The impact of capacitor coupled sub-station in rural electrification of sub-Saharan Africa

Abstract

The overall electricity access rate is still very low in most sub-Saharan African (SSA) countries. The rate is even lower in rural areas where most of the population in these countries lives. One of the main obstacles to rural electrification (RE) is the high cost of laying the distribution infrastructure owing to the dispersed nature of loads and low demand. Thus, electrifying the rural areas needs to be considered holistically and not just on the financial viability. To reduce cost, it is important that un-conventional rural electrification (URE) technologies, which are cheaper than the conventional ones be explored. This paper investigates the adoptability and maximum penetration level of sub-station based URE i.e. Capacitor Coupled Sub-station (CCS) technologies in power transmission networks with regard to voltage quality, stability, and capacity constraints without steady and transient state voltage violation. Quantitative data collected from practical power transmission lines in Kenya were used for empirical and analytical approaches developed in this research. The paper developed a method of determining maximum allowable penetration level of CCS without steady state voltage violation derived from a modified distributed generation analogy. The method was based on determination of voltage sensitivities from linearized power system model. Consequently, this method was used to validate repetitive power flow simulations carried out in the case studies.