Control method and system for optimizing rotating speed fluctuation of wind generating set

Abstract

The invention discloses a control method and system for optimizing the rotating speed fluctuation of a wind generating set, and the method comprises the steps: superposing a torque disturbance with the same phase as the rotating speed fluctuation of a generator on an original generator torque, namely, increasing the transmission chain damping of the wind generating set, thereby inhibiting the rotating speed fluctuation of a transmission chain. Suppression of generator speed fluctuation is realized; wherein the torque disturbance is a resistance-increasing compensation torque which is provided by a transmission chain resistance-increasing controller and is in direct proportion to the rotating speed of the generator, the resistance-increasing compensation torque is a specific multiple of the rotating speed of the generator, and the specific multiple is a gain coefficient. The method can accurately determine the resistance increasing parameter of the transmission chain, and inhibits the rotation speed fluctuation of the transmission chain to the greatest extent.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a control method, system, storage medium and computing device for optimizing the speed fluctuation of a wind power generator set. Background Art

[0002] The large-scale capacity of a single unit is an inevitable trend in the development of current wind power technology. As the blades become longer and more flexible, a slight disturbance in wind speed will cause the blades to vibrate, which will cause the speed fluctuation of the unit's transmission chain. Excessive fluctuations in the transmission chain speed will cause the following hazards: the hardware of the unit, such as the gearbox, coupling, and elastic support, is easily damaged; the power of the unit fluctuates, and it is difficult to meet the power grid's test requirements for power stability under specific working conditions; the various loads of the unit increase, affecting the life of the entire unit. Therefore, how to control the stability of the unit's transmission chain speed has become a key technology in the current field of large-capacity wind turbine control.

[0003] At present, most wind power technology fields use transmission chain resistance algorithms based on simulation level to increase the damping coefficient of the unit transmission chain, thereby suppressing the unit speed fluctuation. However, as the unit blades become larger and more flexible, the multi-order modes of the blades are difficult to simulate realistically in the simulation software. The resistance parameters adjusted based on model simulation are difficult to accurately apply to on-site wind turbines. The transmission chain resistance parameters need to be adjusted back and forth, and it is difficult to achieve the ideal speed fluctuation suppression effect. Summary of the invention

[0004] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a control method for optimizing the speed fluctuation of a wind turbine generator set, which can accurately determine the transmission chain resistance parameters and suppress the speed fluctuation of the transmission chain to the greatest extent.

[0005] A second object of the present invention is to provide a control system for optimizing the rotation speed fluctuation of a wind turbine generator set.

[0006] A third object of the present invention is to provide a storage medium.

[0007] A fourth object of the present invention is to provide a computing device.

[0008] The first purpose of the present invention is achieved through the following technical scheme: a control method for optimizing the speed fluctuation of a wind turbine generator set, which method is to superimpose a torque disturbance with the same phase as the generator speed fluctuation on the original generator torque, so as to increase the transmission chain damping of the wind turbine generator set, thereby suppressing the transmission chain speed fluctuation, that is, achieving the suppression of the generator speed fluctuation; wherein, the torque disturbance is a resistance compensation torque proportional to the generator speed provided by the transmission chain resistance controller, and the resistance compensation torque is a specific multiple of the generator speed, and the specific multiple is the gain coefficient.

[0009] Furthermore, based on the generator speed measurement, converter torque response measurement and generator speed signal communication delay measurement of the wind turbine generator set, a second-order low-pass filter is constructed for phase compensation to ensure that the phase of the output resistance compensation torque is in phase with the generator speed fluctuation;

[0010] The gain coefficient required for debugging the resistance compensation torque is recorded as B1. The gain coefficient B1 requires that the amplitude of the generator speed fluctuation be significantly reduced at the speed fluctuation frequency;

[0011] The transmission chain resistance controller outputs the resistance compensation torque to the torque controller of the wind generator set;

[0012] The torque controller transmits the torque command superimposed with the resistance compensation torque to the frequency converter to suppress the fluctuation of the generator speed.

[0013] Furthermore, a rotation speed sensor is installed on the generator to measure the rotation speed of the generator.

[0014] Furthermore, based on the generator speed measurement of the wind turbine generator set, the inverter torque response measurement and the generator speed signal communication delay measurement, a second-order low-pass filter is constructed for phase compensation, as follows:

[0015] The test obtains the generator speed data transmission to the PLC delay time of the wind turbine generator set is T1, and the pure delay of the torque response is T2. The phase angle that needs to be compensated due to the hardware delay is Where T 转速波动周期 is the speed fluctuation period, f 转速波动 is the speed fluctuation frequency;

[0016] Through the torque step response test, the torque response equivalent first-order link of the inverter is measured to be Where T 变频器 is the equivalent first-order time constant of the frequency converter, s represents the complex variable of Laplace transform;

[0017] Construct a second-order low-pass filter Perform phase compensation so that The speed fluctuation frequency f 转速波动 The Bode diagram at is ahead of (T1+T2)f in phase 转速波动 ·3600, where ξ is the damping coefficient of the second-order low-pass filter and ω is the center frequency of the second-order low-pass filter.

[0018] Further, the adjustment of the gain coefficient B1 is as follows:

[0019] First, use a small negative gain to excite the generator speed fluctuation. By continuously increasing the amplitude of the negative gain until the generator speed fluctuation is excited, record the gain coefficient used at this time, recorded as B2. Since the negative gain for exciting the generator speed fluctuation is on the same order of magnitude as the positive gain for stabilizing the generator speed fluctuation, setting B1=-B2 can significantly reduce the amplitude of the generator speed fluctuation at the speed fluctuation frequency.

[0020] Furthermore, the dynamic characteristic differential equation of the transmission chain is:

[0021]

[0022] Where I is the generator moment of inertia, B is the damping coefficient, K is the transmission chain stiffness, Φ is the transmission shaft rotation angle, Φ.Φ is the generator speed, represents the speed acceleration, T A is the impeller driving torque, T F is the original generator torque;

[0023] The original generator torque T F A resistance compensation torque proportional to the generator speed Φ.Φ is superimposed on The final generator torque is At this time, the dynamic characteristic differential equation of the transmission chain becomes:

[0024]

[0025] The second object of the present invention is achieved by the following technical solution: a control system for optimizing the speed fluctuation of a wind turbine generator set, used to implement the above-mentioned control method for optimizing the speed fluctuation of a wind turbine generator set, comprising:

[0026] A speed sensor is installed on the generator and is used to measure the speed of the generator;

[0027] The transmission chain resistance controller is used to provide a resistance compensation torque that is proportional to the generator speed and transmit it to the torque controller. The torque controller then transmits the torque command with the resistance compensation torque superimposed on it to the frequency converter to suppress the generator speed fluctuation.

[0028] 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 optimizing the speed fluctuation of a wind turbine generator set is implemented.

[0029] The fourth objective of the present invention is achieved through the following technical solution: a computing device, comprising a processor and a memory for storing a program executable by the processor, wherein when the processor executes the program stored in the memory, the above-mentioned control method for optimizing the speed fluctuation of a wind turbine generator set is implemented.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] 1. The phase compensation caused by the speed signal acquisition transmission delay, generator torque execution delay, etc. is determined by a fixed calculation formula, and does not need to be determined by a complex closed-loop system parameter setting method, thus avoiding the differences in human experience.

[0032] 2. How to select a more appropriate resistance gain coefficient to achieve the expected resistance effect. Currently, most solutions are determined by combining mathematical models for parameter adjustment. Due to the complexity of the models of various physical components of real wind turbines, the established mathematical models may not be able to well characterize the actual situation of the on-site units. The coefficients obtained may not be able to obtain the best operating effect when applied to the on-site units. The present invention adopts a field testing method to determine the parameters. According to the test data of the on-site units, the transmission chain resistance parameters can be accurately determined to minimize the fluctuations in the transmission chain speed of the units.

[0033] 3. The present invention is simple to implement and collects unit information through external sensors without the need for additional sensors and hardware. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The control principle diagram of the method of the present invention.

[0035] Figure 2 It is a control flow chart of the method of the present invention.

[0036] Figure 3 The time domain and frequency domain comparison curve of the generator speed curve after adding resistance to the switch transmission chain.

[0037] Figure 4 Schematic diagram of the system of the present invention. DETAILED DESCRIPTION

[0038] 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.

[0039] Example 1

[0040] The dynamic characteristic differential equation of the transmission chain of the wind turbine generator set is:

[0041]

[0042] Where I is the generator moment of inertia, B is the damping coefficient, K is the transmission chain stiffness, Φ is the transmission shaft rotation angle, is the generator speed, represents the speed acceleration, T A is the impeller driving torque, T F is the original generator torque;

[0043] The original generator torque T F A value corresponding to the generator speed is superimposed on Proportional resistance compensation torque The final generator torque is At this time, the dynamic characteristic differential equation of the transmission chain becomes:

[0044]

[0045] It can be seen from the above formula that after adding the resistance compensation torque, the damping of the entire transmission chain increases from B to B+B1. By increasing the damping of the transmission chain, the generator speed fluctuation can be suppressed.

[0046] In summary, the essence of adding resistance to the transmission chain is to superimpose a torque disturbance with the same phase as the speed fluctuation on the original generator torque, so as to increase the transmission chain damping, thereby suppressing the transmission chain speed fluctuation, that is, to suppress the generator speed fluctuation. Then the key point of the problem is 1 how to ensure that the phase of the superimposed torque is in phase with the generator speed, and the key point 2 how to determine the gain coefficient B1. The innovative point of the control method for optimizing the speed fluctuation of a wind turbine generator set disclosed in this embodiment is how to accurately, simply and efficiently solve these two key points, see Figure 1 and Figure 2 The specific plan is as follows:

[0047] After the wind turbine generator set’s PLC is powered on, the transmission chain resistance controller parameters are initialized;

[0048] A speed sensor is installed on the generator, and the measured generator speed is input into the transmission chain resistance controller;

[0049] The conventional method is used to test the transmission data of the generator speed to the PLC of the wind turbine generator set. The delay time is T1, and the pure delay of the torque response is T2. The phase angle that needs to be compensated due to the hardware delay is Where T 转速波动周期 is the speed fluctuation period, f 转速波动 is the speed fluctuation frequency;

[0050] Through the torque step response test, the torque response equivalent first-order link of the inverter is measured to be Where T 变频器 is the equivalent first-order time constant of the frequency converter, s represents the complex variable of Laplace transform;

[0051] Construct a second-order low-pass filter Perform phase compensation so that The speed fluctuation frequency f 转速波动 The Bode diagram at is ahead of (T1+T2)f in phase 转速波动 ·3600, where ξ is the damping coefficient of the second-order low-pass filter and ω is the center frequency of the second-order low-pass filter;

[0052] The gain coefficient required for debugging the resistance compensation torque is recorded as B1. The details are as follows: first, a small negative gain is used to excite the generator speed fluctuation, and the amplitude of the negative gain is continuously increased until the generator speed fluctuation is excited. Then the gain coefficient used at this time is recorded, recorded as B2. Since the negative gain for exciting the generator speed fluctuation is on the same order of magnitude as the positive gain for stabilizing the generator speed fluctuation, setting B1 = -B2 can significantly reduce the amplitude of the generator speed fluctuation at the speed fluctuation frequency. The final evaluation index is as follows: Figure 3 As shown, after the transmission chain speed resistance is turned on, the amplitude energy of the generator speed fluctuation amplitude at the speed fluctuation frequency of 1.44Hz is significantly reduced.

[0053] The transmission chain resistance controller outputs the resistance compensation torque to the torque controller of the wind turbine generator set;

[0054] The torque controller transmits the torque command superimposed with the resistance compensation torque to the inverter to suppress the generator speed fluctuation.

[0055] Example 2

[0056] This embodiment discloses a control system for optimizing the speed fluctuation of a wind turbine generator set, which is used to implement the control method for optimizing the speed fluctuation of a wind turbine generator set described in Embodiment 1, such as Figure 4 As shown, including:

[0057] A speed sensor is installed on the generator and is used to measure the speed of the generator;

[0058] The transmission chain resistance controller is used to provide a resistance compensation torque that is proportional to the generator speed and transmit it to the torque controller. The torque controller then transmits the torque command with the resistance compensation torque superimposed on it to the frequency converter to suppress the generator speed fluctuation.

[0059] Example 3

[0060] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, the control method for optimizing the speed fluctuation of a wind turbine generator set described in Embodiment 1 is implemented.

[0061] 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.

[0062] Example 4

[0063] 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 optimizing the speed fluctuation of a wind turbine generator set described in Embodiment 1 is implemented.

[0064] 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.

[0065] 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 optimizing the speed fluctuation of a wind turbine generator set, characterized in that: The method is to superimpose a torque disturbance with the same phase as the generator speed fluctuation on the original generator torque, so as to increase the transmission chain damping of the wind turbine generator set, thereby suppressing the transmission chain speed fluctuation, that is, to achieve the suppression of the generator speed fluctuation; wherein, the torque disturbance is a resistance compensation torque proportional to the generator speed provided by the transmission chain resistance controller, and the resistance compensation torque is a specific multiple of the generator speed, and the specific multiple is the gain coefficient.

2. A control method for optimizing the speed fluctuation of a wind turbine generator set according to claim 1, characterized in that: Based on the generator speed measurement, inverter torque response measurement and generator speed signal communication delay measurement of the wind turbine, a second-order low-pass filter is constructed for phase compensation to ensure that the output resistance compensation torque is in phase with the generator speed fluctuation. The gain coefficient required for debugging the resistance compensation torque is recorded as B1. The gain coefficient B1 requires that the amplitude of the generator speed fluctuation be significantly reduced at the speed fluctuation frequency; The transmission chain resistance controller outputs the resistance compensation torque to the torque controller of the wind turbine generator set; The torque controller transmits the torque command superimposed with the resistance compensation torque to the frequency converter to suppress the generator speed fluctuation.

3. A control method for optimizing the speed fluctuation of a wind turbine generator set according to claim 2, characterized in that: A speed sensor is installed on the generator to measure the generator speed.

4. A control method for optimizing the speed fluctuation of a wind turbine generator set according to claim 2, characterized in that: Based on the generator speed measurement, inverter torque response measurement and generator speed signal communication delay measurement of the wind turbine, a second-order low-pass filter is constructed for phase compensation, as follows: The test obtains the generator speed data transmission to the PLC delay time of the wind turbine generator set is T1, and the pure delay of the torque response is T2. The phase angle that needs to be compensated due to the hardware delay is Where T 转速波动周期 is the speed fluctuation period, f 转速波动 is the speed fluctuation frequency; Through the torque step response test, the torque response equivalent first-order link of the inverter is measured to be Where T 变频器 is the equivalent first-order time constant of the frequency converter, s represents the complex variable of Laplace transform; Construct a second-order low-pass filter Phase compensation is performed so that The speed fluctuation frequency f 转速波动 The Bode diagram at is ahead of (T1+T2)f in phase 转速波动 ·3600, where ξ is the damping coefficient of the second-order low-pass filter and ω is the center frequency of the second-order low-pass filter.

5. A control method for optimizing the speed fluctuation of a wind turbine generator set according to claim 2, characterized in that: The debugging of the gain coefficient B1 is as follows: First, use a small negative gain to excite the generator speed fluctuation. By continuously increasing the amplitude of the negative gain until the generator speed fluctuation is excited, record the gain coefficient used at this time, recorded as B2. Since the negative gain for exciting the generator speed fluctuation is on the same order of magnitude as the positive gain for stabilizing the generator speed fluctuation, setting B1=-B2 can significantly reduce the amplitude of the generator speed fluctuation at the speed fluctuation frequency.

6. A control method for optimizing the speed fluctuation of a wind turbine generator set according to claim 1, characterized in that: The dynamic characteristic differential equation of the transmission chain is: Where I is the generator moment of inertia, B is the damping coefficient, K is the transmission chain stiffness, Φ is the transmission shaft rotation angle, is the generator speed, represents the speed acceleration, T A is the impeller driving torque, T F is the original generator torque; The original generator torque T F A value corresponding to the generator speed is superimposed on Proportional resistance compensation torque The final generator torque is At this time, the dynamic characteristic differential equation of the transmission chain becomes:

7. A control system for optimizing the speed fluctuation of a wind turbine generator set, characterized in that: The control method for optimizing the speed fluctuation of a wind turbine generator set according to any one of claims 1 to 6 comprises: A speed sensor is installed on the generator and is used to measure the speed of the generator; The transmission chain resistance controller is used to provide a resistance compensation torque that is proportional to the generator speed and transmit it to the torque controller. The torque controller then transmits the torque command with the resistance compensation torque superimposed on it to the frequency converter to suppress the generator speed fluctuation.

8. A storage medium storing a program, characterized in that: When the program is executed by a processor, the control method for optimizing the speed fluctuation of a wind turbine generator set according to any one of claims 1 to 6 is implemented.

9. A computing device comprising a processor and a memory for storing a program executable by the processor, characterized in that: When the processor executes the program stored in the memory, the control method for optimizing the speed fluctuation of the wind turbine generator set according to any one of claims 1 to 6 is implemented.

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