Comparison of D-SVC and D-STATCOMfor performanceenhancement of the distribution networks ConnectedWECS including voltage dependent load models

Todays the WECS or Wind Energy ConversionSystems are developed. WECS are considered as complexsystems, including mechanical sub-systems such as the rotor andthe system of secondary electrical converter, inverter, rectifier, controller, and are once. Turbines used in wind turbines aredivided into two general categories: fixed rate and variable rate.Technical comparison of reactive power compensator types ofcapacitor banks, SVC and STATCOM in wind power plants isnecessary. Therefore, the uses of each of these generators have different impact on the grid voltage fluctuation and it will show.Here two types of compensators include D-SVC and DSTATCOMhas been tested for performance. Also Wind EnergyConversion System is a system that uses a constant speed of asquirrel-cage induction generator connected to a network, themodeling has been done. The purpose of this study is to analysisthe steady state performance of radial network connected WindEnergy Conversion Systems (WECSs). We have used Windturbine model, SVC model and STATCOM model. The WECSconsidered is a fixed-speed system that use from a squirrel-cageinduction generator. But, since the squirrel-cage inductiongenerator consumes the reactive power, increase in wind turbineswill weaken Voltage profiles. Therefore to improve the voltageprofile, FACTS (Flexible AC Transmission System) is used. Inthis paper, for this purpose, Distribution Static COMpensator(D-STATCOM) and Distribution Static VAR Compensator (DSVC)are considered as shunt compensator. An exact model forthis device is defined to use in load flow analysis. In this paperoffer an improved method to solve load flow problem in balancedradial distribution systems. The method is efficient and easy toimplement. Based on electric circuit laws, this method is iterativeand lets the Calculation of both, voltage (rms) values and phaseangles.The method increase Speed convergence. In this paper, thewind turbine and D-FACTS are modeled, and in the analysis ofthe load flow are considered. Also has been study the effect ofmodeling of load on the results of power flow solution. In thispaper, the use of wind turbines and D-FACTS to reduce lossesand improve the voltage profile is visible. Meanwhile, theperformance of D-SVC and D-STATCOM are compared.

Keywords:

D-FACTS , Load flow , Radial distribution networks , STATCOM , SVC , Wind energy