Optimal Sizing and Location of Shunt Capacitors in Medium Voltage Underground Power Cables: A Case of Minimum Cost

This paper introduces a method to determine optimal sizing and location of shunt capacitors in medium voltage Underground Power Cables or in distribution system. To execute this method, two models of standard branch and the Newton-Raphson method are also mentioned to analyze and determine values of bus voltage and currents going through lines in whole system. The EN 50160 standard is introduced to evaluate all operational parameters and propose solutions to reduce risks. In additionally, the cost function method is introduced basing on cost of purchasing compensative device, power loss in own compensators and whole system after compensating. By considering partial derivative of cost function with respect to variables, optimal sizing and location of shunt capacitors can be determined for all buses in the system. Analyzing the system by using the Newton-Raphson method in stable mode, all operational parameters are evaluated to see the benefit of placing capacitors in some criterions: reduce the current going through all lines and increase value of bus voltage in whole system. Theory research is verified by simulation results carried out in Matlab 2016 software.