Research on the influence of Multi-HVDC power coordinated control strategy on frequency stability in multi partitioned power grid

With expanding of power grid and increasing of load, the synchronous power grid in load intensive areas faces many risks that are hard to solve, and the asynchronous partitioned grid will be the development trend in the future. Aiming at the problem of frequency stability of partitioned power grid, this paper proposes a research method of multi HVDC power frequency coordination control strategy between partitioned power grids. Firstly, based on the key index of frequency stability, the influence mechanism of HVDC FLC function on the frequency response characteristics of power grid is discussed. Then, according to the guide on security and stability for power systems, the first level standard of the guide is appropriately considered, and the test evaluation method of coordinated control strategy is studied, then the test scheme design guide is formulated. Last, taking a three-partitioned-grids-seven-HVDC-interconnected-system as an example, based on the large power grid real-time simulation test platform, the single HVDC blocking fault tests are carried out in the form of hardware in the loop simulation tests with different coordinated control schemes. The research results show that the frequency stability of partitioned power grid can be effectively improved by designing multi-HVDC power coordinated control scheme, formulating reasonable control parameters and carrying out real-time simulation test of large power grid.