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. This work is supported by National High Technology Research and Development Program of China (863 Program) (No. 2013AA050105) and National Natural Science Foundation of China (No. 51177042).