Power Quality Analysis of Electrical Distribution Systems with Renewable Energy Sources

Renewable energy sources are promising solutions to cater the energy demand. In this context, research works have been reported by focusing on various aspects of renewable energy sources, for their successful integration into the Electrical Distribution Systems (EDS). Among various renewable energy sources, wind and solar photovoltaic (SPV) units have assumed more prominence. However, in such systems, Power Quality (PQ) problems are encountered during the operation of a EDS. Such problems in a wind unit are mainly due to the rapid output power variations (flicker) from wind turbines. The reasons for flicker are variations of wind speed, wind gust, wind turbulence, tower shadow and wind shear. Further, PQ problems are also probable in EDS with SPV, mainly with a fluctuating cloud affecting irradiation and hence the generation of power. In this context, studies on EDS with Distributed Generation are presented from Power Quality perspective. Suitable Power Quality Indices (PQIs) based on flicker and faults are defined. Two major parameters are considered to arrive at suitable control actions needed for monitoring and control of DGs. These parameters include PQ distortions due to environmental factors, such as change in wind speed and solar irradiations. The flickers produced are mitigated through Volt-VAr control mechanism implemented in MatLab. PQIs under different fault conditions on the EDS are also carried out, which are used further to estimate the performance of a system. A 17-bus test system is modeled using the open source software, Open Distribution System Simulator (OpenDSS). Smart converter control is realized through Volt-VAr control mechanism, so as to initiate proper grid-support functions.