电气化铁路牵引供电用光伏发电系统的接入拓扑及其电流控制策略

提出了电气化铁路牵引供电用光伏发电系统的接入拓扑及其电流控制策略。首先，利用V/V变压器将两相牵引电压转换为与电网电压幅值、相位相同的三相电压，为光伏发电系统的接入提供三相平衡电网环境。然后，提出实施于三相静止坐标系中的分相电流控制策略。该策略利用相电流替代正、负序电流作为被控对象，通过对相电流的闭环控制，可在无需正、负序分离提取的条件下完成不对称与三相对称电流的注入，实现光伏发电为牵引负荷供电的自发自用运行和为电网输送功率的全额上网双模式运行。最后，仿真结果验证了所提出接入拓扑与电流控制策略的有效性。

Connection Topology and Current Control of PV Generation for Traction Power Supply in Electric Railway

A connection topology and the corresponding current control strategy of photovoltaic (PV) generation for the traction power supply of electric railway are proposed. In this topology, a V/V transformer is used to convert two-phase traction voltage to three-phase voltage, which has the same amplitude and phase angle as the grid voltage. This can provide three-phase balanced voltage for the connection of PV generation. Then, an individual phase current (IPC) control strategy is designed in the three-phase stationary reference frame. In the proposed strategy, the phase current values are used as the controlled variables instead of the positive and negative sequence current components. Without any sequence extraction, it can flexibly inject both symmetrical and asymmetrical current by closed loop control of the phase current. In this way, the PV generation system can operate in two modes: one is the self-generation and self-consumption operation for supplying the locomotive, and the other is the grid-connection operation for feeding back to the grid. Finally, simulation results validate the effectiveness of the connection topology and the IPC control.