Reactive Power Compensation And Optimal Configuration Of Wind Farm

With the worldwide energy crisis being increasingly serious, developing renewalenergy is the only way to solve the problem. Wind energy is the most maturetechnology and has the most development potential. But large-scaled wind farmconnecting to the power grid has brought serious problems. The need of reactivepower has an great impact on the grid voltage stability. Thus, reactive powercompensation is necessary.SCIG and DFIG are the two kinds of commonly used wind turbine. SCIG needsto absorb reactive power to build magnetic field. Wind speed changes over time, sowith the reactive power absorbed. Thus, capacitor bank can not satisfy the require ofcompensation precision. So SVC is used to coordinate with capacitor. Capacity of firstgroup of capacitor is Qminand is installed in outlet of fan. Capacity of the last (n-1)groups of capacitor is (Qmax-Qmin)/(n-1),(Qmaxis the highest reactive power needed),and the devices are installed in outlet of wind farm. The first group offers the leastreactive power of SCIG. When the wind speed and the reactive power needed increase,the capacitor bank and SVC installed in the outlet of wind farm compensate the extra.Costs of SVC is high and is related to the number of banks of capacitor, n. To achievethe purpose of lowest costs, under the premise of unchanged reactive power capacitorand reasonable value of voltage, an objective function is set up. Through theoptimization of n, the function obtain the minimum. DFIG can adjust reactive in arange. But ability is uneven. In this paper, capacitor is installed in the outlet of fan toget the ability to even. Also capacitor bank and SVC are installed in the outlet of windfarm. The capacity of capacitor and SVC and the value of n is got as the methodabove.In this paper, two typical kinds of load flow calculation method is used tocalculate the two kinds of wind farm. Then an example is given to prove thecorrection of the research method.