The accurate and reliable switching current information is important for power electronic converters to realize closed-loop control, harmonic suppression and short-circuit protection, which is conducive to further improving the reliability of power devices. The PCB Rogowski coil current sensor has an important research value and application prospect owing to its advantages of high bandwidth, small size, low cost and low intrusion. However, its measurement accuracy is seriously limited by the drift error and droop error in the traditional integral processing circuit. A resettable integrator is used to avoid the continuous accumulation of drift error while eliminating the influence of droop error. At the same time, a digital compensation strategy for the drift error and offset error in the resettable integrator is proposed, which uses a digital signal processor to control the digital-to-analog conversion module to generate an analog compensation signal and eliminates errors by means of a high-speed subtractor. As a result, this method has advantages of a high compensation accuracy and simple adjustment, and it can greatly reduce the influence due to integral errors. Finally, double-pulse, multiple-pulse and short-circuit protection experiments were carried out based on a double-pulse test platform, and the performance of the proposed PCB Rogowski coil current sensor was verified.
关键词
PCB罗氏线圈电流传感器/误差补偿/短路保护/可靠性
Key words
PCB Rogowski coil current sensor/error compensation/short-circuit protection/reliability