New hybrid topology of voltage regulation applied in three-phase four-wire system based on induction generator

This paper deals with the development of a new hybrid topology for voltage regulation in micro hydro power station using self-excited induction generator applied in three-phase four-wire systems. The proposed topology is a combination of a three-phase four legs static VAR compensator (SVC) and capacitor banks connected in parallel to the AC voltage bar. It is considered a three wires generator with no accessible neutral point being the neutral terminal for the load created through the neutral terminal of the excitation capacitor and the fourth leg of SVC, which provides the choice to connect the loads either star or delta configurations. A control algorithm and a project for the variable capacitors are proposed based on the specifications of the SVC. The proposed generating system is modeled and simulated in MATLAB. Simulation results and preliminary experimental results are presented to demonstrate the performance of the proposed new hybrid method for the voltage regulation of the self-excited induction generator. In the sequence, simulation results are presented in order to demonstrate the capability of the proposed system for feeding three-phase and single-phase balanced and unbalanced loads, with no distortion of the generated voltages.