PWM Frequency Noise Cancellation in Two-Segment Three-Phase Motor Using Parallel Interleaved Inverters

This paper proposed a novel method for two-segment three-phase motor to eliminate the harmonics nearby pulsewidth modulation (PWM) frequency. Due to PWM technique and switching losses considerations, ear-piercing high-frequency electromagnetic noise in drive system is common. By using magnetically coupled inductors (MCIs) and interleaved technique, the proposed novel method is able to remove the high-frequency harmonics located nearby the PWM frequency and other odd multiples in two-segment three-phase motor. With this method, the unpleasant acoustic noise could be removed when the PWM frequency is selected near 10 kHz. The size of MCIs mainly depends on the PWM frequency harmonic currents rather than the fundamental frequency currents. Thus, its size is very small compared with LC filter. Moreover, this method remains the control dynamics of two-segment three-phase motor without additional inductance for fundamental-frequency currents. The shift phase of two inverters PWM carriers is π, which is simple to implement. Finally, the effectiveness of the proposed method is verified by experimental results.