Method and device for detecting supercapacitor in pitch system

Abstract

An embodiment of the present invention provides a method and device for detecting a supercapacitor in a pitch system. The method includes: obtaining the output current of the charger in the pitch system at the initial moment of charging to the supercapacitor by using the PID algorithm and the subsequent process , the control input used by the PID algorithm is the voltage deviation between the given voltage value and the actual voltage value of the supercapacitor, the given voltage value is a fixed value, and the voltage deviation at the beginning of charging is 0; according to the output current and the PID The control logic of the algorithm calculates the voltage deviation, and takes the change of the voltage deviation as the change of the actual voltage of the super capacitor during the charging process; it is calculated according to the change of the actual voltage of the super capacitor during the charging process and the output current in the corresponding time period The capacitance of the supercapacitor. The solution provided by the invention can quickly, conveniently and accurately detect the capacity value of the supercapacitor in the pitch system of the wind turbine, and the detection process does not need to be stopped, and online detection can be realized.

Description

technical field [0001] The invention relates to the technical field of wind power, in particular to a method and device for detecting a supercapacitor in a pitch control system. Background technique [0002] When the wind turbine (referred to as "wind turbine") is in normal operation, when the wind speed exceeds the rated wind speed of the unit, in order to control the power output, the pitch control system keeps the speed of the wind rotor constant by controlling the pitch angle of the blades. When the wind turbine fails, the pitch control system will perform an emergency propeller retraction function to realize pneumatic braking and ensure the safety of the unit. In the case of normal power supply from the grid, the pitch control system relies on the grid to work; when the grid fails (such as grid power failure or low voltage ride through), the pitch control system needs to have a backup power supply to power the pitch operation, in order to prevent In the event of a majo...

AI Technical Summary

Problems solved by technology

[0006] 1) In the shutdown mode of the wind turbine, cut off the output of the charger, consume the energy of the supercapacitor through energy-consuming equipment such as a motor, and then turn on the charger to charge the supercapacitor, and test the capacitance of the supercapacitor during the charging process; Because the output of the charger needs to be cut off first, the method must be tested in the shutdown mode, and online detection cannot be realized (detection when the wind turbine is running); in addition, this method is not conducive to the realization of automatic testing, because automatic testing can only use timing measurement When the automatic measurement time is up, all wind turbines will be disconnected from the grid for capacity detection, which will affect the power generation on the one hand, and on the other hand, may cause fluctuations in the grid due to the batch disconnection of wind turbines; while the manual test mode Next, because the charger needs to be cut off, for the sake of safety, the three blades are generally tested one by one, so the whole test takes a long time, generally takes 15 minutes. For the entire wind farm, the loss of power generation cannot be underestimated;

[0007] 2) During the operation of the wind turbine, directly cut off the output of the charger for a period of time, wait for the supercapacitor to drop to a certain value, and then turn on the charger to charge the supercapacitor; the disadvantage of this method is: since the purpose of detecting the supercapacitor is In order to monitor the performance of the supercapacitor, cutting off the charger without knowing the performance of the supercapacitor has certain hidden dangers to the safety of the wind turbine;

[0008] 3) Use a discharge device to manually detect the discharge of the supercapacitor. This method requires shutdown and testers to board the wind turbine for testing, and its labor and time costs are high.

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