Performance improvement of wind‐driven self‐excited induction generator using fuzzy logic controller

Summary This paper deals with a nonlinear control of a wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG) interconnected to the distribution grid. The system connected to the grid is achieved by two IGBT based back‐to‐back converters controlled by pulse width modulation (PWM) and a capacitor as a DC link between them. Firstly, a literature review on the recent studies of nonlinear control in the wind energy field is introduced. Subsequently, a complete description of the wind energy conversion system with its dynamic modeling is presented. The second part of this article focused on the proposed control laws that rely on backstepping control as well as the maximum power point tracking (MPPT) command. The main objective of the control is to optimize the extraction of the wind power in the presence of a real wind profile and to keep the PMSG working properly with the best performance in both static and dynamic modes. The wind profile of this simulation is measured from the Dakhla region in Morocco to test the system robustness against real conditions. The simulation analysis prove the validation of the control strategy using a 2‐MW wind turbine and showed that the backstepping control based on the Lyapunov stability technique offers excellent results in terms of THD rate that does not exceed 0.95%.

Section: Introductionmentioning

confidence: 99%

Nonlinear backstepping control for PMSG wind turbine used on the real wind profile of the Dakhla‐Morocco city

Mourabit

Derouich

Ghzizal

et al. 2020

“…The performances and working characteristics of these generators have been investigated in the literature from many perspectives. [2][3][4][5] Among these generators, permanent magnet List of symbols and abbreviations: T cog , cogging torque; ℜ, air gap reluctance; φ air , air gap flux amount; θ, rotor position; T mk , Fourier coefficient; m, the least multiple of rotor pole number and stator slot number; K sk , skew efficiency; α sk , the ratio of the skew angle to the slot pitch; S, stator slot number; N C , the period of cogging torque; 2P, the number of poles; PMSGs, permanent magnet synchronous generators; FEA, finite elements analysis; FEM, finite elements method; THD, total harmonic distortion; HCF, highest common factor; LCM, least common multiple.. synchronous generators (PMSGs) are machines that have quick temporary response, 6 high efficiency, 7 requiring less maintenance as they do not need gear system, 8 and high reliability. 9 PMSGs have found a wide range of application in parallel with especially the discovery of rare-earth magnets and technological developments in switching elements.…”

Section: Introductionmentioning

confidence: 99%

“…Various types of generators are used in wind turbines. The performances and working characteristics of these generators have been investigated in the literature from many perspectives 2‐5 . Among these generators, permanent magnet synchronous generators (PMSGs) are machines that have quick temporary response, 6 high efficiency, 7 requiring less maintenance as they do not need gear system, 8 and high reliability 9 .…”

Section: Introductionmentioning

confidence: 99%

Cogging torque analysis in permanent magnet synchronous generators using finite elements analysis

Dalcalı

2020

Background: A number of generator types are used as energy converters in wind turbines. Despite the advantages of PMSG such as high-power density, high efficiency and low speed, the effect of the cogging torque occurring in PMSG must be reduced. Aim: The aim of this study is cogging torque optimization of internal rotor, surface mounted, PMSGs used in wind turbines with high number of slots and poles (84/14). Materials and methods: The performance and cogging torque characteristic of the generator have been studied by the finite element analysis (FEA) method. Results: While the cogging torque value of the initial generator 580 mNm, with changing skew it is optimized to 277.04 mNm, with changing pole arc offset it is tuned to 550 mNm. With a notch on the magnet and teeth it is minimized to 417.25 mNm and 383.9 mNm, respectively. Finally, increasing the ratio of slot opening to slot pitch, undermine the value of cogging torque. Conclusions: The obtained results illustrate that any improvement in cogging torque characteristic using the applied methods accordingly compromises other merits such as flux density, output power, labor and cost.

“…A wind energy system with a self‐excited induction generator (SEIG) is a well option in such remote areas due to its low‐cost maintenance, operation at extension speed area, brushless structure, and robust construction. Despite its robustness, poor voltage and frequency regulation depending on several factors are the major drawbacks of this generator …”

Section: Introductionmentioning

confidence: 99%

Thyristor controlled reactor‐based voltage and frequency regulation of a three‐phase self‐excited induction generator feeding unbalanced load

Çalgan

İlten

Demirtaş

2020

Summary A self‐excited induction generator (SEIG) is one of the cost‐effective ways for power generation in remote areas. Unlike common wind energy systems, SEIG needs an excitation capacitor bank to meet the reactive power demand. The terminal voltage of the SEIG depends on the reactive power delivered from excitation capacitor bank which complicates the voltage and frequency regulation. This article presents an unbalanced loaded three‐phase SEIG system controlled by fixed capacitor and thyristor controlled reactor in order to overcome poor voltage regulation problem. Moreover, the output frequency regulation is maintained thanks to the speed controller adjusting the speed of the generator. This regulation process employs a response surface model (RSM) instead of steady state equation that determines accurately the per‐phase triggering angle of TCR and speed of the generator. Therefore, there is no need to utilize the per‐phase equivalent circuit parameters which is the major advantage of the proposed method. The feasibility and reliability of the RSM have been proven by carrying out test experiments. Experimental results of three‐phase SEIG (5.5 kW) feeding unbalanced loads have been performed to confirm the effectiveness of proposed method. According to experimental results, voltage and frequency regulations of SEIG have been well performed by using RSM within the maximum 3% regulation error.