一种电机绝缘在线监测方法及装置，应用于逆变器驱动的电机系统中，该监测方法包括：测量电机三相入线端各相对地电压；获得电机三相入线端各相漏电流；由所述相对地电压及漏电流获得电压共模分量、电压差模分量、电流共模分量及电流差模分量；根据上述分量获得主绝缘等效电容和相间绝缘等效电容。通过得到的主绝缘等效电容和相间绝缘等效电容；将主绝缘监测结果和相间绝缘监测结果进行区分，实现了两种绝缘的分别监测，提高了定子绝缘在线监测结果的精确性和监测的可靠性。

A method and apparatus for online monitoring of motor insulation, applied to an inverter-driven motor system, the monitoring method comprising: measuring each phase of the three-phase incoming voltage of the motor; obtaining each phase leakage current of the three-phase incoming current of the motor; obtaining the voltage common-mode component, the voltage differential-mode component, the current common-mode component and the current differential-mode component from said relative ground voltage and leakage current; obtaining the main insulation equivalent capacitance and the phase-to-phase insulation equivalent capacitance from said components The main insulation equivalent capacitance and the phase to phase equivalent capacitance are obtained from these components. The main insulation equivalent capacitance and phase insulation equivalent capacitance are used to differentiate the main insulation monitoring results from the phase insulation monitoring results, thus enabling separate monitoring of the two types of insulation and improving the accuracy and reliability of the online stator insulation monitoring results.