Decoupling Control Optimization Based on Analysis and Compensation of Back EMF Disturbance in High Precision Current Converter

In high performance applications, LC filter usually is added to power converter for optimizing the output current ripple characteristics of the system. However, the LCL link composed of LC filter and resistor-inductance load causes the resonance, which leads to the traditional closed-loop not appropriate to be applied directly. Consequently, the active damping compensation method based on harmonic current is considered to suppress the resonance, and the suppression effects of different damping parameters on the resonant peak are compared and analyzed. Moreover, back EMF treated as a nonlinear disturbance affects the accuracy of current. Therefore, the current harmonic suppression method based on feedforward control for resonant pole-based dual buck soft-switching converter (RPDBSC) is presented, and the current suppression method of feedforward control is analyzed by the decoupling control model of bias current. This paper focuses on the improvement of the closed-loop control strategy for high precision current converters, and the effectiveness of the proposed method is verified by simulation and experiment.