Static Voltage Stability Analysis Considering The Static Synchronous Series Compensator

With the development of transmission capacity, the complexity of the powernetwork structure has been enhanced increasingly and the operation point of powersystem is pushed closer and closer to its stability limits. The voltage collapse occursmore easily than ever. Voltage instability is widely recognized as one of thesignificant reasons treating the security and stability operation of power system.Therefore, Great concerns over voltage stability have been growing.The flexible AC transmission system (FACTS) is an effective means to improvethe utilization of electrical equipment and stability. Static Synchronous SeriesCompensator is a type of series compensation of FACTS devices, It assesses powersystem through the series transformer, resulting in voltage verticalized with the linecurrent, changing the effective impedance of transmission lines in order to achievethe real time control.This paper studies a new constant power controller model for SSSC. The powerloss of the whole power system before and after the installation of SSSC is comparedand analyzed, the model of SSSC is applied in the sensitivity analysis of voltagestability, the sensitivity of the whole power system before and after the installation ofSSSC in case of increase of power load is compared and analyzed; a new formula tocalculate steady state voltage stability, which is based on P-Q curve of transmissionline, is deduced and corresponding voltage stability index is obtained. This algorithmis applied in the IEEE-14bus system, the index of P-Q curve with and without SSSCis compared; using the continuous power flow, the voltage stability of power systemis compared at the load model of constant power, constant current, constantimpedance load model and ZIP.