Investigation methods for power quality problems in large scale LV network

Abstract

Nowadays the number of nonlinear loads and dispersed generators connected to the LV network increases. The influence of nonlinear devices, like energy saving lamps, computers or photovoltaic inverters on power quality in the grid has to be investigated. Analysis of a large number of nonlinear devices in complex network is difficult since every device has to be simulated with the complete model. For this reason a new method is developed. In this method the complete model of a device is replaced by an equivalent reduced model. Since the model is simple, a large number of the devices can be simulated. In this paper an improved equivalent reduced model is presented. The improved model allows simulations of the behavior of the devices when a dip or swell occurs. Three nonlinear devices are measured and modeled. Experimental and simulation results are presented.