Study On Doubly-Fed Wind Farm Reactive Power And Voltage Coordinated Control Strategy Considering Wind Power Forecasting

With the access capacity of wind power continues to increase, wind power fluctuations andrandom characteristics bring more adverse effects to grid,especially at the grid-connecting point.Currently, induction generator (DFIG) has gradually occupy the mainstream in the domestic due tothe rapid progress and development trend of wind power technology. DFIG is connected to the gridby inverter and it’s active and reactive power can be decoupling controlled through the generatorstator flux oriented vector control technology, it has a flexible capacity of reactive power regulationand voltage support. This paper mainly research the grid-connecting point reactive power andvoltage control of double-fed wind farm based on analyzes of basic principles, related controltechnology, operating characteristics and mathematical model with the doubly-fed wind farms.Then, we propose two wind farm reactive power and voltage control strategy are both counted windpower forecasting. The first strategy is considering the local load forecasting and the second isconsidering reactive power margin. These two strategies are both to control the voltage of thegrid-connecting point under the conditions that the DFIG is main reactive power source and SVC isan auxiliary compensation device.The first strategy is to draw the curve between the wind farm reactive power demand and twofactors that the impacts of wind power and local load changes. Whether SVC putouts reactivepower is based on the voltage of grid-connecting point. The strategy take impacts of the local load，wind power and system voltage of wind farm reactive power demand into account. The secondstrategy determine output reference value of reactive power compensation in a future period of timeusing wind power prediction and Particle Swarm Optimization. Then DFIG putout reactive powerrefer to this value. Whether SVC putouts reactive power is also based on the voltage ofgrid-connecting point in this strategy. This strategy can improve wind turbine reactive powermargin compared with the automatic voltage control. Studies show that both strategies are equallyeffective to support voltage for the wind farms.