While the pulse width modulation (PWM) variable frequency drive improved the efficiency of the AC drive system, higher harmonics were generated, which caused a significant increase in the common mode current. The coupling capacitance between the stator winding and the stator core of the motor was the main path of the common mode current. Accurate calculation of the coupling capacitance between the stator winding and the stator core was important to predict common mode current. Since the internal windings of the motor were irregularly arranged, it was difficult to accurately perform analytical calculations. Simplifying the internal windings into concentrated conductors may result in poor calculation precision. Based on the fullscattered model of the winding, a simplifiedscattered method was proposed. This method could effectively reduce the complexity of the model while keeping the calculation accuracy. The effectiveness of the proposed method was verified by comparing analytical calculations, fullscattered model, simplifiedscattered model and measured values.