Wind power generation units of the hydraulic system is actually brake system drive, the main to execute the rev. Stop the wind generator task. Usually it consists of two pressure keep return composition: all the way through the accumulator is supply impeller brake system; All the way through the accumulator is supply yaw brake system. The two circuit task is when the wind generator during normal operation, make fan brake system always maintain the pressure. When pressure sensors to pressure value is less than the set value system, PLC will control hydraulic pressure station motor start to compensate for the loss of the pressure, the pressure value in the set value above always
Hydraulic system pressure of work is the actual change is always in the state of the reasons within the system, disclosure, the oil temperature change and electromagnetic valve movement and the oil problem. In theory the hydraulic elements not inside leaking, and actually components inside leaking can not be ignored. The higher the oil temperature the rare inside leaking oil, the more serious, the lower the pressure. The hydraulic oil pollution, it is to show from the outside with air, water and various curing content to wait, use of corrosion of metal powder such as mixing, and destroys sealing material, coating and broken substance. The oil contamination, will aggravate the hydraulic element relative motion between parts wear, cause throttling the hole of rotary motion picture card blocked or death hydraulic components can't work normally. Used in hydraulic system of compressibility is very small, in general, oil may think that oil is incompressible. But the air compressibility is very big, about ten thousand times the oil, so even if the system contains a small amount of air, its influence is also a lot of, dissolved in the air, in the low pressure oil will escape from the oil, have a bubble, form caities which act to high in the phenomenon, and under the action of pressure oil, these bubbles and soon breached, by compression, and makes the system sharply in produce noise, and at the same time in the gas by compression suddenly will give off a lot of heat, so as to cause local overheating, speed up the oil temperature is high, make hydraulic components and hydraulic oil were damaged. The air compressibility big, still can bring about working organs have fault creep, destroy the smoothness of the work.
Below will respectively to the yaw braking system and the impeller brake system is analyzed, and the fan operation hydraulic system driver.
A, the impeller brake system
Change propeller system is wind power conversion system's main brake system (the first and the second). It is designed to every blades have independent electric drive, and a battery to ensure the safety of the fault. There is a mechanical brake installed in the transmission chain high-speed side. This mechanical braking system is wind power converter system of the third braking system, but it is not designed to when the first and second brake system failed to keep wind energy conversion system in any conditions not more than speed limit allowed. Machinery brakes is the basic function of as the rotor system by change from the rotor slowdown to stop after it completely. Machinery brakes also used in the emergency stop when wind power conversion system slow down as soon as possible. This the mechanical brake drive mode is a hydraulic drive source for.
Hydraulic system of impeller brake system: normal operation, the brake open and close brake electromagnetic valve, release the brake rotor to electricity. Emergency cases, brake open and close brake electromagnetic valve lose electric, and accumulator pressure oil into the open valve brake the brake caliper, rotor braking. Pressure sensors in the brake oil chamber pressure below a certain value development (broken. Pressure sensor to monitor the accumulator ChongYa 2, when pressure value is less than the set, PLC control the oil pump motor start ChongYa.
Second, the yaw brake system
Yaw braking mechanism consists of 8 ~ 10 hydraulic control yaw brake discs to form. The system has two pressure, provide the damping yaw respectively and yaw end of braking. When the yaw when not working all brake brake locked; When the engineroom of wind all brake discs at half loosen state, set enough, keep smooth damping cabin yaw, at this time the yaw brakes used as a damper; Automatic solution cable, brake yaw released in full.
Hydraulic system yaw brake system: the yaw the electromagnetic valve, pressure to electricity, yaw brake release; Yaw half relief electromagnetic valve to electricity, 45 bar relief valve adjust the pressure when half brake; The throttle control brake up press time.
Three, when the fan operation hydraulic system driver
Hydraulic system in brake with ball valve, so that side of the screw in the piston hydraulic pressure for braking when can the wind generator. When boot instructions issued, brake open electromagnetic valve, brake calipers to electricity to the fuel tank, and brake so far and release. Suspended during the state of the operation to keep. When down instructions issued, brake open electromagnetic valve, losing electricity from the pressure of the pressure reducing valve accumulator and oil can be through the brake open electromagnetic valve into brake hydraulic cylinder, realize the braking when stop. When the emergency stop, brake open electromagnetic valve lose electric, and accumulator will pressure oil through the brake open electromagnetic valve into the brake caliper hydraulic cylinder. Brake hydraulic cylinder of speed by the throttle control.
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