Active supporting method, system and equipment for direct-current wind turbine generator and storage medium

Abstract

The invention relates to the technical field of direct-current wind turbine generator control, in particular to a direct-current wind turbine generator active supporting method, system and device and a storage medium, and the method comprises the following steps: S10, detecting a direct-current bus voltage Vpcc, and if a direct-current bus voltage deviation delta Vpcc exceeds a set dead zone delta Vdb, turning to S20; s20, inputting and switching a virtual direct-current machine control reference power instruction Pref of the direct-current wind turbine generator into an active support module, and recording the current moment as tstart; s30, when t is larger than tstart + delta T, a virtual direct-current machine control reference power instruction input Pref of the direct-current wind turbine generator set is switched into a rotating speed recovery module; and S40, when the end condition of rotating speed recovery is met, the virtual direct current machine control reference power instruction input Pref of the direct current wind turbine generator set is switched to the maximum power tracking module. By detecting the direct current bus voltage in real time and introducing the active support module, voltage deviation can be quickly responded when the power grid fluctuates, the power grid support capability is provided, and the stability and reliability of the power grid are improved while the operation safety of the wind turbine generator is ensured.

Description

Technical Field

[0001] The present invention relates to the field of direct current wind turbine control technology, and in particular to a direct current wind turbine active support method, system, equipment and storage medium. Background Art

[0002] With the development of renewable energy technology, wind power, as one of the important clean energy sources, has been increasing its share in the global energy structure. Existing wind turbines are mainly divided into AC wind turbines and DC wind turbines. Among them, DC wind turbines have gradually attracted widespread attention due to their high efficiency, simple structure, low loss and other advantages. With the expansion of the scale of wind turbines connected to the grid, the impact of their operating stability on the safe operation of the power grid has become increasingly prominent.

[0003] In the related technology, the all-DC offshore wind power system is sent out through DC collection and DC transmission, which will threaten the stability of the sending-end system and its DC bus voltage. The output of DC wind turbines mainly depends on environmental factors such as wind speed, and its volatility and uncertainty have a great impact on the DC bus voltage; at the same time, the DC wind power system is connected to the grid through power electronic converter control, and its output is generally decoupled from the bus voltage. This inertial characteristic further reduces the stability of the system. In response to the demand for active support of the above-mentioned DC wind turbines, a virtual DC machine control strategy with a droop function is proposed to achieve active support for the DC bus voltage. However, the existing active support method for DC wind turbines does not take into account the influence of turbulent wind speed. If the active support function is started in a weakening gust scenario, the DC wind turbine may face the risk of rotor speed instability, causing a greater impact on the DC bus voltage.

[0004] Therefore, there is an urgent need for an active support method for DC wind turbines to improve the stability and reliability of the power grid. Summary of the invention

[0005] In view of at least one of the above technical problems, the present invention provides a method, system, device and storage medium for active support of a DC wind turbine, and adopts an improved method to improve the stability and reliability of the power grid.

[0006] According to a first aspect of the present invention, there is provided a method for actively supporting a DC wind turbine, the method comprising the following steps:

[0007] S10: Detect DC bus voltage V pcc , if the DC bus voltage deviation ΔV pcc Exceeding the set dead zone ΔV db , then go to S20;

[0008] S20: Set the virtual DC machine control reference power instruction P of the DC wind turbine group ref The input is switched to the active support module, and the current time is recorded as tstart ;

[0009] S30: When t>t start +ΔT, the virtual DC machine control reference power command of the DC wind turbine is input to P ref Switch to the speed recovery module;

[0010] S40: When the termination condition of the speed recovery is met, the virtual DC machine control reference power command of the DC wind turbine is input into P ref Switch to the maximum power tracking module.

[0011] In some embodiments of the present invention, the virtual DC machine control of the DC wind turbine group in S20 is:

[0012]

[0013] Where V out_ref is the DC wind turbine output voltage reference value; V n is the rated output voltage of the DC wind turbine; J is the virtual inertia of the virtual DC machine; D is the virtual damping of the virtual DC machine; P e is the output electromagnetic power of the DC wind turbine; s is the Laplace operator.

[0014] In some embodiments of the present invention, the active support module in S20 is:

[0015] P sup =P NSSFC +K D ΔV

[0016] Where P sup K is the reference power command output by the active support module; D is the droop coefficient; ΔV is the DC bus voltage deviation, that is, ΔV=V pcc -V n .

[0017] In some embodiments of the present invention, the P NSSFC The reference power command output by the speed tracking control law:

[0018] P NSSFC =P m -J r sω r.ref -J r a0(ω r.ref -ω r )

[0019] Where: P m is the aerodynamic power of the DC wind turbine; J ris the rotor inertia of the DC wind turbine; a0 is the nonlinear static feedback controller parameter, which is used to adjust the convergence speed of the speed tracking error; ω r is the DC wind turbine rotor speed.

[0020] In some embodiments of the present invention, the r.ref The reference value of DC wind generator rotor speed:

[0021]

[0022] Where: ΔT is the set support time; t is time; ω r.start is the rotor speed of the DC wind turbine when active support starts; ω r.end In order to make the aerodynamic power and the speed recovery stage equal to the electromagnetic power under the average wind speed, the speed margin is increased by 0.05 rad / s.

[0023] In some embodiments of the present invention, the speed recovery module of the DC wind turbine set in S30 is:

[0024] P rec =P e.end -ΔP de

[0025] Where: P rec P is the reference power command output by the active support module; e.end is the electromagnetic power of the DC wind turbine at the end of active support, ΔP de The load reduction is constant.

[0026] In some embodiments of the present invention, the speed recovery termination condition of the DC wind turbine set in S40 is:

[0027]

[0028] Where: K opt is the optimal torque coefficient of the DC wind turbine;

[0029] The maximum power tracking module of the DC wind turbine is:

[0030]

[0031] Where: P MPPT It is the reference power command output by the maximum power tracking module.

[0032] According to a second aspect of the present invention, there is also provided a DC wind turbine active support control system, the system comprising:

[0033] An active support module, used to generate a reference power command of the DC wind turbine generator set during the active support phase;

[0034] A speed recovery module, used for generating a reference power command of the DC wind turbine set during the speed recovery phase;

[0035] A maximum power tracking module, used to generate a reference power command for the DC wind turbine in the maximum power tracking phase;

[0036] The virtual DC machine control module controls the virtual DC machine reference power instruction P ref Switch to the reference power command P output by the active support module sup , the reference power command P output by the active support module rec and the reference power command P output by the maximum power tracking module MPPT , and further according to the reference power instruction P output by the active support module rec Generate DC wind turbine output voltage reference value V out_ref .

[0037] According to a third aspect of the present invention, there is also provided an active support device for a DC wind turbine, comprising a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described above is implemented.

[0038] According to a fourth aspect of the present invention, there is also provided a DC wind turbine active support storage medium, comprising a storage medium on which a computer program is stored, and the computer program implements the above method when executed by a processor.

[0039] The beneficial effects of the present invention are as follows: by real-time detection of the DC bus voltage and introduction of an active support module, the present invention can quickly respond to voltage deviations when the power grid fluctuates and provide power grid support capabilities; compared with the prior art, while ensuring the safe operation of wind turbines, the stability and reliability of the power grid are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A schematic diagram of a flow chart of a method for actively supporting a DC wind turbine generator system according to an embodiment of the present invention;

[0042] Figure 2 A control block diagram of a DC wind turbine active support method according to an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of main parameters of a DC wind turbine grid-connected model constructed by simulation software in an embodiment of the present invention;

[0044] Figure 4 It is a simulation result diagram for verifying the effectiveness of the experimental results in the embodiments of the present invention. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0047] like Figures 1 to 3 The active support method of the DC wind turbine shown in the figure comprises the following steps: Figure 1 As shown:

[0048] S10: Detect DC bus voltage V pcc , if the DC bus voltage deviation ΔV pcc Exceeding the set dead zone ΔV db , then go to S20;

[0049] S20: Set the virtual DC machine control reference power instruction P of the DC wind turbine group ref The input is switched to the active support module, and the current time is recorded as t start ;

[0050] S30: When t>t start +ΔT, the virtual DC machine control reference power command of the DC wind turbine is input to P ref Switch to the speed recovery module;

[0051] S40: When the termination condition of the speed recovery is met, the virtual DC machine control reference power command of the DC wind turbine is input into P ref Switch to the maximum power tracking module.

[0052] In the above embodiment, the present invention detects the DC bus voltage in real time and introduces an active support module, so as to quickly respond to voltage deviations when the power grid fluctuates and provide power grid support capabilities; compared with the prior art, it ensures the safe operation of wind turbines while improving the stability and reliability of the power grid.

[0053] In an embodiment of the present invention, in order to achieve stable active support, as Figure 2 As shown, the virtual DC machine control of the DC wind turbine in S20 is:

[0054]

[0055] Where V out_ref is the DC wind turbine output voltage reference value; V n is the rated output voltage of the DC wind turbine; J is the virtual inertia of the virtual DC machine; D is the virtual damping of the virtual DC machine; P e is the output electromagnetic power of the DC wind turbine; s is the Laplace operator. Virtual damping D provides a direct response mechanism to power changes by adjusting the electromagnetic power P in real time. e The influence of the wind turbine generator system on the dynamic behavior of the wind turbine generator system is greatly reduced, which helps to suppress the oscillation that may occur during the operation of the wind turbine generator system and enhance the dynamic stability of the system. In the embodiment of the present invention, by introducing virtual inertia and virtual damping, the dynamic behavior of the DC wind turbine generator system is matched with the characteristics of the power grid to achieve efficient and stable active support.

[0056] In an embodiment of the present invention, the active support module in S20 is:

[0057] P sup =P NSSFC +K D ΔV

[0058] Where P sup K is the reference power command output by the active support module; D is the droop coefficient; ΔV is the DC bus voltage deviation, that is, ΔV=V pcc -V n .like Figure 2 As shown, the reference power command P output by the active support module sup It is dynamically calculated based on the DC bus voltage deviation: when the bus voltage V pcc When the system is higher than the rated value, that is, ΔV>0, the system will be drooped by the coefficient K D Output a negative power command, that is, reduce the power output to reduce the grid load and reduce the bus voltage; when the bus voltage V pcc When the system is lower than the rated value, that is, ΔV<0, the system will be drooped by the droop coefficient K D Output a positive power command, that is, increase power output to increase bus voltage and provide support. Droop control can quickly adjust power output according to real-time voltage deviation to meet the grid's requirements for wind turbine support capabilities.

[0059] In an embodiment of the present invention, in order to suppress oscillation, Figure 2 As shown, PNSSFC The reference power command output by the speed tracking control law:

[0060] P NSSFC =P m -J r sω r.ref -J r a0(ω r.ref -ω r )

[0061] Where: P m is the aerodynamic power of the DC wind turbine; J r is the rotor inertia of the DC wind turbine; a0 is the nonlinear static feedback controller parameter, which is used to adjust the convergence speed of the speed tracking error; ω r is the rotor speed of the DC wind turbine. In this embodiment, the control logic is based on the current aerodynamic power P m The reference power of the wind turbine is dynamically calculated by combining the dynamic influence of the rotor inertia and the feedback correction of the speed deviation. In this embodiment, through the coordination of inertia and feedback regulation, the system has high stability and can effectively suppress oscillations that may be caused during power adjustment.

[0062] In the embodiment of the present invention, for the stability of the system, ω r.re f is the reference value of DC wind generator rotor speed:

[0063]

[0064] Where: ΔT is the set support time; t is time; ω r.start is the rotor speed of the DC wind turbine when active support starts; ω r.en d is to set the speed at which the aerodynamic power and the speed recovery stage are equal to the electromagnetic power under the average wind speed, and increase the speed margin by 0.05 rad / s. Please continue to refer to Figure 2 , DC wind generator rotor speed reference value ω r.ref Interpolation is performed as time t changes, and the set support time ΔT can be flexibly adjusted according to actual needs, thereby meeting the requirements of different application scenarios for recovery speed. This embodiment provides an efficient and reliable control method for speed recovery of a DC wind turbine, while taking into account dynamic response and system stability.

[0065] In the embodiment of the present invention, in order to achieve a smooth transition of the system, as Figure 2 As shown, the speed recovery module of the DC wind turbine in S30 is:

[0066] P rec =P e.end -ΔP de

[0067] Where: P rec P is the reference power command output by the active support module; e.end is the electromagnetic power of the DC wind turbine at the end of active support, ΔP de The load reduction is a constant. When active support ends, the power output of the unit is usually high. By gradually reducing the electromagnetic power output, the load restriction on the rotor is reduced, and the speed is gradually restored to normal operation. de The constant design ensures that the adjustment range is clear, avoiding incomplete recovery or system oscillation due to too fast or too slow adjustment. In this embodiment, the constant load reduction and linear adjustment method ensure the efficiency of the recovery phase and avoid energy loss caused by unnecessary power fluctuations.

[0068] On the basis of the above embodiments, in order to ensure the energy utilization rate of the wind turbine generator set, as Figure 2 As shown, the speed recovery termination condition of the DC wind turbine in S40 is:

[0069]

[0070] Where: K opt is the optimal torque coefficient of the DC wind turbine;

[0071] The maximum power tracking module of the DC wind turbine is:

[0072]

[0073] Where: P MPPT The reference power command output by the maximum power tracking module. In this embodiment, the maximum power tracking module is regulated to ensure that the wind turbine can capture wind energy as much as possible under any wind speed conditions, thereby improving power generation efficiency.

[0074] It should be noted here that the DC wind turbine grid-connected model is built based on MATLAB / SIMULINK simulation software, in which the main parameters of the wind turbine are as follows Figure 3 Under the same weakening gust, the system DC bus voltage change and wind turbine speed and electromagnetic power change curves are shown in Figure 4 The simulation results show that in the case of weakening gusts, the DC wind turbine using the traditional method may become unstable during active support, causing the DC bus voltage to drop twice; if the active support control method of the DC wind turbine considering the rotor stability constraint of the present invention is adopted, the electromechanical dynamic stability of the wind turbine itself can be effectively guaranteed.

[0075] In an embodiment of the present invention, a DC wind turbine active support control system is also provided, comprising:

[0076] Active support module, used to generate reference power instructions for DC wind turbines in the active support phase, that is, when the DC bus voltage deviation is large, the power output of the wind turbine is quickly adjusted to support the DC bus voltage;

[0077] The speed recovery module is used to generate a reference power command of the DC wind turbine in the speed recovery phase, and gradually restore the speed of the wind turbine to the optimal operating state;

[0078] The maximum power tracking module is used to generate a reference power command for the DC wind turbine in the maximum power tracking phase, so that the wind turbine can capture wind energy to the maximum extent under normal operating conditions;

[0079] The virtual DC machine control module controls the virtual DC machine reference power instruction P ref Switch to the reference power command P output by the active support module sup , the reference power command P output by the active support module rec and the reference power command P output by the maximum power tracking module MPPT , and further according to the reference power instruction P output by the active support module rec Generate DC wind turbine output voltage reference value V out_ref In this embodiment, the active support control system is divided into an active support module, a speed recovery module, a maximum power tracking module and a virtual DC machine control module. The scheduling capability of the virtual DC machine control module enables the system to dynamically adapt to changes in the DC bus voltage and the operating state of the wind turbine, and realizes the full-process optimization control of the wind turbine from voltage support to speed recovery to maximum power capture, thereby improving the stability and reliability of the system operation.

[0080] In the following part of the embodiments of the present invention, the electronic device and computer storage medium embodiments in the embodiments of the present invention are introduced. The electronic device and computer storage medium embodiments in the following correspond to the method embodiments in the above. Those skilled in the art can understand the following implementation process based on the above description, which will not be described in detail here.

[0081] The present application also proposes a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above method is implemented.

[0082] An embodiment of the present application further provides a storage medium on which a computer program is stored, and the computer program implements the above method when executed by a processor.

[0083] Among them, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable red-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, disk or optical disk.

[0084] For the purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use with or in conjunction with an instruction execution system, device or apparatus. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and editable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program may be printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0085] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0086] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for actively supporting a DC wind turbine, characterized in that: The following steps are involved: S10: Detect DC bus voltage V pcc , if the DC bus voltage deviation ΔV pcc Exceeding the set dead zone ΔV db , then go to S20; S20: Set the virtual DC machine control reference power instruction P of the DC wind turbine group ref The input is switched to the active support module, and the current time is recorded as t start ; S30: When t>t start +ΔT, the virtual DC machine control reference power command of the DC wind turbine is input to P ref Switch to the speed recovery module; S40: When the termination condition of the speed recovery is met, the virtual DC machine control reference power command of the DC wind turbine is input into P ref Switch to the maximum power tracking module.

2. The method for actively supporting a DC wind turbine according to claim 1, characterized in that: The virtual DC machine control of the DC wind turbine group in S20 is: Where V out_ref is the DC wind turbine output voltage reference value; V n is the rated output voltage of the DC wind turbine; J is the virtual inertia of the virtual DC machine; D is the virtual damping of the virtual DC machine; P e is the output electromagnetic power of the DC wind turbine; s is the Laplace operator.

3. The active support method for a DC wind turbine according to claim 2, characterized in that: The active support module in S20 is: P sup =P NSSFC +K D ΔV; Where P sup K is the reference power command output by the active support module; D is the droop coefficient; ΔV is the DC bus voltage deviation, that is, ΔV=V pcc -V n .

4. The active support method for a DC wind turbine according to claim 3, characterized in that: The P NSSFC The reference power command output by the speed tracking control law: P NSSFC =P m -J r so r.ref -J r a0(ω r.ref -oh r ); Where: P m is the aerodynamic power of the DC wind turbine; J r is the rotor inertia of the DC wind turbine; a0 is the nonlinear static feedback controller parameter, which is used to adjust the convergence speed of the speed tracking error; ω r is the DC wind turbine rotor speed.

5. The method for actively supporting a DC wind turbine according to claim 4, characterized in that: The ω r.ref The reference value of DC wind generator rotor speed: Where: ΔT is the set support time; t is time; ω r.start is the rotor speed of the DC wind turbine when active support starts; ω r.end In order to make the aerodynamic power and the speed recovery stage equal to the electromagnetic power under the average wind speed, the speed margin is increased by 0.05 rad / s.

6. The method for actively supporting a DC wind turbine according to claim 5, characterized in that: The speed recovery module of the DC wind turbine set in S30 is: P rec =P e.end -ΔP de ; Where: P rec P is the reference power command output by the active support module; e.end is the electromagnetic power of the DC wind turbine at the end of active support, ΔP de The load reduction is constant.

7. The method for actively supporting a DC wind turbine according to claim 6, characterized in that: The speed recovery termination condition of the DC wind turbine in S40 is: Where: K opt is the optimal torque coefficient of the DC wind turbine; The maximum power tracking module of the DC wind turbine is: Where: P MPPT It is the reference power command output by the maximum power tracking module.

8. A DC wind turbine active support control system, characterized in that: include: An active support module, used to generate a reference power command of the DC wind turbine generator set during the active support phase; A speed recovery module, used for generating a reference power command of the DC wind turbine set during the speed recovery phase; A maximum power tracking module, used to generate a reference power command for the DC wind turbine in the maximum power tracking phase; The virtual DC machine control module controls the virtual DC machine reference power instruction P ref Switch to the reference power command P output by the active support module sup , the reference power command P output by the active support module rec and the reference power command P output by the maximum power tracking module MPPT , and further according to the reference power instruction P output by the active support module rec Generate DC wind turbine output voltage reference value V out_ref .

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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