Overload control protection method for variable-pitch brake resistor of wind generating set and related device

Abstract

The invention belongs to the technical field of wind power generation, and provides a variable-pitch brake resistor overload control protection method of a wind generating set and a related device. The method comprises the following steps: acquiring real-time state parameters of a brake resistor of a variable pitch system in the wind driven generator; overload state information of the brake resistor is determined according to the real-time state parameters; if the overload state information indicates that the brake resistor is in an overload state, overload protection is carried out on the brake resistor. According to the wind speed and the variable-pitch angle and variable-pitch current of the wind driven generator blade, the overload state of the brake resistor of the variable-pitch system is recognized, and the overload damage risk of the brake resistor of the variable-pitch system is reduced by dynamically adjusting and controlling the opening margin, the advanced variable-pitch initial power and the advanced variable-pitch maximum angle of the wind driven generator blade.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a method and a related device for controlling and protecting an overload of a variable pitch brake resistor of a wind power generator set. Background Art

[0002] The further enlargement of wind turbines is the main development trend in the future. Major wind turbine manufacturers are competing to enter the field of large wind turbines and have successively launched large-megawatt and long-blade units. In order to reduce the manufacturing cost and the load of the whole machine, the control technology requirements are becoming more and more sophisticated. In order to solve the problem of the whole machine load, the industry usually adopts independent pitch change, advance pitch change and other methods to achieve it.

[0003] Independent pitch control technology superimposes three different pitch angle deviations on the pitch angle instructions obtained by unified pitch control to achieve independent control of each blade, thereby reducing the fatigue load of the wind turbine and the extreme load under some working conditions and improving the load conditions of various components of the unit.

[0004] When the variable pitch system drives the blades to move, it will feed back energy to the system. If the feedback energy is too high, there is a risk of damaging the system. Therefore, a variable pitch braking resistor is used to release excess energy.

[0005] Compared with the unified pitch control method, independent pitch has a higher frequency of blade adjustment. Under extreme turbulent conditions, independent pitch action and large pitch angle difference, frequent acceleration and deceleration of the pitch system, bring more feedback energy, when the pitch brake resistor cannot fully release the feedback energy, as the energy accumulates for a long time, a thermal effect is generated, causing the pitch brake resistor to overload, shortening the life cycle of the brake resistor, or even causing damage, affecting the safety of the unit. Summary of the invention

[0006] In view of the defects in the prior art, the present invention provides a method and related device for overload control protection of a variable pitch brake resistor of a wind turbine generator set, so as to reduce the risk of overload damage to the brake resistor of the variable pitch system.

[0007] The wind turbine generator set pitch brake resistor overload control protection method includes:

[0008] Obtain the real-time status parameters of the brake resistor of the pitch control system in the wind turbine;

[0009] Determine the overload status information of the braking resistor according to the real-time status parameters;

[0010] If the overload status information indicates that the braking resistor is in an overload state, the braking resistor is overload protected.

[0011] Furthermore, the real-time status parameters include wind speed, pitch angle and pitch current of the wind turbine blades.

[0012] Furthermore, the overload status information includes an average value of a pitch angle difference, a root mean square value of a pitch current, and a wind speed turbulence value.

[0013] Further, determining the overload state information of the brake resistor according to the real-time state parameter includes:

[0014] Determine the wind turbulence value based on the wind speed;

[0015] Determine an average value of pitch angle differences according to the pitch angles of the wind turbine blades;

[0016] The root mean square value of the pitch current is determined according to the pitch current of the wind turbine blade.

[0017] Further, determining the average value of the pitch angle difference according to the pitch angle of the wind turbine blades includes:

[0018] Get the maximum and minimum pitch angles of the three blades each time the wind turbine is updated;

[0019] According to the difference between the maximum value and the minimum value of the pitch angle of the three blades when the wind turbine is updated each time, the average value of the difference in the pitch angle of the three blades of the wind turbine updated N times within n time is calculated.

[0020] Further, determining a root mean square value of the pitch current according to the pitch current of the wind turbine blades includes:

[0021] Get the pitch current of the three blades of the wind turbine every time it is updated;

[0022] According to the pitch currents of the three blades each time the wind turbine is updated, the root mean square value of the pitch currents of the three blades of the wind turbine when they are updated N times within n time is calculated.

[0023] Furthermore, it also includes determining a theoretical pitch current value according to an average value of the pitch angle difference and a pitch current reference value,

[0024] The theoretical pitch current value is determined according to the average value of the pitch angle difference and the pitch current reference value, including:

[0025] According to the simulation analysis, the linear relationship between the average value of the pitch angle difference and the pitch current reference value under various working conditions at different times is obtained, and the proportionality coefficient is determined;

[0026] The theoretical pitch current value is determined according to the proportional coefficient, the average value of the pitch angle difference within the n time period and the pitch current reference value.

[0027] Furthermore, the braking resistor is overload protected, including:

[0028] Adjust the opening margin of the wind turbine blades to be equal to the current opening margin of the wind turbine blades *Current ipc / CurrentRMS i ;

[0029] Adjust the wind turbine's advance pitch start power to equal MIN (Power min ,(rated power*G power *CurrentRMS i / Current ipc ));

[0030] Adjust the maximum pitch angle of the wind turbine to be equal to MAX(PP max ,(PP max *G angle *Current ipc / CurrentRMS i ));

[0031] Among them, Current ipc Represents the theoretical pitch current value of the wind turbine blade, CurrentRMS i Indicates the root mean square value of the pitch current of the wind turbine blades, Power min Indicates the current starting power of the wind turbine's advance pitch change, G power represents the optimal power coefficient when independent pitch control is turned off, PP max Indicates the maximum angle of advance pitch change, G angle Indicates the angle coefficient for turning off independent pitch control.

[0032] The wind turbine generator set pitch brake resistor overload control protection device includes:

[0033] An acquisition unit, used for acquiring real-time state parameters of a brake resistor of a pitch control system in a wind turbine;

[0034] A determination unit, used to determine the overload state information of the brake resistor according to the real-time state parameters;

[0035] The protection unit is used to perform overload protection on the braking resistor if the overload status information indicates that the braking resistor is in an overload state.

[0036] A terminal includes a processor, an input device, an output device and a memory, wherein the processor, the input device, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute any of the above-mentioned wind turbine generator set variable pitch brake resistor overload control protection methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific embodiments of the present invention, the following will briefly introduce the drawings required for the specific embodiments or the prior art description. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0038] Figure 1 A flow chart of a method for controlling and protecting a pitch brake resistor overload of a wind turbine generator set provided by an embodiment of the present invention;

[0039] Figure 2 A schematic structural diagram of a wind turbine generator set pitch brake resistor overload control protection device provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0041] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0042] In one embodiment, if Figure 1 As shown, a method for controlling and protecting the overload of a variable pitch brake resistor of a wind turbine generator set is provided, comprising:

[0043] 1. Obtain the real-time status parameters of the brake resistor of the variable pitch system in the wind turbine;

[0044] Preferably, the real-time status parameters include wind speed, pitch angle and pitch current of the wind turbine blades.

[0045] 2. Determine the overload status information of the brake resistor based on the real-time status parameters;

[0046] Preferably, the overload status information includes an average value of a pitch angle difference, a root mean square value of a pitch current, and a wind speed turbulence value.

[0047] Determine the overload status information of the brake resistor based on the real-time status parameters, including:

[0048] (1) Determine the wind turbulence value based on the wind speed;

[0049] The wind speed turbulence value is determined according to the wind speed using the existing technology. The acquisition of the wind speed turbulence value usually relies on methods such as meteorological observation, turbulence gradient method and numerical simulation.

[0050] (2) determining an average value of pitch angle differences according to the pitch angles of the wind turbine blades;

[0051] Preferably, determining the average value of the pitch angle difference according to the pitch angle of the wind turbine blades includes:

[0052] Get the maximum and minimum pitch angles of the three blades each time the wind turbine is updated;

[0053] According to the difference between the maximum value and the minimum value of the pitch angle of the three blades when the wind turbine is updated each time, the average value of the difference in the pitch angle of the three blades of the wind turbine updated N times within n time is calculated.

[0054] The specific calculation formula is:

[0055]

[0056] Among them, Angle avg represents the average value of the pitch angle difference of the three blades of the wind turbine that are updated N times in n time. N represents that the pitch angle of the three blades of the wind turbine is updated N times in n time. K represents the kth update of the wind turbine. Angle ma and Angle min It indicates the maximum and minimum pitch angles of the three blades each time the wind turbine is updated.

[0057] Calculating Angle avg It is used to evaluate the frequency and amplitude of pitch angle adjustment of the three blades of a wind turbine.

[0058] Preferably, n can be set to 10 minutes, setting the wind turbine to update the blade pitch angle Angle in real time at least 10 times per second (or faster). i and pitch current Current i , i = 1, 2, 3. High-frequency data updates help to more accurately monitor the dynamic behavior and system response of wind turbine blades.

[0059] (3) Determine the root mean square value of the pitch current based on the pitch current of the wind turbine blades.

[0060] Preferably, determining the root mean square value of the pitch current according to the pitch current of the wind turbine blades includes:

[0061] Get the pitch current of the three blades of the wind turbine every time it is updated;

[0062] According to the pitch currents of the three blades each time the wind turbine is updated, the root mean square value of the pitch currents of the three blades of the wind turbine when they are updated N times within n time is calculated.

[0063] The specific calculation formula is:

[0064]

[0065] Among them, CurrentRMS i The current represents the root mean square value of the pitch current of the three blades of the wind turbine when they are updated N times in n time. i It indicates the pitch current of the three blades every time the wind turbine is updated.

[0066] In one embodiment, preferably, the method further includes determining a theoretical pitch current value according to an average pitch angle difference value and a pitch current reference value,

[0067] The theoretical pitch current value is determined according to the average value of the pitch angle difference and the pitch current reference value, including:

[0068] According to the simulation analysis, the linear relationship between the average value of the pitch angle difference and the pitch current reference value under various working conditions at different times is obtained, and the proportionality coefficient is determined;

[0069] The theoretical pitch current value is determined according to the proportional coefficient, the average value of the pitch angle difference within the n time period and the pitch current reference value.

[0070] The specific calculation formula is:

[0071] y=k ipc x+b

[0072] Current ipc =k ipc *Angle avg +Current ref

[0073] represents the theoretical pitch current value in time n, k ipc Represents the proportionality coefficient obtained from simulation analysis, Current ref It represents the pitch current reference value obtained through simulation analysis and statistics.

[0074] Based on independent pitch control, the linear relationship between the average pitch angle difference value and the theoretical pitch current value at different times under various working conditions is obtained according to simulation analysis. ipc x+b, calculate the Current in n time ipc .

[0075] Independent pitch control is a technology that allows the pitch angle of each blade of a wind turbine (i.e., the angle between the blade and the rotor plane) to be adjusted independently to optimize the performance of the wind turbine, reduce loads, and increase power generation. Through simulation analysis, researchers can observe that under different operating conditions, there is a linear relationship between the average value of the pitch angle difference and the current required to drive the pitch mechanism (the root mean square value of the pitch current). This relationship can be expressed by the mathematical expression y=kipc *x+b, where y represents the root mean square value of the pitch current (Current ipc ), x represents the average value of pitch angle difference, k ipc is the proportional coefficient obtained by simulation, which represents the current change corresponding to the average value of the unit pitch angle difference, and b represents the pitch current reference value obtained by statistics under different working conditions.

[0076] The operating conditions may include different wind speeds, wind directions, turbulence intensity, temperature, humidity, etc. Each operating condition will have different effects on the performance and load of the wind turbine.

[0077] 3. If the overload status information indicates that the braking resistor is in an overload state, the braking resistor is overload protected.

[0078] If the overload status information meets the following conditions at the same time, it indicates that the brake resistor is in an overload state:

[0079] 0 <Angle avg <=IPC max ,

[0080] CurrentRMS i >Current ipc ,

[0081] The wind speed turbulence is greater than the threshold,

[0082] Among them, IPC max Indicates the maximum opening margin of independent pitch control.

[0083] Preferably, IPC max is a fixed value obtained through simulation analysis.

[0084] Preferably, the threshold of wind speed turbulence is calculated using the following formula:

[0085]

[0086] I l Indicates the threshold of wind speed turbulence, I ref represents the design turbulence intensity of the wind farm, V ave represents the designed annual average wind speed of the wind farm, V mean Indicates the average wind speed, P k Represents the standard deviation calculation coefficient.

[0087] Based on the above conditions, it can be determined that due to the excessively large average value of the pitch angle difference of the independent pitch control under extreme turbulent conditions, the RMS value of the pitch current increases, causing the brake resistor of the pitch system to be in an overloaded state.

[0088] Preferably, the braking resistor is overload protected, including:

[0089] Adjust the opening margin of the wind turbine blades to be equal to the current opening margin of the wind turbine blades *Current ipc / CurrentRMS i ;

[0090] Adjust the wind turbine's advance pitch start power to equal MIN (Power min ,(rated power*G power *CurrentRMS i / Current ipc ));

[0091] Adjust the maximum pitch angle of the wind turbine to be equal to MAX(PP max ,(PP max *G angle *Current ipc / CurrentRMS i ));

[0092] Among them, Current ipc Represents the theoretical pitch current value of the wind turbine blade, CurrentRMS i Indicates the root mean square value of the pitch current of the wind turbine blades, Power min Indicates the current starting power of the wind turbine's advance pitch change, G power represents the optimal power coefficient when independent pitch control is turned off, PP max Indicates the maximum angle of advance pitch change, G angle Indicates the angle coefficient for turning off independent pitch control.

[0093] Specifically, PP max and Power min is a fixed value obtained by simulation analysis, PP max It is used to control the output power of wind turbines or achieve other control goals (such as air braking, reducing mechanical stress, etc.) by adjusting the pitch angle of the blades under specific wind speed or power conditions. min When the output power of the wind turbine reaches or exceeds this value, the pitch system starts to perform advance pitch operation, that is, adjusts the pitch angle of the blades to reduce the captured wind energy, thereby controlling the output power.

[0094] Based on the load simulation safety under various working conditions and reducing the power loss caused by early pitch control, the optimal power coefficient G of turning off independent pitch control is obtained. power and the angle factor G angle .

[0095] Until the root mean square value of the pitch current is less than the theoretical pitch current value, the overload protection of the braking resistor is stopped and normal operation is restored.

[0096] The present invention identifies the overload state of the brake resistor of the pitch system according to the wind speed, the pitch angle and the pitch current of the wind turbine blades, and reduces the risk of overload damage to the brake resistor of the pitch system by dynamically adjusting and controlling the opening margin, advance pitch starting power and advance pitch maximum angle of the wind turbine blades.

[0097] In one embodiment, Figure 2 As shown, a wind turbine generator set pitch brake resistor overload control protection device is provided, including:

[0098] An acquisition unit, used for acquiring real-time state parameters of a brake resistor of a pitch control system in a wind turbine;

[0099] A determination unit, used to determine the overload state information of the brake resistor according to the real-time state parameters;

[0100] The protection unit is used to perform overload protection on the braking resistor if the overload status information indicates that the braking resistor is in an overload state.

[0101] In one embodiment, a terminal is also provided, including a processor, an input device, an output device and a memory, wherein the processor, input device, output device and memory are interconnected, wherein the memory is used to store a computer program, and the computer program includes program instructions, and the processor is configured to call the program instructions to execute the wind turbine generator set variable pitch braking resistor overload control protection method described in the above embodiment.

[0102] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0103] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for controlling and protecting the overload of a variable pitch brake resistor of a wind turbine generator set, characterized in that: include: Obtain the real-time status parameters of the brake resistor of the pitch control system in the wind turbine; Determine the overload state information of the braking resistor according to the real-time state parameter; If the overload status information indicates that the braking resistor is in an overload state, overload protection is performed on the braking resistor.

2. The wind turbine generator set pitch brake resistor overload control protection method according to claim 1, characterized in that: The real-time status parameters include wind speed, pitch angle and pitch current of the wind turbine blades.

3. The wind turbine generator set pitch brake resistor overload control protection method according to claim 2, characterized in that: The overload status information includes an average value of a pitch angle difference, a root mean square value of a pitch current, and a wind speed turbulence value.

4. The wind turbine generator set pitch brake resistor overload control protection method according to claim 2, characterized in that: The step of determining the overload state information of the brake resistor according to the real-time state parameter comprises: Determine the wind turbulence value based on the wind speed; Determine an average value of pitch angle differences according to the pitch angles of the wind turbine blades; The root mean square value of the pitch current is determined according to the pitch current of the wind turbine blade.

5. The wind turbine generator set pitch brake resistor overload control protection method according to claim 4, characterized in that: The step of determining the average value of the pitch angle difference according to the pitch angle of the wind turbine blades includes: Get the maximum and minimum pitch angles of the three blades each time the wind turbine is updated; According to the difference between the maximum value and the minimum value of the pitch angle of the three blades when the wind turbine is updated each time, the average value of the difference in the pitch angle of the three blades of the wind turbine updated N times within n time is calculated.

6. The wind turbine generator set pitch brake resistor overload control protection method according to claim 4, characterized in that: Determining the root mean square value of the pitch current according to the pitch current of the wind turbine blades includes: Get the pitch current of the three blades of the wind turbine every time it is updated; According to the pitch currents of the three blades each time the wind turbine is updated, the root mean square value of the pitch currents of the three blades of the wind turbine when they are updated N times within n time is calculated.

7. The wind turbine generator set pitch brake resistor overload control protection method according to claim 4, characterized in that: It also includes determining a theoretical pitch current value according to an average value of the pitch angle difference and a pitch current reference value, The theoretical pitch current value is determined according to the average value of the pitch angle difference and the pitch current reference value, including: According to the simulation analysis, the linear relationship between the average value of the pitch angle difference and the pitch current reference value under various working conditions at different times is obtained, and the proportionality coefficient is determined; The theoretical pitch current value is determined according to the proportional coefficient, the average value of the pitch angle difference within the n time period and the pitch current reference value.

8. The wind turbine generator set pitch brake resistor overload control protection method according to claim 1, characterized in that: The overload protection of the braking resistor includes: Adjust the opening margin of the wind turbine blades to be equal to the current opening margin of the wind turbine blades *Current ipc / CurrentRMS i ; Adjust the wind turbine's advance pitch start power to equal MIN (Power min ,(rated power*G power *CurrentRMS i / Current ipc )); Adjust the maximum pitch angle of the wind turbine to be equal to MAX(PP max ,(PP max *G angle *Current ipc / CurrentRMS i )); Among them, Current ipc Represents the theoretical pitch current value of the wind turbine blade, CurrentRMS i Indicates the root mean square value of the pitch current of the wind turbine blades, Power min Indicates the current starting power of the wind turbine's advance pitch change, G power represents the optimal power coefficient when independent pitch control is turned off, PP max Indicates the maximum angle of advance pitch change, G angle Indicates the angle coefficient for turning off independent pitch control.

9. The wind turbine generator set pitch brake resistor overload control protection device is characterized by: include: An acquisition unit, used for acquiring real-time state parameters of a brake resistor of a pitch control system in a wind turbine; A determination unit, used to determine the overload state information of the brake resistor according to the real-time state parameters; The protection unit is used to perform overload protection on the braking resistor if the overload status information indicates that the braking resistor is in an overload state.

10. A terminal, characterized in that: The method comprises a processor, an input device, an output device and a memory, wherein the processor, the input device, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program comprises program instructions, and the processor is configured to call the program instructions to execute the method according to any one of claims 1 to 8.

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