Improvement of Power Losses and Voltage Drops 20kV Distribution Network at Intako Feeder Porong Sidoarjo

Electrical energy is required for almost all activities in life, it can be said that electricity is the main support of human life. A reliable and efficient electrical energy distribution system is needed to fulfill this, but power losses and voltage drops will definitely occur. Solutions that can be provided to reduce losses and voltage drops are by setting tap changers on substation transformers and also up-rating overload transformers. The method used in this research is simulation in the ETAP application with the data obtained and focuses on calculating and improving power losses and voltage drops in the 20 kV distribution system of PT PLN (Persero) ULP Intako Porong. Based on the results of load flow analysis, there are 8 overload transformers, namely PC415 (108.7%), PC18 (91.3%), PC82 (89.7%), PC122 (89.3%), PC194 (99.2%), PC533 (81.9%), PC589 (137%), PC671 (87%). There are 3 buses that experience voltage drops exceeding SPLN standards (-10% and +5%) while when referring to IEC standards (-5% and +5%) there are 24 buses that experience voltage drops not according to standards. The total active power loss is 58,8 kW and the total reactive power loss is 285 kVAR. Conditions after setting the tap changer on the substation transformer by -2.5 on the primary side can reduce the critical voltage drop on several buses, but the transformer overload bus has not met the IEC standard of nominal voltage. Conditions after up-rating the transformer experiencing overload conditions can reduce the voltage drop value so that all buses are in accordance with IEC standards (-5% and +5) of the nominal voltage. The value of active power losses has decreased from 58,8 kW to 51.0 kW and the value of reactive power losses has decreased from 285 kVAR to 273.2 kVAR.