Compensation Link Design of a Constant Current Energy Recovery System

When the motor is braked, the rotor kinetic energy is converted into electrical energy and fed back to the power supply bus, recovering this part of the energy can save energy and reduce consumption, and improve the overall efficiency of the system. For the energy recovery system with constant current control, the absence of compensation link will lead to problems such as slow system response, large error, and oscillation dispersion. Therefore, this paper proposes a compensation method based on the configuration of zeros and poles. The open-loop transfer function model of the system is established. The frequency domain Bird's plot is drawn and the RC compensation network is designed to improve the low-frequency and high-frequency response characteristics of the system. The final experimental results show that after adding the compensation circuit, the steady-state error of the charging current is eliminated and the noise peak-to-peak value is reduced by 33%, which verifies the validity of the proposed method and provides a theoretical basis and engineering reference for the optimization of the design of the constant-current energy recovery system.