Circuit for cutting off bidirectional current and control method thereof

Abstract

The invention discloses a circuit for cutting off bidirectional current and a control method thereof. Relates to the field of power system control, and the structure comprises a forced commutation module which is used for switching off current through a resonant commutation mode when an instruction is received; the bidirectional rectification module is connected with the forced commutation module and cooperates with the forced commutation module to realize the turn-off of bidirectional current; wherein the forced commutation module comprises a thyristor T5, a thyristor T6, a resonant capacitor C1, an inductor L1 and a diode D1; the bidirectional rectification module comprises a thyristor T1, a thyristor T2, a thyristor T3 and a thyristor T4. According to the invention, the problem that the cost of a circuit for cutting off bidirectional current is too high in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of power system control, and in particular to a circuit for cutting off bidirectional current and a control method thereof. Background Art

[0002] In AC systems or DC charging and discharging systems, due to the existence of bidirectional currents, the switch is required to have bidirectional current cutting capabilities. In low-current applications, pure solid-state technology is usually used, using fully controlled devices such as IGBTs or MOS tubes, which are connected in reverse series to cut off bidirectional currents. However, in high-current applications, the high cost and poor overcurrent capacity of fully controlled devices limit their application. Therefore, forced commutation technology based on thyristor switches has come on the stage, which has the advantages of low cost and strong overload capacity. Since the forced commutation technology of thyristor switches only has unidirectional current cutting capabilities, two sets of reverse-parallel forced commutation thyristor switches are required in the application of bidirectional current systems. The cost and volume increase of bidirectional switches based on this technology cannot be underestimated.

[0003] With regard to the problem of high cost of circuits for cutting off bidirectional current in related technologies, no effective solution has been proposed so far. Summary of the Invention

[0004] The main purpose of the present application is to provide a circuit for cutting off bidirectional current and a control method thereof, so as to solve the problem of high cost of the circuit for cutting off bidirectional current in the related art.

[0005] To achieve the above objectives, according to one aspect of the present application, a circuit for cutting off bidirectional current is provided. The structure includes: a forced commutation module, which is used to cut off the current through resonant commutation when receiving an instruction; a bidirectional rectifier module, which is connected to the forced commutation module and cooperates with the forced commutation module to achieve bidirectional current cutting; wherein the forced commutation module includes thyristor T5, thyristor T6, resonant capacitor C1, inductor L1 and diode D1; and the bidirectional rectifier module includes thyristor T1, thyristor T2, thyristor T3 and thyristor T4.

[0006] Optionally, the cathode of the thyristor T1 , the cathode of the thyristor T2 , the anode of the thyristor T5 , the anode of the thyristor T6 and one end of the inductor L1 are connected.

[0007] Optionally, the anode of the thyristor T3 , the anode of the thyristor T4 and the cathode of the diode D1 are connected.

[0008] Optionally, the cathode of the thyristor T5 , the anode of the diode D1 , and one end of the resonant capacitor C1 are connected.

[0009] Optionally, the anode of the thyristor T1 and the cathode of the thyristor T3 are connected.

[0010] Optionally, the anode of the thyristor T2 and the cathode of the thyristor T4 are connected.

[0011] Optionally, when the circuit system for cutting off bidirectional current is in the on state, the thyristor T1 , the thyristor T2 , the thyristor T3 , the thyristor T4 and the thyristor T6 are in the on state, and the thyristor T5 is in the off state.

[0012] According to another aspect of the present application, a control method for a circuit for cutting off bidirectional current is provided, which is applied to the above-mentioned circuit for cutting off bidirectional current. The method includes the following steps: when the circuit for cutting off bidirectional current receives a tripping instruction, turning off the drive of thyristor T1, the drive of thyristor T2, the drive of thyristor T3, the drive of thyristor T4 and the drive of thyristor T6; and turning on the drive of thyristor T5.

[0013] According to another aspect of the present application, a readable storage medium is provided, storing a program or instructions thereon. When executed by a processor, the program or instructions implement the control method for a circuit for interrupting bidirectional current as described in any of the above technical solutions. Therefore, the readable storage medium has all the beneficial effects of the control method for a circuit for interrupting bidirectional current as described in any of the above technical solutions, and no further description is given here.

[0014] According to another aspect of the present application, a control device for a circuit that interrupts bidirectional current is provided, comprising a processor and a memory, wherein the memory stores a program or instruction that, when executed by the processor, implements the steps of the control method for interrupting bidirectional current in any of the above-described technical solutions. Therefore, the control device for interrupting bidirectional current has all the beneficial effects of the control method for interrupting bidirectional current in any of the above-described technical solutions, and no further details are given here.

[0015] In an embodiment of the present application, a circuit for cutting off bidirectional current is provided. The structure includes: a forced commutation module, which is used to cut off the current through resonant commutation when receiving an instruction; a bidirectional rectifier module, which is connected to the forced commutation module and cooperates with the forced commutation module to achieve bidirectional current cutting off; wherein, the forced commutation module includes thyristor T5, thyristor T6, resonant capacitor C1, inductor L1 and diode D1; the bidirectional rectifier module includes thyristor T1, thyristor T2, thyristor T3 and thyristor T4, thereby solving the technical problem of high cost of circuits for cutting off bidirectional current in related technologies, thereby achieving the technical effect of reducing the cost of circuits for cutting off bidirectional current. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings: Figure 1 1 is a schematic diagram of a circuit for cutting off bidirectional current according to an embodiment of the present application; Figure 2 is a schematic diagram of another circuit for cutting off bidirectional current provided according to an embodiment of the present application; Figure 3 Schematic diagram of current passing through thyristor T1, thyristor T4, and thyristor T6 according to an embodiment of the present application; Figure 4 1 is a schematic diagram of the current when the thyristor T5 is turned on according to an embodiment of the present application; Figure 5 2 is a schematic diagram of the current when the capacitor C1 is continuously discharging according to an embodiment of the present application; Figure 6 1 is a current diagram of the thyristor T1, the thyristor T2, the thyristor T3, the thyristor T4, the thyristor T5, and the thyristor T6 provided in an embodiment of the present application when the currents are all turned off; Figure 7 This is a structural block diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0018] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0019] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0020] Example 1 This application provides Figure 1 The circuit shown for cutting off bidirectional current includes: The forced commutation module 1 is used to shut off the current through resonant commutation when receiving an instruction; the bidirectional rectifier module 2 is connected to the forced commutation module and cooperates with the forced commutation module to realize the shutoff of the bidirectional current; wherein, the forced commutation module includes thyristor T5, thyristor T6, resonant capacitor C1, inductor L1 and diode D1; the bidirectional rectifier module includes thyristor T1, thyristor T2, thyristor T3 and thyristor T4.

[0021] Optionally, the circuit for interrupting bidirectional current includes a forced commutation module 1 and a bidirectional rectifier module 2, which can be used to interrupt bidirectional current. Bidirectional current refers to current that can flow in two opposite directions within the same circuit. This is commonly seen in alternating current (AC) systems (where the current direction changes periodically) and reversible direct current (DC) systems (such as battery charging and discharging, and forward and reverse rotation of motors). The bidirectional rectifier module 2 includes thyristors T1, T2, T3, and T4, which can uniformly rectify current in any direction into a fixed path. The forced commutation module 1 includes thyristors T5 and T6, a resonant capacitor C1, an inductor L1, and a diode D1, which can quickly shut off the rectified current. Upon receiving a command, the forced commutation module 1 shuts off the current through resonant commutation. Resonant commutation refers to generating a reverse current through an LC oscillating circuit to forcibly offset the main circuit current, causing the thyristors to meet the shutdown conditions (current crossing zero and withstanding reverse voltage).

[0022] Specifically, the cathode of the thyristor T1 , the cathode of the thyristor T2 , the anode of the thyristor T5 , the anode of the thyristor T6 and one end of the inductor L1 are connected.

[0023] Optionally, the cathode of the thyristor T1, the cathode of the thyristor T2, the anode of the thyristor T5, the anode of the thyristor T6, and one end of the inductor L1 are connected to a connection node (assuming it is node X), forming a collection point of bidirectional current, so that regardless of the current direction, the main current must pass through this node when conducting.

[0024] Specifically, the anode of the thyristor T3 , the anode of the thyristor T4 , and the cathode of the diode D1 are connected.

[0025] Optionally, the anode of the thyristor T3, the anode of the thyristor T4 and the cathode of the diode D1 are connected to a node (assuming it is node Y), forming a collection point of bidirectional currents, so that regardless of the current direction, the main current must pass through this node when conducting.

[0026] Specifically, the cathode of the thyristor T5 , the anode of the diode D1 , and one end of the resonant capacitor C1 are connected.

[0027] Optionally, the cathode of the thyristor T5, the anode of the diode D1, and one end of the resonant capacitor C1 are connected to a node (assuming it is node Z). A voltage polarity conversion interface can be provided to achieve capacitor voltage reversal through this node when shutting down.

[0028] Specifically, the anode of the thyristor T1 and the cathode of the thyristor T3 are connected.

[0029] Optionally, the anode of thyristor T1 and the cathode of thyristor T3 are connected to a node (assuming it is node P), so as to construct a positive current input channel and achieve state interlocking of T1 and T3 (they will not be turned on at the same time).

[0030] Specifically, the anode of the thyristor T2 and the cathode of the thyristor T4 are connected.

[0031] Optionally, the anode of thyristor T2 and the cathode of thyristor T4 are connected to a node (assuming it is node Q). A reverse current input channel can be constructed to achieve state interlocking of T2 and T4 (they will not be turned on at the same time).

[0032] Optionally, through the above connection method, the bidirectional current path includes forward current and reverse current, the forward current path is P node → T1 → X node → T6 → load → Y node → T4 → Q node, and the reverse current path is Q node → T2 → X node → T6 → load → Y node → T3 → P node.

[0033] Specifically, when the circuit system for cutting off the bidirectional current is in the on state, the thyristor T1 , the thyristor T2 , the thyristor T3 , the thyristor T4 , and the thyristor T6 are in the on state, and the thyristor T5 is in the off state.

[0034] Optionally, the thyristor T5 is in the off state, and measures to maintain the off state may include applying a reverse bias voltage to the driving circuit, maintaining a high impedance state at the node Z, etc. The thyristor T5 is in the off state to prevent accidental resonance caused by false triggering and avoid shunting the main circuit current.

[0035] Optional, such as Figure 2 Shown is another circuit schematic diagram for cutting off bidirectional current, which can also cut off bidirectional current.

[0036] The circuit for cutting off bidirectional current provided in an embodiment of the present application includes: a forced commutation module, which is used to cut off the current through resonant commutation when receiving an instruction; a bidirectional rectifier module, which is connected to the forced commutation module and cooperates with the forced commutation module to realize the cutting off of the bidirectional current; wherein, the forced commutation module includes thyristor T5, thyristor T6, resonant capacitor C1, inductor L1 and diode D1; the bidirectional rectifier module includes thyristor T1, thyristor T2, thyristor T3 and thyristor T4, thereby solving the technical problem of excessively high cost of the circuit for cutting off bidirectional current in the related art, thereby achieving the technical effect of reducing the cost of the circuit for cutting off bidirectional current.

[0037] Example 2 Based on the circuit for cutting off bidirectional current disclosed in Example 1, Example 2 discloses a control method for cutting off bidirectional current. When the circuit for cutting off bidirectional current receives a tripping instruction, the method includes the following steps: The first step is to turn off the drive of thyristor T1, thyristor T2, thyristor T3, thyristor T4 and thyristor T6; The second step is to turn on the driver of thyristor T5.

[0038] Optionally, when an opening command is received, the forward current (current from left to right) operates in the following mode: 1. If Figure 3 As shown, the drive of thyristor T1, thyristor T2, thyristor T3, thyristor T4, and thyristor T6 is turned off, and thyristor T5 still maintains the original cut-off state; since no current flows through thyristor T2 and thyristor T3, after the drive is turned off, thyristor T2 and thyristor T3 are also turned off and are in the cut-off state; since thyristor T1, thyristor T4, and thyristor T6 are all half-controlled thyristors, they cannot cut off the current, and the current still flows through thyristor T1, thyristor T4, and thyristor T6; 2. If Figure 4 As shown, the drive of thyristor T5 is turned on. For example, the typical drive time can be set to 100us. Since the initial voltage of the capacitor is positive at the upper end and negative at the lower end, capacitor C1 and inductor L1 resonate through thyristor T5 (for example, the resonance period of L1 and C1 is designed to be >> 100us) until the polarity of the capacitor voltage changes (lower end is positive, upper end is negative). When the resonant current becomes zero, the capacitor voltage is the highest. At this time, the current in thyristor T5 drops to zero, and thyristor T5 is subjected to reverse voltage, so thyristor T5 is naturally turned off and is in the cut-off state. 3. If Figure 5 As shown, the capacitor C1 continues to discharge to the outside, and the current flowing through the thyristor T6 gradually decreases until it reaches 0, and the thyristor T6 is turned off and is in the cut-off state; 4. If Figure 6As shown, the current flows through the thyristor T1, inductor L1, capacitor C1, diode D1, and thyristor T4. As the capacitor voltage continues to rise, when the capacitor voltage is greater than the system voltage, the load current gradually decreases until it reaches 0; the thyristor T1 and thyristor T4 are naturally turned off and are in the cut-off state; at this point, all thyristors T1, thyristor T2, thyristor T3, thyristor T4, thyristor T5, and thyristor T6 are turned off.

[0039] Reverse current (current from right to left) works as follows: 1. Turn off the drivers of thyristors T1, T2, T3, T4, and T6, while thyristor T5 remains in its original off state. Since no current flows through thyristors T1 and T4, they are also turned off and in the off state after the drivers are turned off. Since thyristors T2, T3, and T6 are all half-controlled thyristors, they cannot shut off the current, and current still flows through thyristors T2, T3, and T6. 2. Turn on the drive of thyristor T5. For example, the typical drive time can be set to 100µs. Since the initial voltage on the capacitor is positive at the top and negative at the bottom, capacitor C1 and inductor L1 resonate through thyristor T5 (for example, design the resonant period of L1 and C1 to be >> 100µs) until the polarity of the capacitor voltage changes (positive at the bottom and negative at the top). When the resonant current reaches zero, the capacitor voltage is at its highest. At this point, the current in thyristor T5 drops to zero, and thyristor T5 is subjected to reverse voltage, causing it to naturally turn off and enter the cutoff state. 3. Capacitor C1 continues to discharge, and the current flowing through thyristor T6 gradually decreases until it reaches 0. Thyristor T6 is turned off and in the cut-off state. 4. Current flows through thyristor T2, inductor L1, capacitor C1, diode D1, and thyristor T3. As the capacitor voltage continues to rise, when it becomes greater than the system voltage, the load current gradually decreases until it reaches zero. Thyristors T2 and T3 naturally turn off and enter the cutoff state. At this point, all slave thyristors T1, T2, T3, T4, T5, and T6 are turned off.

[0040] In one embodiment according to the present application, Figure 7As shown, a control device 700 for interrupting bidirectional current is proposed. The control device 700 includes a processor and a memory 704. The memory 704 stores a program or instruction. When executed by the processor 702, the program or instruction implements the steps of the control method for interrupting bidirectional current in any of the above-mentioned technical solutions. Therefore, the control device 700 for interrupting bidirectional current has all the advantages of the control method for interrupting bidirectional current in any of the above-mentioned technical solutions, and will not be further described here.

[0041] In one embodiment of the present application, a readable storage medium is provided, on which a program is stored. When the program is executed by a processor, the control method of the circuit for cutting off bidirectional current is implemented as in any of the above embodiments, thereby having all the beneficial technical effects of the control method of the circuit for cutting off bidirectional current in any of the above embodiments.

[0042] The readable storage medium includes a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0043] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0044] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A circuit for cutting off bidirectional current, characterized in that: include: A forced commutation module is used to shut down the current by resonant commutation when receiving an instruction; a bidirectional rectifier module, connected to the forced commutation module, and cooperating with the forced commutation module to realize bidirectional current shutoff; Wherein, the forced commutation module includes thyristor T5, thyristor T6, resonant capacitor C1, inductor L1 and diode D1; The bidirectional rectifier module includes a thyristor T1, a thyristor T2, a thyristor T3 and a thyristor T4.

2. The circuit for cutting off bidirectional current according to claim 1, characterized in that: The cathode of the thyristor T1 , the cathode of the thyristor T2 , the anode of the thyristor T5 , the anode of the thyristor T6 , and one end of the inductor L1 are connected.

3. The circuit for cutting off bidirectional current according to claim 1, characterized in that: The anode of the thyristor T3 , the anode of the thyristor T4 , and the cathode of the diode D1 are connected.

4. The circuit for cutting off bidirectional current according to claim 1, characterized in that: The cathode of the thyristor T5, the anode of the diode D1, and one end of the resonant capacitor C1 are connected.

5. The circuit for cutting off bidirectional current according to claim 1, characterized in that: The anode of the thyristor T1 and the cathode of the thyristor T3 are connected.

6. The circuit for cutting off bidirectional current according to claim 1, characterized in that: The anode of the thyristor T2 is connected to the cathode of the thyristor T4.

7. The circuit for cutting off bidirectional current according to claim 1, characterized in that: When the circuit system for cutting off bidirectional current is in the on state, the thyristor T1 , the thyristor T2 , the thyristor T3 , the thyristor T4 , and the thyristor T6 are in the on state, and the thyristor T5 is in the off state.

8. A control method for cutting off a bidirectional current circuit, characterized in that: Applied to the circuit for cutting off bidirectional current as claimed in any one of claims 1 to 7, when the circuit for cutting off bidirectional current receives a tripping instruction, the method comprises the following steps: Turning off the driving of the thyristor T1, the driving of the thyristor T2, the driving of the thyristor T3, the driving of the thyristor T4 and the driving of the thyristor T6; Turn on the driver of the thyristor T5.

9. A control device for cutting off a bidirectional current circuit, characterized in that: include: processor; A memory, wherein a program or instruction is stored in the memory, and when the processor executes the program or instruction in the memory, the processor implements the steps of the control method for cutting off a bidirectional current circuit as claimed in claim 8.

10. A readable storage medium, characterized in that: The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the steps of the control method for cutting off a bidirectional current circuit as claimed in claim 8 are implemented.

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