Centralized Reactive Power Controller for Grid Stability and Voltage Control

Abstract

The integration of renewable energy sources like solar and wind energy into the transmission and distribution grid has increased gradually for quenching the increasing demand for alternative sources to fossil fuels. However, due to the intermittent nature of the renewable sources primarily solar and wind, the injection of the renewable power generation into the grid shall also be fluctuating which in turn will impact the voltage profile of the transmission and distribution grid. Also, in case of any major load disconnection or generator tripping in a weak grid, the voltage profile will be severely impacted in a weak grid. The aim is to control the sudden major voltage profile disturbance of a weak grid in case of variation of power injected into the weak grid from solar and wind energy and also due to sudden load tripping or generator tripping in the weak grid by controlling the reactive power in the weak grid. In this paper, a centralized reactive power controller has been proposed to control reactive power injection or absorption in the grid. By controlling the reactive power sources and sinks centrally via the centralized controller, any contingency can be met to prevent major disturbance of the voltage profile in the weak grid. This controller shall aim to control the connected reactive power sources & sinks based on the voltage profile of the transmission grid and it shall also engage the Line Commutated Converter (LCC) High Voltage Direct Current (HVDC) Reactive Power Controller. Various cases have been analyzed in this paper for implementation of the centralized reactive power controller for voltage control in the transmission grid.