a reverse voltage detection circuit to detect whether the anode A-cathode K of the thyristor T2 bears a reverse voltage, and also does not need to feed back to the external controller. The time for the switch trigger circuit 10 to stop working can be reduced by reducing the software algorithm, analysis, comparison and the like of the external controller, and the switch T1 trigger circuit 10 is turned off by hardware triggering, so that reliable protection of the thyristor T2 can be realized, and the timeliness of the protection of the thyristor T2 is improved.

[0064] Reference Figure 3 In an embodiment, the thyristor drive circuit further comprises:

[0065] A signal isolation circuit 30 is arranged in series between the control signal receiving end SCR_C and the switch trigger circuit 10, and is configured to isolate and output the input control signal.

[0066] In this embodiment, the signal isolation circuit 30 can be implemented by using a device with electrical isolation function such as an optocoupler U1. The signal isolation circuit 30 can be implemented by using an optocoupler U1. The isolation voltage, creepage distance, electrical clearance, and safety certification of the optocoupler U1 in the selected driving circuit can be used to expand the application of the driving circuit to different power grid levels and different safety insulation requirements.

[0067] With reference to Figure 3 Further, the signal isolation circuit 30 includes a first resistor R1, a second resistor R2, and an optocoupler U1. The first end of the first resistor R1 is the control signal receiving end SCR_C. The second end of the first resistor R1 is connected to the first end of the second resistor R2 and the anode of the primary side of the optocoupler U1. The second end of the second resistor R2 and the cathode of the primary side of the optocoupler U1 are grounded. The collector of the secondary side of the optocoupler U1 is connected to the power supply SCR_P. The emitter of the secondary side of the optocoupler U1 is connected to the controlled end of the switch trigger circuit 10.

[0068] In this embodiment, the silicon controlled drive circuit uses positive logic driving of the control signal SCR_C. When the control signal SCR_C is at a low level (which can be set to 0V), the silicon controlled T2 is not triggered and is in a cut-off state. When the control signal SCR_C is at a high level (which can be set to 3.3V or 5V), the silicon controlled T2 is triggered and is in a conducting state. The positive logic driving can avoid the mismatch between the power supply timing of the control signal SCR_C and the secondary power supply SCR_P of the silicon controlled drive circuit during the power-on and power-off processes, which can cause the silicon controlled drive circuit to be triggered incorrectly.

[0069] It can be understood that the silicon controlled drive circuit can be isolated according to whether the reference ground GND of the input control signal and the gate G or the cathode K of the silicon controlled T2 are isolated. The signal isolation circuit 30 can be used to form an isolated silicon controlled drive circuit. For example, the signal isolation circuit 30 can be used to isolate the external controller and the switch trigger circuit 10, and can be used to isolate the strong current side connected to the silicon controlled T2 and the weak current side connected to the control signal receiving end SCR_C.

[0070] Alternatively, the switch trigger circuit 10 is directly connected with the control signal receiving end SCR_C to form a non-isolated drive circuit, and the reference ground GND of the control signal and the SCR_G and SCR_K of the primary side of the drive circuit do not need to be isolated, that is, the isolation optocoupler U1 and the resistor R1 do not need to be set. Since the thyristor T1 is selected as a micro trigger current Igt type, most of the external controller back-end buffer circuits can directly drive the control signal SCR_C of the circuit, without the need to additionally set a push-pull drive circuit, and the drive circuit form is very simple.

[0071] With reference to Figure 2 Or Figure 3 In an embodiment, the switch trigger circuit 10 includes a drive resistor R3 and a trigger switch T1, a first end of the drive resistor R3 is a controlled end of the switch trigger circuit 10, and a second end of the drive resistor R3 is connected with a controlled end of the trigger switch T1; an input end of the trigger switch T1 is a power input end of the switch trigger circuit 10, and an output end of the trigger switch T1 is a drive output end SCR_G of the switch trigger circuit 10.

[0072] In the embodiment, the trigger switch T1 can be a MOS tube, a triode, a thyristor (thyristor), etc. In the embodiment, the thyristor T1 can be selected, wherein the drive resistor R3 is used to input a control signal and output to a gate of the thyristor T1, an anode of the thyristor T1 is connected with an output end of the unidirectional conduction element 20, and a cathode of the thyristor T1 is connected with a gate of a to-be-driven thyristor. In the switch trigger circuit 10, the selected thyristor T1 selects a high dv / dt (generally required to be >1000V / us) and a micro trigger current Igt (generally Igt <1mA). The micro trigger current thyristor T1 device package can adopt a small patch package, in addition, the micro trigger current Igt can greatly reduce the power consumption of the thyristor drive circuit itself and the loss of the drive resistor R3. By selecting the appropriate voltage resistance of the thyristor T1 and the diode D1 in the drive circuit, the proposed drive circuit can be expanded to be applicable to 220Vac, 380-480Vac and 690Vac and other power grid levels. Compared with the high-voltage MOSFET used to drive the thyristor in the strong electric hardware direct trigger type thyristor drive circuit, the high-voltage MOSFET has a large volume, which is not conducive to improving the power density of the drive board, and the voltage value of the control signal effective level of the external controller is usually 3.3V or 5V, while the drive voltage of the MOSFET needs to be higher than the effective level voltage value, and the MOSFET push-pull circuit also needs to be further set. In the embodiment, the micro trigger current Igt thyristor is used to drive the to-be-driven thyristor T2, which can simplify the circuit design of the thyristor drive circuit, and is conducive to reducing the volume of the circuit board of the thyristor drive circuit and simplifying the assembly of the thyristor drive circuit.

[0073] Specifically, when the trigger switch T1 is a thyristor, a gate of the thyristor is a controlled end of the trigger switch T1, an anode of the thyristor is an input end of the trigger switch, and a cathode of the thyristor is an output end of the trigger switch.

[0074] When the trigger switch T1 is a MOS tube, a gate of the MOS tube is a controlled end of the trigger switch T1, a source of the MOS tube is an input end of the trigger switch T1, and a drain of the MOS tube is an output end of the trigger switch T1.

[0075] With reference to Figure 2 Or Figure 3 In an embodiment, the silicon-controlled drive circuit further comprises a pull-down resistor R2, a first end of the pull-down resistor R2 is connected with the control signal input end and the switch trigger circuit 10 respectively, and a second end of the pull-down resistor R2 is grounded. As the pull-down resistor R2 for the control signal SCR_C, the pull-down resistor R2 can avoid the uncertain state of the control signal SCR_C and improve the anti-interference performance of the control signal SCR_C. In the embodiment applied to the signal isolation circuit 30, for example, when the signal isolation circuit 30 is implemented by using the optocoupler U1, the pull-down resistor R2 can also improve the conduction current threshold of the diode D1 of the optocoupler U1 and improve the anti-interference performance of the control signal SCR_C. In a specific implementation, the resistance value of the pull-down resistor R2 ranges from 2kΩ to 5.1kΩ.

[0076] With reference to Figure 2 Or Figure 3 In an embodiment, the switch trigger circuit further comprises:

[0077] A first anti-mis-triggering circuit 11 is arranged in parallel between the controlled end and the output end of the trigger switch T1.

[0078] In the embodiment, the first anti-mis-triggering circuit 11 can be composed of a resistor R4 and a capacitor C1. The resistor R4 is arranged in series with the drive resistor R3, and the resistor R4 is arranged in parallel with the capacitor C1. By adjusting the resistance value of the resistor R4, the trigger threshold of the control signal output to the switch trigger circuit 10 can be adjusted. The capacitor C1 can filter out the noise in the control signal. By using the first anti-mis-triggering circuit 11 composed of the resistor R4 and the capacitor C1, the risk of mis-triggering of the switch trigger circuit 10 can be reduced.

[0079] With reference to Figure 2 Or Figure 3 In an embodiment, the switch trigger circuit further comprises:

[0080] A second anti-mis-triggering circuit 12 is arranged in parallel between the gate and the cathode end of the silicon-controlled T2.

[0081] In this embodiment, the second anti-mis-triggering circuit 12 can adopt a resistance-capacitance circuit composed of a resistance R5 and a capacitance C2, wherein the resistance R5 is arranged in series with the resistance R4, and the resistance R5 is arranged in parallel with the capacitance C2. By adjusting the resistance value of the resistance R5, the trigger threshold of the control signal output to the gate of the thyristor T2 can be adjusted. The capacitance C2 can filter out the noise in the control signal. By the second anti-mis-triggering circuit 12 composed of the resistance R5 and the capacitance C2, the risk of mis-triggering of the thyristor T2 can be reduced.

[0082] In order to better illustrate the inventive concept of the present application, the working principle of the thyristor driving circuit of the present application will be described below in combination with the above-mentioned embodiments of the present application. Referring to Figure 2 , in the following description, the unidirectional conducting element 20 in the thyristor driving circuit is described by taking the diode D1 as an example, and the trigger switch T1 in the switch trigger circuit 10 is described by taking the thyristor as an example. The thyristor driving circuit is also provided with a signal isolation circuit 30, which is implemented by using an optocoupler U1.

[0083] Specifically, when the control signal SCR_C input to the control signal receiving end is an invalid level (generally 0V), the diode and the photo triode in the optocoupler U1 are both cut off, no current flows through the driving resistor R3, the gate G trigger loop of the thyristor T1 is cut off, the thyristor T1 is cut off, and further, the gate G trigger loop of the thyristor T2 is cut off, and the thyristor T2 is cut off.

[0084] When the control signal SCR_C input to the control signal receiving end is a valid level (generally 3.3V or 5V), the control signal SCR_C drives the diode of the optocoupler U1 to conduct (generally, the conduction current is <10mA) through the resistor R1, the photo triode of the optocoupler U1 is turned on, the driving circuit primary side power supply SCR_P injects a driving current into the gate G of the thyristor T1 through the photo triode of the optocoupler U1 and the driving resistor R3, and the thyristor T1 is turned on (as shown in Figure 3 , the reference ground of the power supply SCR_P can be either SCR_G or SCR_K, which does not affect the conduction of the thyristor T2), and further, when the A-K of the thyristor T2 bears a positive voltage (generally 1-5V), the driving current flows from the anode A of the thyristor T2 to the SCR_A of the driving circuit through the diode D1, and the already turned-on thyristor T1 injects a driving current from the SCR_G of the driving circuit into the gate G of the thyristor T2, and the thyristor T2 is triggered to conduct, and the power current flows from the anode to the cathode of the thyristor T2.

[0085] When the anode A and the cathode K of the thyristor T2 bear reverse voltage, that is, the voltage of the cathode is greater than that of the anode, the thyristor T1 is turned on, the diode D1 and the thyristor T1 are connected in series and then are connected in parallel with the thyristor T2, at this time, the diode D1 also bears reverse voltage, according to the characteristics of the diode D1, the diode D1 is turned on in the forward direction and is turned off in the reverse direction. When the diode D1 bears reverse voltage and is turned off, the gate G trigger loop of the thyristor T2 is disconnected, and the gate of the thyristor T2 has no driving current and is turned off. In this way, no matter what level the control signal SCR_G is, when the A-K of the thyristor T2 bears reverse voltage, the diode D1 bears reverse voltage and is turned off, the gate G trigger loop of the thyristor T2 is disconnected, and the thyristor T2 is turned off, so there is no problem of receiving the control signal to continue to turn on the thyristor, resulting in large leakage current and large loss. The application provides a strong electric hardware direct trigger type thyristor driving circuit which mainly comprises a micro-current thyristor T1, a high-voltage diode D1, a driving circuit R3 and the like, solves the technical defects of the foregoing driving circuit, and has the advantages of simple circuit structure, strong expansion applicability, small size, low cost, simple driving logic of the implementation case, and wide application in the thyristor driving application circuit and the electrical / electronic equipment.

[0086] The application further provides a thyristor driving application circuit which comprises a thyristor and the above-mentioned thyristor driving circuit; the control end of the thyristor driving circuit is connected with the gate of the thyristor, and the thyristor driving circuit is used for driving the thyristor. The detailed structure of the thyristor driving circuit can refer to the above-mentioned embodiments, and will not be described here again. It can be understood that, since the above-mentioned thyristor driving circuit is used in the thyristor driving application circuit, the embodiments of the thyristor driving application circuit of the application include all the technical solutions of all the embodiments of the above-mentioned thyristor driving circuit, and the technical effects achieved are also completely the same, and will not be described here again. The thyristor driving application circuit of the application is suitable for the AC / DC speed regulation, power regulation and follow-up system in the industrial field and the consumer field such as household appliances, and is especially suitable for the thyristor driving application circuit which uses the thyristor as the AC / DC rectifier and the bus buffer switch in the frequency converter application.

[0087] Referring to Figure 2 and Figure 6 In an embodiment, the number of the thyristors is multiple, and the multiple thyristors form a three-phase upper bridge and / or a three-phase lower bridge.

[0088] The number of the thyristor driving circuits is multiple, and each thyristor driving circuit is connected with one thyristor.

[0089] The thyristor driving circuit design in the embodiment can be applied to any thyristor driving application occasions, such as rectifier bridge, inverter bridge, electronic switch, mechanical switch control, and the like, and the embodiment can be applied to three-phase bridge half-controlled rectifier circuit and three-phase bridge full-controlled rectifier circuit. The following exemplary three-phase bridge half-controlled rectifier circuit and three-phase bridge full-controlled rectifier circuit topologies commonly used in the industrial frequency conversion field are taken as implementation cases to describe the driving circuit implementation manner and control logic proposed in the present application. The number of thyristors can be one, two, three, four, six, etc. When the number is one, a non-controlled rectifier high-end / or low-end buffer switch can be formed; when the number is two, a single-phase half-controlled upper bridge rectifier circuit or a single-phase half-controlled lower bridge rectifier circuit can be formed; when the number is four, a single-phase full-controlled rectifier circuit can be formed. When the number is three, a three-phase half-controlled upper bridge rectifier circuit / or a three-phase half-controlled lower bridge rectifier circuit can be formed; when the number is six, a three-phase bridge full-controlled rectifier circuit can be formed.

[0090] In an embodiment, when a plurality of the thyristors form the three-phase upper bridge, the thyristor application circuit further comprises a first power supply, a positive electrode of the first power supply SCR_P is connected to a power supply end of three thyristor driving circuits for driving the thyristors in the three-phase upper bridge, and a negative electrode of the first power supply SCR_P is connected to cathodes of the three thyristors in the three-phase upper bridge; and / or,

[0091] When a plurality of the thyristors form the three-phase lower bridge, the thyristor application circuit further comprises three second power supplies, three second power supplies (SCR_P_RL, SCR_P_SL and SCR_P_TL) are respectively used for supplying power to three thyristor driving circuits corresponding to the thyristors in the three-phase lower bridge, positive electrodes of the second power supplies (SCR_P_RL, SCR_P_SL and SCR_P_TL) are connected to power supply ends of the thyristor driving circuits corresponding thereto, negative electrodes of the second power supplies (SCR_P_RL, SCR_P_SL and SCR_P_TL) are connected to driving signal output ends of the thyristor driving circuits corresponding thereto and gates of the thyristors corresponding thereto.

[0092] Referring to Figure 4 and Figure 6 In an embodiment, the thyristor driving application circuit has a soft start working mode and a normal working mode.

[0093] When a plurality of the thyristors form the three-phase upper bridge and the thyristor driving application circuit works in the soft start working mode, each thyristor driving circuit drives the corresponding thyristor to turn on according to the received control signal with a first preset conduction angle increased every first preset time.

[0094] As Figure 4 shown, the silicon controlled rectifier driving application circuit can be applied to a three-phase bridge half-controlled rectifier circuit including three silicon controlled rectifiers and their driving circuits. Specifically, the three-phase upper bridge of the three-phase bridge half-controlled rectifier circuit adopts silicon controlled rectifiers, and the three-phase lower bridge adopts diodes D1. Therefore, in the implementation case, three driving circuits proposed in the present application are adopted to control the driving of the three-phase upper bridge silicon controlled rectifiers, and share one power supply SCR_P_H (generally 6V-12V). The reference ground of the driving power supply (the first power supply) SCR_P is the high end "+" of the rectified direct current side, and the driving circuit control driving logic is as follows:

[0095] Before the circuit is powered on, the silicon controlled rectifier needs to be controlled for soft start. The rectified direct current bus capacitor voltage is 0V. The external controller first detects the RST voltage and locks the phase sequence of RST. Then, the phase-locked RST line voltage signal starts to give the three-phase upper bridge driving circuit control signal SCR_C a soft start driving signal according to the given conduction angle. Taking the R-phase upper bridge driving circuit control signal SCR_C_RH as an example, the soft start logic is as shown in Figure 5 After the phase-locked R-S line voltage signal is locked at 0, the external controller gives the R-phase upper bridge silicon controlled rectifier driving circuit SCR_C_RH an effective level signal with a duration of 1 / N*360deg every time starting from the locking point. The R-phase upper bridge silicon controlled rectifier is turned on for an angle of 1 / N*360deg (the first preset conduction angle). The R-phase power grid charges the bus capacitor, and the bus voltage Vdc rises by one step. Wherein N=floor(fsw / fin), floor represents rounding down to 0, fsw represents the carrier frequency of the external controller, and fin represents the frequency of the RST power grid. Thereafter, the external controller increases the conduction angle of the driving circuit SCR_C_RH by 1 / N*360deg every R-S power grid cycle (every first preset time) until the conduction angle of the driving circuit SCR_C_RH reaches the maximum of 180deg, and the bus voltage Vdc tends to be stable. The external controller can also control the S-phase upper bridge driving circuit SCR_C_SH and the T-phase upper bridge driving circuit SCR_C_TH according to the given conduction angle by respectively phase-locked S-T line voltage over 0 phase and T-R line voltage over 0 phase. The soft start control logic of the S-phase upper bridge driving circuit SCR_C_SH and the T-phase upper bridge driving circuit SCR_C_TH is the same as that of the R-phase upper bridge driving circuit SCR_C_RH. For details, please refer to the soft start control logic of the R-phase upper bridge driving circuit SCR_C_RH, which will not be described here.

[0096] After the circuit is powered on, the thyristor enters the normal working state. When the RST three-phase upper bridge thyristor drive circuit control signal is all opened to the maximum 180°, the bus voltage Vdc soft start charging tends to end, and the external controller can detect the voltage value of the bus voltage Vdc. If the next beat of the Vdc voltage is not greater than the last beat, it is determined that the soft start is completed, as shown in Figure 4 thereafter, the RST three-phase upper bridge thyristor drive circuit control signal SCR_U can continuously send an effective level, and the three-phase upper bridge thyristor is continuously triggered and turned on.

[0097] Referring to Figure 5 In an embodiment, the thyristor drive application circuit has a soft start working mode and a normal working mode.

[0098] When the thyristor drive application circuit is working in the soft start working mode, two thyristor drive circuits in the same bridge arm drive the corresponding upper bridge thyristor and lower bridge thyristor to turn on according to the received control signal, with an increase of a first preset conduction angle every first preset time.

[0099] Alternatively, one of the thyristor drive circuits in the same bridge arm drives the corresponding upper bridge thyristor to turn on according to the received control signal, with an increase of a first preset conduction angle every first preset time, and the other thyristor drive circuit drives the corresponding lower bridge thyristor to turn on continuously according to the received control signal.

[0100] In this embodiment, the thyristor drive application circuit can be applied to a three-phase bridge full-controlled rectifier circuit, which includes six thyristors and their drive circuits. Specifically, the RST three-phase upper bridge and the three-phase lower bridge each use a thyristor rectifier, so six thyristor drive circuits are used. The RST three-phase upper bridge thyristor drive circuit implementation and the drive signal SCR_C control method can refer to the implementation of the three-phase bridge half-controlled rectifier circuit, which will not be described here. The RST three-phase lower bridge thyristor drive circuit uses independent power supplies (second power supply) SCR_P_RL, SCR_P_SL and SCR_P_TL, and the reference ground of the drive circuit power supply is the SCR_G of each drive circuit. The power supply of the three lower bridge drive circuits and the power supply of the three-phase upper bridge drive circuit meet the functional insulation between each other. The three lower bridge drive circuit SCR_C soft start control logic has two kinds, as shown in Figure 6As shown, after the external controller phase-locks the RST, when a certain conduction angle active level signal is given to the R-phase upper bridge drive circuit SCR_C_RH, a same conduction angle active level signal is synchronously given to the S-phase lower bridge drive circuit SCR_C_SL, wherein the soft start control logic of the R-phase upper bridge drive circuit SCR_C_RH can refer to the soft start control logic of the R-phase upper bridge drive circuit SCR_C_RH in the three-phase bridge half-controlled rectifier circuit. Similarly, when a certain conduction angle active level signal is given to the S-phase and T-phase upper bridge drive circuits SCR_C_SH and SCR_C_TH, a same conduction angle active level signal is synchronously given to the T-phase and R-phase lower bridge drive circuits SCR_C_TL and SCR_C_RL. As shown in FIG. 6, the soft start control logic of the R-phase upper bridge drive circuit SCR_C_RH, the soft start control logic of the S-phase upper bridge drive circuit SCR_C_SH and the soft start control logic of the T-phase upper bridge drive circuit SCR_C_TH can refer to the soft start control logic of the R-phase upper bridge drive circuit SCR_C_RH in the three-phase bridge half-controlled rectifier circuit. The three-phase lower bridge drive circuit control signal SCR_C continuously gives an active level signal. After the soft start is completed, the three-phase lower bridge drive circuit control signal SCR_C also continuously gives an active level signal. Figures 6 to 8 Figure 7 Figure 8 As shown, as another soft start control logic, the soft start control logic of the R-phase upper bridge drive circuit SCR_C_RH, the soft start control logic of the S-phase upper bridge drive circuit SCR_C_SH and the soft start control logic of the T-phase upper bridge drive circuit SCR_C_TH in the three-phase bridge full-controlled rectifier circuit can refer to the soft start control logic of the R-phase upper bridge drive circuit SCR_C_RH in the three-phase bridge half-controlled rectifier circuit. The three-phase lower bridge drive circuit control signal SCR_C continuously gives an active level signal. After the soft start is completed, the three-phase lower bridge drive circuit control signal SCR_C also continuously gives an active level signal.

[0101] The application further provides an electrical / electronic device comprising the silicon controlled rectifier drive circuit as described above; and / or the silicon controlled rectifier drive application circuit as described above. The detailed structure of the silicon controlled rectifier drive circuit and the silicon controlled rectifier drive application circuit can refer to the above embodiments, which will not be described herein again; it can be understood that, since the silicon controlled rectifier drive circuit and the silicon controlled rectifier drive application circuit are used in the electrical / electronic device of the application, the embodiments of the electrical / electronic device of the application include all the technical solutions of all the embodiments of the silicon controlled rectifier drive circuit and the silicon controlled rectifier drive application circuit, and the technical effects achieved are also completely the same, which will not be described herein again.

[0102] The above description is only optional embodiments of the application, and does not limit the inventive scope of the application, and any equivalent structural transformation made under the inventive concept of the application, or direct / indirect application in other related technical fields is included in the inventive protection scope of the application.

Claims

1. A thyristor drive circuit for driving a thyristor connected in an application circuit, characterized in that: The thyristor drive circuit includes: a control signal receiving terminal, a switch trigger circuit and a unidirectional conducting element; The control signal receiving end is connected to the controlled end of the switch trigger circuit, the input end of the switch trigger circuit is connected to the output end of the unidirectional conductive element, the drive signal output end of the switch trigger circuit is connected to the gate of the thyristor, and the input end of the unidirectional conductive element is connected to the anode of the thyristor; wherein: When the control signal receiving end receives an invalid level, the switch trigger circuit is turned off to disconnect the gate circuit of the thyristor, so that the thyristor is in a cut-off state; When the control signal receiving end receives a valid level, the switch trigger circuit is turned on and provides a trigger current to the gate of the thyristor, so as to trigger the thyristor to turn on when a forward voltage is connected between the anode and cathode of the thyristor; When a reverse voltage is applied between the anode and cathode of the thyristor, the unidirectional conducting element is turned off to disconnect the loop where the switch trigger circuit is located, so that the switch trigger circuit is turned off.

2. The thyristor drive circuit according to claim 1, wherein: It also includes a pull-down resistor, a first end of the pull-down resistor is connected to a common point of the control signal receiving end and the switch trigger circuit, and a second end of the pull-down resistor is grounded.

3. The thyristor drive circuit according to claim 1, wherein: The thyristor drive circuit further includes a signal isolation circuit, which is arranged in series between the control signal receiving end and the switch trigger circuit. The signal isolation circuit is used to isolate the input control signal and then output it.

4. The thyristor drive circuit according to claim 3, wherein: The signal isolation circuit includes a first resistor, a second resistor and an optocoupler, the first end of the first resistor is the control signal receiving end, the second end of the first resistor is connected to the second resistor and the primary side anode of the optocoupler; the second end of the second resistor and the primary side cathode of the optocoupler are both grounded; the secondary side collector of the optocoupler is used to connect to the power supply, and the secondary side emitter of the optocoupler is connected to the controlled end of the switch trigger circuit.

5. The thyristor drive circuit according to claim 1, wherein: The switch trigger circuit includes a driving resistor and a trigger switch, the first end of the driving resistor is the controlled end of the switch trigger circuit, and the second end of the driving resistor is connected to the controlled end of the trigger switch; the input end of the trigger switch is the input end of the switch trigger circuit, and the output end of the trigger switch is the driving output end of the switch trigger circuit.

6. The thyristor drive circuit according to claim 5, wherein: The trigger switch is a thyristor or a MOS tube; When the trigger switch is a thyristor, the gate of the thyristor is the controlled end of the trigger switch, the anode of the thyristor is the input end of the trigger switch, and the cathode of the thyristor is the output end of the trigger switch; When the trigger switch is a MOS transistor, the gate of the MOS transistor is the controlled end of the trigger switch, the source of the MOS transistor is the input end of the trigger switch, and the drain of the MOS transistor is the output end of the trigger switch.

7. The thyristor drive circuit according to claim 5, wherein: The switch trigger circuit further includes: A first anti-false triggering circuit is provided in parallel between the controlled end and the output end of the trigger switch.

8. The thyristor drive circuit according to claim 1, wherein: The switch trigger circuit further includes: A second anti-false triggering circuit is provided in parallel between the gate and cathode terminals of the thyristor.

9. A thyristor drive application circuit, characterized in that: The thyristor drive application circuit includes a thyristor and the thyristor drive circuit according to any one of claims 1 to 8, and the thyristor drive circuit is used to drive the thyristor.

10. The thyristor drive application circuit according to claim 9, wherein: There are multiple thyristors, and the multiple thyristors form a three-phase upper bridge and / or a three-phase lower bridge of a three-phase bridge rectifier circuit; There are multiple thyristor drive circuits, and each thyristor drive circuit drives one thyristor.

11. The thyristor drive application circuit according to claim 10, wherein: When a plurality of the thyristors form the three-phase upper bridge, the thyristor application circuit further includes a first power supply, wherein the positive electrode of the first power supply is connected to the power supply ends of three thyristor drive circuits for driving the thyristors in the three-phase upper bridge, and the negative electrode of the first power supply is connected to the cathodes of the three thyristors in the three-phase upper bridge; and / or, When multiple thyristors form the three-phase lower bridge, the thyristor application circuit further includes three second power supplies, which are respectively used to power three thyristor drive circuits corresponding to the thyristors in the three-phase lower bridge. The positive electrode of the second power supply is connected to the power supply end of the corresponding thyristor drive circuit, and the negative electrode of the second power supply is connected to the drive signal output end of the corresponding thyristor drive circuit and the gate of the corresponding thyristor.

12. The thyristor drive application circuit according to claim 11, wherein: The thyristor drive application circuit has a soft start working mode and a normal working mode; When a plurality of the thyristors form the three-phase upper bridge and the thyristor drive application circuit operates in the soft start operating mode, each of the thyristor drive circuits drives the corresponding thyristor to conduct by increasing the first preset conduction angle every first preset time according to the received control signal.

13. The thyristor drive application circuit according to claim 11, wherein: The thyristor drive application circuit has a soft start working mode and a normal working mode; When a plurality of the thyristors form the three-phase upper bridge and the three-phase lower bridge, and the thyristor drive application circuit operates in the soft start mode, the two thyristor drive circuits in the same bridge arm drive the corresponding thyristors of the upper bridge and the thyristors of the lower bridge to conduct according to the received control signal, increasing the first preset conduction angle every first preset time; Alternatively, the thyristor driving circuit of the same bridge arm drives the thyristor of the corresponding upper bridge to conduct by increasing the first preset conduction angle every first preset time according to the received control signal; Furthermore, another thyristor driving circuit drives the thyristor of the corresponding lower bridge to be continuously turned on according to the received control signal.

14. An electrical / electrical device, characterized in that: The method comprises the thyristor drive circuit according to any one of claims 1 to 8; and / or the thyristor drive application circuit according to any one of claims 9 to 13.

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