A Differential Compensated Air Coil Current Sensor for Switching Current Measurement of Power Devices
Ze Zhou, Zhen Xin, Qing Liu, Chushan Li
Abstract
Accurate current measurement is the basis for power devices to achieve switching characteristics evaluation, real-time control, reliability diagnosis, life prediction, etc. With the rapid development of power semiconductor device technology, requirements for current measurement are getting more and more stringent. The printed circuit board Rogowski coil current sensor (PCB RCCS) is a potential competitor, which has excellent bandwidth and integrability. However, the contradiction of the droop and drift phenomena as one of the main challenges restricts the employ of the RCCS in switching current measurements. In this article, a differential compensation scheme that can solve these problems simultaneously with a lower error and cost is proposed. And the sensitivity and bandwidth of this sensor can be accurately obtained. Finally, a buck and single-phase full-bridge inverter experimental platform are built to verify the effectiveness of the PCB RCCS in the measurement of the switching current and inductor current, respectively.