ANALYSIS OF POWER LOSSES DUE TO DISTRIBUTED GENERATION INCREASE ON DISTRIBUTION SYSTEM

Abstract

Small-scale power plants injected into the existing distribution systems are commonly called as embedded or dispersed generation. The continuously increasing penetration of distributed generation becomes a challenge for conventional power systems. Recently developed distributed generation systems are mostly categorized into small scale plants in terms of power output. However, they are expected to be massive in terms of number. The power plants injection as well as their spread in the whole distribution systems will influence the power flow and losses in the network. Some researches have been undertaken recently to relate the embedded plants with the power losses and voltage profile of the networks. This paper presents a study on the influence of penetration level and concentration of distributed generation on power losses in the network. Steady-state power flow analysis is used to examine the power losses variation for a variety of distributed generation penetration. Based on the power flow analysis, voltage profile and power losses due to the power plants injection can be determined. The influence of various technologies used is also considered, including the use of wind power, photovoltaic and micro-hydro power plants. Four different scenarios to determine the effect of dispersed generation injection are proposed, starting from the original grid in the first scenario, being added with photovoltaic plant (0.5MVA) in the second scenario, the addition of wind power plant (0.5MVA) to the grid in the third scenario, and the fourth is the addition of microhydro power plant (1x2.5MVA) to the grid. The considered scenarios are based on the existing potential of the plants in the network system under concern, i.e. the Sengkaling Substation of the Pujon Feeder in Malang, Indonesia. Based on the analysis results, the injection of microhydro power plant (Scenario 4) presents the best influence being compared to the three other scenarios. The microhydro power potential is greater than that of the PV and wind power plants. Besides, it is well located in the middle of distribution system. From the point of view of power loss analysis, Scenario 4 also results in the smallest loss compared to the other scenarios. The least favorable losses reduction is given by Scenario 3 using the wind power plant injection, although the injection of renewable energy power plants in this study in general is proven to improve the voltage profile and reduction of power losses in the system.