相比传统直流输电,模块化多电平换流器型高压直流(MMC-HVDC)输电的一次系统与二次系统都更为复杂,并且控制系统的特性一定程度上决定了MMC-HVDC系统的性能。为研究物理控制器的设计方法,文中首先设计了MMC-HVDC物理模拟系统的主系统结构与电气参数,然后重点研究了分层的MMC-HVDC控制系统架构,运行人员控制系统(上位机)、极控制和保护系统、阀基控制器、子模块控制保护单元等由高到低构成了完备的控制体系,确立了各控制层之间的通信方式与内容,开发调试了控制系统程序。最后,进行了MMC-HVDC物理模拟系统的系统实验。实验表明控制系统可以有效地实现物理模拟系统的启停、子模块电容电压平衡、基本的故障保护以及直流电压与功率的控制。
Compared with the traditional high voltage direct current (HVDC) transmission system,the primary system and secondary system of the modular multilevel converter based HVDC(MMC-HVDC)transmission system are more complicated. In addition,the properties of the MMC-HVDC system are determined by the characteristics of the control system to a certain extent.In order to study the physical controller design strategy,the primary system structure and electrical parameters of MMC-HVDC physical simulation system are designed.Then,the framework of the hierarchical MMC-HVDC control system is focused on.A complete control system is formed by the control system of the operating staff,the pole controller & protection system (PCP),the valve based controller(VBC),and the sub-module controller (SMC) in control layers from high to low. The communication mode and content is established between layers,and the control system program is developed and debugged.Finally,the systematic test is conducted on the MMC-HVDC physical simulation system.It is proved that the control system is capable of realizing efficient start and stop of the physical simulation system,capacitor voltage balance between sub-modules,basic fault protection,and DC voltage and power control.