CN-121566384-B - Power circuit, fault diagnosis method and power electronic equipment

CN121566384BCN 121566384 BCN121566384 BCN 121566384BCN-121566384-B

Abstract

The application provides a power circuit, a fault diagnosis method and power electronic equipment, and relates to the technical field of power electronics. According to the technical scheme provided by the application, the fault type can be analyzed based on the diagnosis data of the diagnosis voltage in the preset time before and after the fault moment of the IGBT, so that the fault type of the power circuit can be rapidly and accurately positioned, and the fault maintenance cost of the power electronic equipment is effectively reduced. In addition, the power circuit provided by the embodiment of the application has a simple structure and no use limitation, and is suitable for different types of power scenes.

Inventors

HONG LEI
ZHANG WEI
XU XIAOBIN

Assignees

杭州飞仕得科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260122

Claims (9)

1. A power circuit comprising a main controller and at least one power cell, the power cell comprising: the IGBT is characterized in that a collector of the IGBT is electrically connected with an anode of a direct current bus, and an emitter of the IGBT is electrically connected with a cathode of the direct current bus; The drive protection board is used for sending a fault signal when detecting that the IGBT breaks down and controlling the IGBT to be turned off; The fault diagnosis device comprises a diode detection circuit, wherein the diode detection circuit comprises a constant current source, a storage capacitor and a diode unit, the diode unit comprises at least one detection diode, the input end of the constant current source is electrically connected with a power supply voltage end, the output end of the constant current source is electrically connected with a first polar plate of the storage capacitor and the positive electrode of the diode unit, a second polar plate of the storage capacitor is electrically connected with a grounding end, the negative electrode of the diode unit is electrically connected with a collector electrode of the IGBT through an electric wire harness, and the fault diagnosis device is used for acquiring diagnosis voltage at the first polar plate of the storage capacitor and storing diagnosis data of the diagnosis voltage in preset time before and after the occurrence of fault of the IGBT when fault signals sent by the driving protection plate are acquired so as to analyze the fault type of the IGBT through the diagnosis data; The fault type comprises one of SC fault, OC fault, wire harness fault and EMC interference fault; When the SC fails, the diagnostic voltage rises from 0V to a power supply voltage value of the power supply voltage end within a time not greater than a first threshold, and the duration of the diagnostic voltage at the power supply voltage value is within a first set duration range; When the OC fails, the diagnostic voltage rises from a set voltage value to a fault voltage value within the first threshold time, the duration that the diagnostic voltage is at the fault voltage value is not less than a second threshold time, the set voltage value is a saturated voltage drop value of the IGBT, the fault voltage value is less than the power supply voltage value, and the upper limit value of the first set duration range is less than the second threshold time; When the wire harness fails, the diagnosis voltage rises from 0V to the power supply voltage value within a third threshold time which is not less than the first threshold time, and the duration of the diagnosis voltage in the power supply voltage value is within the first set duration range; and when the EMC interference faults occur, the diagnosis voltage is in a disordered fluctuation curve within the preset time.
2. The power circuit of claim 1, wherein the fault diagnosis means comprises: The voltage sampling circuit is electrically connected with the first polar plate of the storage capacitor and is used for collecting diagnostic voltage at the first polar plate of the storage capacitor; The processor is electrically connected with the driving protection plate and the voltage sampling circuit, and is used for storing the diagnosis data of the diagnosis voltage in the preset time before and after the IGBT fault occurrence time when the processor is used for acquiring the fault signal sent by the driving protection plate so as to analyze the fault type through the diagnosis data.
3. The power circuit of claim 2, wherein the fault diagnosis means further comprises: the memory is electrically connected with the processor and is used for storing the diagnosis data of the diagnosis voltage in preset time before and after the IGBT breaks down according to the control of the processor.
4. The power circuit of claim 1, wherein the diode detection circuit further comprises: And the first end of the resistor is electrically connected with the first polar plate of the storage capacitor, and the second end of the resistor is electrically connected with the second polar plate of the storage capacitor.
5. The power circuit of claim 1, wherein the drive protection board sends the fault signal when detecting that the IGBT fails based on a Vce voltage of the IGBT.
6. The power circuit of claim 5, wherein the drive protection plate is electrically coupled to the first plate of the storage capacitor, the drive protection plate detecting the failure of the IGBT based on the diagnostic voltage, the diagnostic voltage being the same as a Vce voltage of the IGBT when the diode unit is on.
7. The power circuit of claim 1, wherein the power circuit comprises a single-tube circuit, or a half-bridge circuit, or a full-bridge circuit.
8. A fault diagnosis method, characterized in that the fault diagnosis method is applied to the power circuit of any one of claims 1 to 7, wherein the fault diagnosis method comprises: Acquiring a fault signal sent by the drive protection board; And storing the diagnosis data of the diagnosis voltage in a preset time before and after the fault moment of the IGBT so as to analyze the fault type through the diagnosis data.
9. A power electronic device, characterized in that it comprises a power circuit according to any of claims 1-7.

Description

Power circuit, fault diagnosis method and power electronic equipment Technical Field The present application relates to the field of power electronics, and more particularly, to a power circuit, a fault diagnosis method, and a power electronic device. Background With the development of new energy and electrification, various types of power electronic equipment are more and more widely applied, and compared with traditional power transmission equipment, the power electronic equipment adopts a power circuit at the core. Because the failure rate and the failure rate of the power circuit are high, how to diagnose the failure of the power circuit in the power electronic equipment becomes an urgent problem in the industry. Especially, the high-power high-reliability scenes such as scenes of rail transit, power grid equipment, ship propulsion, high-voltage high-power frequency conversion and the like are realized. Disclosure of Invention In view of the above, the application provides a power circuit, a fault diagnosis method and power electronic equipment, which effectively solve the technical problems existing in the prior art, realize fault detection and type analysis of the power circuit, effectively reduce the fault maintenance cost of the power electronic equipment, and are suitable for different types of power scenes. In order to achieve the above purpose, the technical scheme provided by the application is as follows: A power circuit comprising a main controller and at least one power cell, the power cell comprising: the IGBT is characterized in that a collector of the IGBT is electrically connected with an anode of a direct current bus, and an emitter of the IGBT is electrically connected with a cathode of the direct current bus; The drive protection board is used for sending a fault signal when detecting that the IGBT breaks down and controlling the IGBT to be turned off; the fault diagnosis device comprises a diode detection circuit, wherein the diode detection circuit comprises a constant current source, a storage capacitor and a diode unit, the diode unit comprises at least one detection diode, the input end of the constant current source is electrically connected with a power supply voltage end, the output end of the constant current source is electrically connected with a first polar plate of the storage capacitor and the positive electrode of the diode unit, a second polar plate of the storage capacitor is electrically connected with a grounding end, the negative electrode of the diode unit is electrically connected with a collector electrode of the IGBT through an electric wire harness, and the fault diagnosis device is used for acquiring diagnosis voltage at the first polar plate of the storage capacitor and storing diagnosis data of the diagnosis voltage in preset time before and after the occurrence of fault of the IGBT when fault signals sent by the driving protection plate are acquired so as to analyze fault types through the diagnosis data. Optionally, the fault types include SC fault, OC fault, harness fault and EMC interference fault; When the SC fails, the diagnostic voltage rises from 0V to a power supply voltage value of the power supply voltage end within a time not greater than a first threshold, and the duration of the diagnostic voltage at the power supply voltage value is within a first set duration range; When the OC fails, the diagnostic voltage rises from a set voltage value to a fault voltage value within the first threshold time, the duration that the diagnostic voltage is at the fault voltage value is not less than a second threshold time, the set voltage value is a saturated voltage drop value of the IGBT, the fault voltage value is less than the power supply voltage value, and the upper limit value of the first set duration range is less than the second threshold time; When the wire harness fails, the diagnosis voltage rises from 0V to the power supply voltage value within a third threshold time which is not less than the first threshold time, and the duration of the diagnosis voltage in the power supply voltage value is within the first set duration range; and when the EMC interference faults occur, the diagnosis voltage is in a disordered fluctuation curve within the preset time. Optionally, the fault diagnosis device includes: The voltage sampling circuit is electrically connected with the first polar plate of the storage capacitor and is used for collecting diagnostic voltage at the first polar plate of the storage capacitor; The processor is electrically connected with the driving protection plate and the voltage sampling circuit, and is used for storing the diagnosis data of the diagnosis voltage in the preset time before and after the IGBT fault occurrence time when the processor is used for acquiring the fault signal sent by the driving protection plate so as to analyze the fault type through the diagnosis data. Optionally, the fault diagnosis apparatus further inclu