China’s hydropower has a history of more than a hundred years. According to relevant data, by the end of December 2009, the installed capacity of the Central China Power Grid alone had reached 155.827 million kilowatts. The relationship between hydropower stations and power grids has evolved from the input and exit of a single power station directly affecting the stable operation of the power grid to the input and exit of a single unit of a small hydropower station, which has basically no major impact on the operation of the power grid.
In the past, many functions and technical requirements of our hydropower stations were for the service of the power system. These services not only increased the complexity of power station control and protection, but also increased the investment in equipment and management, and also increased the work pressure of power station operation and management personnel. With the separation of power plants and the weakening of the role of small hydropower stations in the power system, many functions have no practical significance and should not be undertaken by small hydropower stations, and they have constrained the realization of automation of small hydropower stations and increased investment in small hydropower stations.
After the climax of large hydropower station construction in 2003, the transformation of small hydropower stations was also stranded due to lack of funds. Due to the lack of smooth communication and publicity channels for small hydropower, it is difficult to grasp advanced technologies and ideas, resulting in a lag in knowledge update in the entire industry.
In the past ten years, some small hydropower stations and manufacturers have spontaneously discussed and studied the management mode and equipment technology development of small hydropower stations, put forward some good ideas and developed good products, which have high promotion value. 1. When the power system fails, the power station can consider shutting down directly. If there is water leakage in the guide vane, the valve can be closed to reduce the waste of water in no-load operation. 2. The power factor of the generator is increased to 0.85-0.95 to reduce the investment in the generator. 3. The insulation material of the generator is selected as Class B to reduce the investment in the generator. 4. Generators below 1250 kilowatts can use low-voltage units to reduce the investment in generators and electrical equipment and reduce operation and maintenance costs. 5. Reduce the excitation multiple of the excitation. Reduce the investment in excitation transformers and excitation components. 6. Use the oil source of the high-pressure speed regulator to supply brakes and top rotors after reducing the pressure. The oil system and the medium and low-pressure gas systems can be cancelled. Reduce the oil and gas circuit equipment. 7. The valve uses an electric operating mechanism. Reduce the investment in the valve operating mechanism and simplify the valve control circuit. Reduce management and maintenance costs. 8. The runoff power station adopts a constant high water level operation mode. Effectively utilize water resources. 9. Configure well-equipped and high-quality automation components. Realize unmanned operation. 10. Use multifunctional and highly integrated intelligent devices to reduce secondary equipment configuration. 11. Promote the concept of free commissioning, free operation and free maintenance of secondary equipment. Let the power station operation and management personnel work decently and happily. 12. Realize the socialization of power station operation and maintenance. It can quickly improve the overall operation and management level of the small hydropower industry. 13. The low-voltage unit adopts an integrated control protection screen to achieve unmanned operation. 14. The low-voltage unit adopts a new type of low-voltage unit microcomputer high oil pressure automatic speed regulator. It can provide basic automation equipment for unmanned operation. 15. Units with a single unit of less than 10,000 kilowatts can adopt a brushless excitation mode. The excitation equipment can be simplified and the excitation transformer can be cancelled.
1. The optical fiber water level meter is passive, lightning-proof and easy to install. It is a replacement product for the water level meter of a small hydropower station. 2. The optimized structural design of the low-cost microcomputer high oil pressure speed governor is more than 30% lower than the same type of microcomputer high oil pressure speed governor sold on the market under the premise of the same technical indicators, the same functions and the same materials. 3. The microcomputer high oil pressure speed governor of the low-pressure unit is designed according to the national technical standards for the microcomputer high oil pressure speed governor designed for low-pressure units. The price is: 300–1000 Kg·m speed regulation power, 30,000 to 42,000 yuan/unit. This product has become a replacement product for the speed regulation equipment of low-pressure units. Its high cost performance and safety will replace the manual electric speed governor and various energy storage operators that lack safety protection.
4. The new small turbine high oil pressure speed governor (special research product) is suitable for the operation and control of grid-connected non-frequency-regulated hydro-generators. It can be used with the integrated control panel of the low-pressure unit or the intelligent control device of the low-pressure unit to realize manual startup, grid connection, load increase, load reduction, shutdown and other operations at the side or remote of the machine. The turbine speed governor has gone through a period of development, especially in the past two decades. Driven by the development of computer technology, automatic control technology and modern hydraulic technology, the speed governor has undergone essential changes in structure and function. With the continuous increase in the capacity of the power grid, the capacity of a single turbine generator set has reached 700,000 kilowatts. Large power grids and large units have higher and higher requirements for speed governors, and speed governor technology is also developing with the changes in this demand. Almost all small and medium-sized turbine speed governors have transplanted the above framework, concept and structure. Facing units below a few thousand kilowatts, all of the above seems too luxurious. For rural hydropower station units, the simpler the structure, the lower the purchase cost, operation, use and maintenance costs, provided that the operation and control are practical. Because simple things can be used and operated by everyone regardless of their educational level. If the equipment fails, it is also easy to repair. 300–1000 Kg·m speed regulating power, the estimated price is about 20,000 yuan/unit.
5. Low-voltage unit integrated control panel The low-voltage unit integrated control panel is specially designed for low-voltage hydropower stations. The control panel consists of generator outlet circuit breakers, excitation components, intelligent control devices, instruments, etc., which realizes the optimal configuration of the primary and secondary equipment of a hydropower generator set in one panel. The screen adopts a fully enclosed structure with a high level of protection. The control panel is fully functional and easy to operate. It is suitable for low-voltage hydropower generator sets with a single capacity of less than 1000kW. The entire set of equipment has been fully tested by the manufacturer and can be put into operation after on-site installation, which simplifies the joint commissioning work and reduces the commissioning and operation and maintenance costs. The low-voltage unit integrated control panel integrates control, measurement, generator protection, excitation system, speed governor control, sequential control, automatic quasi-synchronization, temperature inspection, automatic economic power generation, metering, monitoring instruments, intelligent diagnosis, remote interaction, safety warning and other functions. The system supports remote monitoring and control functions, and the background computer realizes remote measurement and control (such as forebay water level and operation information, etc.) and management functions of the power station units through communication lines; the system also has real-time data query, active alarm for electrical and non-electrical quantity over-limit and state quantity change, event query, report generation and other functions. This product is a replacement product for the low-voltage unit control and protection screen.
6. Low-voltage unit intelligent control device The low-voltage unit automation control device integrates twelve major functions such as unit sequence control, automatic monitoring, temperature inspection, speed measurement, automatic quasi-synchronization, automatic economic power generation, generator protection, excitation regulation, speed governor control, intelligent diagnosis, remote interaction, safety warning, etc. It has current quick-break protection, overcurrent protection, overload protection, overvoltage and low voltage protection, frequency protection, demagnetization protection, excitation overload, overspeed protection, reverse power protection, and non-electrical quantity protection. 7. Large-capacity low-voltage units With the continuous increase in the construction and management costs of small hydropower stations and the continuous improvement of generator manufacturing technology, the unit capacity of low-voltage unit hydropower stations in my country has reached 1,600 kilowatts, and the operation is good. The heating problem we worried about in the past has been well solved through design, material selection and manufacturing process. Equipped with an integrated screen and a microcomputer speed regulator, it can run automatically without relying on high-quality operators. The control and regulation technology has reached the intelligent level.
Post time: Dec-27-2024
