Accurate Rotor Speed Estimation for Low-Power Wind Turbines

Abstract

Small grid-tied wind turbines based on permanent magnet generators often use a cost-effective power converter topology consisting of a passive rectifier, a boost converter, and an H-bridge inverter. Speed or position sensors are rarely used due to cost issues. Model-based estimators relying on electrical magnitudes are used instead. However, such estimators are parameter sensitive, which limit their accuracy. Further concerns arise if these parameters change with the operating condition of the machine, mainly due to temperature. Speed sensorless control using the rectifier voltage ripple is analyzed in this paper. This technique provides good dynamic response and does not depend on machine parameters. Simulations are provided for speed and power tracking comparison with an accurate modelbased speed estimation method operating at non-rated parameters. They show the speed accuracy and power tracking capability of the proposed method are similar to that provided by a speed sensor. This is translated into a 0.9% power increase when the model-based speed estimator shows 9 % of error. Experimental results are carried out to test the effect of current and temperature in the estimation, showing temperature insensitivity and some distortion due to fast current transients. A speed estimation accuracy of zero mean error and 1.7% standard error is experimentally obtained in the regular operation of the wind turbine.

Wind-Speed Estimation and Sensorless Control for SPMSG-Based WECS Using LMI-Based SMC

“…The proof is made by 1) Lyapunov stability criterion is formulated concerning the solution of a matrix equation and 2) Lyapunov stability of the controller is presented. Theorem 2: Consider the systemẋ = Ax is exponentially stable if and only if, for any symmetric positive-definite matrix M , there exists a unique symmetric positive-definite matrix Y that satisfies (28).…”

“…In [27], the authors presented an MRAS based on active power for speed estimation of a doubly fed reluctance generator. Other methods have also been proposed [28]- [31]. In [28], the rectifier voltage ripples were utilized to achieve sensorless control of a generator, and the direct-current (DC) magnitude of the rectifier output was used in [29]- [31] for the same purpose.…”

Certainty equivalence-based robust sliding mode control strategy and its application to uncertain PMSG-WECS

“…In the current era, due to the depletion of fossil fuels and their environmental impacts, researchers have focused on renewable energy resources (RES). In various renewable energy resources, energy harnesses from wind are getting much importance due to their sustainable and environment-friendly nature [1][2][3]. The system used for the said purpose is Permanent Magnet Synchronous Generator-based Wind Energy Conversion System (PMSG-WECS).…”

Design and Parameter Tuning of Nonlinear Active Disturbance Rejection Controller for Permanent Magnet Direct Drive Wind Power Converter System

“…In recent years, the installed capacity of wind power has gradually increased, and it has occupied a certain proportion in the power grid. The coupling relationship between wind turbine and power grid is getting closer, and the impact on power supply quality, reliability and security of power grid needs to be attached great importance [1,2]. In order to further improve the ability of the grid to absorb wind power and reduce the adverse impact of wind farms on the safety and reliability of the power supply of the grid, it is necessary not only to increase the smart regulation and control capabilities of the grid, but also to improve the adaptability of wind turbines to the grid and machine-side transients [3,4].…”