Test control method of back-up power supply for fan variable pitch control system

Abstract

The invention provides a test control method of a back-up power supply for a fan variable pitch control system, which comprises the following steps of: installing a super capacitor to be tested as the back-up power supply of the fan variable pitch control system, and setting basic conditions for testing the super capacitor; when a main controller of the fan variable-pitch control system issues a super-capacitor test instruction and confirms that basic conditions of super-capacitor test are met, the fan variable-pitch control system disconnects a bus contactor and a charger, when bus voltage reaches back-up power supply voltage, a super-capacitor is controlled to discharge to a brake resistor, and after the voltage of the super-capacitor is reduced to a preset difference value, the super-capacitor is controlled to discharge to the brake resistor. Stopping discharging, then connecting a bus contactor and a charger, charging the super capacitor, and calculating to obtain the capacitance value of the super capacitor; according to the method, professional capacitance testing equipment is not needed, the whole process is convenient to test, long-time shutdown and tower climbing for testing are not needed, and the shutdown time of the fan variable pitch control system is shortened as much as possible under the condition that the selected super capacitor is healthy and reliable.

Description

Technical Field

[0001] The invention belongs to the field of wind power generation, and in particular relates to a test control method for a backup power supply for a wind turbine pitch control system. Background Art

[0002] The main purpose of setting up a backup power supply in a wind turbine pitch control system is to provide the necessary power for the wind turbine in the event of an abnormal power supply from the power grid, to ensure that the blades can be aligned to a safe position, to achieve air braking, and thus to ensure the safety of the wind turbine. With the development of energy storage technology, the use of supercapacitors as a backup power supply has attracted the attention of more and more manufacturers. Supercapacitors are very suitable for backup power supplies for wind turbine pitch systems in harsh working environments due to their high power density, fast charging speed, long cycle life, and wide operating temperature range. Therefore, when selecting supercapacitors for wind turbine pitch control systems, it is particularly important to test the health of supercapacitors. However, existing technologies require special capacitor testing equipment to detect the health of supercapacitors, which is very time-consuming and labor-intensive for wind turbine pitch control system manufacturers.

[0003] Based on the long-term and dedicated research in the field of wind power generation control by the applicant and the applicant's R&D team, it was decided to seek technical solutions to solve the above technical problems. Summary of the invention

[0004] In view of this, the purpose of the present invention is to propose a test control method for a backup power supply for a wind turbine pitch control system, which does not require the use of professional capacitor testing equipment, and the whole process is convenient for testing, without the need to shut down for a long time to climb the tower for testing. While ensuring that the selected supercapacitor is healthy and reliable, the downtime of the wind turbine pitch control system can be reduced as much as possible.

[0005] To this end, the technical solution adopted in the present invention is as follows: A test control method for a backup power supply for a wind turbine pitch control system comprises the following steps: installing a supercapacitor to be tested as the backup power supply for the wind turbine pitch control system, and setting basic conditions for supercapacitor testing; when the main control of the wind turbine pitch control system issues a supercapacitor test instruction and confirms that the wind turbine pitch control system meets the basic conditions for supercapacitor testing, the wind turbine pitch control system disconnects a bus contactor and a charger, and when the bus voltage reaches the backup power supply voltage, controls the supercapacitor to discharge to a brake resistor, stops discharging after the supercapacitor voltage drops by a preset difference, and then connects the bus contactor and the charger to charge the supercapacitor, and calculates the capacitance of the supercapacitor through the output current, charging voltage and charging time of the charger.

[0006] Preferably, the basic conditions for the supercapacitor test include: a). The main control safety chain of the wind turbine pitch control system is normal; b) All three propellers are in the 91-degree limit switch position, and the capacitor voltages of the three propellers are greater than the parameter setting value of the minimum limit of the battery test voltage; c). The pitch system is in the normal shutdown (Stop_Normal) state.

[0007] Preferably, the basic conditions for the supercapacitor test also include: d). The main control system of the wind turbine pitch control system sets the pitch enable signal to 0 through communication, and sets the supercapacitor test enable position to 1.

[0008] Preferably, the basic conditions for the supercapacitor test also include: e) Initializing the variables of the supercapacitor test related program.

[0009] Preferably, the parameter setting value of the minimum limit of the battery test voltage is set to 275 Vdc by default.

[0010] Preferably, the bus supply voltage is 380-420Vdc; during the discharge of the supercapacitor to the braking resistor, the wind turbine pitch control system connects the braking resistor for 450-550ms (milliseconds), and then turns it off for 10-12s (seconds), and this cycle is repeated until the supercapacitor voltage drops by a preset difference.

[0011] Preferably, the preset difference is 18-24V.

[0012] Preferably, before charging the supercapacitor, the discharge function of the brake resistor is turned off and left to stand for 15-30 seconds.

[0013] Preferably, when charging the supercapacitor, when the supercapacitor voltage is charged to the charging voltage U1, the starting charging voltage U1 and the starting charging time t1 are recorded respectively; when the supercapacitor voltage is charged to the charging voltage U2, the cutting-off charging voltage U2 and the cutting-off charging time t2 are recorded respectively; the capacitance of the supercapacitor is calculated by the calculation formula: C=(t2-t1)*I / (U2-U1), where I is the output current of the charger and C is the capacitance of the supercapacitor.

[0014] Preferably, when the test is completed, if the wind turbine pitch control system enters the normal shutdown (Stop_Normal) state, it means that the supercapacitor test is successful, and the wind turbine pitch control system can read the capacitance of the supercapacitor through communication; when the test is completed, if the wind turbine pitch control system enters the capacitor fault shutdown (Stop_UC) state, it means that the supercapacitor test has failed, and the wind turbine pitch control system can read the fault code through communication, reset the pitch fault according to the fault code information, so that the wind turbine pitch control system enters the normal shutdown (Stop_Normal) state.

[0015] The present invention directly uses the wind turbine pitch control system as a testing tool for supercapacitors without the need for professional capacitor testing equipment. During the test, the supercapacitor to be tested is installed as a backup power supply of the wind turbine pitch control system, and basic conditions for supercapacitor testing are set. When the main control of the wind turbine pitch control system issues a supercapacitor test instruction and confirms that the wind turbine pitch control system meets the basic conditions for supercapacitor testing, the bus contactor and the charger are disconnected, and when the bus voltage reaches the backup power supply voltage, the supercapacitor is controlled to discharge the braking resistor, and when the supercapacitor voltage drops by a preset difference, the discharge is stopped, and then the bus contactor and the charger are connected to charge the supercapacitor, and the capacitance of the supercapacitor is calculated by the output current, charging voltage and charging time of the charger, and the health state of the selected supercapacitor is judged by the capacitance obtained by the test. The whole process is convenient for testing, and there is no need to stop the machine for a long time to climb the tower for testing. Under the condition of ensuring that the selected supercapacitor is healthy and reliable, the downtime of the wind turbine pitch control system is reduced as much as possible. DETAILED DESCRIPTION

[0016] The embodiment of the present invention discloses a test control method for a backup power supply for a wind turbine pitch control system, wherein a supercapacitor to be tested is installed as a backup power supply for the wind turbine pitch control system, and basic conditions for supercapacitor testing are set; when the main control of the wind turbine pitch control system issues a supercapacitor test instruction and confirms that the wind turbine pitch control system meets the basic conditions for supercapacitor testing, the wind turbine pitch control system enters a capacitor test (STOP_UC_TEST) state, and the status code is 10; In this embodiment, the wind turbine pitch control system disconnects the bus contactor and the charger, and when the bus voltage reaches the backup power supply voltage, controls the supercapacitor to discharge the brake resistor, and stops discharging after the supercapacitor voltage drops by a preset difference, and then connects the bus contactor and the charger to charge the supercapacitor, and calculates the capacitance of the supercapacitor through the output current, charging voltage and charging time of the charger; When the supercapacitor test is finished, the wind turbine pitch control system will exit the capacitor test (STOP_UC_TEST) state, and the status code will change from 10 to other numbers; Preferably, in this embodiment, the basic conditions for supercapacitor testing include: a). The main control safety chain of the wind turbine pitch control system is normal, which means that the slip ring hardware EFC is normal; b) All three propellers are in the 91-degree limit switch position, and the capacitor voltages of the three propellers are greater than the parameter setting value of the minimum limit of the battery test voltage; c). The pitch system is in the normal shutdown (Stop_Normal) state.

[0017] Further preferably, in this embodiment, the basic conditions for the supercapacitor test also include: d). The wind turbine pitch control system main control system sets the pitch enable signal to 0 through communication, and sets the supercapacitor capacitance test enable position to 1; further preferably, in this embodiment, the basic conditions for the supercapacitor test also include: e). Initializing the variables of the supercapacitor test related programs.

[0018] Preferably, in this embodiment, the parameter setting value of the minimum limit of the battery test voltage is 275Vdc by default; the bus supply voltage is 380-420Vdc; during the discharge of the supercapacitor to the braking resistor, the wind turbine pitch control system connects the braking resistor for 450-550ms (milliseconds), and then turns it off for 10-12s (seconds), and repeats this cycle until the supercapacitor voltage drops by a preset difference; preferably, in this embodiment, the preset difference is 18-24V.

[0019] Preferably, in this embodiment, before charging the supercapacitor, turn off the discharge function of the braking resistor and let it stand for 15-30s; when charging the supercapacitor, when the supercapacitor voltage is charged to the charging voltage U1, record the starting charging voltage U1 and the starting charging time t1 respectively; when the supercapacitor voltage is charged to the charging voltage U2, record the cutting-off charging voltage U2 and the cutting-off charging time t2 respectively; the capacitance of the supercapacitor is calculated by the calculation formula: C=(t2-t1)*I / (U2-U1) (automatically calculated by the wind turbine pitch control system), where I is the output current of the charger and C is the capacitance of the supercapacitor.

[0020] Preferably, in this embodiment, when the test is completed, if the wind turbine pitch control system enters the normal shutdown (Stop_Normal) state, the status code is 0, which means that the supercapacitor test is successful, and the wind turbine pitch control system can read the capacitance of the supercapacitor through communication; when the test is completed, if the wind turbine pitch control system enters the capacitor fault shutdown (Stop_UC) state, it means that the supercapacitor test has failed, and the wind turbine pitch control system can read the fault code through communication, reset the pitch fault according to the fault code information, and make the wind turbine pitch control system enter the normal shutdown (Stop_Normal) state.

[0021] In order to further explain the above implementation scheme of the present application, the applicant proposes the following specific testing process: Step 1: The main controller of the wind turbine pitch control system sends a capacitor test instruction; Step 2: The internal self-check of the pitch control unit is performed. If the following basic conditions for supercapacitor testing are met, jump to Step 3. a). The main control safety chain of the wind turbine pitch control system is normal; b). All three blades are in the 91-degree limit switch position, and the capacitor voltage of the three blades is greater than 275Vdc; c). The pitch system is in the normal stop (Stop_Normal) state; d). The main controller of the wind turbine pitch control system sets the pitch enable signal to 0 through communication, and sets the supercapacitor capacitance test enable position to 1; Step 3: Initialize the variables of the supercapacitor test related programs; Step 4: Disconnect the 400VAC (AC voltage) bus power supply / disconnect the charger output; Step 5: When the bus voltage drops below 400Vdc (DC voltage), the supercapacitor is discharged through the braking resistor (that is, the supercapacitor is controlled to discharge the braking resistor); Step 6: When the voltage of the supercapacitor is discharged from 360Vdc to below 340Vdc (during the discharge process, the brake resistor is controlled to be on for 500ms, off for 11s, and 11.5s is a cycle), turn off the brake resistor discharge function, let it stand for 20s, and wait until the three blade drive shafts are discharged to below 340Vdc, then enter Step 7; Step 7: Close the 400VAC bus power supply and charger output, and record the starting charging voltage U1 and t1 when the supercapacitor voltage is charged to 345Vdc; Step 8: When the voltage of the supercapacitor is charged to 355Vdc, record the end-of-charge voltage U2 and t2; Step 9: The main controller of the wind turbine pitch control system automatically calculates the capacitance of the supercapacitor through the formula C = (t2-t1)*I / (U2-U1), where I is the output current of the charger; If the wind turbine pitch control system enters the normal shutdown (Stop_Normal) state, the status code is 0, which means that the supercapacitor test is successful, and the wind turbine pitch control system can read the capacitance of the supercapacitor through communication; if the wind turbine pitch control system enters the capacitor fault shutdown (Stop_UC) state, it means that the supercapacitor test has failed. The wind turbine pitch control system can read the fault code through communication and reset the pitch fault according to the fault code information, so that the wind turbine pitch control system enters the normal shutdown (Stop_Normal) state.

[0022] This embodiment directly uses the wind turbine pitch control system as a testing tool for supercapacitors, without the need for professional capacitor testing equipment, and the entire testing process is convenient, without the need to shut down for a long time to climb the tower for testing. While ensuring that the selected supercapacitor is healthy and reliable, the downtime of the wind turbine pitch control system is reduced as much as possible.

[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0024] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A test control method for a backup power supply for a wind turbine pitch control system, characterized in that: The supercapacitor to be tested is installed as a backup power supply for the wind turbine pitch control system, and basic conditions for supercapacitor testing are set; when the main control of the wind turbine pitch control system issues a supercapacitor test instruction and confirms that the wind turbine pitch control system meets the basic conditions for supercapacitor testing, the wind turbine pitch control system disconnects the bus contactor and the charger, and when the bus voltage reaches the backup power supply voltage, controls the supercapacitor to discharge to the braking resistor, stops discharging after the supercapacitor voltage drops by a preset difference, and then connects the bus contactor and the charger to charge the supercapacitor, and calculates the capacitance of the supercapacitor through the output current, charging voltage and charging time of the charger.

2. The test control method for a backup power supply for a wind turbine pitch control system according to claim 1 is characterized in that: The basic conditions for the supercapacitor test include: a). The main control safety chain of the wind turbine pitch control system is normal; b) All three propellers are in the 91-degree limit switch position, and the capacitor voltages of the three propellers are greater than the parameter setting value of the minimum limit of the battery test voltage; c). The pitch system is in the normal stop (Stop_Normal) state; The basic conditions for the supercapacitor test also include: d). The main control system of the wind turbine pitch control system sets the pitch enable signal to 0 through communication, and sets the supercapacitor capacitance test enable position to 1; e) Initializing the variables of the supercapacitor test related program.

3. The test control method for a backup power supply for a wind turbine pitch control system according to claim 2 is characterized in that: The default setting value of the battery test voltage minimum limit parameter is 275Vdc.

4. The test control method for a backup power supply for a wind turbine pitch control system according to claim 1 is characterized in that: The bus supply voltage is 380-420Vdc; during the discharge of the supercapacitor to the brake resistor, the wind turbine pitch control system connects the brake resistor for 450-550ms (milliseconds), and then turns it off for 10-12s (seconds), and this cycle is repeated until the supercapacitor voltage drops by a preset difference.

5. The test control method for a backup power supply for a wind turbine pitch control system according to claim 1 or 4, characterized in that: The preset difference is 18-24V.

6. The test control method for a backup power supply for a wind turbine pitch control system according to claim 1 or 4, characterized in that: Before charging the supercapacitor, turn off the discharge function of the brake resistor and let it sit for 15-30 seconds.

7. The test control method for a backup power supply for a wind turbine pitch control system according to claim 1 is characterized in that: When charging the supercapacitor, when the supercapacitor voltage is charged to the charging voltage U1, record the starting charging voltage U1 and the starting charging time t1 respectively; when the supercapacitor voltage is charged to the charging voltage U2, record the ending charging voltage U2 and the ending charging time t2 respectively; the capacitance of the supercapacitor is calculated by the calculation formula: C=(t2-t1)*I / (U2-U1), where I is the output current of the charger and C is the capacitance of the supercapacitor.

8. The test control method for a backup power supply for a wind turbine pitch control system according to claim 1 is characterized in that: When the test is completed, if the wind turbine pitch control system enters the normal stop (Stop_Normal) state, it means that the supercapacitor test is successful, and the wind turbine pitch control system can read the capacitance value of the supercapacitor through communication; When the test is completed, if the wind turbine pitch control system is in the capacitor fault shutdown (Stop_UC) state, it means that the supercapacitor test has failed. The wind turbine pitch control system can read the fault code through communication and reset the pitch fault according to the fault code information, so that the wind turbine pitch control system enters the normal shutdown (Stop_Normal) state.