The effect of variable speed wind turbines on a 21 bus power system

Abstract

The purpose of this paper is to study the effects of variable speed wind turbines (VSWTs) on a power system. The power system model used for this study is the IEEE 21 Bus System. Each system, one powered solely by the diesel powered synchronous generators (DPSGs), and the other powered by both VSWTs and a DPSG, were tested under different conditions including a three phase fault, line outage/break, and load changes. To be able to analyze and simulate these conditions the Power System Analysis Toolbox (PSAT) was used along with Matlab. This paper will begin by giving a brief introduction about variable speed wind turbines. Also, the advantages and disadvantages using wind turbines in the power grid will be discussed. The introduction will conclude by comparing VSWTs to their counterpart, constant speed wind turbines. Many conclusions could be drawn from the tested conditions stated above. When the system with VSWTs was faulted, it resembled the behavior of the diesel generator system. However, when a line outage was applied to the system with VSWTs, it did not behave as expected like the diesel generator system did. Also, when a load is dropped, the generator bus voltage tends to rise.