Research on the Optimization Control Strategy of the Four-Quadrant Rectifiers for High-Speed EMUs

The four-quadrant rectifier is an important component of electric multiple units (EMUs), and the optimization of its control strategy is a hot spot. First, this paper introduces the traditional control strategy and explores the influence of the presence or absence of the secondary filter circuit and dualization on the working performance of the rectifier. Second, for the issues of grid-side harmonics and DC-side voltage overshoot in the rectifier, an improved the voltage outer loop of the transient direct current control strategy is proposed. A low-pass is introduced filter to suppress the secondary ripple on the DC side and reduce the grid-side harmonics. The traditional PI control is improved as a single-neuron PID to reduce the DC-side voltage overshoot. Finally, Simulation analysis was carried out to verify that the optimized control strategy in this paper can achieve the control goals of DC-side voltage, small grid-side current harmonics, and high-power factors of grid-side voltage and current.