Two-level control of photovoltaic systems using global perturbation-based extremum seeking control and model reference adaptive control

2017 ◽  
Vol 40 (13) ◽  
pp. 3709-3720 ◽  
Author(s):  
Reza Dadkhah Tehrani ◽  
Faridoon Shabaninia
Keyword(s):  
Adaptive Control ◽  
Model Reference Adaptive Control ◽  
Extremum Seeking ◽  
Global Maximum ◽  
Maximum Power Point ◽  
Extremum Seeking Control ◽  
Pv Systems ◽  
Control Scheme ◽  
Power Point ◽  
Model Reference Adaptive

One of the main renewable energy sources for the future is photovoltaic (PV) energy. Hence, working of the PV systems at maximum efficiency is taken into consideration in recent years. In this paper, for improving the performance of the global maximum power point tracking under partial shading conditions and uncertainty in parameters of DC-DC converter, a two-level adaptive control scheme is proposed. The proposed controller is capable of efficiently handling the uncertainties in the PV systems and the perturbations in the environment. The first level is global perturbation-based extremum seeking control (GPESC), and the second level is model reference adaptive control (MRAC). GPESC is used to find global maximum power point and MRAC is utilized to handle the dynamics of the DC-DC converter. Adequate difference in the time constants of control levels, causes decoupled control levels, which in turn makes it easy to design the controller. The performance of the proposed control scheme is evaluated through simulation based on four indicators: tracking accuracy, tracking efficiency, tracking speed and searching resolution for different irradiance patterns. The results are compared with GPESC and GPESC with PID controller.

scholarly journals MPPT Based on Sinusoidal Extremum-Seeking Control in PV Generation

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
R. Leyva ◽  
C. Olalla ◽  
H. Zazo ◽  
C. Cabal ◽  
A. Cid-Pastor ◽  
...  
Keyword(s):  
Extremum Seeking ◽  
Control Technique ◽  
Maximum Power Point ◽  
Extremum Seeking Control ◽  
Pv Systems ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
Stability Issues ◽  
Pv Generation

The paper analyses extremum-seeking control technique for maximum power point tracking circuits in PV systems. Specifically, the paper describes and analyses the sinusoidal extremum-seeking control considering stability issues by means a Lyapunov function. Based on this technique, a new architecture of MPPT for PV generation is proposed. In order to assess the proposed solution, the paper provides some experimental measurements in a 100 W prototype which corroborate the effectiveness of the approach.

An Improved Maximum Power Point Tracking Based on Fractional Order Extremum Seeking Control in Grid-Connected Photovoltaic (PV) Systems

2013 ◽  
Author(s):  
Hadi Malek ◽  
Sara Dadras ◽  
YangQuan Chen
Keyword(s):  
Fractional Order ◽  
Harmonic Distortion ◽  
Maximum Power ◽  
Extremum Seeking ◽  
Maximum Power Point ◽  
Extremum Seeking Control ◽  
Integer Order ◽  
Pv Systems ◽  
Point Tracking ◽  
Power Point

This paper presents a fractional order extremum seeking control scheme for grid-connected photovoltaic (PV) systems tasks to better accommodate rapid varying solar irradiance for photovoltaic (PV) arrays. The stability analysis of the proposed control algorithm is presented first. Then the new algorithm is benchmarked against the integer order extremum seeking control. Our extensive simulation and experimental results show that, our proposed maximum power point tracker has faster convergence speed in comparison to integer order and incremental conductance algorithm and also less total harmonic distortion (THD) in the injected current to the grid.

scholarly journals Robust Adaptive HCS MPPT Algorithm-Based Wind Generation System Using Model Reference Adaptive Control

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5187
Author(s):  
Ziyad A. Alrowaili ◽  
Mustafa M. Ali ◽  
Abdelraheem Youssef ◽  
Hossam H. H. Mousa ◽  
Ahmed S. Ali ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Model Reference Adaptive Control ◽  
Maximum Power ◽  
Hill Climbing ◽  
Step Size ◽  
Maximum Power Point ◽  
Model Reference ◽  
Power Fluctuations ◽  
Power Point ◽  
Model Reference Adaptive

To treat the stochastic wind nature, it is required to attain all available power from the wind energy conversion system (WECS). Therefore, several maximum power point tracking (MPPT) techniques are utilized. Among them, hill-climbing search (HCS) techniques are widely implemented owing to their various features. Regarding current HCS techniques, the rotor speed is mainly perturbed using predefined constants or objective functions, which makes the selection of step sizes a multifaceted task. These limitations are directly reflected in the overall dynamic WECS performance such as tracking speed, power fluctuations, and system efficiency. To deal with the challenges of the existing HCS techniques, this paper proposes a new adaptive HCS (AD-HCS) technique with self-adjustable step size using model reference adaptive control (MRAC) based on the PID controller. Firstly, the mechanical power fluctuations are detected, then the MRAC continuously optimizes the PID gains so as to generate an appropriate dynamic step size until harvesting the maximum power point (MPP) under the optimal tracking conditions. Looking specifically at the simulation results, the proposed AD-HCS technique exhibits low oscillations around the MPP and a small settling time. Moreover, WECS efficiency is increased by 5% and 2% compared to the conventional and recent HCS techniques, respectively. Finally, the studied system is confirmed over a 1.5 MW, gird-tied, double-fed induction generator (DFIG) WECS using MATLAB/Simulink.

scholarly journals A Modification of the Perturb and Observe Method to Improve the Energy Harvesting of PV Systems under Partial Shading Conditions

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2521
Author(s):  
Alfredo Gil-Velasco ◽  
Carlos Aguilar-Castillo
Keyword(s):  
Maximum Power ◽  
Global Maximum ◽  
Pv System ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Pv Systems ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
Computational Resources

There are multiples conditions that lead to partial shading conditions (PSC) in photovoltaic systems (PV). Under these conditions, the harvested energy decreases in the PV system. The maximum power point tracking (MPPT) controller aims to harvest the greatest amount of energy even under partial shading conditions. The simplest available MPPT algorithms fail on PSC, whereas the complex ones are effective but require high computational resources and experience in this type of systems. This paper presents a new MPPT algorithm that is simple but effective in tracking the global maximum power point even in PSC. The simulation and experimental results show excellent performance of the proposed algorithm. Additionally, a comparison with a previously proposed algorithm is presented. The comparison shows that the proposal in this paper is faster in tracking the maximum power point than complex algorithms.

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