A Dual-Pathway Current Measurement and Control Scheme for Flat-Top Magnetic Field

Accurate sampling and control of high currents play a crucial role in the realization of flat-top pulsed magnetic fields, directly determining the stability and precision of the magnetic field. Traditional current sampling schemes simultaneously collect all components of the load current, including AC (alternating current) and DC (direct current) components. These components are then amplified and filtered as a whole, with the filtered result serving as the control reference. Such sampling schemes impose significant challenges on the performance of current sensors, including range, bandwidth, and resolution. Additionally, filtering can cause distortion of the high-frequency components in the measurement results, affecting waveform quality. This paper proposes an innovative current measurement and control method based on the skin effect. A dual-pathway shunt is used to separate the DC and AC components of the load current. The AC components are amplified separately and used as the control variable to achieve stability control of the load current. This paper details the working principle and design method of the dual-pathway shunt, theoretically demonstrates its effectiveness, and further verifies the feasibility of the method through simulation results.