METHOD FOR DETECTING OPEN-CIRCUIT FAULT OF BRIDGE ARM OF THREE-PHASE VOLTAGE-SOURCE INVERTER IN REAL TIME

摘要

Provided is a method for detecting an open-circuit fault of a bridge arm of a three-phase voltage-source inverter in real time. The method comprises the following steps: S1, collecting current data of three phases, i.e. a, b and c, at the current moment; S2, updating current vectors of the three phases according to the obtained current data of the three phases, i.e. a, b and c, at the current moment; S3, according to the obtained current vectors of the three phases, constructing a Gram matrix between current vectors of every two phases; S4, calculating the determinant of each Gram matrix and the modulus of each current vector, and calculating an independence coefficient between the currents of every two phases according to the obtained determinant of each Gram matrix and the obtained modulus of each current vector; and S5, obtaining a fault detection result of a bridge arm of each phase by means of comparing the independence coefficient between the currents of every two phases with a threshold th. According to the method for detecting the open-circuit fault of the bridge arm of the three-phase voltage-source inverter in real time, data processing processes such as filtering and noise reduction do not need to be performed on current signals, the amount of calculation is relatively small, the real-time performance is good, and the method has a better robustness and is beneficial for rapid positioning of a faulty bridge arm, thereby providing a basis for rapid maintenance or fault-tolerant control of an inverter.