模块化多电平换流器启停控制策略

摘要

为了平稳快速地启停模块化多电平换流器(Modular Multilevel Converter MMC)，提出了可应用于有源或无源网络的MMC启停控制策略。启动控制策略和停机控制策略均可分为不可控和可控两个阶段，其中可控阶段可进一步分为直流电压可控和功率可控阶段。在不可控阶段，修正了启动过程的限流电阻参数，提出了停机过程的放电电阻选取原则。在直流电压可控阶段，采用子模块电容电压、投切数与直流电压协调控制方法，计算出启动时的直流电压跌落值和停机时的能量反馈比。在功率可控阶段，根据MMC应用于有源和无源网络控制策略的不同，提出了相应的策略。最后基于PSCAD/EMTDC搭建仿真模型，验证了所提启停控制策略的有效性和正确性。%To start/shutdown modular multilevel converter smoothly and quickly, the start/shutdown control strategies applied to MMC connecting active or passive network are proposed. Every strategy can be divided into two stages:uncontrollable and controllable stage. And the controllable stage can be further divided into DC voltage and power control stage. In the uncontrollable stage, the limiting resistance is modified, and the selection principle of the discharge resistance is presented. In the DC voltagecontrol stage, the coordination control between the sub-module capacitor voltage, switching number and DC voltage are adopted. And DC voltage drop value of start strategy and energy feedback ratio of shutdown strategy are calculated. In the power control stage, the corresponding strategy is proposed aiming at MMC connecting active and passive network. Finally, the effectiveness and correctness of the proposed start/shutdown control strategy are verifiedbased on PSCAD/EMTDC simulation model.