CN216390959U

CN216390959U - Silicon controlled rectifier driving circuit, silicon controlled rectifier driving application circuit and electric/electrical equipment

Info

Publication number: CN216390959U
Application number: CN202122445434.0U
Authority: CN
Inventors: 陈健; 吴桢生; 曾金芳; 赵怀阳
Original assignee: Suzhou Huichuan Control Technology Co Ltd
Current assignee: Suzhou Huichuan Control Technology Co Ltd
Priority date: 2021-10-11
Filing date: 2021-10-11
Publication date: 2022-04-26
Anticipated expiration: 2031-10-11

Abstract

The utility model discloses a silicon controlled rectifier driving circuit, a silicon controlled rectifier driving application circuit and electric/electrical equipment, wherein the silicon controlled rectifier driving circuit comprises: the control signal receiving end is used for accessing a control signal; when the control signal receiving end receives the invalid level, the switch trigger circuit is cut off to disconnect a gate pole loop of the controlled silicon to enable the controlled silicon to be in a cut-off state; when the control signal receiving end receives the effective level, the switch trigger circuit is conducted, and provides trigger current for the gate pole of the controlled silicon, so that the controlled silicon is triggered to be conducted when positive voltage is connected between the anode and the cathode of the controlled silicon; when reverse voltage is connected between the anode and the cathode of the controllable silicon, the one-way conduction element is cut off to cut off a loop where the switch trigger circuit is located, so that the switch trigger circuit is cut off. The utility model improves the driving reliability of the controllable silicon and simultaneously improves the protective timeliness of the controllable silicon.

Description

Silicon controlled rectifier driving circuit, silicon controlled rectifier driving application circuit and electric/electrical equipment

Technical Field

The utility model 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 electrical/electric equipment.

Background

The silicon controlled rectifier is widely applied to the field of industrial speed regulation and transmission and the field of household appliance consumption as a switching device. The thyristor is usually provided with a thyristor driving circuit to drive the thyristor to work. However, the known thyristor driving circuit has low reliability, the thyristor is easy to damage, and even the peripheral power circuit is easy to lose control to cause safety accidents in serious cases.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims to provide a silicon controlled rectifier driving circuit, a silicon controlled rectifier driving application circuit and electrical/electrical equipment, aiming at improving the driving reliability of the silicon controlled rectifier and improving the protection timeliness of the silicon controlled rectifier.

In order to achieve the above object, the present invention provides a thyristor driving circuit for driving a thyristor connected in an application loop, the thyristor driving circuit comprising: the control signal receiving end, the switch trigger circuit and the one-way conduction 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 with the output end of the one-way conduction element, the driving signal output end of the switch trigger circuit is connected to the gate pole of the controllable silicon, and the input end of the one-way conduction element is connected to the anode of the controllable silicon; wherein:

when the control signal receiving end receives an invalid level, the switch trigger circuit is cut off to cut off a gate pole loop of the controlled silicon to enable the controlled silicon to be in a cut-off state;

when the control signal receiving end receives an effective level, the switch trigger circuit is conducted, and provides trigger current for the gate pole of the controlled silicon, so that the controlled silicon is triggered to be conducted when forward voltage is connected between the anode and the cathode of the controlled silicon;

when reverse voltage is connected between the anode and the cathode of the controllable silicon, the one-way conduction element is cut off to cut off a loop where the switch trigger circuit is located, so that the switch trigger circuit is cut off.

Optionally, the switch trigger circuit further comprises 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.

Optionally, the thyristor drive circuit further comprises:

and the signal isolation circuit is arranged between the control signal receiving end and the switch trigger circuit in series and is used for isolating the accessed control signal and then outputting the isolated control signal.

Optionally, the signal isolation circuit includes a first resistor, a second resistor, and an optocoupler, where a first end of the first resistor is the control signal receiving end, and a second end of the first resistor is connected to the second resistor and a primary side anode of the optocoupler; the second end of the second resistor and the primary side cathode of the optocoupler are both grounded; and a secondary side collector of the optocoupler is used for being connected with a power supply, and a secondary side emitter of the optocoupler is connected with a controlled end of the switch trigger circuit.

Optionally, the switch trigger circuit includes a driving resistor and a trigger switch, a first end of the driving resistor is a controlled end of the switch trigger circuit, and a 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 power 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.

Optionally, the trigger switch is a thyristor or an MOS transistor;

when the trigger switch is a thyristor, the gate pole 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 an MOS tube, the grid electrode of the MOS tube is the controlled end of the trigger switch, the source electrode of the MOS tube is the input end of the trigger switch, and the drain electrode of the MOS tube is the output end of the trigger switch.

Optionally, the switch trigger circuit further comprises:

the first anti-false-triggering circuit is arranged between the controlled end and the output end of the trigger switch in parallel.

Optionally, the switch trigger circuit further comprises:

and the second false triggering prevention circuit is arranged between the gate pole and the cathode end of the controlled silicon in parallel.

The utility model also provides a silicon controlled rectifier driving application circuit, which comprises a silicon controlled rectifier and the silicon controlled rectifier driving circuit, wherein the silicon controlled rectifier driving circuit is used for driving the silicon controlled rectifier.

Optionally, the number of the thyristors is multiple, and the thyristors form a three-phase upper bridge rectification circuit and/or a three-phase lower bridge rectification circuit;

the number of the silicon controlled rectifier driving circuits is multiple, and each silicon controlled rectifier driving circuit is connected with one silicon controlled rectifier.

Optionally, when the three-phase upper bridge is formed by a plurality of thyristors, the thyristor application circuit further comprises 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 three thyristors in the three-phase upper bridge; and/or the presence of a gas in the gas,

when a plurality of silicon controlled rectifiers form the three-phase lower bridge, the silicon controlled rectifier application circuit further comprises three second power supplies, the three second power supplies are respectively used for supplying power to three silicon controlled rectifier driving circuits corresponding to the silicon controlled rectifiers in the three-phase lower bridge, the anode of each second power supply is connected to the power supply end of the corresponding silicon controlled rectifier driving circuit, and the cathode of each second power supply is connected to the driving signal output end of the corresponding silicon controlled rectifier driving circuit and the gate pole of the corresponding silicon controlled rectifier.

Optionally, the thyristor-driven application circuit has a soft-start operating mode and a normal operating mode;

when the silicon controlled rectifiers form a three-phase upper bridge and the silicon controlled rectifier driving application circuit works in the soft start working mode, each silicon controlled rectifier driving circuit increases a first preset conduction angle every first preset time according to a received control signal to drive the corresponding silicon controlled rectifiers to conduct.

when the silicon controlled rectifiers form a three-phase upper bridge and a three-phase lower bridge and the silicon controlled rectifier driving application circuit works in the soft start working mode, two silicon controlled rectifier driving circuits of the same bridge arm increase a first preset conduction angle every first preset time according to a received control signal to drive the silicon controlled rectifiers of the corresponding upper bridge and the silicon controlled rectifiers of the corresponding lower bridge to conduct;

or, one silicon controlled rectifier driving circuit of the same bridge arm drives the silicon controlled rectifiers of the corresponding upper bridge to be conducted by increasing a first preset conduction angle every first preset time according to the received control signal; and the other silicon controlled rectifier driving circuit drives the silicon controlled rectifier corresponding to the lower bridge to be continuously conducted according to the received control signal.

The utility model also provides electric/electrical equipment, which comprises the silicon controlled rectifier driving circuit; and/or a thyristor driven application circuit as described above.

According to the utility model, the control signal receiving end and the switch trigger circuit are arranged, and the control signal receiving end is connected with a control signal and outputs the control signal to the controlled end of the switch trigger circuit, so that the switch trigger circuit is used for driving the controllable silicon according to the received control signal; the utility model also comprises a one-way conduction element which is connected in series between the anode of the controlled silicon and the input end of the switch trigger circuit and is used for cutting off when reverse voltage is connected between the anode and the cathode of the controlled silicon so as to control the switch trigger circuit to stop working, thus solving the problems of large leakage current, large loss, temperature rise and service life reduction of the controlled silicon caused by that the anode A-cathode K of the controlled silicon bears back voltage and the controlled silicon drive circuit still receives control signals, and being beneficial to improving the reliable turn-off of the controlled silicon. It can be understood that the utility model does not need to set a back pressure detection circuit to detect whether the anode A-cathode K of the silicon controlled rectifier has back pressure, and simultaneously does not need to feed back to an external controller, so that the software algorithm, analysis, comparison and the like of the external controller can be reduced, the time for stopping the work of the switch trigger circuit is controlled, the reliable protection of the silicon controlled rectifier can be realized by switching off the hardware trigger switch trigger circuit, and the improvement of the protection timeliness of the silicon controlled rectifier is facilitated.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic diagram of functional modules of a thyristor driver circuit according to an embodiment of the utility model;

FIG. 2 is a schematic circuit diagram of a thyristor driver circuit according to an embodiment of the utility model;

FIG. 3 is a schematic circuit diagram of a thyristor driver circuit according to another embodiment of the utility model;

FIG. 4 is a schematic structural diagram of an embodiment of a thyristor driver circuit according to the present invention applied to a thyristor driver application circuit;

FIG. 5 is a timing diagram of the control logic of the SCR drive circuit of FIG. 4;

FIG. 6 is a schematic structural diagram of another embodiment of a thyristor driver circuit according to the present invention applied to a thyristor driver application circuit;

FIG. 7 is a timing diagram of control logic for one embodiment of the control signals for the SCR driver circuit of FIG. 6;

FIG. 8 is a timing diagram of control logic for another embodiment of the control signals for the SCR driver circuit of FIG. 6.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Switch trigger circuit	R1	A first resistor
20	One-way conduction element	R2	Pull-down resistor/second resistor
				30	Signal isolation circuit	R3	Driving resistor
11	Second false-triggering prevention circuit	D1	Diode with a high-voltage source
				12	First false triggering prevention circuit	T1、T2	Silicon controlled rectifier
U1	Optical coupler

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

The utility model provides a silicon controlled rectifier driving circuit which is used for driving and triggering the conduction/cut-off of a silicon controlled rectifier.

A Silicon Controlled Rectifier (SCR), also called thyristor, as shown in fig. 1, has 3 electrodes, where the anode a and the cathode K are power electrodes of the SCR, and the gate G is a control electrode of the SCR, when a positive voltage difference exists between the thyristors a and K and an external driving circuit provides a triggerable current to the gate of the SCR and maintains a certain voltage, the SCR triggers to turn on, and a power current flows from the anode to the cathode of the SCR. The controllable silicon has the characteristics of small volume, high efficiency, long service life and capability of controlling high-voltage and high-power equipment by using a low-voltage and low-power driving circuit, and is widely applied to the field of industrial speed regulation and transmission and the field of household appliance consumption. The silicon controlled rectifier drive circuit can be divided into a strong current hardware indirect trigger type and a weak current software trigger type according to the silicon controlled rectifier trigger signal source, and the weak current software trigger type silicon controlled rectifier drive circuit has defects of 2 points: when the silicon controlled rectifiers A-K bear positive pressure, the triggering and the conduction of the silicon controlled rectifiers need to wait for the arrival of software driving control signals, the triggering of the silicon controlled rectifiers is delayed, and the silicon controlled rectifiers are damaged particularly when high-voltage difference triggering is carried out; when the silicon controlled rectifier A-K bears the back pressure, the silicon controlled rectifier driving circuit still receives a software trigger signal, so that the silicon controlled rectifier has large leakage current, large loss, high temperature and short service life. The concrete form of the indirect trigger type silicon controlled rectifier drive circuit of heavy current hardware still adopts the constant voltage drive or the constant current drive type, and its defect has 2 points: the drive of the silicon controlled rectifier adopts strong trigger, and the drive circuit needs to provide more than 5 times of silicon controlled rectifier trigger current required by specification, so that the power of the drive power supply is high, the power consumption of the drive resistor is high, the design cost of the drive power supply is high, the heat dissipation cost of the drive circuit is high, and the size is large, thereby being not beneficial to improving the power density of the drive board; the driving circuit often needs to provide enough driving current through a triode push-pull circuit, the circuit is complex, a plurality of discrete devices are arranged, the improvement of the power density of the driving plate is not facilitated, and the reliability is low. The pulse-driven silicon controlled rectifier driving circuit of the transformer has defects of 2 points: the method is only suitable for isolated pulse driving and is not suitable for normally open type driving; the transformer is large in size, not beneficial to improving the power density of the driving plate, and the winding of the transformer cannot realize full automation and mechanization, so that the reliability is low, and the cost is high.

In order to solve the above problems, the present invention provides a strong electric hardware direct triggering type thyristor driving circuit, which, on one hand, is provided with a control signal receiving terminal and a switch triggering circuit, wherein the control signal receiving terminal is connected to a control signal and outputs the control signal to a controlled terminal of the switch triggering circuit, so that the switch triggering circuit is used for driving the thyristor according to the received control signal; on the other hand, the thyristor is also provided with a one-way conduction element which is serially connected between the anode of the thyristor and the input end of the switch trigger circuit and is used for cutting off when reverse voltage is connected between the anode and the cathode of the thyristor so as to control the switch trigger circuit to stop working, thus solving the problems of large thyristor leakage current, large loss, temperature rise and service life reduction caused by the fact that the thyristor anode A-cathode K still receives a control signal, and being beneficial to improving the reliable turn-off of the thyristor. It can be understood that the utility model does not need to set a back pressure detection circuit to detect whether the anode A-cathode K of the silicon controlled rectifier has back pressure, and simultaneously does not need to feed back to an external controller, so that the software algorithm, analysis, comparison and the like of the external controller can be reduced, the time for stopping the work of the switch trigger circuit is controlled, the reliable protection of the silicon controlled rectifier can be realized by switching off the hardware trigger switch trigger circuit, and the improvement of the protection timeliness of the silicon controlled rectifier is facilitated.

The following describes the thyristor driving circuit provided by the embodiment of the utility model in detail with reference to the accompanying drawings.

Referring to fig. 1 to 3, in an embodiment of the present invention, the thyristor driving circuit includes: a control signal receiving end SCR _ C, a switch trigger circuit 10 and a one-way conduction element 20;

the control signal receiving terminal SCR _ C is connected to the controlled terminal of the switch trigger circuit 10, the input terminal of the switch trigger circuit 10 is connected to the output terminal of the unidirectional conducting element 20, the driving signal output terminal of the switch trigger circuit 10 is connected to the gate of the thyristor T2, and the input terminal of the unidirectional conducting element 20 is connected to the anode of the thyristor T2; wherein:

when the control signal receiving terminal SCR _ C receives an invalid level, the switch trigger circuit 10 is turned off to disconnect the gate loop of the thyristor T2, so that the thyristor T2 is in a cut-off state;

when the control signal receiving terminal SCR _ C receives an active level, the switch trigger circuit 10 is turned on and provides a trigger current to the gate of the thyristor T2, so that when a forward voltage is applied between the anode and the cathode of the thyristor T2, the thyristor T2 is triggered to be turned on;

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 of the switch trigger circuit 10, so that the switch trigger circuit 10 is turned off.

In this embodiment, the control signal receiving terminal SCR _ C may be connected to an external controller, for example, when the control signal receiving terminal SCR _ C is applied to an electrical/electric device, the control signal receiving terminal SCR _ C may be connected to an MCU in the electrical/electric device, so as to receive a control signal output by the MCU and output the control signal to the switch trigger circuit 10. The switch trigger circuit 10 may control the trigger current of the gate of the thyristor T2 according to whether the received control signal is an active level or an inactive level, specifically, when the received control signal is an active level, the switch trigger circuit 10 is turned on and outputs the 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 may be turned on; when the control signal receiving terminal SCR _ C receives the 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 the off state. The active level may be a high level, for example: may be at a 3.3V or 5V level; the inactive level is low, for example: may be 0V. Of course, in other embodiments, it may also be: the active level is low and the inactive level is high.

The switch trigger circuit 10 includes a controlled terminal, a driving output terminal SCR _ G and a power supply input terminal, and the switch trigger circuit 10 may further have a power supply output terminal SCR _ K connected to a cathode of the thyristor T2. Or the driving output terminal SCR _ G of the switch trigger circuit 10 is connected to the gate of the thyristor T2. The unidirectional element 20 may be implemented by a diode D1 or the like having a forward-conducting and reverse-blocking characteristic. The unidirectional conducting element 20 of this embodiment can be implemented by using a high-voltage fast recovery diode D1, which can increase the trigger turn-on speed of the thyristor T2, and at the same time, can reduce the reverse leakage current that is connected when the switch trigger circuit 10 is closed when the anode a-cathode K of the thyristor T2 is under the reverse voltage. The input end of the unidirectional conducting element 20 is connected with the anode of the thyristor T2 to be driven, and is also connected with a driving power supply, and the output end of the unidirectional conducting element 20 is connected with the power supply input end of the switch trigger circuit 10. When the unidirectional conducting element 20 is conducting in the forward direction, the connected driving power is output to the power input terminal of the switch trigger circuit 10.

When the switch trigger circuit 10 receives an effective control signal, the switch trigger circuit is closed, and 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 of the switch trigger circuit 10 and the power output end SCR _ K, so that the driving current is injected to the gate of the thyristor T2, and the thyristor T2 is driven to be conducted.

When the switch trigger circuit 10 receives an invalid control signal, the switch trigger circuit is turned off, and the driving current output by the driving power supply cannot form a conductive current loop, and cannot be output to the gate of the thyristor T2, that is, the gate driving loop of the thyristor T2 is in an off state, and cannot inject the driving current to the gate of the thyristor T2, so as to drive the thyristor T2 to be turned off.

When the anode a-cathode K of the thyristor T2 is under the back voltage, that is, the voltage of the cathode is greater than the voltage of the anode, when the switch trigger circuit 10 is closed, the unidirectional conducting element 20 and the switch trigger circuit 10 are connected in series and then connected in parallel with the thyristor T2, at this time, the unidirectional conducting element 20 is under the back voltage, and the unidirectional conducting element 20 is turned on in the forward direction and turned off in the reverse direction according to the characteristic that the unidirectional conducting element 20 is turned on in the reverse direction. When the unidirectional conducting element 20 bears the back voltage, the unidirectional conducting element is cut off, so that the driving power supply cannot be output to the switch trigger circuit 10 through the unidirectional conducting element 20, the driving current output by the driving power supply cannot form a conducting current loop, and cannot be output to the gate pole of the thyristor T2, the gate-level G trigger loop of the thyristor T2 is cut off, and the thyristor T2 is driven to be cut off, and at the moment, even if an external controller still outputs an effective control signal, the thyristor T2 keeps a cut-off state.

According to the utility model, by arranging the control signal receiving terminal SCR _ C and the switch trigger circuit 10, the control signal receiving terminal SCR _ C is connected with a control signal and outputs the control signal to the controlled terminal of the switch trigger circuit 10, so that the switch trigger circuit 10 is used for driving the silicon controlled rectifier T2 to be switched on/off according to the received control signal; the utility model is also provided with a unidirectional conducting element 20 which is arranged between the driving power supply and the power supply input end of the switch trigger circuit 10 in series; the utility model cuts off when the controlled silicon T2 is connected with reverse voltage through the unidirectional conducting element 20 to control the switch trigger circuit 10 to stop working. Therefore, the problems that the thyristor T2 is large in leakage current, large in loss, high in temperature and short in service life due to the fact that the anode A-cathode K of the thyristor T2 bears back pressure and the thyristor driving circuit still receives a control signal are solved. It can be understood that a back pressure detection circuit is not required to be arranged to detect whether the anode A-cathode K of the thyristor T2 has back pressure or not, and meanwhile, feedback to an external controller is not required, so that the time for stopping the operation of the switch trigger circuit 10 after software algorithm, analysis, comparison and the like of the external controller are reduced, the switch trigger circuit 10 is triggered to be disconnected through the hardware trigger switch T1, reliable protection on the thyristor T2 can be realized, and meanwhile, the protection timeliness of the thyristor T2 is improved.

Referring to fig. 3, in an embodiment, the thyristor driving circuit further includes:

and the signal isolation circuit 30 is serially connected between the control signal receiving terminal SCR _ C and the switch trigger circuit 10, and the signal isolation circuit 30 is configured to isolate the accessed control signal and then output the isolated control signal.

In this embodiment, signal isolation circuit 30 can adopt devices that have electrical isolation functions such as opto-coupler U1 to realize, and this embodiment can be selected to realize for opto-coupler U1, and through parameters such as isolation voltage, creepage distance, electric clearance, safety regulation authentication of opto-coupler U1 device among the type selection drive circuit, the drive circuit that provides can expand the function insulation requirement and the different safe insulation requirements that are suitable for different electric wire netting grades.

Referring to fig. 3, further, the signal isolation circuit 30 includes a first resistor R1, a first resistor R2, and an optical coupler U1, a first end of the first resistor R1 is the control signal receiving terminal SCR _ C, and a second end of the first resistor R1 is connected to the first resistor R2 and a primary side anode of the optical coupler U1; the second end of the first resistor R2 and the primary side cathode of the optocoupler U1 are both grounded; a secondary side collector of the optocoupler U1 is used for being connected with a power supply SCR _ P, and a secondary side emitter of the optocoupler U1 is connected with a controlled end of the switch trigger circuit 10.

In this embodiment, the SCR driving circuit is positively driven by the control signal SCR _ C, that is, when the control signal SCR _ C is at an inactive level of a low level (which may be set to 0V), the thyristor T2 is not triggered and is in an off state, and when the control signal SCR _ C is at an active level of a high level (which may be set to 3.3V or 5V), the thyristor T2 is triggered and is turned on. By adopting positive logic driving, the mistrigger of the driving circuit caused by mismatching of the power supply time sequence of the control signal SCR _ C and the time sequence of the secondary power supply SCR _ P of the controllable driving circuit in the power-on and power-off processes of the driving circuit can be avoided.

It is understood that the thyristor driving circuit may be formed as an isolated thyristor driving circuit by providing the signal isolation circuit 30 according to whether the ground reference GND of the input control signal is isolated from the gate G or the cathode K of the thyristor T2. For example, the signal isolation circuit 30 is used to isolate the external controller from the switch trigger circuit 10, so that the strong current side connected to the thyristor T2 and the weak current side connected to the control signal receiving terminal SCR _ C can be isolated.

Or, the switch trigger circuit 10 is directly connected to the control signal receiving terminal SCR _ C to form a non-isolated drive circuit, the reference ground GND of the control signal and the primary side SCR _ G and SCR _ K 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 provided, since the thyristor T1 selects the micro-trigger current Igt type, most of the rear buffer circuits of the external controller can directly drive the control signal SCR _ C of the circuit, and a push-pull drive circuit does not need to be additionally provided, so that the drive circuit is very simple in form.

Referring to fig. 2 or fig. 3, in an embodiment, the switch trigger circuit 10 includes a driving resistor R3 and a trigger switch T1, a first end of the driving resistor R3 is a controlled end of the switch trigger circuit 10, and a second end of the driving resistor R3 is connected to a controlled end of the trigger switch T1; the input end of the trigger switch T1 is the power input end of the switch trigger circuit 10, and the output end of the trigger switch T1 is the driving output end SCR _ G of the switch trigger circuit 10.

In this embodiment, the trigger switch T1 may be an MOS transistor, a triode, a thyristor (thyristor), or the like, and the embodiment may be a thyristor T1, where the driving resistor R3 is used to access the control signal and output the control signal to the gate of the thyristor T1, the anode of the thyristor T1 is connected to the output end of the unidirectional conducting element 20, and the cathode of the thyristor T1 is connected to the gate of the thyristor to be driven. The switch trigger circuit 10 can select high dv/dt (generally required to be more than 1000V/us) and micro-trigger current Igt (generally Igt less than 1mA) by using a controllable silicon T1. The silicon controlled rectifier T1 device of little trigger current can adopt the little encapsulation of paster, and in addition, little trigger current Igt can greatly reduce silicon controlled rectifier drive circuit self power consumption and drive resistance R3 loss. Through the appropriate withstand voltage values of the devices of the controllable silicon T1 and the diode D1 in the model selection driving circuit, the driving circuit can be expanded and applied to the power grid grades of 220Vac, 380-480 Vac, 690Vac and the like. Compared with a strong-current hardware direct-triggering type silicon controlled rectifier driving circuit which adopts a high-voltage MOSFET to drive a silicon controlled rectifier, the high-voltage MOSFET is large in size and not beneficial to improving the power density of a driving plate, the voltage value of the effective level of a control signal of an external controller is usually 3.3V or 5V, the driving voltage of the MOSFET needs to be higher than the voltage value of the effective level, and a push-pull circuit of the MOSFET needs to be further arranged. In the embodiment, the thyristor with the micro trigger current Igt is used for driving the thyristor T2 to be driven, the circuit design of the thyristor driving circuit can be simplified, the reduction of the circuit board volume of the thyristor driving circuit is facilitated, and the assembly of the thyristor driving circuit is simplified.

Specifically, when the trigger switch T1 is a thyristor, the gate of the thyristor is the controlled end of the trigger switch T1, 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 T1 is an MOS transistor, the gate of the MOS transistor is the controlled terminal of the trigger switch T1, the source of the MOS transistor is the input terminal of the trigger switch T1, and the drain of the MOS transistor is the output terminal of the trigger switch T1.

Referring to fig. 2 or fig. 3, in an embodiment, the SCR driving circuit further includes a pull-down resistor R2, a first end of the pull-down resistor R2 is connected to the control signal access terminal and the switch triggering circuit 10, respectively, and a second end of the pull-down resistor R2 is grounded and serves as the pull-down resistor R2 of the control signal SCR _ C, so that an uncertain state of the control signal SCR _ C can be avoided, and the anti-interference performance of the control signal SCR _ C can be improved. In an embodiment provided with 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 may further increase a conduction current threshold of the optocoupler U1 and the diode D1, and improve the anti-interference performance of the control signal SCR _ C. In a specific implementation, the resistance of the pull-down resistor R2 ranges from 2k Ω to 5.1k Ω.

Referring to fig. 2 or 3, in an embodiment, the switch trigger circuit further includes:

and the first false trigger prevention circuit 11 is arranged between the controlled end and the output end of the trigger switch T1 in parallel, wherein the first false trigger prevention circuit 11 is connected between the controlled end and the output end of the trigger switch T1.

In this embodiment, the first false triggering prevention circuit 11 may adopt a resistor-capacitor circuit composed of a resistor R4 and a capacitor C1, wherein the resistor R4 is connected in series with the driving resistor R3, the resistor R4 is connected in parallel with the capacitor C1, a trigger threshold value of the control signal output to the switch triggering circuit 10 may be adjusted by adjusting a resistance value of the resistor R4, the capacitor C1 may filter noise in the control signal, and the false triggering prevention circuit 11 composed of the resistor R4 and the capacitor C1 may reduce a risk of false triggering of the switch triggering circuit 10.

and the second false triggering prevention circuit 12 is arranged between the gate and the cathode of the controllable silicon T2 in parallel, and the second false triggering prevention circuit 12 is connected between the gate and the cathode of the controllable silicon T2 in parallel.

In this embodiment, the second false triggering prevention circuit 12 may adopt a resistor-capacitor circuit composed of a resistor R5 and a capacitor C2, wherein the resistor R5 is connected in series with the resistor R4, the resistor R5 is connected in parallel with the capacitor C2, by adjusting the resistance of the resistor R5, the trigger threshold of the control signal output to the gate of the thyristor T2 can be adjusted, the capacitor C2 can filter noise in the control signal, and the false triggering prevention risk of the thyristor T2 can be reduced by the second false triggering prevention circuit 12 composed of the resistor R5 and the capacitor C2.

In order to better illustrate the inventive concept of the present invention, the following description is made of the operating principle of the thyristor driving circuit of the present invention in conjunction with the above-described embodiments of the present invention. Referring to fig. 2, in the following description, a diode D1 is used as an exemplary illustration of the unidirectional conducting element 20 in the thyristor driving circuit, a thyristor is used as an exemplary illustration of the trigger switch T1 in the switch trigger circuit 10, the thyristor driving circuit is further provided with a signal isolation circuit 30, and the signal isolation circuit 30 is implemented by using an optical coupler U1.

Specifically, when the control signal received by the control signal receiving terminal SCR _ C is at an inactive level (generally 0V), the diode and the phototransistor in the optocoupler U1 are both turned off, no current flows through the driving resistor R3, the gate-level G trigger circuit of the thyristor T1 is turned off, the thyristor T1 is turned off, the gate-level G trigger circuit of the thyristor T2 is turned off, and the thyristor T2 is turned off.

When a control signal accessed by a control signal receiving terminal SCR _ C is an effective level (generally 3.3V or 5V), the control signal drives a U1 diode of an optical coupler to be conducted through a resistor R1 (generally, the conducting current is less than 10mA), a U1 phototriode of the optical coupler is conducted, a primary side power supply SCR _ P of a driving circuit injects driving current into a gate G of a controllable silicon T1 through the U1 phototriode of the optical coupler and the driving resistor R3, and the controllable silicon T1 is conducted (as shown in FIG. 6, the reference ground of the power supply SCR _ P can be SCR _ G or SCR _ K, and the conduction of the controllable silicon T2 is not influenced), furthermore, when the A-K of the controllable silicon T2 bears positive voltage (generally 1-5V), the driving current flows into the SCR _ A of the driving circuit from the anode A of the controllable silicon T2 and passes through the diode D1, the conducted controllable silicon T1 is injected into the gate G of the controllable silicon T2 from the SCR _ G of the driving circuit, thyristor T2 is triggered to conduct and power current flows from the anode to the cathode of thyristor T2.

When the anode a and the cathode K of the silicon controlled T2 bear the back voltage, that is, the voltage of the cathode is greater than that of the anode, when the silicon controlled T1 is turned on, the diode D1 and the silicon controlled T1 are connected in series and then connected in parallel with the silicon controlled 2, and at this time, the diode D1 also bears the back voltage, according to the forward turning-on and reverse turning-off characteristics of the diode D1. When the diode D1 is cut off when the diode is subjected to the back voltage, the gate-level G trigger circuit of the thyristor T2 is disconnected, and the gate of the thyristor T2 is cut off without driving current. Therefore, no matter what the level of the control signal SCR _ G is, when A-K of the thyristor T2 bears the back voltage, the diode D1 bears the back voltage and is cut off, the gate G trigger circuit of the thyristor T2 is cut off, and the thyristor T2 is cut off, so that the problems of large leakage current and large loss caused by continuous conduction of the thyristor after receiving the control signal do not exist. The utility model provides a strong-current hardware direct-triggering type silicon controlled drive circuit which mainly comprises a micro-current silicon controlled T1, a high-voltage diode D1, a drive circuit R3 and the like, solves the technical defects of the drive circuit, and has the advantages of simple circuit structure, strong expanding applicability, small volume, low cost, simple drive logic of implementation cases and wide application in silicon controlled drive application circuits and electric/electrical equipment.

The utility model also provides a silicon controlled rectifier driving application circuit, which comprises a silicon controlled rectifier and the silicon controlled rectifier driving circuit; the control end of the controlled silicon driving circuit is connected with the gate pole of the controlled silicon, and the controlled silicon driving circuit is used for driving the controlled silicon. The detailed structure of the silicon controlled driving circuit can refer to the above embodiments, and is not described herein; it can be understood that, because the thyristor driving application circuit is used in the thyristor driving application circuit of the present invention, the embodiment of the thyristor driving application circuit of the present invention includes all technical solutions of all embodiments of the thyristor driving circuit, and the achieved technical effects are also completely the same, and are not described herein again. The utility model relates to a silicon controlled rectifier driving application circuit, which is suitable for the consumption fields of AC/DC speed regulation, power regulation, follow-up systems, household appliances and the like in the industrial field, in particular to a silicon controlled rectifier driving application circuit which adopts silicon controlled rectifiers as AC/DC rectification and bus buffer switches in the application of frequency converters.

Referring to fig. 4 and 6, in an embodiment, the number of the thyristors is multiple, and a plurality of thyristors form a three-phase upper bridge and/or a three-phase lower bridge;

In this embodiment, the thyristor driving circuit design can be applied to any thyristor driving application, for example, electronic switches such as a rectifier bridge, an inverter bridge, a relay, a circuit breaker, and mechanical switch control, and the present embodiment can be selectively applied to a three-phase bridge half-controlled rectifier circuit and a three-phase bridge full-controlled rectifier circuit. The following description of the present invention exemplarily combines three-phase bridge half-controlled rectifier circuit and three-phase bridge full-controlled rectifier circuit topologies, which are commonly used in the field of industrial frequency conversion, as an implementation case to explain the implementation mode and control logic of the driving circuit proposed by the present invention. The quantity of silicon controlled rectifier can be one, two, three, four, six etc. when setting up to one, can constitute and not control rectification high-end/low end buffer switch, when setting up to two, can constitute single-phase half accuse upper bridge rectifier circuit or single-phase half accuse lower bridge rectifier circuit, when setting up to four, then can constitute single-phase full controlled rectifier circuit. When the number of the rectifier circuits is three, a three-phase half-control upper bridge rectifier circuit or a three-phase half-control lower bridge rectifier circuit can be formed, and when the number of the rectifier circuits is six, a three-phase bridge full-control rectifier circuit can be formed.

In an embodiment, when the three-phase upper bridge is formed by a plurality of thyristors, the thyristor application circuit further comprises a first power supply, wherein the anode of the first power supply SCR _ P is connected to the power supply terminals of three thyristor drive circuits for driving the thyristors in the three-phase upper bridge, and the cathode of the first power supply SCR _ P is connected to the cathodes of three thyristors in the three-phase upper bridge; and/or the presence of a gas in the gas,

when the three-phase lower bridge is formed by the silicon controlled rectifiers, the silicon controlled rectifier application circuit further comprises three second power supply sources, the three second power supply sources (SCR _ P _ RL, SCR _ P _ SL and SCR _ P _ TL) are respectively used for supplying power to three silicon controlled rectifier driving circuits corresponding to the silicon controlled rectifiers in the three-phase lower bridge, the anodes of the second power supply sources (SCR _ P _ RL, SCR _ P _ SL and SCR _ P _ TL) are connected to the power supply ends of the silicon controlled rectifier driving circuits corresponding to the second power supply sources, and the cathodes of the second power supply sources (SCR _ P _ RL, SCR _ P _ SL and SCR _ P _ TL) are connected to the driving signal output ends of the silicon controlled rectifier driving circuits corresponding to the second power supply sources and the gates of the silicon controlled rectifiers corresponding to the second power supply sources.

Referring to fig. 4 and 5, in an embodiment, the scr driving application circuit has a soft start operation mode and a normal operation mode;

As shown in fig. 4, the SCR driving application circuit can be applied to a three-phase bridge half-controlled rectifier circuit, which includes three thyristors and their driving circuits, specifically, the three-phase upper bridge in the three-phase bridge half-controlled rectifier circuit employs thyristors, and the three-phase lower bridge employs a diode D1, so in the implementation case, three driving circuits proposed by the present invention are employed to respectively control and drive the three-phase upper bridge thyristors, and share one power supply (SCR _ P _ H) (generally 6V to 12V), and the reference of its driving power supply (first power supply) SCR _ P is the high-end "+" of the rectified dc side, and its driving circuit controls the driving logic as follows:

before the circuit is powered on, the controlled silicon is required to be controlled to carry out soft start, the voltage of a direct current bus capacitor at the rectifying side is 0V, an external controller firstly detects RST voltage and locks the phase sequence of RST, then a phase-locked RST line voltage signal starts to respectively send soft start driving signals to a three-phase upper bridge driving circuit control signal SCR _ C according to a given conduction angle, taking an R-phase upper bridge driving circuit control signal SCR _ C _ RH as an example, soft start logic is shown in figure 5, the external controller carries out phase locking on 0 phase voltage signal of R-S, an effective level signal with a continuous angle of 1/N360 deg is sent to the R-phase upper bridge controlled silicon driving circuit SCR _ C _ RH from the phase locking point, the R-phase upper bridge controlled silicon is conducted at an angle of 1/N360 deg (a first preset conduction angle), an R-phase power grid charges the bus capacitor, and the bus voltage Vdc rises by one step, wherein N is flow (fsw/fin), flow represents rounding to 0, fsw represents the carrier frequency of the external controller, fin represents the RST grid frequency, and thereafter, every R-S grid cycle (every first preset time), the external controller increases the conduction angle of the driving circuit SCR _ C _ RH by 1/N360 deg until the conduction angle of the driving circuit SCR _ C _ RH reaches the maximum 180deg, and the bus voltage Vdc tends to be stable. The external controller may also respectively control 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 according to a given conduction angle by respectively phase-locking the S-T line voltage over-0 phase and the T-R line voltage over-0 phase, where the S-phase upper bridge driving circuit SCR _ C _ SH and the T-phase upper bridge driving circuit SCR _ C _ TH are the same as the soft start control logic of the R-phase upper bridge driving circuit SCR _ C _ RH, and details thereof are omitted here.

After the circuit is powered on, the silicon controlled rectifier enters a normal working state, when RST three-phase bridge-connected silicon controlled rectifier driving circuit control signals are all switched on to the maximum 180 degrees, bus voltage Vdc soft start charging tends to be finished, an external controller can continuously judge that one beat of the Vdc voltage is not larger than the previous beat of the Vdc voltage by detecting the voltage value of the bus voltage Vdc, the soft start is determined to be finished, and as shown in figure 6, the RST three-phase bridge-connected silicon controlled rectifier driving circuit control signals can continuously send effective levels, and the three-phase bridge-connected silicon controlled rectifier is continuously triggered to be conducted.

Referring to fig. 6 to 8, in an embodiment, the scr driving application circuit has a soft start operation mode and a normal operation mode;

In this embodiment, the SCR driving application circuit may be applied to a three-phase bridge full-control rectifier circuit, where the three-phase bridge full-control rectifier circuit includes six thyristors and their driving circuits, and specifically, six bridge arms of the RST three-phase upper bridge and the RST three-phase lower bridge are all rectified by thyristors, so that the six thyristor driving circuits, the RST three-phase upper bridge thyristor driving circuit implementation manner, and the driving signal SCR _ C control manner provided in the present invention may refer to the implementation case of the three-phase bridge half-control rectifier circuit, and are not described herein again. The RST three-phase lower bridge silicon controlled drive circuit respectively uses independent power supplies (second power supplies) SCR _ P _ RL, SCR _ P _ SL and SCR _ P _ TL, reference ground of the power supply of the drive circuit is SCR _ G of various drive circuits, and power supplies SCR _ P _ H shared by the three-phase lower bridge drive circuit power supply and the three-phase upper bridge drive circuit meet functional insulation. As shown in fig. 7, after the external controller locks the phase sequence of the RST, and after a certain conduction angle effective level signal is given to the R-phase upper bridge driving circuit SCR _ C _ RH, the same conduction angle effective level signal of the S-phase lower bridge driving circuit SCR _ C _ SL is synchronously given, wherein the soft start control logic of the R-phase upper bridge driving circuit SCR _ C _ RH can refer to the soft start control logic of the R-phase upper bridge driving circuit SCR _ C _ RH in the three-phase bridge semi-controlled rectifying circuit. Similarly, after the S, T phase upper bridge driving circuits SCR _ C _ SH and SCR _ C _ TH are given certain conduction angle effective level signals, T, R phase lower bridge driving circuits SCR _ C _ TL and SCR _ C _ RL are given the same conduction angle effective level signals synchronously. As another soft start control logic, as shown in fig. 8, the soft start control logic of the R-phase upper bridge driving circuit SCR _ C _ RH, 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 in the three-phase bridge fully-controlled rectifier circuit may refer to the soft start control logic of the R-phase upper bridge driving circuit SCR _ C _ RH in the three-phase bridge semi-controlled rectifier circuit. The three-phase lower bridge driving circuit control signal SCR _ C continuously gives an effective level signal. After the soft start is finished, the control signal SCR _ C of the three-phase lower bridge driving circuit is continuously given to the effective level signal.

The utility model also provides electric/electrical equipment, which comprises the silicon controlled rectifier driving circuit; and/or a thyristor driven application circuit as described above. The detailed structure of the silicon controlled driving circuit and the silicon controlled driving application circuit can refer to the above embodiments, and are not described herein again; it can be understood that, because the thyristor driving circuit and the thyristor driving application circuit are used in the electrical/electric apparatus of the present invention, the embodiment of the electrical/electric apparatus of the present invention includes all technical solutions of all embodiments of the thyristor driving circuit and the thyristor driving application circuit, and the achieved technical effects are also completely the same, and are not described herein again.

The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by using the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A thyristor drive circuit for driving a thyristor connected in an application loop, the thyristor drive circuit comprising: the control signal receiving end, the switch trigger circuit and the one-way conduction element;

2. The silicon controlled rectifier driving circuit as claimed in claim 1, further comprising a pull-down resistor, wherein a first end of the pull-down resistor is connected to a common point of the control signal receiving terminal and the switch trigger circuit, and a second end of the pull-down resistor is grounded.

3. The silicon controlled rectifier driving circuit according to claim 1, further comprising a signal isolation circuit serially connected between the control signal receiving terminal and the switch trigger circuit, wherein the signal isolation circuit is configured to isolate the control signal received and output the control signal.

4. The silicon controlled rectifier driving circuit as claimed in claim 3, wherein the signal isolation circuit comprises a first resistor, a second resistor and an optical coupler, a first end of the first resistor is the control signal receiving end, and a second end of the first resistor is connected to the second resistor and a primary side anode of the optical coupler; the second end of the second resistor and the primary side cathode of the optocoupler are both grounded; and a secondary side collector of the optocoupler is used for being connected with a power supply, and a secondary side emitter of the optocoupler is connected with a controlled end of the switch trigger circuit.

5. The silicon controlled rectifier driving circuit according to claim 1, wherein the switch trigger circuit comprises a driving resistor and a trigger switch, a first end of the driving resistor is a controlled end of the switch trigger circuit, and a second end of the driving resistor is connected with 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 silicon controlled rectifier drive circuit as claimed in claim 5, wherein said trigger switch is a thyristor or a MOS transistor;

7. The thyristor driver circuit of claim 5, wherein said switch trigger circuit further comprises:

8. The thyristor driver circuit of claim 1, wherein the switch trigger circuit further comprises:

9. A thyristor drive application circuit, characterized in that the thyristor drive application circuit comprises a thyristor and a thyristor drive circuit according to any one of claims 1 to 8, the thyristor drive circuit being configured to drive the thyristor.

10. The silicon controlled rectifier driving application circuit according to claim 9, wherein the number of the silicon controlled rectifiers is plural, and the plural silicon controlled rectifiers form a three-phase upper bridge and/or a three-phase lower bridge of a three-phase bridge rectifier circuit;

the number of the silicon controlled rectifier driving circuits is multiple, and each silicon controlled rectifier driving circuit correspondingly drives one silicon controlled rectifier.

11. The silicon controlled rectifier driving application circuit of claim 10, wherein when a plurality of the silicon controlled rectifiers form the three-phase upper bridge, the silicon controlled rectifier application circuit further comprises a first power supply, wherein the positive pole of the first power supply is connected to the power supply terminals of three silicon controlled rectifier driving circuits for driving the silicon controlled rectifiers in the three-phase upper bridge, and the negative pole of the first power supply is connected to the cathodes of three silicon controlled rectifiers in the three-phase upper bridge; and/or the presence of a gas in the gas,

12. The silicon controlled rectifier driver application circuit of claim 11, wherein the silicon controlled rectifier driver application circuit has a soft start mode of operation and a normal mode of operation;

when the three-phase upper bridge is formed by the silicon controlled rectifiers, and the silicon controlled rectifier driving application circuit works in the soft start working mode, each silicon controlled rectifier driving circuit increases a first preset conduction angle every first preset time according to a received control signal to drive the corresponding silicon controlled rectifier to conduct.

13. The silicon controlled rectifier driver application circuit of claim 11, wherein the silicon controlled rectifier driver application circuit has a soft start mode of operation and a normal mode of operation;

when the three-phase upper bridge and the three-phase lower bridge are formed by the silicon controlled rectifiers, and the silicon controlled rectifier driving application circuit works in the soft start working mode, two silicon controlled rectifier driving circuits of the same bridge arm increase a first preset conduction angle every first preset time according to a received control signal to drive the silicon controlled rectifiers of the corresponding upper bridge and the silicon controlled rectifiers of the corresponding lower bridge to conduct;

14. An electric/appliance apparatus, characterized by comprising a thyristor drive circuit according to any one of claims 1 to 8; and/or a thyristor driven application circuit as claimed in any one of claims 9 to 13.