Modeling and implementation of a smart current sensor

The modeling and implementation of a high-performance current sensor are presented. In order to improve the dynamic response in the following primary current and frequency bandwidth, a measurement system with feedback based on the principle of zero magnetic field detection is proposed. The system model is estimated by introducing two current components sensed by a Hall device and induced by the magnetic core, respectively. The performance of the proposed measurement system is confirmed by simulations, the implementation of the current sensor is carried out, and analyses of the effects of key elements on system performance are performed. The simulation and experimental results indicate that good following performances are achieved in the frequency range from DC to above 100 kHz. In addition, the proposed current sensors have been successfully applied in servo control systems and process control systems that need to accurately detect transient current signals with a wide frequency range