Analysis Design and Implementation of Subsynchronous Resonance Damping Controller for DFIG Based Wind Energy Conversion System

Abstract

wind energy is the world s fast growing source of renewable energy. To newlineabate the global climatic changes, commercialization of the renewable energy newlinetechnologies and wind power in particular, are growing fast across the world. Every newlineyear, the grid connected wind power is growing and India is one among such countries newlinewhere the large scale deployment of renewable energy is massively expanding. Among newlinethe different renewable energy sources, the cost of producing electrical energy from the newlinewind power is the cheapest. This is possible because of the recent advancements in the newlineelectrical and power electronic technologies. The primary component of Wind Energy newlineConversion Systems (WECs) is the Wind Turbine Generator (WTG) and among many newlinetypes of generators, Doubly Fed Induction Generator (DFIG) based WTG is the most newlinepopular. The wind farms are established at distant places from the consumer end and the grid system, which demands long transmission systems that can cause reduction in the power transfer capability of the line. In order to sustain the large amount of power flow, series capacitors are incorporated with the transmission line system which can cause Subsynchronous Resonance (SSR) in the turbine-generator set. This SSR effect can lead to electrical instability and shaft failure. The main focus of this thesis is to investigate the risk of SSR effect on type 3 newlinegrid connected series compensated 2MW DFIG based WTG. The detailed analysis of newlineSSR is carried out for different operating conditions such as varying wind speed, newlinecompensation level etc. For this purpose, a unique mathematical model of DFIG based newlinewindfarms is developed in state space. The proposed model includes the model of newlinesubsystems such as wind turbine, DFIG, series compensated grid connected line and newlinenovel Rotor Side Converter (RSC)- Grid Side Converter (GSC) model. The analysis of newlineSSR on the proposed model is carried out using Eigen value approach and different newlinemodes of oscillations of the system are identified for different operating conditions. newline