Renewable Energy Resources and Technologies
Sajad Saberi; Behrooz Rezaie
Abstract
This paper presents a sensorless speed control algorithm based on Finite Control Set Model Predictive Control (FCS-MPC) for Permanent Magnet Synchronous Motor (PMSM) fed by a 3-level Neutral-Point Clamped (NPC) converter. The proposed scheme uses an anti-windup Proportional-Integral (PI) controller concept ...
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This paper presents a sensorless speed control algorithm based on Finite Control Set Model Predictive Control (FCS-MPC) for Permanent Magnet Synchronous Motor (PMSM) fed by a 3-level Neutral-Point Clamped (NPC) converter. The proposed scheme uses an anti-windup Proportional-Integral (PI) controller concept to generate the reference electromagnetic torque using the error of speed. Then, FCS-MPC uses this torque reference and other parameters such as a current limitation, neutral point voltage unbalance, and switching frequency to control the converter gate signals. Also, an Adaptive Nonsingular Fast Terminal Sliding Mode Observer (ANFTSMO) was employed to estimate rotor position precisely in positive (clockwise) and negative (counterclockwise) speed to eliminate the encoder. The proposed algorithm has fast dynamics and low steady-state error. Moreover, torque fluctuation and current distortion reduced compared with Space Vector Pulse Width Modulation (SVPWM) based speed control and Direct Predictive Speed Control (DPSC). Simulation results using MATLAB/SIMULINKÒ demonstrate the performance of the proposed scheme.
Renewable Energy Resources and Technologies
Hossein Dastres; Ali Mohammadi; Behrooz Rezaie
Abstract
This paper deals with the problem of maximizing the extracted power from a wind turbine in the presence of model uncertainties and input saturation. An adaptive second-order integral terminal sliding mode speed control method is utilized to address this problem. The presented method benefits from the ...
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This paper deals with the problem of maximizing the extracted power from a wind turbine in the presence of model uncertainties and input saturation. An adaptive second-order integral terminal sliding mode speed control method is utilized to address this problem. The presented method benefits from the advantages of several control techniques, i.e., adaptability, robustness, finite-time convergence, and the capability of coping with the input saturation. The robust nature of the designed controller causes its high performance in facing the uncertainties in the wind turbine model. In this paper, to compensate for the effect of input saturation, an auxiliary dynamic variable is added to the tracking error and also an adaptation law is designed so that the finite-time convergence of the closed-loop system can be achieved. Moreover, to reduce the mechanical stresses which are the result of the chattering phenomenon, a second-order sliding surface is employed. The finite-time convergence of the designed controller has been proven by the Lyapunov stability theorem in which the finite-time convergence of the tracking error to zero is guaranteed. Finally, to illustrate the effectiveness and satisfactory performance of the proposed controller, two comparative simulations are carried out. The results of this comparison show that the proposed controller has less error to track the optimal speed and when the model uncertainties and input saturation occur in the wind turbine system, the proposed controller is almost 3 % more efficient than the existing controllers.
Renewable Energy Resources and Technologies
Arash Abedi; Behrooz Rezaie; Alireza Khosravi; Majid Shahabi
Abstract
This paper presents a novel local control method for the converter-based renewable energy resources in a stand-alone DC micro-grid based on energy analysis. The studied DC micro-grid comprises the renewable energy resources, back-up generation unit, and battery-based energy storage system, which are ...
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This paper presents a novel local control method for the converter-based renewable energy resources in a stand-alone DC micro-grid based on energy analysis. The studied DC micro-grid comprises the renewable energy resources, back-up generation unit, and battery-based energy storage system, which are connected to the common DC-bus through the buck and bidirectional buck-boost converters. The proposed control method satisfies the stability of the micro-grid output variables, along with current control and voltage regulation by controlling the switching functions of the converters, regardless of the energy resource dynamics. The dynamic component of the switching function is extracted as a control signal using the state-feedback through a mathematical method. The control inputs are designed based on Lyapunov stability theorem to guarantee the stability of output variables (DC-bus voltage and generated currents) in a stand-alone DC micro-grid through an energy analysis. The proposed distributed controller can be easily generalized as a platform with all kinds of the stand-alone DC micro-grids comprising any type or number of distributed generations such as renewable energy resources, fossil-fuel-based generations, and energy storage units. Other features of this local control method are simplicity, celerity, comprehensiveness, and independence of the distributed generations. The dynamic performance assessment of the proposed controller is verified through a simulation in MATLAB/SIMULINKÒ environment. The results validate the accuracy and stability of the proposed control strategy in various operating conditions.