Magnetic Saturation Suppression of Common-Mode Choke Coil by Selecting Suitable Inverter Carrier Frequency

Common-mode choke (CMC) plays an important role in suppressing the leakage current produced during operation of pulse width modulation (PWM) inverters. However, when common-mode path exhibits a large series stray capacitance, particularly capacitance by long shielded cables, CMC core reaches magnetic saturation. This paper presents technique selecting suitable carrier frequency for inverter to suppress saturation CMC. First, analytical approach leads non-saturation condition, and clarifies maximum minimum design conditions. Subsequently, effect is demonstrated non-linear circuit simulation experimental tests using actual system demonstrate effectiveness technique.