Research on Reactive Power Planning Technology of Power Grid Containing UHVDC System with High Proportion of Renewable Energy Integration

Abstract

In large-scale renewable energy bases, thousands of renewable energy power generation units are often installed, but wind power is different from the reactive characteristics of traditional thermal power plants, the renewable energy power plant is essentially a weak grid with strong voltage sensitivity. Weak-end power grids have weak voltage support capabilities and prominent reactive power problems. Under the operating conditions of large-scale renewable energy generation, heavy line load and other operating conditions, the randomness and fluctuation of renewable energy generation will lead to the voltage of the local power grid in the connected area. Large fluctuations can easily induce serious system security and stability accidents. The occurrence of multiple large-scale wind power off-grid accidents has highlighted the problem of system reactive voltage stability caused by large-scale renewable energy grid connection. The existing reactive voltage control method based on a single renewable energy power plant has been unable to meet the needs of large-scale renewable energy development, and it is urgent to study the renewable energy power generation unit in a large renewable energy power plant that takes into account the voltage distribution and rapid change of active power in the field, and centralized reactive power compensation equipment reactive voltage control mode. The impact of large-scale renewable energy centralized connect to the reactive voltage stability of the power grid is not only a local issue but has become a global issue. It is necessary to carry out research on reactive power allocation of power systems that takes into account the large-scale renewable energy grid connection. By coordinating the reactive power control of large-scale renewable energy bases and the main grid, the voltage stability level of the entire system is improved to prevent large-scale wind power off-grid accidents.