对模块化多电平换流器(MMC)采用站级控制器、子模块控制器(SMC)和阀基控制器(VBC)3层控制系统。设计了SMC与VBC之间的时序逻辑,保证了控制系统的实时性。当硬件模拟电路检测到子模块出现过电压或者欠电压时,如果过电压或者欠电压时间超过20μs,则SMC将故障信息传送至上层控制,有效降低了保护系统误动的概率。对采用了上述控制系统的MMC物理模拟系统进行了稳态实验,实验结果表明,系统能够有效控制直流电压、输送功率,并使子模块电压稳定在150 V左右。
A three-layer control system consisting of the station controller, SMC (Sub-Module Controller) and VBC(Valve Base Controller) is applied to MMC(Modular Multilevel Converter). The sequential logic between SMC and VBC is designed to guarantee its real-time performance. In order to effectively reduce the malfunction probability of protection system,only the information of a sub-module overvohage or undervoltage fault,which is detected by the hardware analog circuit for more than 20 ~s,is sent to the superordinate controller by SMC. A steady-state experiment of the proposed control system is carried out in a physical MMC simulation system and the results show that it controls the DC voltage and transmission power effectively and keeps the sub-module voltage around 150 V.