A case study of underground bus chiller SCADA system and the development of custom design systems

This paper shall introduce the Taipei City Mass Rapid Transit underground section stations chiller Supervisory Control And Data Acquisition (SCADA) system and customized application software system development. Each station's existing chiller machine microprocessor Human Machine Interface (HMI) utilizes a standard communication protocol convertor and the environmental control system control room Open Protocol Master(OPM) communication equipment to pass the chiller machine operational data to the existing environmental control systems communication machine room Pulse Code Modulation (PCM)/Synchronous Digital Hierarchy(SDH) equipment. From there the signals are passed to the Central Control Environmental Room(CCER) communication machine room PCM/SDH equipment, and finally sent to the CCER data acquisition server (DAS). The operational data and settings from the station chiller machines are sent to two computer mainframe databases for monitor, control, and storage. The main contribution of this piece is to provide the CCER personnel with real-time air handling chiller machine operation data improving the environment control system reliability based on actual case studies. The air handling units are operated more efficiently, saving air conditioning electricity costs and providing a more comfortable platform and lobby environment to passengers in the high volume line underground stations. Second, the chiller machine operation data is electronically transmitted, saving the manual labor of reading the chiller data, and provides repair personnel with trend operation data and analysis. This makes the anticipated maintenance of chiller equipment possible. Finally, standard open communications protocol equipment and software format is provided, for expansion of future underground section station chiller units communication.