Completion of a 1,120-MVA Turbine Generator for Huadian International Zouxian Power Plant in China

INTRODUCTION THERE has been a trend in recent years toward larger capacity turbine generators. Larger output systems draw worldwide interest, and from the standpoint of efficient use of resources, expectations are particularly focused on large-capacity 2-pole generators for coalfired power plants. Hitachi has been in the forefront of efforts to develop better large-output 2-pole generators to meet these needs, and recently delivered a 1,025-MVA 60-Hz generator to a power plant in the U.S. in 2005(1),(2). This was Hitachi’s first 1,000-MVAclass installation of a 2-pole type generator, and extensive factory and onsite testing at the plant has proven the generator’s performance and reliability. OVERVIEW: Hitachi, Ltd. has completed construction of a 1,120-MVA turbine generator (2 poles, 50 Hz) for the Huadian International Zouxian Power Plant of China Huadian Corporation in China, and its performance has been fully verified through factory testing. With a maximum output of 1,230 MVA — some 1.6 times greater capacity than the 778-MVA output of Hitachi’s next larger similar generator — the generator is one of the world’s largest-class single unit turbine generators ever developed for a thermal power plant. This substantial increase in output could only be achieved through a combination of sophisticated technologies, including an advanced hydrogen gas and distilled water cooling system and 27-kV high-voltage insulation. Every effort was made to enhance the performance and reliability of the generator by fully exploiting advanced analytical procedures and tests including rotor vibration analysis, stator core end electromagnetic analysis, network ventilation analysis, and stress analysis of all key parts of the generator. Fullscale rotational tests including efficiency, temperature increases, shaft vibration, and other performance measures confirm that the 1,120-MVA turbine generator more than satisfies all design specifications.