Author : R.Madhan Mohan 1
Date of Publication :7th March 2017
Abstract: The renewable policies in various countries are driving significant growth of grid connected renewable generation sources such as Solar Photovoltaic (PV), wind, biomass, Fuel Cell (FC), or micro turbines. Among all the proportion of photovoltaic (PV) generation into existing power system generation mix has significantly increased in recent times. Most of the PV plants are getting connected to low/medium voltage distribution level as distributed generation (DG). The uptake of an intermittent power from the PVs is challenging the power system operation and control. The network voltage control is one of the major challenges during the operation of the distribution connected PVs. The active power injection from a PV plant causes variable voltage rise. This forces the existing voltage control devices such as on-load tap-changer (OLTC) and voltage regulator (VR) to operate continuously. The consequence is the reduction of the operating life of the voltage control mechanism. Also, the conventional non coordinated reactive power control results in the operation of the VR at its control limit (VR runaway condition). But the existing methods are does not consider detailed impact of DG such as PV on autonomous local control setting of voltage regulator. This paper proposes a new technique for voltage regulation of a radial medium (MV) distribution system in presence of distribution generation (DG) units. The proposed technique consists of the coordinated actions of on-load tap changer (OLTC) of transformer and reactive power coordination in the distribution network by the impact of PV generation. Simulation results reveal that the proposed control method is capable of maintaining the system voltage within the permitted range.
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