Magnetic flux converter module with self-checking function and circuit breaker

Abstract

The utility model discloses a magnetic flux converter module with a self-checking function. The magnetic flux converter module comprises a magnetic flux converter and a magnetic flux driving circuit which are connected in series between a working power supply and the ground, the magnetic flux driving circuit comprises a switching tube, and current on-off control of the magnetic flux converter can be realized by controlling on-off of the switching tube; the magnetic flux converter module further comprises a sampling resistor R1 connected between the magnetic flux converter and the magnetic flux driving circuit in series, a voltage detection circuit used for detecting voltages at the two ends of the sampling resistor R1, and a level inversion circuit with the input end connected to a common end point of the sampling resistor R1 and the magnetic flux driving circuit. The utility model also discloses a circuit breaker. According to the utility model, accurate detection of a driving loop fault of the magnetic flux converter, a disconnection fault of the magnetic flux converter and an unreliable connection fault of the magnetic flux converter and the controller can be realized.

Description

Technical Field

[0001] This utility model relates to a flux converter module, and more particularly to a flux converter module with a self-test function. Background Technology

[0002] Circuit breakers are one of the main components in low-voltage power distribution systems, playing a crucial role in the safe and reliable operation of these systems. Intelligent controllers are the central components of circuit breakers, undertaking various protection, alarm, display, and control functions, and are widely used in low-voltage circuit breakers. The flux converter, as the tripping actuation component of the intelligent controller, is a small energy storage tripping device. Under normal circumstances, it relies on a permanent magnet to attract the iron core, keeping it in a closed state. When the controller issues a tripping command, current flows through the coil, generating reverse excitation that overcomes the original magnetic flux of the permanent magnet coil. The return spring releases the moving iron core, and then overcomes the friction of the connecting transmission parts and the tripping force of the operating structure, thereby actuating the circuit breaker. Therefore, the reliability of the flux converter and its drive circuit has a decisive impact on the overall performance of the circuit breaker.

[0003] In existing technologies, due to the long service life and complex environments of circuit breakers, flux converters need to have good reliability to ensure reliable tripping of the circuit breaker in the event of a fault. When the flux converter coil is disconnected or the connection with the intelligent controller is unreliable, the intelligent controller detects the fault signal and sends a tripping pulse. The flux converter will then be unable to push the circuit breaker to trip, failing to protect the power distribution circuit. As a passive device, the reliability of the flux converter mainly depends on its design and manufacturing process. Currently, most circuit breakers do not have the function of detecting whether the flux converter itself is faulty, and the few circuit breakers with flux converter detection function can only detect the open circuit state of the flux converter, not the state of the flux converter drive circuit. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the existing technology in that it cannot detect the status of the flux converter drive circuit, and to provide a flux converter module with self-test function, which can accurately detect the faults of the flux converter drive circuit, the flux converter disconnection faults, and the unreliable connection faults between the flux converter and the controller.

[0005] The present invention specifically adopts the following technical solution to solve the above-mentioned technical problems:

[0006] A flux converter module with self-test function includes a flux converter connected in series between the power supply and ground, and a flux drive circuit. The flux drive circuit includes a switching transistor, and the current switching of the flux converter can be controlled by controlling the switching transistor. The flux converter module also includes: a sampling resistor R1 connected in series between the flux converter and the flux drive circuit, a voltage detection circuit for detecting the voltage across the sampling resistor R1, and a level inversion circuit whose input terminal is connected to the common terminal of the sampling resistor R1 and the flux drive circuit.

[0007] In one embodiment, the voltage detection circuit includes resistors R2 to R5 and operational amplifier N1; one end of resistor R2 is connected to the common terminal of the flux converter and resistor R1, the other end of resistor R2 is connected to one end of resistor R4 and the inverting input terminal of operational amplifier N1, one end of resistor R3 is connected to the common terminal of the sampling resistor R1 and the flux drive circuit, the other end of resistor R3 is connected to one end of resistor R5 and the non-inverting input terminal of operational amplifier N1, the other end of resistor R4 is connected to the output terminal of operational amplifier N1, and the other end of resistor R5 is grounded.

[0008] In one embodiment, the flux driving circuit includes a switch V1 and resistors R6 and R7. The input terminal of the switch V1 is connected to one end of the sampling resistor R1, and the output terminal of the switch V1 is connected to one end of the resistor R6 and then grounded. The control terminal of the switch V1 is connected to one end of the resistor R7 and the other end of the resistor R6. The other end of the resistor R7 is the control terminal of the flux driving circuit.

[0009] In one embodiment, the level inversion circuit includes a transistor V2 and resistors R8 to R10. One end of resistor R8 serves as the input terminal of the level inversion circuit and is connected to the common terminal of the sampling resistor R1 and the magnetic flux drive circuit. The other end of resistor R8 is connected to the base of transistor V2 and one end of resistor R9. The other end of resistor R9 is connected to the emitter of transistor V2 and then grounded. The base of transistor V2 is connected to one end of resistor R10 and serves as the output terminal of the level inversion circuit. The other end of resistor R10 is connected to the operating power supply.

[0010] A circuit breaker includes a controller and a flux converter module. The flux converter module is a flux converter module with self-testing function as described in any of the above technical solutions. The output terminal of the voltage detection circuit is connected to an AD sampling port of the controller. The control terminal of the flux drive circuit is connected to an output I / O port of the controller. The output terminal of the level inversion circuit is connected to an input I / O port of the controller. The controller can detect short circuit and open circuit faults of the switching transistor, as well as open circuit faults of the flux converter and unreliable connection faults between the flux converter and the controller, based on different combinations of the output level of the level inversion circuit and the control level of the flux drive circuit, and the voltage across the sampling resistor detected by the voltage detection circuit.

[0011] Compared with the prior art, the technical solution of this utility model has the following beneficial effects:

[0012] This invention connects a sampling resistor in series between the flux converter and the flux drive circuit, and configures a corresponding voltage detection circuit and level inversion circuit. By detecting the voltage across the sampling resistor and the level between the sampling resistor and the flux drive circuit, and combining this with the input level of the flux drive circuit, accurate detection of faults in the flux converter drive circuit, flux converter open circuit faults, and unreliable connection faults between the flux converter and the controller can be achieved, significantly improving the safety and reliability of the circuit breaker. This invention can be implemented using various existing functional circuit combinations, and has the advantages of simple circuit and low implementation cost, thus possessing high practical value. Attached Figure Description

[0013] Figure 1 This is a circuit diagram of a specific embodiment of the flux converter module with self-testing function of this utility model;

[0014] Figure 2 This is a schematic diagram of the process by which the circuit breaker controller performs a self-test on the flux converter module. Detailed Implementation

[0015] To address the shortcomings of existing technologies in detecting the status of flux converter drive circuits, this invention proposes connecting a sampling resistor in series between the flux converter and the flux drive circuit, along with a corresponding voltage detection circuit and level inversion circuit. By detecting the voltage across the sampling resistor and the level between the sampling resistor and the flux drive circuit, and combining this with the input level of the flux drive circuit, accurate detection of faults in the flux converter drive circuit, as well as faults such as flux converter open circuit failures and unreliable connections between the flux converter and the controller, can be achieved, significantly improving the safety and reliability of the circuit breaker.

[0016] The present invention specifically adopts the following technical solution to solve the above-mentioned technical problems:

[0017] A flux converter module with self-test function includes a flux converter connected in series between the power supply and ground, and a flux drive circuit. The flux drive circuit includes a switching transistor, and the current switching of the flux converter can be controlled by controlling the switching transistor. The flux converter module also includes: a sampling resistor R1 connected in series between the flux converter and the flux drive circuit, a voltage detection circuit for detecting the voltage across the sampling resistor R1, and a level inversion circuit whose input terminal is connected to the common terminal of the sampling resistor R1 and the flux drive circuit.

[0018] When the above-mentioned flux converter module experiences a drive circuit fault, a flux converter disconnection fault, or an unreliable connection between the flux converter and the controller, the input level of the flux drive circuit, the voltage across the sampling resistor, and the level between the sampling resistor and the flux drive circuit will exhibit different combinations. By combining the detection signal of the voltage detection circuit and the output level of the level inversion circuit with the input level of the flux drive circuit, the above-mentioned faults can be accurately identified and detected.

[0019] The flux drive circuit, voltage detection circuit, and level reversal circuit in the above technical solution can all adopt various existing specific circuit structures, and can be flexibly configured according to the actual situation.

[0020] To facilitate public understanding, the technical solution of this utility model will be described in detail below through a specific embodiment and in conjunction with the accompanying drawings:

[0021] The circuit structure of the flux converter module with self-test function in this embodiment is as follows: Figure 1 As shown, the circuit includes: a flux converter circuit, a sampling resistor R1, a voltage detection circuit, a flux drive circuit, and a level conversion circuit. The positive terminal of the flux converter is connected to the operating power supply VCC1, and the negative terminal of the flux converter is connected to one end of the sampling resistor R1. The other end of the sampling resistor R1 is connected to the flux drive circuit. The flux drive circuit includes a switching transistor. The control terminal of the flux drive circuit is connected to an output I / O port of the circuit breaker controller. The circuit breaker controller can control the current flow of the flux converter by controlling the switching transistor. The two input terminals of the voltage detection circuit are respectively connected to the two ends of the sampling resistor R1. The output terminal of the voltage detection circuit is connected to an AD sampling port of the circuit breaker controller for detecting the voltage across the sampling resistor R1. The input terminal of the level inversion circuit is connected to the common terminal of the sampling resistor R1 and the flux drive circuit. The output terminal of the level inversion circuit is connected to an input I / O port of the circuit breaker controller. The level inversion circuit can convert the high / low level of the common terminal of the sampling resistor R1 and the flux drive circuit to a low / high level.

[0022] like Figure 1As shown, the voltage detection circuit in this embodiment includes resistors R2 to R5 and operational amplifier N1. One end of resistor R2 is connected to the common terminal of the flux converter and resistor R1, and the other end of resistor R2 is connected to one end of resistor R4 and the inverting input terminal of operational amplifier N1. One end of resistor R3 is connected to the common terminal of the sampling resistor R1 and the flux drive circuit, and the other end of resistor R3 is connected to one end of resistor R5 and the non-inverting input terminal of operational amplifier N1. The other end of resistor R4 is connected to the output terminal of operational amplifier N1 and an AD sampling port of the circuit breaker controller, and the other end of resistor R5 is grounded.

[0023] like Figure 1 As shown, the flux drive circuit in this embodiment includes a MOS transistor V1 and resistors R6 and R7. The drain of the MOS transistor V1 is connected to one end of the sampling resistor R1. The source of the MOS transistor V1 is connected to one end of the resistor R6 and then grounded. The gate of the MOS transistor V1 is connected to one end of the resistor R7 and the other end of the resistor R6. The other end of the resistor R7 is connected to an output IO port of the circuit breaker controller.

[0024] like Figure 1 As shown, the level inversion circuit in this embodiment includes a transistor V2 and resistors R8 to R10. One end of resistor R8 serves as the input terminal of the level inversion circuit and is connected to the common terminal of the sampling resistor R1 and the magnetic flux drive circuit. The other end of resistor R8 is connected to the base of transistor V2 and one end of resistor R9. The other end of resistor R9 is connected to the emitter of transistor V2 and then grounded. The base of transistor V2 is connected to one end of resistor R10 and serves as the output terminal of the level inversion circuit, which is connected to an input IO port of the circuit breaker controller. The other end of resistor R10 is connected to the operating power supply VCC2.

[0025] When the circuit breaker detects a fault in the protected circuit, the controller issues a trip command and outputs a high-level trip pulse to the flux drive circuit through the output IO port, driving the flux converter to operate.

[0026] When the controller does not issue a trip command, by detecting the AD sampling interface and the input I / O port signals, combined with the output I / O port signals, it can be determined whether the flux converter is disconnected or unreliable in its connection with the intelligent controller, or whether the MOSFET V1 is faulty (drain-source short circuit, drain-source open circuit). This enables the flux converter module to perform a self-test, the self-test process of which is as follows: Figure 2 As shown, the specific fault diagnosis method is as follows:

[0027] 1. When the output IO port outputs a low level, and the input IO port signal is high, and the voltage value corresponding to the signal acquired by the AD sampling port is less than the preset threshold, it is determined that the flux converter is disconnected or the connection with the intelligent controller is unreliable.

[0028] 2. When the output IO port outputs a low level, and the input IO port signal is high, and the voltage value corresponding to the signal acquired by the AD sampling port is greater than or equal to the preset threshold, it is determined that the MOS transistor V1 is faulty (short circuit between drain and source).

[0029] 3. Output a high-level self-test pulse from the output IO port (the width of the self-test pulse should be less than the minimum pulse width of the trip pulse to avoid malfunction of tripping). When the input IO port signal is low and the voltage value corresponding to the signal acquired by the AD sampling port is less than the preset threshold, it is determined that the MOS transistor V1 is faulty (open circuit between drain and source).

[0030] The above threshold can be obtained through experimentation or calculation. Specifically, when the drain and source of MOSFET V1 are short-circuited, the voltage value collected by the controller's AD sampling port is... Where UCC1 is the voltage of power supply VCC1, and R0 is the internal resistance of the coil in the flux converter. The threshold can be set according to U1. To prevent the influence of voltage fluctuations, the threshold can be set to 0.8 to 0.9 times U1.

Claims

1. A flux converter module with self-test function, comprising a flux converter connected in series between the power supply and ground, and a flux driving circuit, wherein the flux driving circuit includes a switching transistor, and the current on / off control of the flux converter can be realized by controlling the switching transistor; characterized in that, The flux converter module further includes: a sampling resistor R1 connected in series between the flux converter and the flux drive circuit; a voltage detection circuit for detecting the voltage across the sampling resistor R1; and a level inversion circuit whose input terminal is connected to the common terminal of the sampling resistor R1 and the flux drive circuit.

2. The flux converter module with self-test function as described in claim 1, characterized in that, The voltage detection circuit includes resistors R2 to R5 and operational amplifier N1. One end of resistor R2 is connected to the common terminal of the flux converter and resistor R1, and the other end of resistor R2 is connected to one end of resistor R4 and the inverting input terminal of operational amplifier N1. One end of resistor R3 is connected to the common terminal of the sampling resistor R1 and the flux drive circuit, and the other end of resistor R3 is connected to one end of resistor R5 and the non-inverting input terminal of operational amplifier N1. The other end of resistor R4 is connected to the output terminal of operational amplifier N1, and the other end of resistor R5 is grounded.

3. The flux converter module with self-test function as described in claim 1, characterized in that, The flux drive circuit includes a switch V1 and resistors R6 and R7. The input terminal of the switch V1 is connected to one end of the sampling resistor R1, and the output terminal of the switch V1 is connected to one end of the resistor R6 and then grounded. The control terminal of the switch V1 is connected to one end of the resistor R7 and the other end of the resistor R6. The other end of the resistor R7 is the control terminal of the flux drive circuit.

4. The flux converter module with self-test function as described in claim 1, characterized in that, The level inversion circuit includes a transistor V2 and resistors R8 to R10. One end of resistor R8 serves as the input terminal of the level inversion circuit and is connected to the common terminal of the sampling resistor R1 and the magnetic flux drive circuit. The other end of resistor R8 is connected to the base of transistor V2 and one end of resistor R9. The other end of resistor R9 is connected to the emitter of transistor V2 and then grounded. The base of transistor V2 is connected to one end of resistor R10 and serves as the output terminal of the level inversion circuit. The other end of resistor R10 is connected to the operating power supply.

5. A circuit breaker, comprising a controller and a flux converter module, characterized in that, The flux converter module is a flux converter module with self-test function as described in any one of claims 1 to 4. The output terminal of the voltage detection circuit is connected to an AD sampling port of the controller, the control terminal of the flux drive circuit is connected to an output I / O port of the controller, and the output terminal of the level inversion circuit is connected to an input I / O port of the controller. The controller can detect short circuit and open circuit faults of the switching transistor, as well as open circuit faults of the flux converter and unreliable connection faults between the flux converter and the controller, based on different combinations of the output level of the level inversion circuit and the control level of the flux drive circuit and the voltage across the sampling resistor detected by the voltage detection circuit.

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