Research On Small Hydro-generators' Speed-adjustment Schemes And Integrated Devices Of Protection, Measurement And Control

Most of our country's running small hydropower stations are old and out of date in its design and equipments. Because of technology restraint, they are in a low level of equipments, automation and technology status. Problems such as low in operation level, low in economic benefit and frequent in accidents are widely exist. So, it's necessary to reconstruct small hydropower stations. Nowadays, automation and Unattended Control reconstructions are carrying out in domestic small hydropower stations, because of no automatic equipments that are reasonable in its qualities and prices available, it will increase the investment and make operations and maintenance more complex , all this make it hard to level up the automation status of small hydropower stations. It's necessary to develop a kind of automatic integrated devices that are low in price just for hydropower stations to meet the demands of the market.In this paper, the research and development status of integrated devices of protection, measurement and control used in small hydropower stations in and abroad are analyzed, especially the automation status of domestic small hydropower stations. According to the actual requirements of working spots, the characteristics of small hydropower stations are analyzed, a design scheme including generators'protection, speed-adjustment, excitation and synchronization functions is proposed, and the hardware structure and software structure of the device are explained in details.Based on brief, economic and reliable design principles, a protection configuration scheme of small hydro-generators that predigests generators'protection functions and logic management is proposed in this paper.. and automatic Quasi-Synchronization functions are also included in this device. The synchronization approaches and conditions are analyzed, and the devices'automatic Quasi-Synchronization procedure chart is given.Nowadays, the mainly used speed-adjustment methods in small hydro-power stations are manual adjustment and manual-motor driven adjustment. In this paper, based on economic and automatic principles, the traditional manual-motor driven governing approach is automated and can achieve generators'turn-on and shutdown flexibly. During the paralleling period between generators and system, we can adjust generators'rotate speed automatically by the governing system and adjust the voltage by cooperating with the excitation system.