Wayang Windu Integrated Control System - The Control Concept for Modern Geothermal Plant?

Abstract

An Integrated Control System for geothermal plant is a new control and operation concept. The system is applied for the first time on Wayang Windu Geothermal Project. The system objectives, design concept and the hardware environment are presented. The main objective of the system is to integrate the steamfield and the station through a common operation and control philosophy. This enables the plant to operate automatically at its nominal electrical output for the total operation time, at the same time keeping the separation pressure stable with no steam venting during normal operation. The system is designed as a software package running within the project DCS. It controls the turbo generator by operating the turbine control valves through the governor. On the steamfield side the system operates remotely operable wellhead valves that particular wells are equipped with. A dynamic model of the project has been designed and implemented during the factory acceptance test. At present the system that controls one unit and the steamfield has been partially commissioned. However, the system has been designed to enable more units to operate as a set. An Integrated Control System, although developed for a new project, could easily be implemented on existing geothermal plants.