Rotor Speed Stability Analysis of Constant Speed Wind Turbine Generators

This paper presents an analysis of rotor speed stability of a constant speed wind turbine generator with active stall control. To analyze the rotor speed stability, a 3-phase short circuit fault on a sample system with a constant speed WTG has been simulated using DIgSILENT software package. From the simulation results, it has been shown that the operating point of wind turbine generator has influence on rotor speed stability. Using this phenomenon, how a constant speed wind turbine generator with active stall controls the operating point has been reported. Negative pitch control strategy of active stall controlled wind turbine generator to enhance rotor speed stability has been described with the help of simulation results.

I. Introduction

Among all renewable resources, wind power is the most booming renewable technology all over the world. India ranks fourth in the world with total installed capacity of more than 5, 000 MW [1]. Most of the wind turbine generators (WTGs) installed in India are constant speed (squirrel cage) induction generators. This is because of their robustness, mechanical simplicity and low price. However, a constant speed WTG always demands reactive power, hence reactive power compensation is needed.