System modeling of the impact of multiple capacitor coupled substations located at different proximities on a transmission network

Abstract

Electricity plays a vital role in the economy of any nation, and its availability has transformed from being a luxury to being an essential requirement. However, the implementation of conventional distribution networks in sparsely populated rural areas is often deemed economically impractical. Consequently, the exploration of alternative technologies for rural electrification becomes imperative. One such technology is the Capacitor Coupled Substation (CCS), which taps electrical power from high-voltage lines through coupling capacitors. Given that capacitors can introduce interference in an electrical system, the deployment of a CCS necessitates consideration to minimize these network disturbances. This paper modelled and analyzed the impact of multiple CCSs on the electrical transmission network, with a specific focus on the impact on the transmission line voltage when multiple CCSs are located at different proximity to one another. A typical electrical transmission network with fixed supply voltage represented as 230kVac and downstream parameters with a 230kVac and 100 kW load was selected. A system model comprising three CCSs, located at known proximities from one another, was developed using MATLAB/Simulink to simulate the network's response when one or more CCS units are connected or disconnected from the electrical transmission network. Three prototypes were also constructed to represent real-world electrical systems with different loads. The model simulation was executed while connecting and disconnecting one or more CCS at a time and at different proximities from one another within the electrical transmission network. The same procedure was repeated on the prototypes where they were connected and disconnected from the selected network. The proximity to one another was represented by different resistances which represented the electrical transmission lines between the different locations of each CCS on the electrical network. The obtained test results were subjected to comparison across three platforms: the MATLAB/Simulink model, physical prototype testing using a multimeter, and digital testing using an oscilloscope. The results showed negligible disruptions on the supply side and downstream side of the transmission network. The primary goal of this research was to provide valuable insights into the potential application of CCS technology in rural electrification by examining its impact on the transmission network. Further analysis is recommended to understand the impact of each critical component within a CCS.Capacitor Coupled Substation; Rural Electrification; System Modeling; Multiple CCS