Nuclear-Reactor Secondary-Coolant-Pump Control with a Variable Frequency Drive System

摘要

This paper presents the use of a variable-frequency-drive (VFD) system in the nuclear-energy field. The new design provides improved control of a reactor secondary-coolant system with considerable energy and operating cost savings. Prior to using the VFD system, the flow was controlled by several coolant pumps in parallel feeding through an inline-flow-control butterfly valve. Process control used temperature feedback to position the large butterfly valve which varied the hydraulic resistance of the system, resulting in substantial energy losses at low flow rates. The new design will add a variable-frequency-drive system and an automatic-feedback control loop to one of the existing parallel 350-hp motors. The benefits of the new design are improved accuracy and flow control with decreased operating cost. Innovative techniques were required to comply with stringent safety requirements, an existing 4160-volt power system, and providing failsafe protection. (ERA citation 08:038938)