Possible interconnections for the Katsina wind farm using synchronous compensators (STATCOM)

Abstract

Squirrel-cage induction generator wind power plant requires the provision of reactive power for self-excitation and to sustain the generated voltage. The Katsina wind power plant comprising of several squirrel cage generators, each has a fixed capacitor bank connected in shunt to the wind turbine generator provide the needed reactive power. These capacitors are selected to enable the excitation of the generators under various wind speeds which are greater than the cut in speed. All of these generators, through underground cables are connected to the main substation. This solution has limitations of under or over-exciting the generators depending on the wind speeds and the local load demand. Furthermore, because of the voltage drops in the underground cables and potential faults in the lines connecting the substation to the wider power systems, the voltages at the turbine terminals and the substation can vary leading to potential under-voltage and over voltage problems. Especially in weak power systems — such as the Nigeria power systems — Static Var Compensators (SVC) and Static Synchronous Compensators (STATCOM) which provide variable reactive power (both leading and lagging) as when needed to maintain the substation voltage at the rated and desired values.