Effect of Synchronous Compensator in Leading-Phase Operation on Transient and Steady State of the Hunan Network

There are two synchronous compensators (SCs) with the capacity of 300 MW in Hunan network. At present, a SC is normally controlled within ± 50 Mvar and the other one operates in spare. There are rarely participates in regional voltage control. However, the problem of high voltage occurs frequently in the central Hunan during low load periods. Under the voltage safety premise of the most serious three phase fault, the SC participating in the regional voltage control method will improve the grid operating characteristics, and improve the safety and economics of the grid operation. In addition, this paper analyzes the relationship between the SC output reactive power and the number of thermal powers must on and its rotation reserve. By replacing the thermal power units and its rotation reserve which are the requirements for system stable operation, the SC in leading-phase operation can therefore improve the operation flexibility of power grid, increase the maximum transmission power of DC and the power supply capacity of Hunan power grid.