Research on the Adaptability Test of New Energy Units Accessed the Dual-high Power System

With the rapid development of new energy power generation and DC transmission technology in the power grid, the power grid has formed a development trend towards a dual-high power system with a high proportion of renewable energy and a high proportion of power electronic equipment in China. In a dual-high power system, the steady-state and transient characteristics of the new energy generator set are more complex after it is connected to the grid and coupled to the system. Whether the new energy generators of different types can output normally according to the set value and maintain stable operation in the system when they are connected to the power grid, especially the power grid with weaker system strength has become an urgent problem to be studied. In this paper, an adaptability test scheme for new energy units connected to the network points of different system strengths is proposed. Based on the multiple renewable energy station short-circuit ratio (MRSCR), test of the steady-state operation characteristics and fault ride-through characteristics can be done after new energy units are connected to the power system such as photovoltaic power generation, direct-drive wind generation, and doubly-fed wind generation. According to the conclusions obtained by each new energy unit in the test grid and the test scheme, each new energy unit can be configured in a reasonable position according to the adaptability in the system, so as to provide a theoretical basis for connecting new energy units in the actual system and the system can maintain safe and stable operation after the new energy unit is connected.