Research Of STATCOM Model Based On Measured Data And Its Effects On Operational Performance Of Wind Farm Group

The ability of reactive power adjustment in wind farm is the main factor that affect the regional voltage stability and wind power usage level. As a regulation mean for reactive power, the static synchronous compensator (STATCOM) has been widely used in wind farms due to its superior properties. However, many problems of STATCOM devices exposed in actual operation could affect the reactive voltage regulating ability of wind farm group and may even threaten steady operation of the electric power system. Therefore, it is necessary to understand that whether the existing STATCOM devices meet the requirements of safe operation in the wind power collecting area, which is urgently needed in-depth research.First of all, the simulation model of typical STATCOM device under the constant-voltage control mode and the constant-reactive power control mode used in wind farm are set up in this paper. Then the models are valided utilizing the measured real data, proving that two STATCOM control models and the corresponding parameters base are available and could be used to research the actual STATCOM devices. Secondly, using the model above, the effects of STATCOM on the power system transmission capability and the transient voltage stability of wind farm group are analyzed and studied. The research results showed that the power system transmission capability under the constraint condition of steady-state voltage stability could be significantly improved by increasing the compensation capacity and adopting dispersed compensation of the reactive power devices. Under the short-circuit faults occurring in power systems, the control level of the existing STATCOM is hard to effectively improve the abilities of Low Voltage Ride through (LVRT) of wind farms. The different characteristics of the STATCOM have a great impact on suppression of the high voltage occured after fault recovery. If the dynamic response time can not meet the requirements and the capacity of STATCOM is too large, the high voltage effect would be aggravated. Therefore, from the perspective of suppressing the high voltage, the specific requirements on the dynamic response time and the capacity of STATCOM are proposed in this paper. In addition, the effects between two control methods of STATCOM on the transient voltage stability of wind farms are also compared in this paper.