基于电机电流检测的高压隔离开关机械故障诊断

Mechanical Fault Diagnosis of High Voltage Disconnector Based on Motor Current Detection

为了实现高压隔离开关机械故障诊断,基于霍尔效应和电阻应变测量技术实时检测了GW6H—252型隔离开关分合闸动作过程中的电机定子电流和操作轴扭转应变,推导并验证了电机电流与操动机构输出力矩的函数关系,分析了隔离开关传动机构卡涩、平衡弹簧失效、合闸不到位等机械故障情况下的电机电流信号特征,提出了基于电机电流检测的隔离开关卡涩故障诊断流程。研究结果表明:电机定子电流与操作力矩存在二次函数关系,当隔离开关发生机械故障时,驱动电机电流波形发生畸变,电流峰值增大,峰值出现时刻偏移,电流频谱中的边频成分增大。该方法具有广泛适用性,可有效检测高压隔离开关的机械故障,从而提高设备运行的可靠性。

In order to diagnose the mechanical fault of high voltage disconnectors, taking GW6H-252 type disconnector as an example, the stator current of the drive motor and torsional strain of the operating shaft in switch-on and off process were measured in real time, respectively based on Hall effects and the resistance strain measuring technique. The functional relationship between the motor current and the output torque of operating mechanism was derived and verified. The motor current signals in mechanical fault condition of the disconnector were analyzed, including the case of jammed transmission mechanism, balance spring failure and incompletely switch-on. The clamping stagnation diagnosis process was proposed. The results indicate that there is a quadratic function relationship between the motor stator current and the operating torque. The stator current waveform of the drive motor may distort when mechanical faults occur on the disconnector, the peak value will increase, and the peak time will shift, while there is more component of side frequency in the spectrum. This method is of general applicability and can effectively detect mechanical faults of disconnectors, so as to improve operational reliability of power equipment.