Voltage Stability Analysis And Control Studies Of Large-scale Wind Power Plants

Voltage stability analysis and control of large scale wind power plant is an important problem. In recent years, the problem has been highly concerned, but not thoroughly studied. This text with engineering of wind power plants for background, based on establishing the static and dynamic mathematics model, the steady-state analysis and transient simulation are respectively adopted for thorough researching voltage stability of large scale wind power plants. This paper main research and conclusion include:1. Deducing and testing static power-voltage mathematics model of large scale wind power plants is applicable to the steady-state voltage stability analysis.2. The continuation power flow method of wind power system has been confirmed considering induction generator power-voltage characteristic and power increases in combination with general and continual method. The steady-state voltage stability critical point or limit of wind power plant can be effectively and accurately calculated in the method.3. Lead in steady-state voltage stability indices to wind power plants, including inreactive-voltage sensitivity (ηi) for deciding steady-state voltage stability, voltage collapse proximity indicator ( VCPIPi) for scaling voltage fluctuation, power margin (KPi )or power margin coefficient (KQi) for forecasting voltage stability of wind power plants directly and reactive power reserve (Qr) or reactive power reserve coefficient (KQ) for estimating transient voltage stability.4. Studies show that the lack of reactive power is an ultimate reason of the voltage collapse of wind power plants. The thesis advances a criterion for steady-state voltagestability of wind power plants and an estimation method for assuring transient voltage stability of wind power plants.5. Put forward the conception of steady voltage and transient voltage stability control of wind power plants. The studies shows that compensation capacitor banks and district load in connect node ensure an allowable steady voltage change range around wind power plants. The SVC in wind power plants is a useful device of reducing voltage fluctuation and improving transient voltage stability of wind power plants.wind power generation; wind power plants; asynchronous generator ;voltage stability; voltage collapse; SVC...