PROJECT TITLE: Protection Coordination for Multi-Terminal HB-MMC based HVDC grids
Collaborators: Institute of Electrical Engineering (IEE), Chinese Academy of Sciences (CAS)
Funding: SDC Project
High Voltage Direct Current (HVDC) transmission system is a promising solution for integration of large scale Renewable Energy Sources (RES) into electrical power systems. Growing number of large scale RESs including remote Offshore Wind Farms (OWFs) calls for Multi-Terminal (MT) transmission system for power delivery to the main grid. New generation of Power Electronic Converter (PEC), called Voltage Source Converter (VSC), provides power system with robust control of voltage and power. Also, there is no restriction on multiple infeeds and MT connection in HVDC grid using the VSCs. With development of HVDC system technology, Modular Multilevel Converters (MMC) are introduced that have a superior performance comparing to conventional VSC system. However, protection coordination in such a new structure of power transmission system i.e. the MT-HVDC grid using the MMCs, is a great challenge.
In this project, the main objective is to propose a protection coordination in multi-terminal HVDC grids based on Half Bridge (HB)-MMCs. The key motivation of the study is shedding light on potential grid code requirements for power system security and protection of the HB-MMC based HVDC grids. Investigation of transient behavior of a MT-HVDC grid with HB-MMCs will be carried out under DC fault condition. Coordination between DC link protections as main and backup protection will be suggested to secure the HVDC grid against DC faults. Potential coordination between MMC protection and DC link protection will be proposed to maintain the maximum power delivery and system security. Then, the performance of the proposed protection coordination will be evaluated under different fault conditions using PSCAD software and Real Time Digital Simulator (RTDS) platform.
Publications in journals and conference papers may be found at VBN.