Adaptive DC Voltage Control Strategy for Three-Phase PWM Rectifier in Permanent Magnet Maglev Train

Traction power supply technology serves as the core support for medium-low speed and capacity permanent magnet maglev train.The performance of DC-link voltage control is critical to the operational stability and energy efficiency of such systems. To address the specific technical challenges of permanent magnet maglev train, which include current collection reliability variations caused by dynamic suspension height and the nonlinear, mobile, highly fluctuating, and harmonic-rich characteristics of traction loads, this paper proposes an adaptive DC-link voltage control strategy based on the train’s operating speed. First, a mathematical model of a three-phase Voltage Source Rectifier (VSR) in the synchronous rotating dq reference frame is established. Then, a dual-loop control structure is designed based on active disturbance rejection control. On this basis, the key contribution of this work lies in the integration of a novel adaptive voltage reference generator within the voltage outer loop, which smoothly adjusts the DC voltage reference according to the train speed. This approach optimizes switching losses and harmonic currents under light-load or low-speed conditions while ensuring sufficient power margin under heavy-load or high-speed conditions. The simulation results demonstrate that the proposed adaptive strategy achieves rapid and stable DC voltage tracking under varying speed and load conditions. In comparison to conventional fixed DC voltage control methods,the proposed approach significantly reduces the total harmonic distortion (THD) of the grid-side current and demonstrates strong performance in suppressing load disturbances.