The wind turbine hydraulic system related to the electromagnetic valve

Wind turbine hydraulic system with solenoid valve solenoid valve better work on wind turbine wind turbine electrical network admin time of hydraulic system is actually the driving mechanism of the braking system, mainly to perform the wind turbine start-stop task. It usually consists of two pressure loop is all the way through the supply of accumulator impeller braking system; All the way through the supply of accumulator yaw brake system. The two circuits work task is to make fan when normal operation of wind turbines braking system always maintain a certain pressure. When the pressure sensor measured value is less than the system Settings, PLC can control the motor of the hydraulic pressure station start to compensate for the loss of pressure, the pressure value is always above the set value. Figure fan control block diagram of hydraulic system of hydraulic system working pressure is always in a state of change, actual reason mainly has a leak, the oil temperature in the system change and the action of electromagnetic valve and the problem of the oil. In theory there is no inside leaking hydraulic components, and components inside leaking actually cannot be ignored. Within the oil temperature, the higher the oil more thin, drain, the lower the pressure. Hydraulic oil pollution, it is to point to from the outside world into air, water, and all kinds of curing, etc. , used in such as metal powder mixed with rust, damage to the sealing material, coatings, such as broken. Oil pollution, exacerbate hydraulic components of relative motion between the parts of wear and tear, block or slide valve throttle holes of motion picture card dead, make hydraulic components can't work normally. Used in the hydraulic system oil compressibility is small, in the general case of oil can be thought of as incompressible. But air compressibility is very big, is about ten thousand times the oil, so even if the system contains a small amount of air, it is also very big, the influence of dissolved in the oil in the air, in the low pressure will escape from the oil, have bubbles, form the cavity phenomenon, in the high, under the effect of pressure oil, the bubbles and was quickly break, sharply under compression, noise in the system, at the same time in the gas is compressed when suddenly let out a lot of heat, so as to cause local overheating and accelerated the oil temperature is high, make the hydraulic components and hydraulic oil damage. Air compressibility is big, can also lead to crawl working organs such as fault, destroyed the work stability. Below are for yaw brake system and brake system were analyzed, and the impeller and fan operation of hydraulic system of the driver. A variable propeller system, wheel brake system is the main brake system of wind energy conversion system ( The first and second) 。 It became each blade has the independent design of electric drives, and have the battery to ensure the safety of the failure. There is also a mechanical brake installation on the high side of the transmission chain. The mechanical brake system is the third braking system of wind energy conversion system, but it is not designed to be as the first and second brake system fails to keep wind energy conversion system in any conditions shall not exceed the limits of speed allowed. Mechanical brake when the rotor by variable pitch system is the basic function of the rotor deceleration let it stop completely after operation. Mechanical brake is used for emergency stop as soon as possible to slow down the wind energy conversion system. The hydraulic drive system, the mechanical brake is used as the driving source. Figure of the hydraulic system of brake system is above the hydraulic system of impeller impeller braking system during normal operation, the brake opens and electric braking electromagnetic valve closed, the rotor brake release. Emergency cases, the brakes on and brake off solenoid valve, losing electricity accumulator pressure oil is entered into the brake caliper, brake to open the valve rotor brake. Pressure sensor in the brake oil cavity pressure below a certain value when the fault development. Pressure sensor to monitor the accumulator charging - case, when the pressure value is less than the set value, PLC control pump pressurized motor start. Second, yaw brake system yaw brake mechanism is composed of ~ a hydraulic control yaw brake disc. Yaw system, there are two pressure, providing yaw damping and yaw system at the end of the power. When the yaw brake pads when not working all the brake locked; When the aircraft to the wind all brake disc is loosen condition, set up enough damping, maintain stable cabin yaw, the yaw brake used as damper; Automatic unmoor, yaw brake pads to be released in full. Fan hydraulic system diagram of the yaw brake system above, the hydraulic system of the yaw brake system drift may bring electric pressure solenoid valve, yaw brake release; Yaw half pressure solenoid valve electric, bar overflow valve adjustment half when the brake pressure; Throttle valve control of braking pressure time. Three, fan runtime drive hydraulic system of hydraulic system at the side of the brake equipped with ball valve, so that the screw was used for pressurized piston in the hydraulic can't brake wind turbines. When the boot order is issued, the brake open electrical solenoid valve, brake calipers discharge of oil to the fuel tank, brake and release. Pause during runtime condition. After the stop order issued, brake open the electromagnetic valve, losing electricity from the accumulator and the relief valve pressure oil can be opened by the brake solenoid valve into the brake cylinder, implementation while parking brake. When the emergency stop, brake open the electromagnetic valve, losing electricity accumulator will open the solenoid valve with brake pressure oil into the hydraulic pressure brake calipers. The speed of the brake hydraulic cylinder is controlled by a throttle valve.