Monitoring of power and wind parameters during the

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Monitoring of power and wind parameters during wind turbine operation

the power parameters to be continuously monitored by wind turbine include three-phase voltage, three-phase current output by the generator, electrical frequency, generator power factor, etc. These parameters are monitored whether the wind turbine is in parallel state or off state. They are used to judge the starting conditions, working state and fault conditions of the wind turbine. They are also used to count the active power, reactive power and total power generation of the wind turbine. In addition, the input and output of the compensation capacitor are determined according to the power parameters, mainly the generator active power and power factor

1. voltage measurement

voltage measurement mainly detects the following faults:

(1) the electric impulse phase voltage exceeds 450V for 0.2S

(2) overvoltage phase voltage exceeds 433v for 50s

(3) low voltage phase voltage is lower than 329v for 50s

(4) the electric voltage drop phase voltage is lower than 260V for 0.1s

(5) phase sequence fault

respond quickly to voltage fault requirements. Overvoltage protection is set in the main circuit, and its action setting value can refer to the impulse voltage setting protection value. In case of voltage failure, the wind turbine generator must be powered off. Generally, normal shutdown is adopted, and then it is handled according to the situation

the measured voltage can be used to calculate the power and generating capacity of the computer group after being processed by the average value algorithm

2. current measurement

faults related to current include:

(1) one phase current drops by 80% within 0.1s of current drop

(2) there is a large difference between one phase current and other two phases in three-phase asymmetric three-phase, with a phase current difference of 25%, or when the average current is lower than 50a, the phase current difference is 50%

(3) during the soft start of thyristor fault, if the current of a phase is greater than the rated prosthetic limb, it is a symmetrical current or the current is 0 continuously for 0.1s after the trigger pulse is sent

rapid response to current fault is also required. Generally, the control system has two current protections, namely, current short-circuit protection and overcurrent protection. The circuit breaker is used for current short-circuit protection. The action current is set according to the internal phase to phase short-circuit current of the generator, and the action time. 0~0.5s。 The over-current protection is controlled by software. The action current is set at twice the rated current, and the action time is 1 ~ 3S. The measured current is processed by the average value algorithm and combined with voltage and power factor to form active power, reactive power and other power parameters

current is a wind turbine generator unit that needs to be continuously monitored. It is to strive to create a new situation of high-quality transformation and development in Huaibei and inject powerful dynamic energy. If the cut-off current is less than the allowable limit, the thyristor conduction angle will not increase. When the current begins to decline, the conduction angle will gradually open until it is fully opened. During this period, short circuit and three-phase current unbalance signals of generator or thyristor can be detected through current measurement. If the three-phase current imbalance exceeds the allowable range, the control system will issue a fault shutdown command, and the wind turbine will power off

3. frequency

electrical frequency is continuously measured. The measured value is processed by the average value algorithm and compared with the upper and lower limits of the power frequency. When the measured value exceeds the limit, the wind turbine will power off

the electric frequency directly affects the synchronous speed of the generator, and then affects the instantaneous output of the generator

4. power factor

power factor is obtained by measuring voltage phase angle and current phase angle respectively. After being processed by phase shift compensation algorithm and average value algorithm, it is used to count the active power and reactive power of generator

due to reactive power, the electric current increases, the line loss increases, and the system capacity is occupied. Therefore, the load required for power transmission and the elongation value between corresponding markings shall be read. The less the inductive reactive power component, the better. Generally, the power factor shall be kept above 0.95. Therefore, the wind turbine uses capacitors to compensate reactive power. Considering that the output power of wind turbine generator often changes in a large range, the compensation capacitor is generally divided into several groups according to different capacities. It is input and output according to the power output of the generator, which is the construction site power of the 600000 ton environmental friendly adsorption new material project of Chalco Qilu Industrial Park

when the compensation capacitor is input in this way, it may cause over compensation. At this time, capacitive reactive power will be input to electricity

capacitance compensation does not change the generator operation. After compensation, the current on the generator contactor shall be greater than that of the main contactor

(II) wind parameter monitoring

1. wind speed

wind speed is measured by digital anemometer outside the engine room. The computer collects the wind speed data from the anemometer once a second; The average value is calculated every 10min to distinguish the starting wind speed (when the wind speed is v>3m/s, start the small generator, and when the wind speed is v>8m/s, start the large generator) and the shutdown wind speed (v>25m/s). The anemometer installed on the top of the engine room is located in the downwind direction of the wind turbine, which is not accurate, and is generally not used to generate the power curve

2. wind direction

wind vanes are installed on both sides of the top of the engine room, mainly to measure the deviation angle between the wind direction and the center line of the engine room. Generally, two wind vanes are used to check each other and eliminate possible false signals. The controller starts the yaw system according to the wind direction signal. When the two wind vanes are inconsistent, yaw will be automatically interrupted. When the wind speed is lower than 3m/s, the yaw system will not start. (end)

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