基于混合逻辑动态模型的逆变器开路故障诊断

摘要

The hybrid system model of the inverter and motor was built based on mixed logic dynamic modeling method , with IGBT switching signal being defined as discrete control variable and the diode conducting state as discrete conditional variable . Residual was defined as the difference between estimated value and measured val‐ue of three‐phase current . When IGBT suffers open circuit fault , the three‐phase current residual will be monotonically increasing or decreasing .Based on the current variation rule , the current residual table was cre‐ated to locate the fault and the threshold was set to restrain the impact of noise and measurement error . At last , the validity and effectiveness of diagnostic method were verified through MATLAB/Simulink simulation and dSPACE hardware‐in‐the‐loop platform with only 1/8 fundamental period required for diagnosis time .%依据混合逻辑动态建模方法，将逆变器IGBT开关信号定义为离散控制变量，二极管导通与否定义为离散条件变量，建立逆变器‐电机混杂系统模型。定义残差为三相电流估计值与实测值的差值，发生IGBT开路故障后，三相残差电流单调上升或下降，根据电流变化规律建立残差信息表定位故障，通过设定阈值抑制噪声、测量误差等影响。通过MATLAB／Simulink仿真和dSPACE半实物平台验证了诊断方法的正确性和有效性，诊断时间仅需1／8个基波周期。