Analysis of Distribution Systems with DSTATCOM

Abstract

Distribution system, as the name suggest, is the medium through which power is distributed among the end consumers. Among the distribution systems, Radial Distribution System is popular due to cost and operational issues. In such systems due to high R/X ratio of the cables/lines, the voltage decreases as moved away from the source and results in high losses. Such issues of poor voltage regulation, high loses are related to the reactive power deficiency. This problem of poor voltage or reactive power compensation can be minimized or sometimes overcome by using suitable FACTS devices such as DSTATCOM. The DSTATCOM is also capable of solving various power quality issues such as voltage unbalance etc. DSTATCOMs are voltage source inverter (VSI) based devices, which regulate distribution bus voltage using reactive power compensation. The work reported in this thesis is carried out with the objective of identifying the optimal location of DSTATCOM, as well as to carry out load flow analysis with a given rating of DSTATCOM. For these purpose two stage methodologies is used. In the first stage pre-compensated load flow of the distribution system is performed. On the basis of load flow solution the voltage drop in each bus is observed. DSTATCOM is applied individually, one by one to those buses which are below the safe limit. After compensation the Rate of Under Voltage Mitigated Nodes (RUVMN) of that compensation are computed. This process is carried out for each bus and the optimal location of DSTATCOM is computed upon these two parameters. Load flow is realized using Backward – Forward sweep algorithm and the effectiveness is tested on 33 and 69 Bus radial distribution system.