Focusing on the application of an optimized current injection control system for low-voltage type current transformer banding measurement

this paper aims to achieve accurate autonomous modulation of industrial frequency current under dynamic working conditions. A charged circuit modulation system based on sinusoidal pulse width modulation (SPWM) technology is constructed

which generates an AC signal through an inverter circuit and works in concert with the transformer to quickly and accurately inject current into the measured circuit. For the delay problem

the effects of filter circuit and actuator response are analyzed

and double closed-loop control strategy are adopted to effectively reduce the filtering pressure and decrease the hysteresis delay. The system stability is verified using the root trajectory method

and the proportional-integral(PI) control parameters are optimized by the frequency domain analysis method. Simulink simulation results show that the injected current control system realizes autonomous modulation of the industrial frequency current in the range of 1% to 120% of the rated current. Finally

the full-range regulation of the test loop current under charged conditions is successfully achieved

providing a reliable solution for high-precision current measurement in power system.