Modelling and analysis of direct-driven permanent magnet synchronous generator wind turbine based on wind-rotor neural network model

Abstract

A new practical way of modelling direct-driven permanent magnet synchronous generator (PMSG) wind turbines is proposed. The model emphasizes on the wind-rotor-to-PMSG-to-converter-to-grid system, which is the main energy flow system of the direct-driven wind turbine. In this article, a new wind-rotor back propagation neural network is proposed, which consists of a four-layer network and is used to describe the wind-rotor aerodynamic characteristics. According to the orthogonal experimental method, 1200 sets of wind-rotor aerodynamic data, which are calculated based on combining blade element momentum-modified theory with a dynamic stall model, are adopted as the sample data; and the wind-rotor neural network is trained using the Levenberg-Marquardt algorithm. Then, the coupling dynamic models of the wind-rotor and PMSG, and AC-DC-AC converter model are established, respectively; the control strategies for the generator-side and grid-side converters are constructed, too. The mechanical model, electric model, and control model are integrated into the whole simulation model, and the numerical simulation are carried out. The research results show that all the wind-rotor aerodynamic characteristics, electrical characteristics, and control characteristics can be obtained quickly and efficiently from the constructed model, and are helpful for optimization design and control for large-scale direct-direct PMSG wind turbines.

Modeling, control and electromagnetic transient simulation of the doubly fed induction generator-based wind energy generation system

“…Normally, the rated power rating, the angular speed and the shaft inertia are provided by manufacturer, and the high speed Ω h and active power P are measured and calculated. 1,7–10,12,21–28…”

“…The HCM is one of the most popular optimization algorithms, which requires the deduction of the gradients of Ω h and P , thus the derivative of the power P with respect to Ω h can be derived. The procedure for computing the MPPT is devised as follows: 1,7–10,13–28…”

Cogging Torque Minimization Using Skewed and Separated Magnet Geometries

“…Indeed, PM machines are preferred for their low speed and variable speed applications. Since the parameters such as efficiency and power coefficient are independent of rotation speed in the performance of PM machine, the machines can suit for low cycle applications [10][11][12][13]. In addition to its advantages, one of the major disadvantages of PM machines is the generation of cogging torque.…”

“…In fact, those methods for cogging torque reduction can be classified into two main groups: Machine-based and control-based. Optimization of cogging torque can be accomplished by skewing stator slots or rotor magnets, injection the harmonic current, changing the embrace and offset of the magnet, designing a fractional slot, and adding additional slots or teeth [11,[14][15][16][17]. In terms of control method, the torque harmonic spectrum of a 12/10 pole machine is investigated for the optimization of the cogging torque.…”

Passivity-based robust controller design for a variable speed wind energy conversion system

“…Due to the advantages of the controllable power factor, bidirectional power flows, reduced current distortions, and high reliability, 2-level back-to-back PWM converters have been widely applied in the wind power industry [1][2][3][4][5][6]. In traditional applications, the DC link capacitors are used to decouple the generator-side converter and grid-side converter so that the 2 converters can be driven independently.…”