An Introduction to Wind Energy Conversion System with Low Voltage Ride-Through Capability

Abstract

The global demand for electrical energy is expanding twice as quickly as the demand for primary energy. Highly reliable and fine quality power are demanded in the present-day power system scenario. Distributed generation including wind turbines and solar photovoltaic systems are significant in the perception of green energy. Electricity generation with renewable power generators like wind and solar are preferred to avoid CO2 emissions. In the sustainable alternatives, wind energy is considered as one among the fastest evolving energy resources. The percentage of renewable energy in the worldwide generation increases day by day. In this chapter, evolution of various wind energy conversion systems (WECSs) with their benefits and demerits are addressed. The increasing entry of power electronic converter (PEC) based renewable energy is transforming power system dynamics with new stability concerns. Several challenges like power quality issues, low voltage ride-through (LVRT) capability, fault ride-through (FRT) capability, power oscillations, primary frequency regulation (PFR), virtual inertia support etc in power system with the inclusion of wind energy are also discussed. Low voltage ride-through capability means that during grid faults (with voltage dip) the WECS has to remain connected to the grid (as per the grid code) and provide a certain amount of reactive power. Grid code requirements in various countries are to be satisfied by the DFIG based WECS by providing support to the grid during the voltage dip caused by the various faults in grid. Rotor side converter (RSC) and grid side converter (GSC) can be properly controlled according to the grid code requirements to achieve fault ride-through capability.