Feasibility of using wind turbines to provide reactive compensation for voltage improvement on an electric utility Ring

The electrical power demand in Trinidad and Tobago has almost doubled in the last decade and is anticipated to continue to increase at a rapid pace in the near future due to projected growth in the industrial sector. The utility is therefore challenged to keep up with the anticipated rapid rate of load growth and has to continuously examine the impact this may have on the transmission infrastructure and the network stability. The South-East 33 kV Ring is a small part of the entire transmission system in Trinidad with a slow paced load increase. However, it supplies power to critical geographic areas namely Mayaro and Galeota. These areas contribute significantly to the country´s economy through the oil and natural gas sector; hence voltage stability and system reliability is of utmost importance in the delivery of goods and services in that sector. This paper examines the steady state voltage stability of the South-East 33 kV Ring by performing computer aided power flow simulation for various operating scenarios. The load data used for conducting the simulation coincides with the evening peak. The study then examines the impact with the use of wind turbines to provide reactive power compensation for voltage stability and support on this ring. It also examines the possibility of voltage upgrade of the Ring to reduce the losses and improve voltage stability. Finally the paper compares the risks and financials of the options of line upgrade versus using a wind generating system and outlines the steps that must be taken before a utility can decide on the way forward.