CN-121655876-B - Electromechanical coupling loading method and system for wind turbine generator drive chain test platform

CN121655876BCN 121655876 BCN121655876 BCN 121655876BCN-121655876-B

Abstract

The invention belongs to the technical field of wind power generation ground tests, and provides an electromechanical coupling loading method and system for a wind turbine generator drive chain test platform, which are used for acquiring real-time wind speed and power grid frequency; the method comprises the steps of calculating dynamic nonlinear aerodynamic load, gravity load and inertial load according to real-time wind speed, forming a basic load component through coordinate transformation and conversion, carrying out comprehensive inertia control according to real-time power grid frequency, calculating an electromagnetic torque command required by a generator, calculating pitch angle acceleration of the top end of a tower barrel based on a physical mechanism of pitching of the tower barrel caused by reverse moment of the generator, calculating an additional inertial bending moment generated at a main shaft due to pitching motion, carrying out driving control of a load motor system according to the electromagnetic torque command so as to simulate electromagnetic torque impact, superposing the basic load component and the additional inertial bending moment, and carrying out control of a six-degree-of-freedom loading device so as to simulate a structural side vibration bending moment and realize synchronous loading. The invention greatly improves the authenticity of the test.

Inventors

DING LEI
CHEN MING
BAO WEIYU

Assignees

山东大学

Dates

Publication Date: 20260508
Application Date: 20260206

Claims (8)

1. The electromechanical coupling loading method for the wind turbine generator transmission chain test platform is characterized by comprising the following steps of: acquiring real-time wind speed and grid frequency; calculating dynamic nonlinear aerodynamic load, gravity load and inertial load according to the real-time wind speed, and converting through coordinate transformation to form a basic load component; according to the real-time power grid frequency, comprehensive inertia control is carried out, and an electromagnetic torque command required by the generator is calculated; Based on the physical mechanism of the tower pitching caused by the reverse moment of the generator, the process of calculating the pitch angle acceleration of the top end of the tower comprises the steps of taking the abrupt change T f of the electromagnetic torque T e as an excitation source for causing the tower pitching vibration; And according to a torque-tower pitching dynamics model, the method comprises the following steps of: ; Wherein, the 、、、 The equivalent rotational inertia coefficient, damping coefficient, rigidity coefficient and pitch angle acceleration of the tower barrel of the wind turbine generator are respectively calculated; The process of calculating the additional bending moment of inertia at the main shaft due to the pitching motion comprises generating an additional bending moment of inertia at the main bearing M add of: ; wherein J eq is equivalent moment of inertia of the transmission chain in the pitching direction of the tower; And according to the electromagnetic torque command, driving control of a load motor system is performed to simulate electromagnetic torque impact, the basic load component and the additional inertia moment are overlapped, and the six-degree-of-freedom loading device is controlled to simulate the vibration bending moment of the structural side so as to realize synchronous loading.
2. The electromechanical coupling loading method of the wind turbine generator drive train test platform according to claim 1, wherein the process of calculating dynamic nonlinear aerodynamic load, gravity load and inertial load according to real-time wind speed and converting through coordinate transformation to form a basic load component comprises the steps of obtaining aerodynamic load, gravity load and inertial load according to real-time wind speed through a phyllin-momentum theory, decomposing the obtained load into five-degree-of-freedom non-torque load along the axial direction and other directions, and converting into a hub coordinate system through coordinates.
3. The electromechanical coupling loading method of the wind turbine generator system driving chain test platform according to claim 1, wherein the wind turbine generator system driving chain test platform performs torque load simulation through a load motor system, non-torque load of the wind turbine generator system is simulated through hydraulic cylinder output, and the rest five-degree-of-freedom non-torque load is symmetrically simulated through hydraulic cylinder devices in the wind turbine generator system driving chain test platform.
4. The electromechanical coupling loading method of the wind turbine generator transmission chain test platform according to claim 1, wherein the process of performing comprehensive inertia control according to the real-time power grid frequency comprises the steps of utilizing virtual inertia control to change the active power output by the wind turbine generator according to the frequency change rate; The droop control is utilized, and the active power output by the wind turbine generator is changed according to the frequency deviation; and combining virtual inertia control and sagging control to form comprehensive inertia control.
5. The electromechanical coupling loading method of the wind turbine generator drive chain test platform according to claim 1, wherein the process of calculating the electromagnetic torque command required by the generator comprises obtaining frequency modulation power through comprehensive inertia control, and overlapping the frequency modulation power with a power value obtained through maximum power point tracking control to obtain a power reference value of the wind turbine generator, wherein the frequency modulation power of the comprehensive inertia control is as follows: ; Wherein, the Frequency modulation power for integrated inertia control; the virtual inertia coefficient is used for simulating inertia response; for droop control, for simulating primary frequency modulation, For the frequency deviation of the power grid, The power grid frequency change rate is given, and t is time; dividing the obtained modulated power by the real-time rotational speed to obtain the torque increment needing additional contribution at the moment : ; For the rotor angular speed, the total electromagnetic torque T e eventually acting on the drive train is: ; T opt is the basic torque under the tracking control of the maximum power point of the wind turbine.
6. The electromechanical coupling loading method of the wind turbine generator system transmission chain test platform according to claim 1, wherein the process of superposing the basic load component and the additional bending moment of inertia and controlling the six-degree-of-freedom loading device comprises the following steps of: ; wherein M y is the basic pitching bending moment caused by aerodynamic factors, and M add is the calculated additional inertia bending moment caused by tower pitching vibration.
7. An electromechanical coupling loading system of a wind turbine generator drive chain test platform, characterized in that the electromechanical coupling loading method of the wind turbine generator drive chain test platform according to any one of claims 1-6 is adopted, comprising: The data acquisition module is configured to acquire real-time wind speed and grid frequency; The basic aerodynamic load calculation module is configured to calculate dynamic nonlinear aerodynamic load, gravity load and inertial load according to real-time wind speed, and form basic load components through coordinate transformation and conversion; the dynamic electromagnetic torque calculation module under the frequency support is configured to perform comprehensive inertia control according to the real-time power grid frequency and calculate an electromagnetic torque instruction required by the generator; An additional load module under electromechanical-structural coupling configured to calculate a pitch angle acceleration at a top end of the tower based on a physical mechanism of the generator counter moment causing the tower to pitch, and to calculate an additional moment of inertia at the main shaft due to the pitch motion; and the double-channel synchronous loading module is configured to perform driving control of the load motor system according to the electromagnetic torque command so as to simulate electromagnetic torque impact, superimpose the basic load component and the additional inertia moment, and perform control of the six-degree-of-freedom loading device so as to simulate the vibration bending moment of the structural side and realize synchronous loading.
8. The wind turbine generator set transmission chain test platform comprises a driving motor system, a six-degree-of-freedom loading device, a transmission chain system and a load motor system which are sequentially arranged, wherein the driving motor system is used for simulating wind wheel pneumatic torque input; The six-degree-of-freedom loading device is used for simulating the additional bending moment generated by the coupling of the wind wheel non-torque load and the tower; A drive train system for transmitting torque; the load motor system is used for simulating the electromagnetic torque of the generator and the frequency response characteristic of the power grid; The mechanical and electrical coupling loading system of the wind turbine generator transmission chain test platform is characterized by further comprising the mechanical and electrical coupling loading system of the wind turbine generator transmission chain test platform; or, further comprising a controller for performing the steps of the method of any of claims 1-6.

Description

Electromechanical coupling loading method and system for wind turbine generator drive chain test platform Technical Field The invention belongs to the technical field of wind power generation ground tests, and particularly relates to an electromechanical coupling loading method and system for a wind turbine generator drive chain test platform. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. The transmission chain (comprising a main shaft, a gear box, a coupling and the like) of the wind generating set is a core link of energy conversion, and the reliability of the transmission chain directly influences the operation benefit of a wind power plant. At present, the ground test of the transmission chain of the wind turbine mainly focuses on simulating the pneumatic load of a wind wheel end, and comprises the step of simulating wind shear, torque fluctuation caused by turbulent wind and non-torque load (such as bending moment and shearing force) by utilizing a six-degree-of-freedom loading device. However, with the construction of a novel power system mainly comprising new energy, the wind turbine generator is no longer a simple passive grid-connected device, but is required to bear frequency support functions such as primary frequency modulation and inertia response. The prior art has the following remarkable defects: First, feedback simulation of grid frequency dynamics is lacking. Existing test benches typically reduce the grid side load to a constant or power curve varying drag torque. In practice, when a disturbance (e.g., a frequency dip) occurs in the grid frequency, the fan controller will rapidly increase the generator electromagnetic torque to release the rotor kinetic energy (inertia response). The abrupt torque change of millisecond level can generate severe bidirectional extrusion impact on the tooth surface of the gear box, and the existing test bed for only simulating pneumatic load can not reproduce the working condition. Second, the coupling effects of the mechanics and structure are ignored. In the existing test, six-degree-of-freedom loading (simulated wind) and loading (simulated electricity) of a load motor are decoupled. In fact, when the generator generates a sudden change in the moment of reaction to support the grid frequency, this moment acts on the top of the tower, causing it to undergo instantaneous pitching vibrations or deformations. This structural vibration in turn creates additional bending moments of inertia on the drive train main shaft. The existing test method can not convert the power grid impact into structural deformation, so that the loading boundary condition is simpler than the actual working condition, and the hidden danger of bearing failure under the complex working condition is difficult to find. Disclosure of Invention In order to solve the problems, the invention provides an electromechanical coupling loading method and system for a wind turbine generator drive chain test platform, which take the frequency support characteristic of a power grid and the electromechanical-structure coupling effect into consideration to load a drive chain, and provide an effective means for dynamic response analysis of the drive chain and service life assessment of the wind turbine generator. According to some embodiments, the present invention employs the following technical solutions: an electromechanical coupling loading method of a wind turbine generator drive chain test platform comprises the following steps: acquiring real-time wind speed and grid frequency; calculating dynamic nonlinear aerodynamic load, gravity load and inertial load according to the real-time wind speed, and converting through coordinate transformation to form a basic load component; according to the real-time power grid frequency, comprehensive inertia control is carried out, and an electromagnetic torque command required by the generator is calculated; based on a physical mechanism of tower pitching caused by generator reverse moment, calculating pitch angle acceleration at the top end of the tower, and calculating an additional inertia moment generated at a main shaft due to pitching motion; And according to the electromagnetic torque command, driving control of a load motor system is performed to simulate electromagnetic torque impact, the basic load component and the additional inertia moment are overlapped, and the six-degree-of-freedom loading device is controlled to simulate the vibration bending moment of the structural side so as to realize synchronous loading. As an alternative implementation mode, the dynamic nonlinear aerodynamic load, gravity load and inertial load are calculated according to the real-time wind speed, and the process of forming the basic load component through coordinate transformation comprises the steps of obtaining aerodynamic load, gravity load and inertial load