Use of Smart Pv Inverters For Reactive Power Management In Distribution Grids

Due to changing behavior of loads, enhanced installation of underground cables and increased amount of renewable energy sources connected to both transmission and distribution grids, the flow of capacitive reactive power (CRP) is becoming difficult to manage. Several control measures are taken to keep CRP within limits but these control measures are expensive. These control measures are normally taken at transmission level while high proportion of CRP sources reside in distribution level. PV inverters are used in the distribution grids to generate active power during day and remain idle for nighttime. The available capacity of smart PV inverters apart from active power generation could be considered as an asset to handle the CRP issue. In this paper we propose to use smart PV inverters to keep CRP within limits in the distribution grid and controlling its flow at T-D interface. To validate this concept smart PV inverter control is developed for inverters to work as reactive power compensation device for daytime and nigttime operation. During the daytime PV inverter works in active power priority mode and at nighttime the whole capacity of the inverter can be used for reactive power control. To analyze the impact of this control strategy on a larger network a simplified model of proposed strategy is used on a case study network. The results show that CRP flow can be managed in distribution grids with the smart inverters.