Development on the Current Sensor with Zero Flux based on Active Compensation Method
Zhao You-jun · IEEE Transactions on Power Electronics · 2009
The accuracy of the common current sensor is only 3%～5% and it is difficult to meet the requirements of the high-precision measurement.Through the study of the current sensor's equivalent circuit and phasor diagram,the error and its causes exiting in the conversion process of first current and secondary current are arrived.The limitations of the traditional error compensation methods are analyzed.On this basis through the design of all aspects in electronic compensation circuits,a type of low current sensor is developed which can track the variation of magnetizing current and compensate it by active electronic circuit to assure the magnetic core working in zero flux condition.The performance test shows that the compensation gets satisfactory results,the accuracy of the current sensor is improved and it meets the requirements for online monitoring of the insulation equipments.