Interfacing solar PV power plant with rural distribution grid: challenges and possible solutions

Abstract

In rural India and similar countries, the distribution grid is radial in nature where the power generation stations are located far away from the consumption points which makes the grid weak in nature at the site of consumption. Significant penetration of solar photovoltaic within the weak distribution network can cause voltage issues such as voltage rise and dip. A comprehensive simulation method as well as a simple mathematical modelling are developed. The study reveals that the voltage quality issue occurs not only due to the considerable penetration of photovoltaic (PV) but also due to the connected load and X/R ratio of the feeder. The proposed model describes a method to estimate the permissible PV penetration ratio for the distribution feeder. This helps in the (i) selection of overhead conductors to improve the X/R ratio, (ii) utilisation of the on load tap changing facility within the distribution transformer and (iii) connecting/disconnecting flexiloads for improving PV penetration.

Keywords

• x/r ratio
• short circuit ratio
• weak distribution grid
• solar pv (photovoltaic)
• permissible pv penetration ratio
• oltc (on load tap changing)