Steady state impedance estimation of a weak grid to assist optimal current injection for minimal power losses

摘要

Nowadays, latest advancements in power electronics have devised new ways to optimise power systems by reducing power losses. These developments provide convenience for private power producers to harness renewable energy and allow injection of optimised reactive currents to compensate for the reactive power drawn from the grid. This paper presents the development of an efficient laboratory based system that can monitor a transmission line, sense changes in the load and redistribute the optimal currents in a manner that ensures minimized power (I2R) losses at the point of common coupling (PCC). A method is discussed and implemented to calculate and feed the required optimal currents into the grid. This method depends on the measurement of dynamic parameters of the electrical grid which are calculated by applying a steady state impedance estimation technique. Once parameters are obtained, the aforementioned method is applied which allows the flow of optimal currents in the system. National Instruments (NI) PXI controller with built-in FPGA module is used for experimental investigation which demonstrates capability of the discussed technique to produce the required results.