ABSTRACT

Nathaniel Bijang, The South Sulawesi Electrical Power Transmission System Load Flow Analysis using the Direct Current Method (supervised by Muhammad Arief and Muhammad Tola).

Load flow analysis of an electrical power transmission system is required to provide accurate information regarding the condition of the generation and loading system and the performance of the electrical power system in general. This is a case study of the electrical power system in South Sulawesi, Indonesia. The analysis is primarily derived using the direct current (DC) method with the current is assumed constant.

The analysis has shown that the power flow from bus 11 at Sengkang to bus 10 at Soppeng is the largest inter-bus power flow carrying 120.4 MW of power. This figure is compared to the result of a simulation using the Power World Simulator (PWS) Version 8.0, a software package known to be based on the alternating current (AC) method or the Newton-Raphson method of power flow analysis. The AC method is different from the DC method in terms of the calculation of the transmission losses. The AC method calculates the power flow at the generator bus as the sum of the power flow at the load bus and the transmission losses, while the DC method assumes the power flow at the generator bus is equal to the power flow at the load bus.

The transmission loss measured from the difference between the power flow calculated using the AC method and the power flow calculated using the DC method is 5.44%. This is tolerable, since the local electrical power company tolerates 4% to 6% of transmission losses in the system.