Hardware in Loop Real-Time Simulation Test Research and Engineering Application of Multi-Terminal Hybrid Ultra High Voltage DC Current Control and Protection System

The multi-terminal hybrid ultra-high voltage direct current (MTH-UHVDC) transmission technology combining line commuted converter ultra-high voltage direct current (LCC-UHVDC) technology and modular multilevel converter ultra-high voltage direct current (MMC-UHVDC), provides a more flexible and advanced mode to meet the needs of longer distance and larger capacity clean energy transmission. Compared with the two-end HVDC system, the control and protection (C&P) functional and dynamic characteristics of MTH-UHVDC transmission system are more complex. The real-time simulation technology must be used to carry out the experimental research before the engineering application. However, the hardware in loop (HIL) real-time simulation test of MTH-UHVDC transmission system is faced with many technical problems, such as multi-type interface of test system, accurate modeling of UHVDC MMC valve, full access of C&P devices, etc. Therefore, from the perspective of simulation test research and engineering application, this paper proposes a HIL real-time simulation test method for C&P system of MTH-UHVDC transmission system. The design of test system, accurate modeling of primary system, modeling of C&P system, interface technology of test system, functional and performance test method of C&P system and engineering application are deeply studied. Taking kunliulong project, the world’s first MTH-UHVDC project, as the application background, a real-time simulation test system for C&P system is established by the proposed method. The functional performance test (FPT) and dynamic performance test (DPT) are carried out using the established test system, and the simulation test waveforms are compared with the field test waveforms. The results show that the response characteristics of the two systems are consistent, and the test system established in this paper can meet the needs of accurate real-time simulation test and research, and can provide technical support for the application of MTH-UHVDC technology.