An Active Common-noise Canceler Combined with Feedback Control

This paper describes the methods for improving the performance of an active common-noise canceler (ACC) that suppresses the common-mode (CM) voltage generated by inverters. Whereas the already proposed ACC (ACC0) compatible with space vector pulse width modulation requires two emitter follower circuits, this paper proposes an improved ACC (ACC1) that requires a single emitter follower. In addition, an ACC (ACC2) that improves the CM voltage suppression performance by adding a feedback circuit to ACC1 is also proposed. The experimental results show that ACC1 improved the CM voltage attenuation by -10dB compared to ACC0, and ACC2 improved the CM voltage attenuation by -20dB compared to ACC1. ACC2 has a large CM voltage attenuation of up to -53dB in the wide frequency range from 100kHz to 5MHz.