Implementation of Free Governor Action in Power Plant to Increase System Resilience of Jawa Bali Power System Network

Indonesia consists of many isolated power system networks. Jawa Bali power system is the main power system networks in Indonesia. It represents 80% of total Indonesia load and consists of various types of generator units. More than 50% of the generation come from coal steam. Due to acceleration project, in the next couple years the contribution of coal steam will increase up to 75%. In term of customer, there are significant numbers of industrial customer come from steel furnished industry. Their contribution is up to 20% of total load. The loading fluctuation of those customers, mixed with other customer loading characteristic, and slow reaction of coal steam power plant may cause instability of system frequency. In 2009, there are more than 200 times frequency excursions only caused by load fluctuation and the system resilience only about 2.86% or equivalent with 500 MW/Hz. This paper will explain about processes in implementing free governor action of power plant in Jawa Bali power system start from September 2009 until now and the impact to the system resilience of Jawa Bali power system. This paper will start with theoretical background of primary control in generator, including international standard for speed droop and dead band of unit generator and followed by historical background of the situation in the system. There will be explanation of the steps in implementing free governor action in all power plants, including coordination meeting, working group creation, site visit, individual test, simultaneously test and activation, and monitoring of free governor status in each power plant. Furthermore, constraints faced by the team will be covered as well. The impact of implementation of free governor action during normal and big disturbance is described comprehensively, including comparison with the similar situation before the implementation. Finally, this paper will tell about lesson learned in implementing free governor action of power plants in Jawa Bali power system.