Control method and system for limiting active power rise rate of full-power wind turbine generator
By adding a power change rate limiter to the grid-side converter of a full-power wind turbine, and using DC capacitors and Chopper circuits to absorb excess input power, the problem that the input power is much greater than the output active power when the wind speed fluctuates, achieving effective limits on the rise rate of active power and guaranteeing unit stability.
Patent Information
- Application Number
- CN202411968342.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-05-06
AI Technical Summary
When the wind speed fluctuates, the input power of the full-power wind turbine may be much greater than the output active power, resulting in the inability to output energy in time, causing the unit to fail and shut down.
By adding a power change rate limiter to the grid-side converter, the active power set value is limited and the difference is output to the machine-side converter. The excess input power is absorbed through the DC capacitor and the Chopper circuit to limit the active power rise rate.
It effectively limits the active power rise rate of the full-power wind turbine, avoids unit failure and shutdown caused by the inability to output energy in time, and does not require additional hardware costs.
Smart Images
Figure CN119944799A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of full-power wind turbine control, and in particular to a control method, system, storage medium and computing device for limiting the active power increase rate of a full-power wind turbine. Background Art
[0002] In order to adapt to the grid's restrictions on wind power changes, full-power wind turbines need to add power change rate limits in active control. However, the energy source of wind turbines - wind energy is not controllable. In some cases (such as gusts), the kinetic energy captured by wind turbines increases sharply, and actions such as pitch change cannot take effect in time, resulting in the input power of wind turbines being much greater than the output active power (especially in some areas where the active power change rate required is relatively low). After adding output power change rate limits (especially lower change rates) to the conventional grid-following control or grid-building control of full-power wind turbines, when the wind speed fluctuates greatly, the input power of full-power wind turbines will be greater than the output power. The energy that cannot be output in time (the energy during this period cannot be dissipated) will cause the wind turbine to fail and shut down. Summary of the invention
[0003] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a control method for limiting the active power rise rate of a full-power wind turbine set. By introducing a power difference signal into the DC voltage control, when the power is unbalanced, on the one hand, the voltage increase of the DC capacitor is used to absorb part of the power. On the other hand, when the voltage of the DC capacitor is too high, the Chopper circuit is used to dissipate excess energy, thereby limiting the power change rate and ensuring the safe operation of the set.
[0004] A second object of the present invention is to provide a control system for limiting the rate of increase of active power of a full-power wind turbine generator set.
[0005] A third object of the present invention is to provide a storage medium.
[0006] A fourth object of the present invention is to provide a computing device.
[0007] The first object of the present invention is achieved through the following technical solutions: a control method for limiting the active power rise rate of a full-power wind turbine set, for the grid-side converter and the machine-side converter of the full-power wind turbine set, a power change rate limiter is added to the control of the grid-side converter to limit the active power setting value of the grid-side converter, and the difference between the limited active power setting value and the original active power setting value is output to the control of the machine-side converter to compensate for the active current of the machine-side converter, thereby changing the DC voltage of the machine-side converter. When the DC voltage increases, the DC capacitor connected in parallel between the machine-side converter and the grid-side converter can absorb a part of the active power from the machine-side converter. When the DC voltage is greater than a preset threshold, a Chopper circuit is invested between the machine-side converter and the grid-side converter to absorb more active power of the machine-side converter, thereby consuming excess input power, so as to achieve the purpose of limiting the active power rise rate and balancing the input and output power.
[0008] Furthermore, the control method for limiting the active power increase rate of a full-power wind turbine generator system comprises the following steps:
[0009] The original active power setting value and the limited active power setting value are obtained, and the difference between them is calculated, which is called the power change rate limit difference;
[0010] Outputting the power change rate limit difference to the control of the machine-side converter to calculate the active current compensation value, superimposing the active current compensation value with the active current command value generated by the original DC voltage control of the machine-side converter to obtain the compensated active current command value;
[0011] The compensated active current command value is input into the current control of the machine-side converter to increase the current of the machine-side converter, so that the DC voltage of the DC capacitor will rise due to the power imbalance between the input and output sides. Finally, the excess input power is consumed by the DC capacitor and the Chopper circuit, so as to limit the power change while maintaining the stability of the full-power wind turbine.
[0012] Furthermore, the calculation formula of the power change rate limit difference is:
[0013]
[0014] Where ΔP set is the power change rate limit difference, P set1 is the original active power setting value, P set2 It is the set value of active power after limitation.
[0015] Furthermore, the difference ΔP is limited according to the power change rate set Calculate the active current compensation value I com , the relationship between the two is:
[0016] I com =K com ×ΔP set
[0017] In the formula, K com is the compensation coefficient;
[0018] The active current compensation value I com The active current command value I generated by DC voltage control dref1 The active current command value I after compensation is obtained by superposition. dref2 , the active current command value I dref2 Input into the current control of the machine-side converter.
[0019] Furthermore, the switching control logic of the Chopper circuit is as follows:
[0020] In Flag cp = 0, if U dc ≥U cut_in , then Flag cp Set to 1; if U dc cut_in , then Flag cp Keep it at 0;
[0021] In Flag cp =1, if U dc ≥U cut_out , then Flag cp Keep it at 1; if U dc cut_out , then Flag cp Set to 0;
[0022] Flag cp The signal is output to the Chopper circuit; when Flagcp is 1, the Chopper circuit is turned on; when Flagcp is 0, the Chopper circuit is turned off;
[0023] Among them, Flag cp Chopper enable signal, U cut_in Chopper input threshold, U cut_out is the Chopper cut-out threshold, U dc is the DC voltage value.
[0024] Furthermore, the Chopper cut-out threshold U cut_out The value is less than the Chopper input threshold U cut_in .
[0025] Furthermore, the compensation coefficient K com Set to 1 / Udc .
[0026] Furthermore, the active current command value I dref1 It is the active current command value after limiting.
[0027] Furthermore, the original active power setting value P set1 Master control from full power wind turbine.
[0028] The second object of the present invention is achieved by the following technical solution: a control system for limiting the active power increase rate of a full-power wind turbine generator set, used to implement the above-mentioned control method for limiting the active power increase rate of a full-power wind turbine generator set, comprising:
[0029] A power rise rate limiting module, which adds a power change rate limiter to the control of the grid-side converter to limit the active power setting value of the grid-side converter, thereby limiting the active power rise rate output by the grid-side converter to the power grid, and outputs the power change rate limit difference to the control of the generator-side converter;
[0030] The machine-side active current compensation module calculates the active current compensation value according to the power change rate limit difference, and superimposes the active current compensation value with the active current command value generated by the original DC voltage control of the machine-side converter to obtain the compensated active current command value;
[0031] The Chopper on / off control module controls the on / off of the Chopper circuit according to the DC voltage value.
[0032] The third object of the present invention is achieved through the following technical solution: a storage medium stores a program, and when the program is executed by a processor, the above-mentioned control method for limiting the active power increase rate of a full-power wind turbine is implemented.
[0033] The fourth purpose of the present invention is achieved through the following technical solution: a computing device, comprising a processor and a memory for storing processor executable programs, when the processor executes the program stored in the memory, the above-mentioned control method for limiting the active power rise rate of the full-power wind turbine is implemented.
[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0035] The present invention can limit the rising rate of output power when the input power of a full-power wind turbine generator set changes dramatically, so as to better adapt to the needs of different power grids.
[0036] Excess input power is dissipated through DC capacitors and Chopper circuits, limiting power changes while maintaining the stability of full-power wind turbines without adding additional hardware costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 This is the structural block diagram of a full-power wind turbine.
[0038] Figure 2 This is a schematic diagram of power increase limit control.
[0039] Figure 3 This is an example diagram of power rise limit control for grid-type full-power wind turbines.
[0040] Figure 4 This is an example diagram of power rise limit control for grid-following full-power wind turbines.
[0041] Figure 5 Schematic diagram of the system of the present invention. DETAILED DESCRIPTION
[0042] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.
[0043] Example 1
[0044] See also Figure 1 and Figure 2 As shown, this embodiment discloses a control method for limiting the active power rise rate of a full-power wind turbine set. For the grid-side converter and the machine-side converter of the full-power wind turbine set, a power change rate limiter is added to the control of the grid-side converter to limit the active power setting value of the grid-side converter, and the difference between the limited active power setting value and the original active power setting value is output to the control of the machine-side converter to compensate for the active current of the machine-side converter, thereby changing the DC voltage of the machine-side converter. When the DC voltage increases, the DC capacitor connected in parallel between the machine-side converter and the grid-side converter can absorb a part of the active power from the machine-side converter. When the DC voltage is greater than a preset threshold, a Chopper circuit is invested between the machine-side converter and the grid-side converter to absorb more active power of the machine-side converter, thereby consuming excess input power to achieve the purpose of limiting the active power rise rate and balancing the input and output power; it includes the following steps:
[0045] 1) Get the original active power setting value P set1 And the active power setting value after limitation P set2 , and calculate the difference between them, which is called the power change rate limit difference ΔP set , the calculation formula is:
[0046]
[0047] Where ΔP set is the power change rate limit difference, P set1is the original active power setting value, the original active power setting value P set1 From the main control of the full-power wind turbine, P set2 It is the set value of active power after limitation.
[0048] 2) Limit the power change rate to the difference ΔP set Output to the control of the machine-side converter, limiting the difference ΔP according to the power change rate set Calculate the active current compensation value I com , the relationship between the two is:
[0049] I com =K com ×ΔP set
[0050] In the formula, K com is the compensation coefficient, generally set to 1 / U dc , U dc It is the DC voltage value, which can also be adjusted according to needs;
[0051] The active current compensation value I com The active current command value I generated by DC voltage control dref1 (After limiting) superposition, the compensated active current command value I is obtained dref2 .
[0052] 3) The active current command value after compensation I dref2 The current control input to the machine-side converter increases the current of the machine-side converter, so that the DC voltage of the DC capacitor will rise due to the power imbalance between the input and output sides. Finally, the excess input power is consumed by the DC capacitor and the Chopper circuit, so that the power change is limited while maintaining the stability of the full-power wind turbine. Among them, the switching control logic of the Chopper circuit is as follows:
[0053] In Flag cp = 0, if U dc ≥U cut_in , then Flag cp Set to 1; if U dc cut_in , then Flag cp Keep it at 0;
[0054] In Flag cp =1, if U dc ≥U cut_out , then Flag cp Keep it at 1; if U dc cut_out , then Flag cp Set to 0;
[0055] Flag cp The signal is output to the Chopper circuit; when Flagcp is 1, the Chopper circuit is turned on; when Flagcp is 0, the Chopper circuit is turned off;
[0056] Among them, Flag cp Chopper enable signal, U cut_in Chopper input threshold, U cut_out Chopper cut-out threshold, generally U cut_out The value will be slightly smaller than U cut_in .
[0057] See also Figure 3 and Figure 4 As shown in the figure, there are example diagrams of power rise limit control of grid-building type and grid-following type full-power wind turbines, from which the specific control principles of the grid-side converter and the machine-side converter can be more clearly understood.
[0058] Example 2
[0059] This embodiment discloses a control system for limiting the rate of increase of active power of a full-power wind turbine generator set, which is used to implement the control method for limiting the rate of increase of active power of a full-power wind turbine generator set described in Embodiment 1, such as Figure 5 As shown, it includes the following functional modules:
[0060] A power rise rate limiting module, which adds a power change rate limiter to the control of the grid-side converter to limit the active power setting value of the grid-side converter, thereby limiting the active power rise rate output by the grid-side converter to the power grid, and outputs the power change rate limit difference to the control of the generator-side converter;
[0061] The machine-side active current compensation module calculates the active current compensation value according to the power change rate limit difference, and superimposes the active current compensation value with the active current command value generated by the original DC voltage control of the machine-side converter to obtain the compensated active current command value;
[0062] The Chopper on / off control module controls the on / off of the Chopper circuit according to the DC voltage value.
[0063] Example 3
[0064] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, the control method for limiting the active power increase rate of a full-power wind turbine generator set described in Embodiment 1 is implemented.
[0065] The storage medium in this embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, or other media.
[0066] Example 4
[0067] This embodiment discloses a computing device, including a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the control method for limiting the active power increase rate of a full-power wind turbine set described in Example 1 is implemented.
[0068] The computing device described in this embodiment may be a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.
[0069] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.
Claims
1. A control method for limiting the active power increase rate of a full-power wind turbine generator set, characterized in that: For the grid-side converter and machine-side converter of the full-power wind turbine generator set, a power change rate limiter is added to the control of the grid-side converter to limit the active power setting value of the grid-side converter, and the difference between the limited active power setting value and the original active power setting value is output to the control of the machine-side converter to compensate for the active current of the machine-side converter, thereby changing the DC voltage of the machine-side converter. When the DC voltage increases, the DC capacitor connected in parallel between the machine-side converter and the grid-side converter can absorb part of the active power from the machine-side converter. When the DC voltage is greater than the preset threshold, a Chopper circuit is added between the machine-side converter and the grid-side converter to absorb more active power of the machine-side converter, thereby consuming excess input power, so as to achieve the purpose of limiting the active power increase rate and balancing the input and output power.
2. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 1, characterized in that: The following steps are involved: The original active power setting value and the limited active power setting value are obtained, and the difference between them is calculated, which is called the power change rate limit difference; Outputting the power change rate limit difference to the control of the machine-side converter to calculate the active current compensation value, superimposing the active current compensation value with the active current command value generated by the original DC voltage control of the machine-side converter to obtain the compensated active current command value; The compensated active current command value is input into the current control of the machine-side converter to increase the current of the machine-side converter, so that the DC voltage of the DC capacitor will rise due to the power imbalance between the input and output sides. Finally, the excess input power is consumed by the DC capacitor and the Chopper circuit, so as to limit the power change while maintaining the stability of the full-power wind turbine.
3. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 2, characterized in that: The calculation formula of the power change rate limit difference is: Where ΔP set is the power change rate limit difference, P set1 is the original active power setting value, P set2 It is the set value of active power after limitation.
4. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 3, characterized in that: Limit the difference ΔP according to the power change rate set Calculate the active current compensation value I com , the relationship between the two is: I com =K com ×ΔP set In the formula, K com is the compensation coefficient; The active current compensation value I com The active current command value I generated by DC voltage control dref1 The active current command value I after compensation is obtained by superposition. dref2 , the active current command value I dref2 Input into the current control of the machine-side converter.
5. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 4, characterized in that: The switching control logic of the Chopper circuit is as follows: In Flag cp = 0, if U dc ≥U cut_in , then Flag cp Set to 1; if U dc cut_in , then Flag cp Keep it at 0; In Flag cp =1, if U dc ≥U cut_out , then Flag cp Keep it at 1; if U dc cut_out , then Flag cp Set to 0; Flag cp The signal is output to the Chopper circuit; when Flagcp is 1, the Chopper circuit is turned on; when Flagcp is 0, the Chopper circuit is turned off; Among them, Flag cp Chopper enable signal, U cut_in Chopper input threshold, U cut_out is the Chopper cut-out threshold, U dc is the DC voltage value.
6. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 5, characterized in that: The Chopper cut-out threshold U cut_out The value is less than the Chopper input threshold U cut_in .
7. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 6, characterized in that: The compensation coefficient K com Set to 1 / U dc .
8. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 7, characterized in that: The active current command value I dref1 It is the active current command value after limiting.
9. A control method for limiting the active power increase rate of a full-power wind turbine according to claim 8, characterized in that: The original active power setting value P set1 Master control from full power wind turbine.
10. A control system for limiting the active power increase rate of a full-power wind turbine, characterized in that: A control method for limiting the active power increase rate of a full-power wind turbine generator set according to any one of claims 1 to 9, comprising: A power rise rate limiting module, which adds a power change rate limiter to the control of the grid-side converter to limit the active power setting value of the grid-side converter, thereby limiting the active power rise rate output by the grid-side converter to the power grid, and outputs the power change rate limit difference to the control of the generator-side converter; The machine-side active current compensation module calculates the active current compensation value according to the power change rate limit difference, and superimposes the active current compensation value with the active current command value generated by the original DC voltage control of the machine-side converter to obtain the compensated active current command value; The Chopper on / off control module controls the on / off of the Chopper circuit according to the DC voltage value.