Abstract：Printed circuit board (PCB) air-core coil has advantages of high accuracy and parameters consistency in the current measurment. T-integrator has a good suppress ability to low-frequency noise among various analog integrators. Therefore, a kind of electronic current transformer based on PCB air-core coil and T-integrator is presented, and its transfer function and transient mathematical models are deduced. The transient current measurement behaviors of this current transformer are analyzed especially. Simulation results confirm the validity of the proposed models, which can give some instructions to improve the transient behaviors of current transformer. Compared with the resistance type current sensor, the transient peak error is about ±1%, and the match extent of two output waveforms is good. The dynamic simulation experiments show that PCB air-core coil current transformer has the pleased ability to accurately respond the fault current transient process in the power system, and can meet the demand of power system for current measurement and protection.
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2010, Vol. 25 
