Minimum excitation capacitance requirements for wind turbine coupled stand-alone self-excited induction generator with voltage regulation based on SVC

In this paper, the nodal admittance approach steady-state frequency domain analysis of the minimum excitation capacitance required for the squirrel cage rotor type three-phase self-excited induction generator (SEIG) driven by variable-speed prime movers (VSPMs) such as a wind turbine and a micro gas turbine is presented. The steady-state analysis of this power conditioner designed for the renewable energy is based on the principle of equating the input mechanical power of the three-phase SEIG to the output mechanical power of the variable-speed prime mover with using the approximate frequency domain based equivalent circuit of the three-phase SEIG. Furthermore, a feedback closed-loop voltage regulation of the three-phase SEIG as a power conditioner which is driven by a variable-speed prime mover employing the static VAR compensator (SVC) composed of the fixed excitation capacitor bank FC in parallel with the thyristor phase controlled reactor (TCR) and the thyristor switched capacitor (TSC) is designed and considered herein for the wind turbine coupled the power conditioner. To validate the effectiveness of the SVC-based voltage regulator for the terminal voltage of the three-phase SEIG, the inductive load parameter disturbances in a stand-alone power generation are applied and characterized in this paper. In the stand-alone power utilization system, the terminal voltage response and the thyristor triggering angle response of the TCR are plotted graphically. The simulation and experimental results prove the effectiveness and validity of the proposed SVC controlled by the PI controller in terms of fast response and high performances of the three-phase SEIG driven directly by the rural renewable energy utilization like a variable-speed wind turbine.