Analysis of overspeed protection device for hydro-generator When the hydro-generator set is affected by sudden accidents, it is easy to cause the governor of the hydro-turbine to fail, resulting in the overspeed phenomenon of the generator. In order to effectively limit the overspeed phenomenon of hydro-generators, overspeed protection devices and. Based on this, this paper briefly analyzes the principle of overspeed protection device of hydro-generator, and further introduces the operation and maintenance of overspeed protection device of generator. Label: hydroelectric generator; Overspeed protection device; Preface of device maintenance The overspeed protection device of hydro-generator set is formed by the interaction of overspeed ring and control valve. This protection device is more suitable for various types and models of hydro-generators. When the speed of the generator exceeds the allowable value, the protection device will start immediately and stop the continuous rotation of the guide vane. Emergency stop solenoid valve of action governor. Close the guide vane quickly. The protection device is simple, reliable and relatively accurate in structure, and can play a good role in preventing overspeed accidents, thus supporting the long-term stable and safe operation of hydro-generators. 1, principle analysis of overspeed protection device for hydro-generator 1. 1 structural principle The hydro-generator is composed of overspeed ring and control valve, and the specific working principle is as follows: there is a gear ring on the main shaft of the turbine, and there are a large number of centrifugal flyweights on the gear ring, which run synchronously with the generator set and are controlled by springs. When the generator set rotates normally, the spring pressure is greater than its eccentricity, so the centrifugal pendulum will remain fixed; When the generator rotates too fast, the spring pressure will gradually be less than its centrifugal force, and the centrifugal pendulum will compress the spring to fly out and hit the control valve. Due to the control valve, the emergency stop valve will be connected to the oil circuit, and the hydro-generator will be forced to stop running and send an alarm to the control center. 1.2 principle of action In the overspeed protection device of hydro-generator, the overspeed ring is installed on the main shaft of the generator. In the above structural principle, when the generator set overspeed, the centrifugal pendulum will produce a swing angle, which will increase the maximum radius of its operation. Only in this case can it accurately hit the projection on the control valve. Under the impact, the control valve core loses its function and is pushed by the spring, so that the oil circuit is further connected, and the main and standby pressure distribution valves are opened to complete the shutdown operation of the hydro-generator. The control valve consists of a valve core, a valve body, a recovery handle, a collision block and a travel switch. Under the normal operation of the hydro-generator, each structure is relatively fixed, and only when the generator overspeed will it stop further. In addition, the main function of the travel switch is to send a stop signal to the control center; The function of the recovery handle is to manually control the valve core, reset the condition and restart the generator.

2. Operation of the overspeed protection device of the hydro-generator The overspeed protection device of the hydro-generator is used to realize the protection closing operation, which can be carried out in the following three forms: pure manual operation; When the generator set is not in the fully closed position, the electro-hydraulic reversing valve YV0 1 is in the initial position, and the hydraulic turbine relay is fixed in the pull-out position, manual operation can be adopted. During operation, firstly, turn the double-coil electro-hydraulic reversing valve YV0 1 to the only position, and carry out forced reversing operation on the valve position, so that the system input will be closed and the generator set protection will be closed to the fully closed position; On this basis, if the governor's main valve is in the centering position, the electro-hydraulic directional valve YV0 1 can be manually switched to the initial position, thus realizing the normal operation of the governor control relay. Pure electric operation; For the protection and closing operation of electric operation, the input coil of special electro-hydraulic reversing valve YV0 1 needs to be energized instantly, and the input coil will be automatically cut off after 2 seconds, and the valve position will be forced to change direction, so that the system input will be closed, and the guide vane protection of generator set will be closed to the fully closed position; If the main valve of the governor is in the centering position, the normal operation of the governor control relay can be realized by electrically switching the electro-hydraulic reversing valve YV0 1 to the initial position. Pure hydraulic operation; The control signal is sent by the reversing valve of the mechanical and hydraulic overspeed protection device to complete the protection closing operation. When the overspeed protection device is turned off after operation, it is necessary to investigate the cause of the accident in detail, and finally restore the overspeed protection device through manual reset. 3. Maintenance of the overspeed protection device of the hydro-generator For the daily maintenance of the overspeed protection device of the hydro-generator, it is necessary to clean the dust in time to ensure the clean state of the whole device; Make a regular inspection plan to ensure that the cleanliness of oil in the hydraulic system meets the ISO standard16/13; During the operation of the device, monitor the system pressure and oil temperature in real time to ensure that they are within a reasonable range; After the generator set is put into use for a period of time, it is necessary to check the device components and fixing screws in detail to avoid the phenomenon of loose device or poor contact. When the protection device is not activated, the hydraulic components should be filled with L-TSA46 turbine oil; Grease should be applied to the unpainted processing surface to prevent the equipment from rusting and affecting its performance; Sealing measures should be taken at the hole of the pipe joint to prevent dust or dirt from invading the equipment. In addition, the overspeed protection device and its components of the hydro-generator should be inspected and maintained regularly to ensure the good performance of the 0-type sealing ring of the valve block; After disassembly and inspection, before installation, ensure that the specifications of the sealing ring are standard and can be completely put into the groove; Butter paste can also be used to ensure its compactness.

To sum up, the analysis of overspeed protection device of hydro-generator is of great significance to promote and improve the operation performance of hydro-generator. Through correlation analysis, the stability and safety of hydro-generator operation can be further improved, especially during the outage of auxiliary power in power plant, and major accidents such as runaway of hydro-generator set can be effectively avoided under the action of overspeed protection device. Therefore, the overspeed protection device of hydro-generator should be extended to power plants all over the country to improve the operation efficiency and safety of the whole power plant in China. Reference: [1] Jiang Tao. Analysis of several factors affecting the accuracy of mechanical overspeed protection device [J]. Electromechanical Technology of Hydropower Station, 2016,39 (04): 20-21. [2] Wu Zhou. Miscontrol of purely mechanical overspeed protection device for hydro-generator set [A]. Information Committee of China Hydropower Engineering Society and Hydropower Control Equipment Committee of China Hydropower Engineering Society. Proceedings of 20 15 academic exchange meeting of China hydropower engineering society [C]

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Analysis of overspeed protection device for hydrogenerator

Analysis of overspeed protection device for hydrogenerator

When the hydro-generator set is affected by sudden accidents, it is easy to cause the governor of the turbine to fail, which will lead to the overspeed of the generator. In order to effectively limit the overspeed phenomenon of hydro-generators, overspeed protection devices and. Based on this, this paper briefly analyzes the principle of overspeed protection device of hydro-generator, and further introduces the operation and maintenance of overspeed protection device of generator.

Label: hydroelectric generator; Overspeed protection device; plant maintenance

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The overspeed protection device of hydro-generator set is formed by the joint action of overspeed ring and control valve. The protection device is suitable for various types and models of hydro-generators. When the speed of the generator exceeds the allowable value, the protection device will start immediately and stop the continuous rotation of the guide vane actively.