pitch system failure analysis
6.1 Common causes and treatment methods of pitch control system
6.1.1 Difference in pitch angle
Reason: The blade angle obtained by the rotary encoder (A encoder) on the pitch motor will be compared with the blade angle obtained by the blade angle counter (B encoder). The difference between the two cannot be too large. If the difference is too large, an error will be reported.
Treatment method: 1. Since the B encoder is a mechanical cam structure, it meshes with the pitch gear of the blade, the precision is not high and will wear continuously, and there may be a large deviation when there is a large sway, so the first reset, the trouble of troubleshooting 2. If the fault is reported repeatedly, enter the hub to check the A and B encoders. The check procedure is to look at the encoder wiring and plug first. If the plug is loose, you can manually adjust the encoder to see if the encoder value changes consistently after tightening. If the value is constant or irregular, check the line for broken wires. The mechanical strength of the encoder wiring is relatively low. When the hub rotates, under the action of centrifugal force, it may be loose with the pin, or the core is half-cut and half-closed. At this time, although it can be reset, the rotation speed is high and loose. When the signal reaches a certain level, it will be lost. Therefore, you can use the hand to shake the line and the plug. If it is found that the value is jumping during the shaking, you can unplug the plug and use the multimeter to measure the on/off. If there is no way, the time and time will be broken. Re-spin the pins or wiring, and replace the new line directly if it is not easy to handle. Excluding these two points indicates that the encoder body may be damaged and replaced. Since the cam structure of the B encoder is fragile, the cam is broken many times, so the cam should also be inspected.
6.1.2 Blade does not reach the limit switch action setting value
Cause: The blade is set to the 91° trigger limit switch. If there is a certain deviation between the angle and 91° when the trigger occurs, the fault will be reported.
Treatment: Check the actual position of the blade. When the limit switch is running for a long time, it will loosen, resulting in a large angle when hitting the limit position. At this time, one person needs to enter the blade. One person finely adjusts the blade angle on the central controller, observes the angle of reaching the limit position, and then refers to this angle. When the position of the position switch is re-adjusted to just trigger, the angle is cleared back to 91° on the central controller. The limit switch is bolted to the hub and requires 2 small adjustable wrenches or 8mm forks for adjustment.
6.1.3 A blade 91° or 95° trigger
Sometimes it is triggered by mistake, reset. If it can't be reset, enter the wheel hub check, there is a garbage card main limit switch, causing the limit switch to trigger in advance, or the 91 degree limit switch wiring or its own damage failure, resulting in 95° limit. The switch triggers.
Cause: The blade reaches the 91° trigger limit switch, but the blade cannot move or disengage from the limit switch during reset.
Treatment method: firstly manually pitch the blade and then try to reset it. If the blade does not move, there are some possible reasons: 1 The manual pitch signal of the cabin cabinet cannot be transmitted to the central controller; the terminal can be 141 in the cabin cabinet and After the terminal below the 140 terminal is shorted, the manual pitching 2 checks whether the switch in the axis control cabinet is likely to jump due to overcurrent. If the blade is adjusted to 90° after the switch is closed, the control paddle in the 3-axis control box can be reset. The leaf change will damage the 6K1 contactor, check if the damage is replaced, and check other electrical components for damage.
6.1.4 pitch motor temperature is high
Cause: The temperature is too high, most of which is caused by the heating of the coil. It may be caused by the internal short circuit of the motor or the external load, and the overcurrent also causes the temperature to rise.
Treatment method: first check the external cause that may cause the fault: the pitch gear box is stuck, the pitch gear is clipped with foreign matter; then the cause caused by the electrical circuit is checked. It is common that the electric brake of the pitch motor is not turned on, and the electrical can be checked. Whether the brake circuit has a broken wire, whether the contactor has a card or the like. Exclude external faults and check if the internal insulation of the motor is aging or damaged, resulting in a short circuit.
6.1.5 Slurry control communication failure
Reason: The communication between the hub controller and the main controller is interrupted. Under the premise that the central controller of the control cabinet is not faulty, the main fault range is the signal line. From the cabin cabinet to the slip ring, the slip ring enters the hub. Interference, disconnection, damage to the aviation plug, poor contact of the slip ring, damage to the communication module, etc.
Treatment method: use a multimeter to measure the voltage at the incoming end of the central controller is about 230v, and the voltage at the outlet end is about 24v, indicating that the central controller is fault-free, continue to check, and pull out the communication line of the hub side hub, red and white lines, green and white. Line, the red and white line is grounded, the hub side multimeter is grounded by a test lead. If there is resistance indicating conduction, there is no disconnection, there is a disconnect to enable the spare line. If the fault persists, continue to check the slip ring. Communication failures are caused by slip rings. When the gearbox leaks seriously, the oil enters the slip ring. The oil adheres to the oil film between the slip ring and the pin, which acts as insulation, causing the pitch communication signal to be intermittent, the oil becomes sticky in winter, and the pitch communication failure is more It is common. Generally, the fault can be eliminated after cleaning the slip ring, but this method is not a cure for the problem, and the solution from the root cause is to solve the oil leakage problem of the gear box. The pitch communication caused by the slip ring may be caused by pin damage, unstable fixing, etc. If there is no problem with the slip ring, the hub end wiring must be disconnected from the slip ring end line for alignment. The purpose of the calibration line is to Check the line for faults, short connections, broken skin, grounding, etc. The slip ring seat rotates with the main shaft, and the inner wire is easy to rub against the slip ring seat, causing the grounding to be broken, and can also cause pitch failure.
6.1.6 pitch error
Cause: The fault that is sent inside the pitch controller, the pitch controller OK signal is interrupted, the pitch controller may be faulty, or the signal output is faulty.
Treatment method: This fault generally occurs together with other pitch faults. When the controller fails to control the pitch, the PITCHCONTROLLEROK signal is 0. It can enter the hub to check whether the central controller is damaged. Generally, the central controller is faulty, which may result in manual failure. Paddle, if you can manually pitch, check whether the signal output line has a virtual connection, disconnection, etc., the aforementioned slip ring problem can also cause this failure.
6.1.7 Pitch failure
Reason: When the wind wheel rotates, the cabin cabinet controller should adjust the pitch position according to the speed to make the wind wheel rotate according to the fixed value. If the transmission error or delay within 300ms can not convey the motion command to the pitch controller, then in order to avoid the speeding Reported an error.
Treatment method: The signal of the cabin cabinet controller cannot be transmitted to the pitch controller mainly caused by signal failure. The main signal that affects this signal is the signal line and the slip ring. Check whether there is voltage at the signal terminal. If there is voltage, the controller will pitch the signal. Issue, continue to check the cabin to the slip ring part, if there is no fault, continue to check the slip ring, then check the slip ring to the hub, and check the fault step by step.
Cause: The detected pitch speed exceeds 31° per second. Such a speed generally does not occur, mostly due to a rotary encoder failure. Or caused by the RPMOK signal line problem from the hub.
Treatment method: Refer to the encoder problem that checks the faulty processing method of the pitch encoder, and the encoder is turned to check the signal transmission problem without failure.
