CN-122026754-A - Output and input power calculation method and system after demagnetization of permanent magnet wind driven generator

CN122026754ACN 122026754 ACN122026754 ACN 122026754ACN-122026754-A

Abstract

The invention relates to a method for calculating output and input power after demagnetization of a permanent magnet wind driven generator, which relates to the technical field of permanent magnet wind driven generator control and comprises the steps of obtaining first and second average electromagnetic torques of the permanent magnet wind driven generator after demagnetization and short circuit demagnetization under rated current, and calculating torque loss; the method comprises the steps of dividing an operating wind speed interval of a generator after short circuit demagnetization into a first wind speed interval and a second wind speed interval based on torque loss, calculating input power and output power of the generator in the first wind speed interval and the second wind speed interval after short circuit demagnetization based on torque loss, splicing the obtained input power and output power to obtain an input power curve and an output power curve of the generator in a full wind speed range after short circuit demagnetization, and controlling the permanent magnet wind driven generator according to the input power curve and the output power curve. The invention can solve the problem of maximizing the output power of the permanent magnet wind driven generator on the premise of ensuring the reliability, thereby ensuring the maximum generated energy.

Inventors

XIE YUYI
DU YIDONG
WU GUOJIAN
XIAO YANG
HOU JUNYI
YU LEI

Assignees

苏州大学

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The method for calculating the output and input power of the demagnetized permanent magnet wind driven generator is characterized by comprising the following steps: S1, acquiring a first average electromagnetic torque of a non-demagnetized permanent magnet wind driven generator under rated current, acquiring a second average electromagnetic torque of the permanent magnet wind driven generator after short circuit demagnetization under the rated current, and calculating torque loss caused by short circuit demagnetization according to the first average electromagnetic torque and the second average electromagnetic torque; S2, dividing a wind speed interval of the operation of the generator after the short circuit demagnetization into a first wind speed interval and a second wind speed interval based on the torque loss; Step S3, calculating the output power of the generator in a first wind speed interval after short circuit demagnetization based on the torque loss, wherein the input power is kept unchanged; step S4, splicing the input power of the short-circuit demagnetized generator in the first wind speed interval and the second wind speed interval, and splicing the output power of the short-circuit demagnetized generator in the first wind speed interval and the second wind speed interval to obtain the input power curve and the output power curve of the short-circuit demagnetized generator in the full wind speed range; and S5, controlling the permanent magnet wind driven generator according to an input and output power curve of the generator in the full wind speed range after the short circuit demagnetizing.
2. The method for calculating output and input power of a demagnetized permanent magnet wind turbine according to claim 1, wherein step S1 calculates torque loss due to short circuit demagnetization according to the first and second average electromagnetic torques, expressed as: ; Wherein, the In order to provide a loss of torque, For the first average electromagnetic torque to be the first average electromagnetic torque, Is the second average electromagnetic torque.
3. The method for calculating output and input power of a demagnetized permanent magnet wind turbine according to claim 1, wherein said step S2 comprises dividing the wind speed interval of the operation of the short-circuit demagnetized wind turbine into a first wind speed interval and a second wind speed interval based on the torque loss, and the method comprises: Dividing the wind speed interval of the operation of the generator after the short circuit demagnetization into a first wind speed interval based on the torque loss And a second wind speed interval , wherein, For the cut-in wind speed, Is the critical wind speed and is , In order to provide a loss of torque, For the rated output power of the generator before demagnetization, To cut out wind speed.
4. The method for calculating output and input power of the demagnetized permanent magnet wind driven generator according to claim 3, wherein the method comprises the following steps: in the first wind speed interval To ensure the maximization of the output power of the generator, the input power corresponding to each wind speed is calculated Keeping consistent with the state before short circuit demagnetization, and simultaneously carrying out complete compensation on the stator current of the generator, wherein the complete compensation is to compensate the current amplitude of the stator current without limitation until the electromagnetic power after compensation plus various losses of the generator are equal to the input power; In the second wind speed interval To ensure that the generator winding temperature does not exceed the insulation limit, the generator stator current is subjected to limited compensation, the limited compensation is to compensate the current amplitude of the stator current, and the compensated stator current does not exceed the rated current before short circuit demagnetization While adjusting the generator input power to ensure power flow balance.
5. The method for calculating output and input power of a demagnetized permanent magnet wind turbine according to claim 1, wherein the step S3 is characterized in that the method for calculating the output power of the power generator of the demagnetized short-circuit wind turbine in the first wind speed interval based on the torque loss comprises the following steps: In the first wind speed interval Setting the input current amplitude of the generator as The phase angle of the current is Based on generator finite element model, calculating to obtain electromagnetic power of generator under current Rotor side loss , wherein, In order to provide a loss of torque, For a corresponding current magnitude at a wind speed v i , As an inverse cosine function of the sign of the wave, For the grid-tie voltage, For the corresponding back emf at wind speed v i , Is a phase resistance; If it is If the preset condition is met, calculating the stator side loss based on the generator finite element model The final generator output power is ; If it is If the preset condition is not satisfied, changing the input current amplitude of the generator to be The phase angle of the current is Up to If the preset condition is met, calculating the stator side loss based on the generator finite element model The final generator output power is , wherein, For a corresponding input power at a wind speed v i , For the electromagnetic power corresponding to the jth iteration at wind speed v i , For the rotor side loss corresponding to the jth iteration at wind speed v i , And is an integer.
6. The method for calculating output and input power of the demagnetized permanent magnet wind driven generator according to claim 5, wherein the method is characterized in that The preset condition is satisfied, expressed as: 。
7. the method for calculating output and input power of the demagnetized permanent magnet wind turbine according to claim 1, wherein the step S3 is characterized in that the method for calculating the input power and output power of the generator of the demagnetized short-circuit wind turbine in the second wind speed interval based on the torque loss comprises the following steps: in the second wind speed interval Based on the generator finite element model after short circuit demagnetization, the input current amplitude of the generator is set as The phase angle of the current is adjusted to Based on generator finite element model, calculating to obtain electromagnetic power of generator under current Stator side loss The final generator output power is , wherein, In order to provide a loss of torque, As an inverse cosine function of the sign of the wave, For the grid-tie voltage, For the corresponding back emf at wind speed v i , In order to be a phase resistance, Is rated current; Meanwhile, the generator rotor side loss is calculated based on the generator finite element model Regulating the input power of the generator to , wherein, Is the corresponding input power at wind speed v i .
8. The output and input power computing system after demagnetization of the permanent magnet wind driven generator is characterized by comprising: The acquisition module is used for acquiring a first average electromagnetic torque of the non-demagnetized permanent magnet wind driven generator under the rated current, acquiring a second average electromagnetic torque of the permanent magnet wind driven generator after short circuit demagnetization under the rated current, and calculating torque loss caused by short circuit demagnetization according to the first average electromagnetic torque and the second average electromagnetic torque; The dividing module is used for dividing the running wind speed interval of the generator after the short circuit demagnetization into a first wind speed interval and a second wind speed interval based on the torque loss; The calculation module is used for calculating the output power of the generator in the first wind speed interval after the short circuit demagnetization based on the torque loss, wherein the input power is kept unchanged; The splicing module is used for splicing the input power of the short-circuit demagnetized generator in the first wind speed interval and the second wind speed interval, splicing the output power of the short-circuit demagnetized generator in the first wind speed interval and the second wind speed interval, and obtaining the input power curve and the output power curve of the short-circuit demagnetized generator in the full wind speed range; And the control module is used for controlling the permanent magnet wind driven generator according to the input and output power curves of the generator in the full wind speed range after the short circuit demagnetizing.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and operable on the processor, wherein the processor, when executing the computer program, performs the steps of the method for calculating output and input power after demagnetization of a permanent magnet wind power generator according to any of claims 1 to 7.
10. A computer readable storage medium having stored thereon a computer program, wherein the computer program, when executed by a processor, performs the steps of the method for calculating output and input power after demagnetization of a permanent magnet wind generator according to any of claims 1 to 7.

Description

Output and input power calculation method and system after demagnetization of permanent magnet wind driven generator Technical Field The invention relates to the technical field of permanent magnet wind power generator control, in particular to a method and a system for calculating output and input power after demagnetization of a permanent magnet wind power generator. Background Wind energy is a typical clean energy source. The wind power resources in China are rich, and the development of wind power generation is not only a necessary way for realizing carbon peak and carbon neutralization, but also one of core strategies for constructing a clean low-carbon, safe and high-efficiency energy system. Permanent magnet wind power generators (called "generators" for short) become the preferred scheme of wind turbines due to high torque density and efficiency, but the application of permanent magnet materials also brings irreversible demagnetization (called "demagnetization" for short) risks. The generator can normally continue to operate after the short circuit demagnetizes, except that the output power decreases. Because the amplitude of the back electromotive force fundamental wave is reduced after the short circuit demagnetizing, the amplitude of the stator current can be compensated for the purpose of maximizing the output power, and an iterative calculation method of the stator current and the rotor side loss of the generator under constant input power is researched. In addition, stator current compensation is limited by winding insulation, grid-tied voltage, and other factors, especially at full and near full conditions. Therefore, the problem of maximizing the output power of the permanent magnet wind driven generator on the premise of ensuring the reliability is required to be solved, and meanwhile, the problem of accurately and rapidly calculating the input and output power of the generator after the short circuit demagnetization is also required to be solved. Disclosure of Invention Therefore, the invention aims to solve the technical problems that the output power of the permanent magnet wind driven generator cannot be maximized on the premise of ensuring the reliability in the prior art, and the problem of accurate and rapid calculation of the input and output power of the generator after short circuit demagnetization cannot be effectively solved. In order to solve the technical problems, the invention provides a method for calculating output and input power of a permanent magnet wind driven generator after demagnetization, which comprises the following steps: S1, acquiring a first average electromagnetic torque of a non-demagnetized permanent magnet wind driven generator under rated current, acquiring a second average electromagnetic torque of the permanent magnet wind driven generator after short circuit demagnetization under the rated current, and calculating torque loss caused by short circuit demagnetization according to the first average electromagnetic torque and the second average electromagnetic torque; S2, dividing a wind speed interval of the operation of the generator after the short circuit demagnetization into a first wind speed interval and a second wind speed interval based on the torque loss; Step S3, calculating the output power of the generator in a first wind speed interval after short circuit demagnetization based on the torque loss, wherein the input power is kept unchanged; step S4, splicing the input power of the short-circuit demagnetized generator in the first wind speed interval and the second wind speed interval, and splicing the output power of the short-circuit demagnetized generator in the first wind speed interval and the second wind speed interval to obtain the input power curve and the output power curve of the short-circuit demagnetized generator in the full wind speed range; and S5, controlling the permanent magnet wind driven generator according to an input and output power curve of the generator in the full wind speed range after the short circuit demagnetizing. In one embodiment of the present invention, the step S1 calculates torque loss caused by short circuit demagnetization according to the first average electromagnetic torque and the second average electromagnetic torque, which is expressed as: ; Wherein, the In order to provide a loss of torque,For the first average electromagnetic torque to be the first average electromagnetic torque,Is the second average electromagnetic torque. In one embodiment of the present invention, the method of dividing the wind speed interval of the operation of the short-circuit demagnetized generator into the first wind speed interval and the second wind speed interval based on the torque loss in the step S2 includes: Dividing the wind speed interval of the operation of the generator after the short circuit demagnetization into a first wind speed interval based on the torque loss And a second wind speed interval, wherein,For t