A redundant trigger circuit powered by a single power supply

Abstract

A redundant trigger circuit powered by a single power supply includes a first trigger circuit of a bypass switch and a second trigger circuit of a bypass switch; the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch are powered by the same power supply; and also includes a bypass switch trigger coil; the upper end of the bypass switch trigger coil is connected to the positive end of the power supply; the lower end of the bypass switch trigger coil is respectively connected to the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch. When a single power unit fails, it is necessary to reliably bypass the redundant trigger circuit powered by a single power supply. On the basis of the above-mentioned traditional design, another set of trigger circuits is added, and a diode for anti-backflow is configured to realize the redundant trigger function. When any one of the charging resistors, energy storage capacitors, thyristors, etc. in the redundant trigger circuit fails, the other set of trigger circuits can still continue to execute the bypass command and trigger the bypass switch to close to ensure reliable operation of the equipment.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a redundant trigger circuit powered by a single power supply. Background Art

[0002] The main circuit structures of the bridge arm of the MMC flexible DC transmission converter valve, the inverter unit of the cascaded reactive power compensation device, the cascaded active filter device, the inverter unit of the cascaded high-voltage frequency conversion device, and the chopper unit of the cascaded DC power supply device are all composed of many power units in series. When a single power unit fails, a reliable bypass is required to ensure the continued operation of the equipment. Since the equipment is generally equipped with only a single power supply, the current traditional practice is to only configure a set of charging resistors, a capacitor, and a thyristor in series with the trigger coil of the bypass switch. When the thyristor is triggered to turn on, the capacitor discharges to the trigger coil of the bypass switch, triggering the bypass switch to close. However, when the charging resistor, capacitor or thyristor fails, it may cause the bypass switch to refuse to operate, which will cause the entire equipment to trip and stop operating, and the reliability needs to be improved. Summary of the invention

[0003] In order to solve the technical problems in the background technology, the present invention provides a redundant trigger circuit powered by a single power supply. When a single power unit fails, it is necessary to reliably bypass the redundant trigger circuit powered by the single power supply. On the basis of the above-mentioned traditional design, another set of trigger circuits is added, and a diode for anti-backflow is configured to realize the function of redundant triggering. When any one of the charging resistors, energy storage capacitors, thyristors, etc. in the redundant trigger circuit fails, the other set of trigger circuits can still continue to execute the bypass command and trigger the bypass switch to close to ensure the reliable operation of the equipment.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A redundant trigger circuit powered by a single power supply, the trigger circuit comprising a first trigger circuit of a bypass switch and a second trigger circuit of a bypass switch; the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch are powered by the same power supply; the trigger circuit also comprises a bypass switch trigger coil; the upper end of the bypass switch trigger coil is connected to the positive end of the power supply; the lower end of the bypass switch trigger coil is respectively connected to the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch.

[0006] Furthermore, the circuit structures of the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch are the same;

[0007] The first trigger circuit of the bypass switch includes a first charging resistor, a first energy storage capacitor, a first blocking diode, and a first thyristor; the upper end of the first energy storage capacitor is connected to the positive end of the power supply; the lower end of the first energy storage capacitor is connected to the upper end of the first charging resistor and to the lower end of the first thyristor; the lower end of the first charging resistor is connected to the negative end of the power supply; the upper end of the first thyristor is connected to the cathode of the first blocking diode; the anode of the first blocking diode is connected to the lower end of the bypass switch trigger coil;

[0008] The second trigger circuit of the bypass switch includes a second charging resistor, a second energy storage capacitor, a second blocking diode, and a second thyristor; the upper end of the second energy storage capacitor is connected to the positive end of the power supply; the lower end of the second energy storage capacitor is connected to the upper end of the second charging resistor and to the lower end of the second thyristor; the lower end of the second charging resistor is connected to the negative end of the power supply; the upper end of the second thyristor is connected to the cathode of the second blocking diode; and the anode of the second blocking diode is connected to the lower end of the bypass switch trigger coil.

[0009] Furthermore, the control end of the first thyristor is connected to a first thyristor trigger circuit, and the control end of the second thyristor is connected to a second thyristor trigger circuit.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1) The present invention proposes a redundant trigger circuit powered by a single power supply, which is used for bypass triggering of the bridge arm of the MMC flexible DC transmission converter valve and the power unit of the inverter unit of the cascaded reactive power compensation device, the cascaded active filter device, the cascaded high-voltage frequency conversion device and the chopper unit of the cascaded DC power supply device. The trigger circuit is only powered by a single power supply and has strong adaptability.

[0012] 2) The present invention proposes a redundant trigger circuit powered by a single power supply. When a single power unit fails, it is necessary to reliably bypass the redundant trigger circuit powered by a single power supply. On the basis of the traditional design, another set of trigger circuits is added, and a diode for anti-backflow is configured to realize the redundant trigger function. When any one of the charging resistors, energy storage capacitors, thyristors, etc. in the redundant trigger circuit fails, the other set of trigger circuits can still continue to execute the bypass command and trigger the bypass switch to close to ensure the reliable operation of the equipment.

[0013] 3) The present invention proposes a redundant trigger circuit powered by a single power supply, which uses a blocking diode. When a charging resistor, energy storage capacitor, thyristor, or thyristor trigger circuit in one group of bypass switch trigger circuits fails, it does not affect the bypass action of another group of bypass switch trigger circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a topological block diagram of a redundant trigger circuit powered by a single power supply of the present invention;

[0015] Figure 2 It is a circuit diagram of a redundant trigger circuit powered by a single power supply of the present invention.

[0016] In the figure: 1-first energy storage capacitor 2-second energy storage capacitor 3-first charging resistor 4-second charging resistor 5-bypass switch trigger coil 6-first blocking diode 7-second blocking diode 8-first thyristor 9-second thyristor 10-first thyristor trigger circuit 11-second thyristor trigger circuit. DETAILED DESCRIPTION

[0017] The specific implementation modes provided by the present invention are described in detail below with reference to the accompanying drawings.

[0018] like Figure 1 As shown, a redundant trigger circuit powered by a single power supply, the trigger circuit includes a first trigger circuit of a bypass switch and a second trigger circuit of a bypass switch; the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch are powered by the same power supply; the trigger circuit also includes a bypass switch trigger coil 5; the upper end of the bypass switch trigger coil 5 is connected to the positive end of the power supply; the lower end of the bypass switch trigger coil 5 is respectively connected to the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch.

[0019] like Figure 2 As shown, the bypass switch first trigger circuit and the bypass switch second trigger circuit have the same structure.

[0020] The first trigger circuit of the bypass switch includes a first charging resistor 3, a first energy storage capacitor 1, a first blocking diode 6, and a first thyristor 8; the upper end of the first energy storage capacitor 1 is connected to the positive end of the power supply; the lower end of the first energy storage capacitor 1 is connected to the upper end of the first charging resistor 3 and to the lower end of the first thyristor 8; the lower end of the first charging resistor 3 is connected to the negative end of the power supply; the upper end of the first thyristor 8 is connected to the cathode of the first blocking diode 6; the anode of the first blocking diode 6 is connected to the lower end of the bypass switch trigger coil 5.

[0021] The second trigger circuit of the bypass switch includes a second charging resistor 4, a second energy storage capacitor 2, a second blocking diode 7, and a second thyristor 9; the upper end of the second energy storage capacitor 2 is connected to the positive end of the power supply; the lower end of the second energy storage capacitor 2 is connected to the upper end of the second charging resistor 4 and to the lower end of the second thyristor 9; the lower end of the second charging resistor 4 is connected to the negative end of the power supply; the upper end of the second thyristor 9 is connected to the cathode of the second blocking diode 7; the anode of the second blocking diode 7 is connected to the lower end of the bypass switch trigger coil 5.

[0022] The control end of the first thyristor 8 is connected to the first thyristor trigger circuit 10, and the control end of the second thyristor 9 is connected to the second thyristor trigger circuit 11. The first thyristor trigger circuit 10 and the second thyristor trigger circuit 11 can both adopt thyristor trigger circuits conventionally used in the art.

[0023] The working principle of the present invention is: the power supply charges the first energy storage capacitor 1 through the first charging resistor 3, and when the first thyristor 8 functions normally, the first energy storage capacitor 1 will gradually charge to a voltage close to the power supply; the power supply charges the second energy storage capacitor 2 through the second charging resistor 4, and when the second thyristor 9 functions normally, the second energy storage capacitor 2 will gradually charge to a voltage close to the power supply. The circuit principle is as follows:

[0024] 1. When all components in the circuit work normally, the working process is as follows:

[0025] (1) Before the redundant trigger circuit powered by a single power supply is started, the voltage of the first energy storage capacitor 1 and the second energy storage capacitor 2 is 0V, the first thyristor trigger circuit 10 and the second thyristor trigger circuit 11 have no trigger signal, and the first thyristor 8 and the second thyristor 9 are in the cut-off state;

[0026] (2) After the power supply is powered on, the power supply charges the first energy storage capacitor 1 through the first charging resistor 3, and the power supply charges the second energy storage capacitor 2 through the second charging resistor 4;

[0027] (3) Since the first thyristor 8 and the second thyristor 9 are both in the cut-off state and no current flows, the voltage of the first energy storage capacitor 1 and the second energy storage capacitor 2 is continuously charged to a voltage close to the power supply voltage.

[0028] (4) When the first thyristor trigger circuit 10 or the second thyristor trigger circuit 11 receives a trigger signal, the first thyristor 8 or the second thyristor 9 is triggered to turn on, so that the first energy storage capacitor 1 or the second energy storage capacitor 2 discharges to the bypass switch trigger coil 5, triggering the bypass switch to close.

[0029] 2. When an abnormality occurs in individual components of the circuit, taking the short circuit fault of the second thyristor 9 as an example, the working process is as follows:

[0030] (1) Before the redundant trigger circuit powered by a single power supply is started, the voltage of the first energy storage capacitor 1 and the second energy storage capacitor 2 is 0V, the first thyristor trigger circuit 10 and the second thyristor trigger circuit 11 have no trigger signal, the first thyristor 8 is in the off state, and the second thyristor 9 is in the short-circuit state;

[0031] (2) After the power supply is powered on, the power supply charges the first energy storage capacitor 1 through the first charging resistor 3;

[0032] (3) Since the second thyristor 9 is in a short-circuit state, after the power supply is powered on, the power supply flows through the bypass switch trigger coil 5, the second blocking diode 7, the second thyristor 9, and the second charging resistor 4, so that the second energy storage capacitor 2 cannot be charged.

[0033] (4) Since the first thyristors 8 are all in the cut-off state and no current flows, the voltage of the first energy storage capacitor 1 is continuously charged to a voltage close to the power supply voltage.

[0034] (5) When the first thyristor trigger circuit 10 receives the trigger signal, the first thyristor 8 is triggered to turn on, so that the first energy storage capacitor 1 discharges to the bypass switch trigger coil 5. Since the second blocking diode 7 has the function of reverse blocking current, the discharge current of the first energy storage capacitor 1 completely flows through the bypass switch trigger coil 5, realizing the redundant triggering function and triggering the bypass switch to close.

[0035] Those skilled in the art should understand that what is shown above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred examples, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

[0036] The above is a detailed introduction to a redundant trigger circuit powered by a single power supply provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A redundant trigger circuit powered by a single power supply, characterized in that: The trigger circuit includes a first trigger circuit of the bypass switch and a second trigger circuit of the bypass switch; the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch are powered by the same power supply; the trigger circuit also includes a bypass switch trigger coil; the upper end of the bypass switch trigger coil is connected to the positive end of the power supply; the lower end of the bypass switch trigger coil is respectively connected to the first trigger circuit of the bypass switch and the second trigger circuit of the bypass switch; The bypass switch first trigger circuit and the bypass switch second trigger circuit have the same structure; The first trigger circuit of the bypass switch includes a first charging resistor, a first energy storage capacitor, a first blocking diode, and a first thyristor; the upper end of the first energy storage capacitor is connected to the positive end of the power supply; the lower end of the first energy storage capacitor is connected to the upper end of the first charging resistor and to the lower end of the first thyristor; the lower end of the first charging resistor is connected to the negative end of the power supply; the upper end of the first thyristor is connected to the cathode of the first blocking diode; the anode of the first blocking diode is connected to the lower end of the bypass switch trigger coil; The second trigger circuit of the bypass switch includes a second charging resistor, a second energy storage capacitor, a second blocking diode, and a second thyristor; the upper end of the second energy storage capacitor is connected to the positive end of the power supply; the lower end of the second energy storage capacitor is connected to the upper end of the second charging resistor and to the lower end of the second thyristor; the lower end of the second charging resistor is connected to the negative end of the power supply; the upper end of the second thyristor is connected to the cathode of the second blocking diode; and the anode of the second blocking diode is connected to the lower end of the bypass switch trigger coil.

2. A single-power-supply redundant trigger circuit according to claim 1, characterized in that: The control end of the first thyristor is connected to the first thyristor trigger circuit, and the control end of the second thyristor is connected to the second thyristor trigger circuit.

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