Maximum Power Point Tracking Operation Research Articles

Optimizing solar panel maximum power point tracking and parasitic parameter extraction in partial shading with Enhanced Slime Mold optimization

Solar energy offers several environmental, economic, and energy security advantages. Parasitic parameters and shading on solar panels can reduce efficiency. This paper presents a bio-inspired Enhanced Slime Mold (ESM) algorithm search strategy to find near-optimal power points by simulating the behaviour of slime molds in a virtual environment. In a solar panel, proposed ESM provides not only for parameter extraction but also serves as Maximum Power Point Tracking (MPPT) during Partial Shading Conditions (PSC). The proposed ESM dynamic behaviour is examined under solar irradiation and various temperature conditions. The effectiveness of proposed technique has been validated by extracting parameters from conventional polycrystalline and monocrystalline modules in the form of a 5 S–5P arrangement. In the instance of MPPT operation, the proposed ESM algorithm is compared with Ant Bee Colony and Perturb& Observe (ABC-PO) to determine its efficacy. Moreover, during extraction of unknown parameters of solar cell ESM is compared with existing optimization algorithms such as Artificial Bee Swarm Optimization (ABSO), Genetic Algorithm (GA), Covariant Matrix (CM), Ant Bee Colony (ABC), and Advanced Particle Swarm Optimization (APSO). In this connection, proposed ESM algorithm is superior to the above-mentioned algorithms due to high accuracy, a smaller number of computations, and minimum computational time.

Metaheuristics-based maximum power point tracking for PV systems: a review

<span lang="EN-US">Over the years, numerous maximum power point tracking (MPPT) methods have been developed to extract the maximum available power from PV arrays. They are generally categorized as conventional or metaheuristic methods. The most employed conventional methods include perturb and observe (P&O), hill climbing (HC), and incremental conductance (INC), due to their simplicity and ease of implementation. However, under partial shading condition (PSC), none of them can effectively locate a global maximum power point (GMPP) out of many local maximum power points (LMPPs). This results in significant power loss during PSC, prompting the development of various metaheuristic-based MPPT methods to address the problem. This paper reviews 38 existing metaheuristic-based MPPTs and 27 metaheuristic methods that have not yet been applied to any MPPT operation up to date. Metaphorically, these methods are divided into four categories: (i) evolutionary-based, (ii) physics-based, (iii) swarm-based, and (iv) human-based. The different MPPTs are compared in terms of complexity, converter topology, and PSC tracking capability. This paper is intended to serve as a one-stop resource for any researcher, practitioner, or advanced student seeking to develop a new metaheuristic-based MPPT method.</span>

An Improved Optimally Designed Fuzzy Logic-Based MPPT Method for Maximizing Energy Extraction of PEMFC in Green Buildings

Recently, the concept of green building has become popular, and various renewable energy systems have been integrated into green buildings. In particular, the application range of fuel cells (FCs) has become widespread due to the various government plans regarding green hydrogen energy systems. In particular, proton exchange membrane fuel cells (PEMFCs) have proven superiority over other existing FCs. However, the uniqueness of the operating maximum power point (MPP) of PEMFCs represents a critical issue for the PEMFC control systems. The perturb and observe, incremental conductance/resistance, and fuzzy logic control (FLC) represent the most used MPP tracking (MPPT) algorithms for PEMFC systems, among which the FLC-based MPPT methods have shown improved performance compared to the other methods. Therefore, this paper presents a modified FLC-based MPPT method for PEMFC systems in green building applications. The proposed method employs the rate of change of the power with current (dP/dI) instead of the previously used rate of change of power with voltage (dP/dV) in the literature. The employment of dP/dI in the proposed method enables the fast-tracking of the operating MPP with low transient oscillations and mitigated steady-state fluctuations. Additionally, the design process of the proposed controller is optimized using the enhanced version of the success-history-based adaptive differential evolution (SHADE) algorithm with linear population size reduction, known as the LSHADE algorithm. The design optimization of the proposed method is advantageous for increasing the adaptiveness, robustness, and tracking of the MPP in all the operating scenarios. Moreover, the proposed MPPT controller can be generalized to other renewable energy and/or FCs applications. The proposed method is implemented using C-code with the PEMFC model and tested in various operating cases. The obtained results show the superiority and effectiveness of the proposed controller compared to the classical proportional-integral (PI) based dP/dI-based MPPT controller and the classical FLC-based MPPT controller. Moreover, the proposed controller achieves reduced output waveforms ripple, fast and accurate MPPT operation, and simple and low-cost implementation.

Maximum Power Extraction for PMVG-Based WECS Using Q-Learning MPPT Algorithm With Finite-Time Control Scheme

This study is concerned with the problem of maximum power extraction for a permanent magnet vernier generator (PMVG)-based wind energy conversion system (WECS) using the Q-learning maximum power point tracking (MPPT) algorithm with the finite-time control (FTC) scheme. To do this, the model-free sensorless reinforcement Q-learning algorithm-based MPPT method is firstly proposed. At this time, the reward and learning rate are updated by the Q-values for each state-action pair. Next, the proposed learning algorithm is used to construct an optimal speed–power curve for achieving the fast and steady MPPT operation for the WECS using the learned action values. Besides, the wind-speed change detection algorithm is added to the proposed method so that the PMVG-based WECS can work in various wind speed conditions. And then, the FTC method is proposed to track the reference speed of PMVG which support to achieving the maximum power extraction, and Lyapunov stability theory is derived to ensure the overall system's stability. Finally, the simulation and experimental results from the 5 kW PMVG-based WECS are presented to demonstrate the applicability and superiority of the proposed control method.

Adaptive Control Technique for Portable Solar Powered EV Charging Adapter to Operate in Remote Location

Every EV (Electric Vehicle) comes with limited energy storing capability. After travelling a certain distance, a charging facility is required to recharge the EV batteries, which is easy to be made available in cities. But, in remote locations, charging s ervice is challenging. Therefore, big countries like USA, Canada, China, Russia, India, Australia, and few Arabian countries are planning to provide pillar top solar panels on remote locations for EV charging in emergency situations. To operate in this sit uation, a special charging adapter is required to extract maximum power from the panel using the MPPT (Maximum Power Point Tracking) technique, monitor the charging current, and safely complete the charging process. In this paper, a single sensor based eco nomical charging adapter is presented for EVs to fulfil this objective. Moreover, the Single Input Fuzzy Logic tuned Deterministic Optimization (SIFL DO) algorithm is proposed to accomplish MPPT operation and battery charging management. Because of its low cost and fast response, the single current sensor based charging adapter is highly economical. Additionally, the SIFL DO algorithm has very good condition estimation and decision making capability, which accurately performs MPPT and charging management. I n this work, the capability of the developed adapter with the SIFL DO algorithm is evaluated on Hardware prototype. Also, comparative studies are performed w.r.t. state of the art techniques. Further to determine the industry’s suitability, the developed t echnique is tested on European Standard EN50530.

A novel auxiliary unit based high gain DC-DC converter for solar PV system with MPPT control

<span lang="HR">Solar photovoltaic (PV) system becomes popular to generate the electricity in Asian region and helps to reduce the burden to utility. The power converter plays crucial role to interconnect with DC- grid. Traditional type power DC-DC converter can able to extract the maximum power from solar PV. However, most of the applications, it often fails to meet the voltage level of the DC bus and additional converter is required to boosting p the DC voltage. In order to overcome this drawback, this paper proposes a novel DC-DC converter to extract the maximum power from solar PV and helps to enhance the voltage level to meet the DC-bus. The PV and IV characteristics of practical solar PV cell and mathematical modelling have been done and implemented the same to proposed high gain converter. The maximum power point tracking (MPPT) algorithm and operation details are addressed and the detailed operation waveform of proposed high voltage gain DC-DC converter with mathematical evident is reported in this paper. The simulation study was carried out in the PSCAD/EMDTC software. From the measured results, it is investigated in further to validate the MPPT operation, gain values achievement and performance analysis of proposed converter. The corresponding explanations and results are presented in this article.</span>

Highly efficient and wide input range maximum power point tracking circuit with coarse and fine stages for energy harvesting systems

This letter presents a highly efficient and wide input range maximum power point tracking (MPPT) circuit for energy harvesting systems (EHSs). The conventional MPPT circuit shows attenuation of the power conversion efficiency (PCE) at low input voltages due to insufficient distribution of conversion ratio (CR) in switched capacitor (SC) dc–dc converters. To overcome this critical issue, the proposed circuit implements coarse and fine stages to increase the number of CR. The proposed MPPT operation can be accurately achieved with CR tuning only (without switching frequencies), which results in high PCE. This work is fabricated in the 180-nm CMOS process and measured with the commercial photovoltaic (PV) cells to demonstrate the advantages of the proposed circuit. The measurement results show that the EHS achieves a flat and improved PCE over a wide input range of 0.4 to 1.6 V. The PCE is as high as 88% for an output power below 50 μW and the active area occupies 1.2 mm2.

High‐power DC‐DC converter with proposed HSFNA MPPT for photovoltaic based ultra‐fast charging system of electric vehicles

AbstractThis research paper describes the implementation of a photovoltaic (PV) fed energy‐efficient high‐power DC‐DC converter for ultra‐fast charging systems with a proposed hybrid simplified Firefly and neighborhood attraction firefly (HSFNA) algorithm for maximum power point tracking (MPPT). The proposed high‐gain step‐up SEPIC converter is employed to deliver efficient MPPT operation, higher step‐up voltage gain, higher efficacy, and a more straightforward controlling mechanism. It provides continuous input current, maximum current handled ability, and higher quality DC voltage generation suitable for battery charging operation. Moreover, an isolated unidirectional dual‐bridge converter (IUDBC), DC‐DC converter, has been employed for ultra‐fast battery charging of electric vehicles. This accomplishes higher current charging to load, providing power transmission ability per battery demand by controlling several charging actions. Moreover, an ideal PV model approach has been implemented in this research work, providing accurate analysis of estimation of model parameters mathematically. Further, a proposed HSFNA based MPPT provides higher convergence velocity, fast‐tracking, accurate responses, higher efficiency, and can track global maximum power point (GMPP) under partial shade and varying operating conditions. Simulation and practical responses confirmed the effectiveness of the system design for ultra‐fast charging systems.

Current Sensorless MPPT Control for PV Systems Based on Robust Observer

Photovoltaic (PV) systems are among the most used alternatives for electrical power generation from renewable sources. To ensure that PV systems make the most of the available solar energy, maximum power point tracking (MPPT) schemes must be implemented, which usually require voltage and current sensors to track the PV power. This paper presents the design of a robust observer using the Attractive Ellipsoid Method to achieve a precise estimation of PV current under parametric uncertainty and output perturbations. The application of such an observer enables the PV generation system to operate in a current sensorless mode, which reduces the overall cost of the system and enhances its reliability. The convergence of the observer is guaranteed by solving an optimization problem which generates the optimal gains using Linear Matrix Inequalities (LMI). To prove the effectiveness of the proposed sensorless scheme, simulations are performed in Matlab under test profiles based on the EN50530 standard and parameter uncertainty conditions, obtaining an accurate estimation which is used for MPPT operation.

Coordinated VSG Control of Photovoltaic/Battery System for Maximum Power Output and Grid Supporting

In a two-stage photovoltaic (PV) system, batteries are generally connected to the DC-link via a converter for buffering the power imbalance induced by the grid supportive services of grid-side inverter and the maximum power point tracking (MPPT) of PV source. Considering the limited battery capacity, the MPPT operation is easily compromised to avoid over-energizing the batteries in the conventional virtual synchronous generator (VSG) control, degrading the energy efficiency and extending the payback period. To concurrently achieve grid supporting and maximum PV power harvesting without increasing batteries, a coordinated VSG control for the photovoltaic/battery (PV/Bat) system is proposed in this paper. In the proposed strategy, the DC-link voltage level is segmented to differentiate the operations of converters. When the DC-link voltage is within the safety margin, the PV source operates at MPPT mode and the inverter output frequency is programmed proportionally to the DC-link voltage deviation. Meanwhile, droop control is implemented to associate the battery power with the DC-link voltage. When the DC-link voltage goes beyond the safety margin, PV de-loading and inverter rectification will be adaptively activated to restore DC-link voltage within the predefined range. The effectiveness and advantages of the proposed strategy are eventually verified by simulations and experiments.

Wide-Range Light Harvesting Module for Autonomous Sensor Nodes

A large number of autonomous devices is nowadays supported by renewable and green energy sources. A vital sub-circuit in such systems is the power converter circuit, which should efficiently transform and store the available energy. In order to obtain the maximum efficiency under varying energy conditions, various maximum power point tracking (MPPT) methods are used. In this work a complete harvesting module with battery management and MPPT is presented, suitable for a plethora of autonomous applications. A novel, low-complexity and ultra-low power consumption design is proposed, which offers very wide operating voltage and power range with high MPPT efficiency and very low power consumption. It can be combined with different harvesters, such as thermoelectric generators or photovoltaic panels and is able to work under widely varying energy conditions. As supported by experimental results, the proposed module covers a very wide working input power range, from 40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> up to 4 W, as well as a very wide input voltage range, from 650 mV up to 2.8 V with 96.5% average MPPT efficiency and a total power consumption of 3.9 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> at 3.6 V. The module relies on an embedded ultra-low power microcontroller unit (MCU) to perform the power management and MPPT operations, which can also be used for extra tasks (e.g., sensor reading). Using the proposed module, an autonomous sensor node was built, able to acquire acceleration measurements, and wirelessly communicate with a remote user in order to send an alert or stream the acquired sensor data in real time.

Two-Phase Short-Term Frequency Response Scheme of a DFIG-Based Wind Farm

The kinetic energy stored in the doubly-fed induction generators (DFIG)-based wind farm can be utilized to sustain the dynamic system frequency. However, difficulties arise in determining the control gain to effectively improve the frequency nadir and smoothly return to the maximum power point tracking (MPPT) operation. This paper addresses a two-phase short-term frequency response (STFR) scheme to boost the frequency nadir and minimize the second drop in the system frequency based on a piecewise control gain. To achieve the first goal, a constant control coefficient, which is determined according to the initial operating conditions of the DFIG-based wind farm, is employed until the frequency nadir produces. To achieve the second goal, the control coefficient, which changes with time, facilitates to smoothly return to the MPPT operation. The effectiveness of the proposed two-phase STFR scheme is verified under various wind power penetration levels, wind speeds, and disturbances. The results reveal that the frequency nadir is improved, and simultaneously, it smoothly returns to the MPPT operation and minimizes the second drop in the system frequency.

A Novel MPPT Technique Based on the Envelope Extraction Implemented With Passive Components for Piezoelectric Energy Harvesting

This article presents a rectifierless synchronized switch harvesting on inductor interface with a novel maximum power point tracking (MPPT) technique assistance for piezoelectric energy harvester (PEH). The proposed MPPT solution captures vibration states through an envelope extractor and then adjusts the rectified voltage to achieve the maximum power harvest. The MPPT method tracks the vibration amplitude through an envelope extractor, which no longer disconnects the PEH from the converter to measure its open-circuit voltage. Hence, energy harvesting and maximum power point finding can be achieved simultaneously. Besides, the MPPT solution was implemented through discrete passive analog components with ultralow power consumption, which can achieve the MPPT operation when the harvester was cold started. The experiment confirms the simplicity and efficiency of the proposed MPPT solution for the PEH, and the maximum MPPT efficiency can reach 99.5%.

Precise performance diagnosis of photovoltaic string by operation voltage and current: Experimental verification

Improvement of the quantitative performance characterization of photovoltaic (PV) strings was investigated, based on their monitoring data during maximum power point tracking (MPPT) operation. The maximum power voltage Vmp and current Imp of the PV strings under MPPT were continuously monitored, and corrected to standard temperature of 25 °C by using the temperature correction formulas, which were recently developed for PV modules. The irradiance G was measured by using a PV module irradiance sensor. It was verified that the formulas are applicable to PV strings, enabling reproducible temperature correction of Vmp and Imp with relative standard deviation (σ) of about 0.4–0.9% under various weather conditions. Comparison of the outdoor results with indoor current–voltage curve measurements of the constituent modules in the strings showed that the maximum output power Pmax under the standard test conditions STC, i.e. 25 °C and 1 kWm−2, estimated from the temperature-corrected Vmp and Imp, agreed with the indoor result typically within ±1.5%. The experimental results also showed that other information of the string such as partial shading and activation of bypass diodes can be also sensitively detected by analyzing the temperature-corrected Vmp and Imp. The outdoor measurements and data analysis of this study can be carried out without stopping the MPPT operation of the string. The analysis is performed by using the real-time data. The present method is expected to be applicable to most kinds of crystalline silicon PV strings without modification.

An Effective Power Tracking Algorithm for Partially Shaded Solar PV Array Employing Micro Converters Feeding to DC Microgrid

This paper proposes the analysis of power enhancement in partially shaded PV system supplying DC microgrid employing micro converters with a modified Perturb and Observe (P &amp; O) based on Maximum Power Point Tracking (MPPT) technique by sensing the load parameters alone. The proposed technique is effective in power tracking under both normal and partially shaded conditions with the reduced number of sensing devices as compared to those used in the conventional DMPPT (Distributed Maximum Power Point Tracking) techniques. In this work, two series configured micro converters are considered for supplying 120 V DC microgrid from partially shaded PV panels. The complete steady-state analysis is developed and predicted the performance of the proposed MPPT operation and compared with the simulation and experimental results. The PV panels are emulated in the experiments. The effectiveness of the proposed technique is demonstrated and substantiated by theoretical, simulation and experimental results under various operating conditions.

Detection of shading effect by using the current and voltage at maximum power point of crystalline silicon PV modules

Estimation of the performance of photovoltaic (PV) module and system by using continuous monitoring data is an important issue, since the output power of PV modules is changeable, affected by the irradiance, temperature and shading effect, as well as degradation. This work proposes a method to detect partial shading on a module during its maximum power point tracking (MPPT) operation. It identifies whether there is shading on a module or not by analyzing data of the voltage at maximum power (Vmp) and the current at maximum power (Imp). Recently developed temperature correction formulas for the Vmp and Imp are used, in order to analyze them under various temperatures and irradiances. The experimental and simulation results show that the shading effect usually results in larger Vmp than the shadeless case, compared at the same Imp. Therefore, the Imp − Vmp curve shifts toward higher voltages by the shading effect, thereby enabling detection of the existence of the shading effect. A method to identify the shading effects on a PV module from the Imp – Vmp curve has been clarified, which does not require I–V curve measurements. Slight partial shading such as a drop in the photocurrent of a single cell in a module by about 5–10% is possibly detected. The present results are also applicable to PV systems that include multiple modules. They are expected to be useful for accurately monitoring the performance of PV modules and systems under operation, since the Vmp and Imp are measurable without breaking the MPPT operation.

Design &amp; Real-time Implementation of MIDO Converter Based PV Water Pumping System with BES

Background: Despite so many developments, most of the farmers in the rural areas are still dependent on rainwater, rivers or water wells, for irrigation, drinking water etc. The main reason behind such dependency is non-connectivity with the National grid and thus unavailability of electricity. To extract the maximum power from solar photovoltaic (SPV) based system, implementation of Maximum Power Point Tracking (MPPT) is mandatory. PV power is intermittent in nature. Variation in the irradiation level due to partial shading or mismatching phenomena leads to the development of modular DC-DC converters. Methods: A stand-alone Multi-Input Dual-Output (MIDO) DC-DC converter based SPV system, is installed at a farm; surrounded with plants for water pumping with stable flow (not pulsating) along with battery energy storage (BES) for lighting. The proposed work has two main objectives; first to maximize the available PV power under shadowing and mismatching condition in case of series/ parallel connected PV modules and second is to improve the utilization of available PV energy with dual loads connected to it. Implementation of proposed MIDO converter along with BES addresses these objectives. First, MIDO controller ensures the MPPT operation of the SPV system to extract maximum power even under partial shading condition and second, controls the power supplied to the motor-pump system and BES. The proposed system is simulated in MATLAB/ SIMULINK environment. Real-time experimental readings under natural sun irradiance through hardware set-up are also taken under dynamic field conditions to validate the performance. Results and Conclusion: The inherent advantage of individual MPPT of each PV source in MIDO configuration, under varying shadow patterns due to surrounding plants and trees is added to common DC bus and therefore provides a better impact on PV power extraction as compared to conventional PV based water pumping system. Multi-outputs at different supply voltages is another flag of MIDO system. Both these aspects are implemented and working successfully at 92.75% efficiency.

Optimal Power Flow Control in a Stand-Alone PV System with a Battery-Assisted Quasi-Z-Source Inverter

Abstract This paper presents a photovoltaic (PV) power system with a battery storage unit and the quasi-Z-source inverter (qZSI). This inverter belongs to the group of transformerless single-stage inverters with buck/boost capability. The considered system is designed for autonomous load supply and battery charging in areas isolated from the utility grid. The batteries ensure continuous operation in the case of energy shortage/surplus and compensate for the oscillations of the PV power due to changes in atmospheric conditions. They also enable capturing of the maximum available power from the PV modules. The maximum power point tracking (MPPT) algorithm utilized in this study belongs to the group of perturb-and-observe (P&amp;O) algorithms, which are widely used in commercial PV systems. The state of charge (SOC) of the employed batteries represents an important factor in the context of MPPT operation and is taken into account in the proposed power flow control algorithm. The performance of the proposed system has been tested through simulations in the MATLAB Simulink over wide ranges of solar irradiation, PV module temperatures, and SOC levels.

A 580 nW Dual-Input Energy Harvester IC Using Multi-Task MPPT and a Current Boost Converter for Heterogeneous Source Combining

Herein, we present a multi-energy harvesting interface integrated circuit (IC) that enables the efficient combination of heterogeneous power sources. An electromagnetic vibration energy generator (EVG) and a thermoelectric energy generator (TEG) are the two energy sources, which have quite different internal resistance (tens and kilo-Ohms). To solve the challenge of combining heterogeneous sources, we propose a current boost converter (CBC), which achieves the resistance transformation as well as the source type conversion. The challenge of realizing maximum power point tracking (MPPT) for each source is tackled by using a multi-task MPPT controller, which is efficiently shared between the two sources. To achieve energy harvesting under uncertain and random source conditions, we propose an input ( $V_{\text {IN}}$ )-dependent clock generator (VCG) and a vibration pulse detector (VPD). The VCG tracks the change of source conditions to generate the clock for the MPPT controller. The VPD allows tracking of the random amplitude and frequency changes of the EVG. The energy harvester is fabricated in a 0.18 $\mu \text{m}$ process with a thick top-metal option. Measured results show successful source detection, switching, and MPPT operation. The proposed IC provides an output power of up to 119 $\mu \text{W}$ with an end-to-end peak efficiency of 82% by consuming 582 nW.

Cascaded Multilevel PV Inverter With Improved Harmonic Performance During Power Imbalance Between Power Cells

The difference in power cell irradiances in cascaded multilevel converters results in different duty cycles among those cells when maintaining the maximum power point tracking (MPPT). However, the difference in cell duty cycles is undesired since it is proportional to the output voltage and current distortions. To this regard, a multilevel topology for photovoltaic (PV) applications is proposed, where an H6 bridge power cell is used instead of an H-bridge one. In case of solar irradiance mismatch among the power cells, the proposed converter injects power with lower voltage from the shaded cells without altering the PV voltage; hence maintaining the MPPT operation. This modification allows us to retain an equal duty cycle in all the power cells whatever the meteorological conditions are present; consequently, maintaining good output voltage and current waveform qualities. To test the effectiveness of the proposed solution, a detailed simulation model as well as an experimental prototype is built. The obtained results show that the proposed topology provides significantly improved output voltage and current qualities compared to the cascaded H-bridge one. The performance of the proposed topology compared to one offering improved harmonics performance, according to the European efficiency, has been also compared, where an enhancement of 2.64% has been registered.