Voltage abnormality diagnosis method, controller, and wind turbine generator system

Abstract

The present disclosure provides a voltage anomaly diagnosis method, a controller and a wind turbine generator set. The pitch system includes a number of backup power sources corresponding to the number of blades. The voltage anomaly diagnosis method of the backup power source of the pitch system includes: obtaining the backup power source voltage value, the blade angle value and the pitch motor temperature value of each shaft at a first time and a second time, wherein the second time is a sampling time before the first time; determining whether the voltage of the backup power source of the first shaft is abnormal according to the backup power source voltage value, the blade angle value and the pitch motor temperature value of each shaft. The voltage anomaly diagnosis method of the backup power source of the pitch system according to the embodiment of the present disclosure can distinguish the voltage drop caused by other working conditions, accurately identify the voltage drop caused by the voltage fluctuation of the backup power source, and has high detection accuracy.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of wind power, in particular, to a voltage abnormality diagnosis method for a backup power supply of a variable pitch system, a controller and a wind turbine generator. BACKGROUND

[0002] For the variable pitch system, when the grid voltage is normal, the power for driving the variable pitch motor to pitch in is provided by the grid rectification; when the grid voltage drops or is powered off, the backup power supply needs to provide DC voltage to the variable pitch driver to achieve safe feathering of the blades and safe operation.

[0003] The wind turbine generator forms a complex energy conversion system through integrated technologies, so the same fault may be caused by different reasons.

[0004] In order to analyze the fault cause of the unit, the fault data at the time of unit fault need to be recorded. This function can automatically, accurately and timely record the changes of various electrical quantities before and after the fault, which plays a very important role in analyzing and processing accidents, judging whether the protection is correctly actuated, and ensuring the safe and reliable operation of the wind turbine generator. In actual data analysis, it is found that since the fault file used may only be recorded and generated after the unit fails, the unit may not generate a fault file for a long time, that is, no operation data can be analyzed for fault warning; manual data collection is not realistic due to the large number of wind turbines involved and the huge workload.

[0005] The existing technical solution at least has the following disadvantages:

[0006] 1) The voltage of the backup power supply of the variable pitch system cannot be diagnosed abnormally;

[0007] 2) For the relatively random fault, it is difficult to collect data because it is not clear what situation will cause the fault;

[0008] 3) If the interval time of the fault is long, for example, small wind shutdown causes the unit to trigger a fault, since small wind shutdown is completely related to natural wind conditions, in practice, small wind shutdown may not occur for tens of days, and a large amount of data will increase the burden of data collection software, and frequent restart of collection by personnel will also consume a certain amount of energy and time. SUMMARY

[0009] One of the purposes of the present disclosure is to provide a voltage abnormality diagnosis method capable of judging whether the voltage of the backup power supply of the variable pitch system fluctuates.

[0010] It is one of the objectives of the present disclosure to provide a voltage anomaly diagnosis method capable of improving the accuracy of determining whether a voltage fluctuates.

[0011] According to a first aspect of the present disclosure, a voltage anomaly diagnosis method for a backup power supply of a variable pitch system is provided, the variable pitch system comprising a number of backup power supplies corresponding to the number of blades, the voltage anomaly diagnosis method comprising: obtaining backup power supply voltage values, blade angle values and variable pitch motor temperature values of each shaft at a first time and a second time, wherein the second time is a sampling time before the first time; determining whether the voltage of the backup power supply of the first shaft is abnormal according to the backup power supply voltage values, the blade angle values and the variable pitch motor temperature values of each shaft.

[0012] According to a second aspect of the present disclosure, a computer readable storage medium is provided, the computer readable storage medium storing instructions or software, when the instructions or code are executed by a processor, the above-mentioned voltage anomaly diagnosis method for a backup power supply of a variable pitch system is executed.

[0013] According to a third aspect of the present disclosure, a main controller is provided, the main controller comprising a memory and a processor, the memory storing instructions or code, when the instructions or code are executed by the processor, the above-mentioned voltage anomaly diagnosis method for a backup power supply of a variable pitch system is executed.

[0014] According to a fourth aspect of the present disclosure, a variable pitch controller is provided, the variable pitch controller comprising a variable pitch control module, the variable pitch control module being configured to control the backup power supply of the current shaft to stop supplying power to the variable pitch motor of the shaft in response to a variable pitch control signal received from the above-mentioned main controller.

[0015] According to a fifth aspect of the present disclosure, a wind turbine generator is provided, the wind turbine generator comprising the above-mentioned main controller and / or the above-mentioned variable pitch controller.

[0016] The voltage anomaly diagnosis method according to the embodiments of the present disclosure can distinguish voltage fluctuations and other abnormal phenomena caused by different working conditions based on the working characteristics of the variable pitch system, so that it can accurately identify voltage drop and other abnormal conditions caused by voltage fluctuations, and has high detection accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other objectives and features of the present disclosure will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 is a schematic diagram showing the electrical connection relationship of the variable pitch system according to an embodiment of the present disclosure.

[0019] Figure 2 is a fluctuation curve diagram when the voltage of the backup power supply of the variable pitch system is abnormal.

[0020] Figure 3is a graph showing voltage drop of the backup power supply of the pitch system caused by various factors.

[0021] Figure 4 is a graph showing the change of the pitch motor temperature when the brake valve is slightly worn.

[0022] Figure 5 is a graph showing the change of the blade angle when the brake valve is severely worn or the encoder incremental signal is abnormal.

[0023] Figure 6 is a flowchart showing the voltage abnormality diagnosis method of the first embodiment of the present disclosure.

[0024] Figure 7 is a flowchart showing the voltage abnormality diagnosis method of the second embodiment of the present disclosure.

[0025] Figure 8 is a flowchart showing the voltage abnormality diagnosis method of the third embodiment of the present disclosure.

[0026] Figure 9 is a graph showing a large, non-fluctuating, continuous drop in the voltage of the backup power supply of the pitch system.

[0027] Figure 10 is a graph showing Figure 9 is a graph showing the change of the blade angle value in the case shown in FIG. 8.

[0028] Figure 11 is a flowchart showing the voltage abnormality diagnosis method of the fourth embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings, in which like reference numerals indicate like parts throughout the various figures. The terms used in the present disclosure are explained below.

[0030] SCADA (Supervisory Control And Data Acquisition) is a computer-based DCS (Distributed Control System) and power automation monitoring system.

[0031] The pitch system can include a main controller, a pitch controller for each shaft, a pitch driver, and a pitch motor. The pitch controller for each shaft can include a pitch control module.

[0032] Backup power supply: In the field of wind power, a power supply used to provide energy support for the pitch system when the power grid is powered off. A super capacitor is generally used as a backup power supply. For example, a super capacitor module formed mainly by a plurality of super capacitor units connected in series can be used as a backup power supply for the pitch system. Due to the series connection, any problem with an individual super capacitor unit will cause the entire backup power supply to fail or malfunction. Therefore, it is necessary to monitor and diagnose the voltage of the backup power supply of the pitch system in order to timely detect voltage fluctuations / abnormalities.

[0033] Figure 1 is a schematic diagram showing the electrical connection relationship of the pitch system of the embodiment of the present disclosure.

[0034] As shown in Figure 1 , each shaft blade has a corresponding pitch controller 110, pitch driver 120 and pitch motor 130 and backup power supply (not shown), the number of which corresponds to the number of blades.

[0035] The main controller 100 of the wind turbine generator is connected to the pitch controller 110 of each shaft (first shaft, second shaft and third shaft).

[0036] When the pitch of each shaft blade needs to be adjusted, the pitch controller 110 first calculates the current pitch angle of the shaft blade according to the electrical signal output by the encoder installed on the shaft of the pitch motor 130 of the blade, then generates a pitch instruction for controlling the speed of the pitch motor 130 according to the difference between the current pitch angle and the target pitch angle, and issues the pitch instruction to the pitch driver 120, so that the pitch driver 120 controls the pitch motor 130 to pitch according to the pitch instruction.

[0037] The working principle of the charger of the backup power supply is as follows: the voltage of the backup power supply is detected, and if the voltage of the backup power supply drops, the charger starts to work; therefore, during the operation of the pitch motor, the voltage of the backup power supply drops first due to the energy consumption of the pitch motor, and at the same time, due to the abnormality of the backup power supply, the voltage drops rapidly; after the voltage drops, the charger starts to charge the backup power supply, and once the charging starts, the voltage of the backup power supply will quickly rise, and so on, which will cause the voltage of the backup power supply to fluctuate sharply, resulting in failure of the backup power supply. The situation when the voltage of the backup power supply is abnormal will be described in detail below.

[0038] Figure 2 is a fluctuation curve diagram showing the voltage abnormality of the backup power supply of the pitch system.

[0039] When the backup power supply of the pitch system is abnormal, the voltage fluctuates. As shown in Figure 2 , curve G1 represents the voltage change curve of the backup power supply of the first shaft over time, curve G2 represents the voltage change curve of the backup power supply of the second shaft over time, and curve G3 represents the voltage change curve of the backup power supply of the third shaft over time.

[0040] From Figure 2It can be seen that the voltage of the third-axis backup power supply represented by the curve G3 fluctuates at a high frequency, and the fluctuation amplitude is greater than 20V, and the minimum value of the voltage of the third-axis backup power supply is about 10V lower than the rated voltage (the voltage of the backup power supply of the first axis and the second axis corresponding to the curves G1 and G2) (normally, the voltage drop of the backup power supply during the feathering process is generally only 0.4V-0.5V), and the curve G3 fluctuates at a high frequency, which causes the pitch drive to trigger a No. 82 fault, causing the blade to jam. The reason is that according to C = It / ΔU, the current I is proportional to the change amount ΔU of the voltage, so the fluctuation of the voltage causes a large current to flow into the pitch drive, which causes the pitch drive to malfunction.

[0041] When the voltage of the backup power supply of the pitch system fluctuates, the temperature of the pitch motor will rise; the pitch motor will stall, which will cause the voltage to drop, that is, the energy consumption of the capacitor will increase. At the same time, the pitch motor will stall, which will cause the current of the pitch motor to increase, and according to the heating formula of the coil, the temperature of the pitch motor will inevitably rise. The difference between the two lies in that the stall will cause the pitch speed to slow down, that is, when the pitch motor of a certain axis stalls, at the same time, the blade angle value of the corresponding axis will be different from the blade angle values of the other axes, and at different times, the change rate of the blade angle value of the corresponding axis will decrease, that is, the pitch speed will slow down.

[0042] In other words, whether the voltage of the backup power supply is abnormal can be determined according to the voltage value of the backup power supply, the blade angle value, and the temperature value of the pitch motor of each axis. For example, in the case where only the temperature value of the pitch motor of the first axis exceeds a predetermined threshold value, the voltage of the backup power supply of the first axis decreases, and the blade angle values of each axis are consistent, it can be determined that the backup power supply of the first axis is abnormal.

[0043] It should be noted that the voltage drop described in the present disclosure refers to the voltage drop of a certain axis exceeding a predetermined threshold value at a certain time, or the voltage drop of a certain axis exceeding a predetermined threshold value at multiple times, so as to be distinguished from small changes within a normal range.

[0044] Figure 3 is a curve diagram showing the voltage drop of the backup power supply of the pitch system caused by various factors.

[0045] As shown in Figure 3 , the curve G1 represents the change curve of the voltage of the first-axis backup power supply with time, the curve G2 represents the change curve of the voltage of the second-axis backup power supply with time, and the curve G3 represents the change curve of the voltage of the third-axis backup power supply with time.

[0046] As shown in Figure 3 , only the voltage of the backup power supply of the third axis in the three axes decreases, Figure 3The voltage fluctuation pattern of the backup power supply shown is similar to... Figure 2 The possible causes of this fluctuation are: (1) slight abnormality of the brake valve; (2) power grid voltage failure; (3) backup power charger failure; (4) abnormal incremental signal of the encoder, abnormal brake valve, or stalled pitch motor; (5) frozen gear oil.

[0047] Figure 4 This is a graph showing the temperature change of the pitch motor when the brake valve is slightly worn.

[0048] like Figure 4 As shown, curve G1 represents the temperature change of the first shaft pitch motor over time, curve G2 represents the temperature change of the second shaft pitch motor over time, and curve G3 represents the temperature change of the third shaft pitch motor over time. Figure 4 It can be seen that since brake valve wear is a mechanical damage, the temperature of the pitch motor will rise whenever the pitch system adjusts the pitch. The temperature value represented by curve G3 is about 23°C higher than the temperature values ​​represented by G1 and G2.

[0049] Figure 5 This is a graph showing the change in blade angle when the brake valve is severely worn or the encoder incremental signal is abnormal.

[0050] like Figure 5 As shown, curve G1 represents the change of the blade angle of the first axis over time when the brake valve is severely worn or the encoder incremental signal is abnormal; curve G2 represents the change of the blade angle of the second axis over time; and curve G3 represents the change of the blade angle of the third axis over time.

[0051] from Figure 5 It can be seen that the blade angle value of the first axis, represented by curve G1, deviates significantly from the blade angle values ​​of the second and third axes at the same time. In other words, abnormal encoder incremental signals and brake valve malfunctions both increase the resistance experienced by the pitch motor, further slowing down the blade pitch speed and potentially causing the pitch motor to stall. Abnormal brake valve malfunctions, abnormal encoder incremental signals, and pitch motor stalling all lead to differences in blade angle values.

[0052] In other words, reason (1) may cause a voltage drop and a pitch motor temperature increase, but will not result in a significant difference in blade angle values; reasons (2) and (3) may cause a voltage drop, but generally will not cause a pitch motor temperature increase; each of reasons (4) may cause a voltage drop and a pitch motor temperature increase, and will affect the blade angle value (resulting in a slower blade pitch speed); reason (5) will cause the pitch motor temperature to rise rapidly and continuously.

[0053] Therefore, whether the voltage of the backup power supply is abnormal can be determined according to the backup power supply voltage value of each shaft, the blade angle value of each shaft, and the pitch motor temperature value of each shaft, and the accuracy of detection and judgment can be improved by eliminating any one of the above reasons. The voltage abnormality diagnosis method according to the embodiment of the present disclosure will be described in detail below.

[0054] Figure 6 is a flowchart illustrating a voltage abnormality diagnosis method of a first embodiment of the present disclosure.

[0055] As shown in Figure 6 , the voltage abnormality diagnosis method according to the first embodiment of the present disclosure can include steps S610 and S620.

[0056] In step S610, the backup power supply voltage value of each shaft, the blade angle value of each shaft, and the pitch motor temperature value of each shaft at a first time (i.e., at time t1) and a second time (i.e., at time t2) (a sampling time before t1) are obtained. The time interval between adjacent times can be the same, and each can be a predetermined time (e.g., 1s, 2s, etc.).

[0057] In step S620, whether the voltage of the backup power supply is abnormal is determined according to the backup power supply voltage value of each shaft, the blade angle value, and the pitch motor temperature value.

[0058] The voltage of the backup power supply of a certain shaft can be determined to be abnormal in the case where the voltage of the shaft is detected to decrease, the blade angle values of each shaft are consistent, and the pitch motor temperature of the shaft changes greatly.

[0059] As an example, the voltage fluctuation of the first shaft can be determined in the case where a predetermined condition is met.

[0060] The predetermined condition can include that only the voltage of the first shaft decreases at time t1, the blade angle values of each shaft are consistent at time t1, and the change rate (ratio of the two temperature values) of the pitch motor temperature value of the first shaft at time t1 relative to the pitch motor temperature value of the first shaft at time t2 is greater than a first predetermined threshold value, where the first predetermined threshold value can be determined in advance according to actual temperature data, for example, the first predetermined threshold value can be 1.2. Details will be described below Figure 7 with reference to

[0061] Figure 7 is a flowchart illustrating a voltage abnormality diagnosis method of a second embodiment of the present disclosure.

[0062] The voltage abnormality diagnosis method according to the embodiment of the present disclosure can include steps S710, S720, S730, S740, and S750.

[0063] At step S710, the backup power supply voltage value, the blade angle value, and the pitch motor temperature value of each axis at consecutive time points are acquired. The consecutive time points here can be at least two consecutive time points (for example, 2 time points or 5 time points).

[0064] At step S720, it is determined whether only the backup power supply voltage value of the first axis is detected to decrease at t1. If the voltage values of the backup power supplies of all the axes are detected to decrease, it is generally a problem of power grid outage, slip ring communication interruption, or system control.

[0065] If only the backup power supply voltage value of the first axis is detected to decrease at t1, at step S730, it is determined whether the blade angle values of all the axes at t1 are consistent. If the blade angle values of all the axes at t1 are consistent, at step S740, it is determined whether the change (for example, the change rate or the change amount) of the pitch motor temperature value of the first axis at t1 relative to the pitch motor temperature value of the first axis at t2 is large (for example, greater than a first predetermined threshold value). If the change rate or the change amount of the pitch motor temperature value of the first axis at t1 relative to the pitch motor temperature value of the first axis at t2 is large, at step S750, a backup power supply voltage fluctuation alarm is output.

[0066] If the above conditions are not met, the voltage abnormality diagnosis of the backup power supply can be ended.

[0067] As an example, it can be determined whether the pitch is occurred within a predetermined time before t1 while determining whether the blade angle values of all the axes are consistent, or before determining whether the blade angle values of all the axes are consistent. The predetermined time here can be determined as needed, as long as it can be distinguished between the case where the pitch is occurred and the case where the pitch is not occurred. Figure 5 That is, as long as it can be removed the influence of the brake valve severe wear or the encoder incremental signal abnormality by means of whether the blade angle values are consistent when the pitch is occurred.

[0068] As an example, determining whether the change rate or the change amount of the pitch motor temperature value of the first axis at t1 relative to the pitch motor temperature value of the first axis at t2 is greater than a first predetermined threshold value can also be replaced by the following steps: determining whether the pitch motor temperature values of all the axes at t2 are consistent, whether the difference between the pitch motor temperature values of the second axis and the third axis is within a preset range (for example, within a temperature difference range of 4°C), or determining whether the pitch motor temperature value of the first axis at t1 is higher than the pitch motor temperature value of the second axis or the third axis at t1 by a predetermined threshold value (for example, 10°C), that is, the temperature difference between the pitch motor of the first axis and the pitch motor of the second axis or the third axis is greater than the temperature difference between the pitch motor of the second axis and the pitch motor of the third axis.

[0069] In other words, the detection accuracy can be further improved by at least one of the following conditions: the pitch motor temperature values of the axes at time t2 are consistent, the pitch adjustment occurs within a predetermined time before time t1, and the difference between the pitch motor temperature values of the second and third axes is within a preset range (or the difference between the pitch motor temperature values of the second and third axes is less than a second predetermined threshold value and the difference between the pitch motor temperature values of the first and second axes is greater than a third predetermined threshold value, the third predetermined threshold value being greater than the second predetermined threshold value).

[0070] As an example, it can be determined whether the pitch adjustment occurs within a predetermined time before time t1 after determining whether the voltage of the first axis decreases and before determining whether the blade angle values of the axes are consistent, or simultaneously with determining whether the blade angle values of the axes are consistent. As described above, the predetermined time here can be set as needed, as long as it can be distinguished from the time when the pitch adjustment does not occur. Figure 5

[0071] It should be noted here that the determination condition of the consistent blade angle values can be that the pairwise differences of the three blade angles are each less than a predetermined angle (for example, 2 degrees), and the determination condition of the consistent three pitch motor temperatures can be that the pairwise differences of the three pitch motor temperatures are each less than a predetermined temperature (for example, 4°C).

[0072] In the case where the predetermined condition is not met, the voltage abnormality diagnosis of the backup power supply can be ended.

[0073] Figure 8 is a flowchart showing a voltage abnormality diagnosis method of a third embodiment of the present disclosure.

[0074] The voltage abnormality diagnosis method according to the embodiments of the present disclosure can include steps S810, S820, S830, S840, S850, S850, S860, and S870.

[0075] In step S810, the backup power supply voltage values, the blade angle values, and the pitch motor temperature values of the axes at consecutive time points are acquired. The consecutive time points here can be at least two consecutive time points (for example, 2 time points or 5 time points).

[0076] In step S820, it is determined whether only the backup power supply voltage value of the first axis decreases at time t1.

[0077] ​If only the backup power supply voltage of the first shaft is detected to drop at time t1, then in step S830, it is determined whether pitch adjustment has occurred before time t1 (e.g., time t2). If pitch adjustment has occurred, then in step S840, it is determined whether the blade angle values ​​of each shaft are consistent at time t1. If the blade angle values ​​of each shaft are consistent at time t1, then in step S850, it is determined whether the pitch motor temperature values ​​of each shaft are consistent at time t2. If the pitch motor temperature values ​​of each shaft are consistent, then in step S860, it is determined whether the temperature difference between the pitch motor of the first shaft at time t1 and the pitch motor of the first shaft at time t2 exceeds a predetermined threshold (or it is determined whether the temperature difference between the pitch motors of the second and third shafts is within a preset range). If it exceeds the predetermined threshold, then in step S870, a backup power supply voltage fluctuation alarm can be output.

[0078] Step S820 can remove the effects of cause (2) and cause (3), steps S830 and S840 can remove the effects of cause (1) and (4), step S850 can remove the effects of cause (5), and finally step S860 can determine that the voltage of the backup power supply is abnormal and the voltage of the backup power supply fluctuates within a large range.

[0079] Furthermore, it is possible to help determine whether the backup power supply voltage is fluctuating abnormally by detecting whether the voltage of the backup power supply exceeds the rated voltage by more than a predetermined threshold.

[0080] Figure 9 It is a graph showing a large, non-fluctuating, continuous decrease in the voltage of the backup power supply for the pitch system. Figure 10 It is shown Figure 9 The graph shows the variation of the blade angle value under the given conditions.

[0081] like Figure 9 As shown, curve G1 represents the voltage change of the first axis backup power supply over time, curve G2 represents the voltage change of the second axis backup power supply over time, and curve G3 represents the voltage change of the third axis backup power supply over time. From... Figure 9 It can be seen that the voltage of the backup power supply for the first shaft drops significantly and continuously without fluctuations. This may be due to an abnormality in the pitch motor brake valve or an abnormality in the incremental signal, which leads to an increase in the pitch motor current.

[0082] In addition, since the pitch motor still has a certain speed in this situation, the energy consumption of the backup power supply does not change instantaneously. In addition, the backup power supply charger continuously charges the backup power supply, so the voltage drop of the backup power supply is slower and lasts for a longer period of time.

[0083] like Figure 9As shown, the time range for the G1 curve to decrease is from -20 seconds (20 seconds before the fault is triggered) to 15 seconds (15 seconds after the fault is triggered), with a total duration of 35 seconds. For the data collected by SCADA, at least 35 / 7 = 5 data points can be collected in this fault file.

[0084] like Figure 10 As shown, curve G1 represents the change of the blade angle value of the first axis over time, curve G2 represents the change of the blade angle value of the second axis over time, and curve G3 represents the change of the blade angle value of the third axis over time. From Figure 10 It can be seen that the pitch speed shown by curve G1 is consistently slow, and the blade angle value is smaller than that of the other two shafts.

[0085] In other words, the backup power supply voltage value of each shaft, the blade angle value of each shaft, and the pitch motor temperature value of each shaft can be obtained at least three times, and the voltage of the first shaft can be determined accordingly.

[0086] Under predetermined conditions, it can be determined that the voltage of a certain axis (e.g., the first axis) continuously decreases.

[0087] Therefore, the method for diagnosing voltage anomalies in the backup power supply of the pitch system may also include: obtaining the backup power supply voltage value, blade angle value and pitch motor temperature value of each shaft at the third time point, where the third time point (denoted as t3) is the sampling time before the second time point (i.e., time point t2).

[0088] The predetermined conditions here may include: the voltage of the first shaft decreases (e.g., decreases continuously) at times t3, t2 and t1; the difference between the blade angle values ​​of the first shaft, the second shaft and the third shaft increases continuously at times t3, t2 and t1; and the temperature value of the pitch motor of the first shaft increases continuously at times t3, t2 and t1.

[0089] To further aid in the judgment, the predetermined conditions may also include a continuous decrease in the voltage of the backup power supply for the first shaft at times t3, t2, and t1, and no decrease in the rate of change of the blade angle value of the first shaft at times t2 and t1, or no decrease in the pitch speed. Here, "no decrease in the rate of change of the blade angle value" or "no decrease in the pitch speed" is used to distinguish between a stalled pitch motor and a stalled pitch motor. Therefore, the degree to which "the rate of change did not decrease" or "the pitch speed did not decrease" is sufficient to distinguish it from a stalled pitch motor. This will be discussed in conjunction with... Figure 11 This will be described in detail.

[0090] Figure 11 This is a flowchart illustrating a voltage anomaly diagnosis method according to a fourth embodiment of the present disclosure.

[0091] likeFigure 11 The abnormality diagnosis method according to the fourth embodiment of the present disclosure can include steps S1110, S1120, S1130, S1140, S1150, and S1160, as shown.

[0092] In step S1110, the backup power supply voltage value, the blade angle value, and the pitch motor temperature value of each shaft at consecutive time points are acquired. The consecutive time points here can be at least three consecutive time points (for example, 3 time points or 5 time points).

[0093] In step S1120, it is determined whether the backup power supply voltage value of the first shaft continuously decreases at the t3 time point, the t2 time point, and the t1 time point.

[0094] If it is determined that the backup power supply voltage value of the first shaft continuously decreases at the t3 time point, the t2 time point, and the t1 time point, it is determined in step S1130 whether the difference between the blade angle values of the first shaft, the second shaft, and the third shaft continuously increases at the t3 time point, the t2 time point, and the t1 time point, for example, the difference between the blade angle values of the first shaft and the other two shafts continuously increases at the t3 time point, the t2 time point, and the t1 time point, and it is determined in step S1140 whether the rate of change of the blade angle value of the first shaft slows down, if not, it is determined in step S1150 whether the pitch motor temperature value of the first shaft continuously increases at the t3 time point, the t2 time point, and the t1 time point, if so, a backup power supply voltage continuous decrease warning is output in step S1160.

[0095] In the case where the above conditions are not met, the voltage abnormality diagnosis of the backup power supply can be ended.

[0096] Each operation of the above steps can be written as a software program or instruction, therefore, the voltage abnormality diagnosis method of the backup power supply according to the exemplary embodiments of the present disclosure can be implemented via software, and the computer readable storage medium of the exemplary embodiments of the present disclosure can store a computer program which, when executed by a processor, implements the voltage abnormality diagnosis method of the above exemplary embodiments.

[0097] The computer readable storage medium includes magnetic media such as floppy disks and magnetic tapes, optical media (including CD ROM and DVD ROM), magneto-optical media such as floptical disks, hardware devices designed to store and execute program commands such as ROM, RAM, and flash memory. The program commands include language codes executable by a computer using an interpreter and machine language codes generated by a compiler. The above hardware devices can be implemented by one or more software modules for performing the operations of the various embodiments of the present disclosure.

[0098] As Figure 1The illustrated main controller can include a memory and a processor, the memory can store the above-mentioned instructions or codes, when the instructions or codes are executed by the processor, the above-mentioned voltage abnormality diagnosis method can be executed.

[0099] As Figure 1 The illustrated pitch controller can include a pitch control module, the pitch control module can be configured to control the backup power supply to stop supplying power to the corresponding pitch motor in response to the pitch control signal received from the main controller.

[0100] The above-mentioned main controller and / or pitch controller can be part of a pitch system or a wind turbine generator set.

[0101] According to embodiments of the disclosure, at least a part of the modules or units can be implemented (for example, executed) by a processor. At least a part of the programming module can include a module, a program, a routine, an instruction set, and a process for executing at least one function. In one example, the instructions or software include machine code (such as machine code generated by a compiler) directly executed by one or more processors or computers. In another example, the instructions or software include higher level code that is executed by one or more processors or computers using an interpreter. The instructions or software can be written based on the block diagrams and flowcharts shown in the drawings and the corresponding descriptions in the specification using any programming language.

[0102] The modules or programming modules of the present disclosure can include at least one of the foregoing components with some components omitted or other components added. The operations of the modules, programming modules, or other components can be executed sequentially, in parallel, cyclically, or heuristically. In addition, some operations can be executed in a different order, can be omitted, or can be extended with other operations.

[0103] The voltage abnormality diagnosis method according to embodiments of the disclosure can solve the problem of fewer B files of SCADA (B files are only generated when the machine stops), and can realize 24-hour monitoring of the voltage data of the backup power supply of the pitch system.

[0104] The voltage abnormality diagnosis method according to embodiments of the disclosure can not modify the PLC program, the SCADA program, and the communication protocol between the wind turbine and the central monitoring, which is convenient and has small development workload.

[0105] The voltage abnormality diagnosis method according to embodiments of the disclosure combines the working characteristics of the pitch system, and fewer variables need to be detected, which can only involve voltage, motor temperature value, and blade angle. The detection algorithm is simple and easy to implement, and can be effectively distinguished from a plurality of other working conditions.

[0106] The voltage anomaly diagnosis method according to the embodiments of the present disclosure is based on 24-hour uninterrupted collection of SCADA data, so that the backup power voltage fluctuation phenomenon can be detected and identified as early as possible, and early warning information can be sent.

[0107] The voltage anomaly diagnosis method according to the embodiments of the present disclosure can distinguish the voltage drop phenomenon caused by other working conditions, so that the voltage drop caused by voltage fluctuation can be accurately and identified, and the detection accuracy is high.

[0108] Although some exemplary embodiments of the present disclosure have been shown and described, those skilled in the art should understand that modifications and improvements can be made to these embodiments without departing from the principles and spirits of the present disclosure, for example, technical features of different embodiments can be combined. These modifications and improvements are within the scope of the present disclosure.

Claims

1. A voltage abnormality diagnosis method for a backup power source of a variable pitch system, the variable pitch system including a number of backup power sources corresponding to the number of blades, characterized by, The voltage anomaly diagnosis method comprises: obtaining backup power supply voltage values, blade angle values and pitch motor temperature values of each shaft at a first time and a second time, wherein the second time is a sampling time before the first time; determining whether the voltage of the backup power supply of the first shaft is abnormal according to the backup power supply voltage values, the blade angle values and the pitch motor temperature values of each shaft, wherein the voltage anomaly diagnosis method further comprises: obtaining backup power supply voltage values, blade angle values and pitch motor temperature values of each shaft at a third time, wherein the third time is a sampling time before the second time; the step of determining whether the voltage of the backup power supply of the first shaft is abnormal according to the backup power supply voltage values, the blade angle values and the pitch motor temperature values of each shaft comprises: determining that the voltage of the backup power supply of the first shaft continuously decreases under the condition that a predetermined condition is met, wherein the predetermined condition comprises: the backup power supply voltage of the first shaft continuously decreases through the third time, the second time and the first time, and the difference between the blade angle values of each shaft continuously increases through the third time, the second time and the first time; the pitch motor temperature value of the first shaft continuously increases through the third time, the second time and the first time.

2. The voltage abnormality diagnosis method for a back-up power source of a variable pitch system according to claim 1, characterized by, The step of determining whether the voltage of the backup power supply of the first shaft is abnormal according to the backup power supply voltage values, the blade angle values and the pitch motor temperature values of each shaft further comprises: determining that the voltage of the backup power supply of the first shaft fluctuates under the condition that a predetermined condition is met, wherein the predetermined condition comprises: at the first time, only the voltage of the backup power supply of the first shaft decreases, the blade angle values of each shaft are consistent, and the change rate of the pitch motor temperature value of the first shaft relative to the pitch motor temperature value of the first shaft at the second time is greater than a first predetermined threshold.

3. The voltage anomaly diagnosis method of the backup power supply of the pitch system according to claim 2, characterized in that the predetermined condition further comprises at least one of the following conditions: the pitch motor temperature values of each shaft at the second time are consistent, pitch adjustment occurs within a predetermined time before the first time, and the difference between the pitch motor temperature values of the second shaft and the third shaft is within a preset range.

4. The voltage abnormality diagnosis method for a backup power source of a variable pitch system according to claim 1, characterized by, The predetermined condition further comprises: the backup power supply voltage value of the first shaft at the third time, the second time and the first time all decreases, and the change rate of the blade angle value of the first shaft at the second time and the first time does not decrease.

5. The voltage abnormality diagnosis method of a backup power source of a variable pitch system according to any one of claims 1 to 4, characterized by, The voltage anomaly diagnosis method further comprises: generating a pitch control signal in response to determining that the voltage of the backup power supply is abnormal, the pitch control signal being used to control the backup power supply to stop supplying power to the corresponding pitch motor.

6. A computer readable storage medium, characterized in that, The computer readable storage medium stores instructions or software, when the instructions or code are executed by the processor, the voltage anomaly diagnosis method of the backup power supply of the pitch system according to any one of claims 1 to 5 is executed.

7. A host controller, characterized by The main controller comprises a memory and a processor, and the memory stores instructions or code, when the instructions or code are executed by the processor, the voltage anomaly diagnosis method of the backup power supply of the pitch system according to any one of claims 1 to 5 is executed.

8. A pitch controller characterized by including a pitch control module configured to control the back-up power supply of the current shaft to stop supplying power to the pitch motor of the shaft in response to a pitch control signal received from the master controller according to claim 7.

9. A wind power unit, characterized in that including a master controller according to claim 7 and / or a pitch controller according to claim 8.

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