Suitable For Low Voltage Ride Through Capability Analysis Of Wind Farm Equivalent Model

Wind power as a representative of clean energy, has been a priority in most countries around the world.However, large-capacity, high proportion of wind power as a result of the volatility and the intermittent characteristics of energy sources, so has brought great challenges to the mature of the wind technology. Currently, there are a lot of experts and scholars in the study of how to improve wind turbine LVRT capability, and how to detect low voltage ride-through capability of the actual wind farm study lacks. Our country has imported some equipment from Germany, which can detect the LVRT of the wind farm. However, because of its limited capacity, only one or two experimental wind turbines, and a long detection time. It is difficult to meet the low voltage ride through the wind farm requires the ability to detect, for which it is necessary to study for low voltage ride through capability analysis and testing of wind farms, etc. effect modeling.This paper focus on the wind farm consist on fixed-speed wind turbine(FSWT) and doubly fed induction generator(DFIG), and set up equivalent model which adapt low voltage ride though capability and analysis of FSWT and DFIG. The main research in this article as follows:Nowadays, when people tend to study the equivalence of wind farm, few people compare the different methods of wind farm for network. So this chapter describes two kinds of dynamic equivalence method of wind farm collector for network, such as network-based method of equivalent voltage(the voltage method) and network-based power loss method(the loss method). The theoretical analysis of the mechanism of the two methods of derivation,and through dynamic equivalent simulation modeling, which the conclusion, which the conclusion is the voltage method is more accurate than the loss method.For fixed-speed unit wind farm, this chapter as a result of build adapted equivalent model of low voltage ride through for fixed-speed wind turbine wind farm. Theoretical analysis of transient mechanism for fixed speed wind turbine, proposed a index which can find the easiest Off-grid operation turbine. Then set up equivalent model of the wind farm. what’s more, through simulation to test the method is reasonable.For DFIG unit wind farm, This chapter as a result of build adapted equivalent model of low voltage ride through for doubly fed induction generator wind farm. By analyzing the operating characteristics for the Crowbar and the transient characteristics of short-circuit current of the DFIG, propose an indicator parameter which could accurately determine the earliest Off-grid operation turbine.Build the equivalent model of the DFIG wind farm for LVRT, then to test the accuracy of the method by the simulation, the conclusion is the three machines model is reasonable.