Maximum Power Of Photovoltaic Array Research Articles

Simplified control algorithm for stable and efficient standalone PV systems: An assessment based on real climatic conditions

This research addresses the critical challenge of optimizing efficiency and performance in solar photovoltaic (PV) systems. It focuses on duty cycle optimization of DC/DC converters for maximum power point tracking (MPPT). The study introduces an innovative hybrid MPPT solution that integrates a novel temperature-based single-sensor approach with an integral backstepping controller. This method precisely achieves the PV array's maximum power point (MPP) under varying weather conditions while optimizing the converter's duty cycle to best align with the MPP voltage. Comprehensive simulations in MATLAB/Simulink reveal that the hybrid method surpasses conventional MPPT systems in key metrics, achieving faster convergence time (below 0.66 ms), reduced power ripple (<0.3 W), and enhanced tracking efficiency (exceeding 97.67 %). Notably, experimental data validates the practical efficacy of the proposed system under real-world conditions in the context of El Jadida, Morocco. This integrated approach advances the theoretical understanding of MPPT optimization and demonstrates tangible improvements in PV system performance, offering significant potential for enhancing solar energy utilization in variable climate regions.

Voltage Detection-Based Selective Harmonic Current Compensation Strategies for Photovoltaic Inverters

Voltage and current detection-based harmonic current compensation (VDB-HCC and CDB-HCC, respectively) strategies allow the use of photovoltaic (PV) inverters to enhance the grid power quality. CDB-HCC strategies require converter hardware retrofit by inserting an extra current sensor to measure load or downstream grid currents. On the other hand, VDB-HCC strategies are straightforward solutions employing only embedded measurements used for protection, control, and synchronization purposes. This paper provides a comprehensive comparison of three VDB-HCC strategies: VDB-HCC based on a single current loop (SCL); VDB-HCC based on dual parallel current control loops (DCL); and VDB-HCC based on parallel voltage and current control loops (VCL). The comparison includes the requirement of harmonic detection algorithms, PV array maximum power point tracking (MPPT) performance, stability over grid impedance variations and inverter power rating, steady-state harmonic compensation, enabling transient response, and computational burden. Experimental results using a 1.5-kW commercial PV inverter are conducted. Based on distributed HCC applications by PV systems, VCL has shown the best performance in terms of voltage distortion reduction under weak grids.

Power quality improvement of grid-connected photovoltaic systems using PI-fuzzy controller

To ensure enhanced reliability and availability of electricity to consumers, grid-connected photovoltaic systems need to improve their power quality, this paper uses a three-phase five levels cascaded H-bridge inverter in grid-connected mode to improve the flexibility and efficiency of the photovoltaic system. Each photovoltaic (PV) array in the proposed system has a maximum power point tracker (MPPT) to extract the PV array maximum power point for a particular irradiance and temperature and reduce the mismatch that causes an imbalance in the power sent from the inverter to the main grid. The fuzzy logic controller is used to tune the proportional-integral (PI) controller to regulate the current and voltage of the grid-connected inverter by changing the gain of the PI controller (Kp, Ki) to obtain a fast response and improve the power quality of the system despite different load disturbances and inputs. The system was simulated in MATLAB/Simulink, and the results show the superiority of the proposed control unit, in which a pure and stable sine output voltage and current waveforms. Finally, the total harmonic distortion (THD) is improved to reach 3.81% based on the fuzzy PI controller, while 7.77% is based on the PI controller.

A novel adaptive dynamic photovoltaic reconfiguration system to mitigate mismatch effects

Unequal solar irradiance of the Photovoltaic (PV) modules diminishes the PV array's maximum power output; this effect is due to Partial Shading Conditions (PSCs). There are a few technical options to fix this issue. One of these is the dynamic reconfiguration technique, which means that the electrical connections between the PV modules in the array are dynamically modified to spread shading effects and increase the power output. This paper proposed a novel adaptive reconfiguration method for 3×3 Total-Cross-Tied (TCT) PV array to enhance the maximum power under partial shading conditions. In this work, the PV module's electrical connections are altered dynamically with the proposed logic algorithm's help to maintain the identical row currents in the array. This technique is implemented on 3×3 size of an array using MATLAB and validated experimentally using OPAL-RT software. Further, the proposed technique performance is compared with the existing PV array connections such as Series-Parallel (SP), Total-Cross-Tied (TCT), Bridge-Link (BL), Honey-Comb (HC), and Shade Dispersion Positioning (SDP). Additionally, for different reconfiguration methods, revenue generation from energy savings is estimated. Based on the observations from the results, it is understood that the proposed technique enhanced the maximum power of the TCT array at a higher level as compared to the other PV array connections under PSCs.

用于农业大棚的光伏阵列最大功率点跟踪算法研究

In order to enhance the utilization of solar energy in photovoltaic greenhouse, this paper takes the optimization strategy of photovoltaic array's maximum power point tracking algorithm as research object. According to the changing rule of the slope of photovoltaic array's output P-U curve, this paper proposes a new variable-step conductance increment method to track the maximum power point. When the working point is located on the left side of maximum power point, the logarithmic function value of curve’s slope is adopted as the voltage step to adjust the position of working point. When the working point is located on the right side of maximum power point, the exponential function value of curve’s slope is adopted as the voltage step to adjust the position of working point. Through the MPPT modelling and simulation in MATLAB/Simulink and the corresponding circuit test, the result shows that comparing with the traditional variable-step conductance increment method, the proposed algorithm can find the maximum power point faster, and it can effectively reduce the power loss caused by step oscillation in the searching process, which achieves the goal of enhancing conversion efficiency of photovoltaic power generation.

Control and Implementation of a Multifunctional Solar PV-BES-DEGS Based Microgrid

A three-phase four-wire microgrid comprising of a solar photovoltaic (PV) array—battery energy storage—a diesel engine generator set (DEGS) is presented in this article. Here an enhanced adaptive filter (EAF) control and an incremental conductance (INC) maximum power point tracking algorithm are used to improve the power quality and to extract the maximum power from the PV array. The EAF control provides higher disturbance rejection capability over other controls. The EAF control is applied to the voltage source converter (VSC) to improve the power quality, such as compensation of harmonics, reactive power, and load unbalance. The INC control is used to harvest the PV array maximum power. For controlling the voltage output of the DEGS, an electronic automatic voltage regulator is provided at the synchronous generator field winding. The neutral current compensation is achieved by controlling the fourth-leg of VSC. This microgrid is simulated using MATLAB/Simulink tool. The robustness of the EAF control strategy is tested on a developed system prototype in the laboratory.

Effect of Partially Shaded Conditions on Photovoltaic Array's Maximum Power Point Tracking

Maximum power point tracking algorithm is widely implemented in photovoltaic system to maximize the PV array output power. In general, Perturb and Observe (P&O) is simple thus being selected to continuously track the array maximum power point (MPP). Under uniform solar irradiance, PV array characteristic is non-linear and consisting only one MPP along the functional operating voltage. However, when the PV array is partially shaded, the P-V characteristic becomes more complex with multiple MPPs. The occurrence of multiple MPP might cause the PV array to be trapped at the local MPP. At this operating condition of local MPP, PV array will generate lesser output power. In this study, the performance of PV array is explored especially when each PV module is at 30% and 70% shaded conditions. Simulation results show that PV array at absolute MPP can generate greater output power with the largest increased by 74.6% hence achieving higher power efficiency.

MPPT control of PV array based on PSO and adaptive controller

In general, photovoltaic (PV) array is not able to generate maximum power automatically, because some partial shading caused by trees, clouds, or buildings. Irradiation imperfections received by the PV array are overcome by applying maximum power point tracking (MPPT) to the output of the PV array. In order to overcome these partial shading problems, this system is employing particle swarm optimization (PSO) as MPPT method. It optimizes the output power of the solar PV array by Zeta converter. Output voltage of MPPT has high rate such that it needs stepdown device to regulate certain voltage. Constant voltage will be the input voltage of buck converter and controlled using adaptive PID. Adaptive control based on model reference adaptive control (MRAC) has design that almost same as the conventional PID structure and it has better performance in several conditions. The proposed system is expected to have stable output and able to perfectly emulate the response of the reference model. From the simulation results, it appears that PSO have high tracking accuracy and high tracking speed to reach maximum power of PV array. In the output voltage regulation, adaptive control does not have a stable error status and consistently follows the set point value.

Adaptive voltage control for MPPT-firefly algorithm output in PV system

In general, Photovoltaic (PV) array is not able to generate maximum power automatically, because some partial shading caused by trees, clouds, or buildings. Irradiation imperfections received by the PV array are overcome by applying Maximum Power Point Tracking (MPPT) to the output of the PV array. In order to overcome these partial shading problems, this system is employing Firefly Algorithm (FA) as MPPT method. It optimizes the output power of the solar PV array by Zeta Converter. Output voltage of MPPT has high rate such that it needs stepdown device to regulate certain voltage. Constant voltage will be the input voltage of Buck Converter and controlled using Adaptive PID. Adaptive control based on MRAC has design that almost same as the conventional PID structure and it has better performance in several conditions. The proposed system is expected to have stable output and able to perfectly emulate the response of the reference model. From the simulation results, it appears that FA have high tracking accuracy and high tracking speed to reach maximum power of PV array. In the output voltage regulation, adaptive control does not have a stable error status and consistently follows the set point value.

Lithium-ion energy storage battery in PV-smart building application

Photovoltaic (PV) panels with energy storage batteries represents a feasible solution for powering domestic loads. The service life of the batteries and the power management are the main challenges by developing the energy supply system of smart homes. Therefore, in this paper an efficient algorithm is developed in order to power a house by extracting the maximum power from the PV panels, enhancing the battery service life and minimizing the power supply from the smart grid. The smart metering, advanced inverter and rule-based energy management strategy ensure safe and optimal operation of the energy supply system. Matlab/Simulink model of typical PV array, lithium-ion battery, inverter with the associated controllers are developed to evaluate the performance of the proposed system. Starting from the actual solar irradiance data, the maximum power of PV array will be extracted as a function of the available irradiance and ambient temperature. The daily battery state of charge (SOC) and its internal temperature are calculated depending on the load, PV power and the battery charge/discharge modes. Simulation results show that the proposed algorithm can enhance the performance of energy supply system, extract the maximum solar power and minimize the power from smart grid. Key words PV array, MPPT controller, Li-ion storage battery, energy management, hybrid power system.

Photovoltaic Array Maximum Power Point Tracking Based on Improved Perturbation and Observation Method

The output characteristics of photovoltaic cells are strong non-linearity, and maximum power point tracking technology can improve the efficiency of photovoltaic systems. Based on improved perturbation and observation method, this paper takes the advantages of both long and small steps to realize the maximum power tracking of the photovoltaic system. Firstly, the absolute value of the real-time power rate of change is used as a reference for the automatic variable step size, and the maximum power is quickly tracked with a large step when the external conditions change. Then, after reaching the maximum power point, the system automatically becomes a small step to reduce the power oscillation loss. Finally, average calculation module is added to the power sampling to reduce the impact of clutter on the system and prevent the “sharp peak” of power. The results of the maximum power point tracking example show that the model has significantly improved the tracking speed of the maximum power point and the range of oscillation near the maximum power point.

A novel technique to extract the maximum power of photovoltaic array in partial shading conditions

Photovoltaic (PV) arrays are composed of PV cells which have a nonlinear power-voltage characteristic. To extract maximum amount of energy from a PV array, it is essential to track maximum power point (MPP). When all PV cells are subject to the same solar energy, MPP is found easily. However, in some ambient conditions, PV cells are partially or completely shadowed. Under partial shading conditions (PSCs), overall power-voltage curve will have several peaks. This paper presents a novel approach for MPP tracking, utilizing configuration of PV cells in series and parallel that may deliver maximum power in shading conditions. As such, instead of blindly searching for the global MPP among local MPPs, the proposed method limits the search space by calculating the required combination of series and parallel PV cells that can deliver global MPP. This efficient technique leads to a faster dynamic response when partial shadowing is encountered, while maintaining the conventional MPP tracking in normal condition. Moreover, the method does not require any additional hardware. Rather, the existing MPP tracking algorithm should be modified to accommodate PSCs. The efficiency of proposed technique is investigated via time-domain studies, where results verify the superiority of proposed method compared to other approaches.

Assessment of a proposed hybrid photovoltaic array maximum power point tracking method

Photovoltaic arrays have limited conversion efficiency and thus, a maximum power point tracking technique is essential. This makes the maximum power point tracking (MPPT) require prior prediction of the mentioned point in spite of the undeniable changes in the environment. In this manuscript an introduction and assessment of the different techniques of MPPT is presented. The categorization scheme of the MPPT techniques is according to either the predefinition of operating points without system data update (offline methods) or continuous sampling of system variables, to update the PV module measurements (online methods). Whereas hybrid method is a combination of both. A number of techniques from each class were simulated in MATLAB/Simulink environment in order to compare their performance. Moreover, the hybrid method was simulated in two successive steps without pre-assumption of the output of the offline method. The results demonstrated the relevance of the hybrid method when applied to a photovoltaic system due to its good performance, fast response and less fluctuations, when subjected to sudden climatic changes.

Photovoltaic Array Maximum Power Point Tracking Based on Improved Method

At present, a good deal of methods for the Maximum Power Point Tracking (MPPT) has been used in engineering applications. However, Matlab simulation proved that they were difficult to harmonize the stability and speed ability of system. In addition, in order to maximize the use of PV panels ‘power, the paper focused on aneonatalalgorithm for Maximum Power Point Tracking (MPPT). Based on the algorithm, this paper designed an improved and feasible variable step perturbation and observation method which well alleviated the conflict that the maximum power point tracking could not take into account the stability and speed of response efficiently.

Model Building of Photovoltaic Array with MPPT Function and Research on Single Phase Grid Connected

With the continued development of solar photovoltaic technology, research on distributed grid connected photovoltaic system has become a research focus in the field of photovoltaic grid power plant and the computer simulation technology is an effective technology means in the study. On the basis of the photovoltaic array output characteristic equation, the photovoltaic array maximum power control simulation model based on M function is established by using MATLAB/Simulink and the simulation model of single phase grid connected photovoltaic array is proposed. It overcomes the shortcomings of the process of building the model of the PV array by using Simulink component library and provides the basic guarantee for the realization of system simulation, guiding theory research and system design.

Implementation of a modified incremental conductance MPPT algorithm with direct control based on a fuzzy duty cycle change estimator using dSPACE

Maximum power point tracking (MPPT) is a necessary function in all photovoltaic (PV) systems. The classic incremental conductance (IC) MPPT algorithm is widely used in the literature. However, when large changes occur in the irradiance, the performance of this algorithm is degraded. To eliminate all of the disadvantages of the classic IC algorithm, we developed a new IC controller based on a fuzzy duty cycle change estimator with direct control. A fuzzy logic estimator (FLE) is used to estimate the new duty cycle used to track the PV array maximum power point. Compared with the fixed step IC MPPT method with direct control, the proposed algorithm reaches the MPP more accurately and faster during dynamic and steady-state conditions. A controlled Cuk DC–DC converter was implemented and connected to a SunTech STP085B PV panel to verify the accuracy of the proposed method. Matlab/Simulink was used for the simulation studies. Additionally, the algorithms were digitally implemented on the dSPACE ACE1104 platform. The results obtained confirm the advantages of the proposed algorithm.

Passivity–Based Control of Photovoltaic Grid-Connected Inverter

Photovoltaic (PV) grid-connected system requires the inverter possesses excellent dynamic and static characteristics. In the view of the mathematical model of the inverter is nonlinear, we will adopt a kind of nonlinear control strategy called Passivity–Based Control (PBC). First we establish the standard Euler – Lagrange (EL) mode for inverter, then we also prove that this inverter is strictly passive. Based on passivity of inverter, we can redistribute the system energy, and adopt the approaches of injecting damping and decoupling to improve system performance. In this paper, we can control the active and reactive power of system to make system can fast track the PV array maximum power point, and possess the capacity of compensating the reactive power. Simulation results show that passivity-based control method can make the inverter possess better robustness and dynamic.

Power quality enhancement of renewable energy source power network using SMES system

This paper deals with power quality enhancement of renewable energy source power network using SMES system and describes the operation characteristics of HTS SMES system using real-toroidal-type SMES coil for smoothening the fluctuation of large-scale renewable energy source such as photovoltaic (PV) power generation system. It generates maximum power of PV array under various weather conditions. SMES unit charges and discharges the HTS coil to mitigate the fluctuation of PV system output power. The SMES unit is controlled according to the PV array output and the utility power quality conditions. The grid connected PV and SMES system has been modeled and simulated using power-hard-in-the-loop simulation (PHILS). The PHILS results demonstrated the effectiveness of the SMES system for enhancing power quality in power network including large-scale renewable energy source, especially PV power generation system.

An intelligent maximum power point tracking method based on extension theory for PV systems

The purpose of this paper is to propose a novel maximum power point tracking (MPPT) technique to fully utilize photovoltaic (PV) array output power that depends on solar insolation and ambient temperature. The proposed intelligent MPPT algorithm based on extension theory can automatically adjust the step size to track the PV array maximum power point (MPP). Compared with the conventional fixed step size perturbation and observation (P&O) and incremental conductance (INC) methods, the presented approach is able to effectively improve the dynamic response and steady-state performance of the PV systems simultaneously. Theoretical analysis and the design principle of the proposed method are described in detail. Some simulations are performed to demonstrate the effectiveness of the proposed extension MPPT method.

A Variable Step Size INC MPPT Method for PV Systems

Maximum power point tracking (MPPT) techniques are employed in photovoltaic (PV) systems to make full utilization of PV array output power which depends on solar irradiation and ambient temperature. Among all the MPPT strategies, the incremental conductance (INC) algorithm is widely used due to the high tracking accuracy at steady state and good adaptability to the rapidly changing atmospheric conditions. In this paper, a modified variable step size INC MPPT algorithm is proposed, which automatically adjusts the step size to track the PV array maximum power point. Compared with the conventional fixed step size method, the proposed approach can effectively improve the MPPT speed and accuracy simultaneously. Furthermore, it is simple and can be easily implemented in digital signal processors. A theoretical analysis and the design principle of the proposed method are provided and its feasibility is also verified by simulation and experimental results.