Maximum Power Point Tracking Converter Research Articles

Novel Control of PV-Battery Powered Standalone Power Supply System with Neuro-Fuzzy Controller

Photovoltaic (PV) powered standalone electrical power supply systems are becoming more precious networks nowadays worldwide. Many challenging tasks are existed in PV based standalone systems due to random changes in solar irradiances, load and it is absent during nighttime. Innovative controllers are necessary to uphold power quality in these systems. A battery pack is required in this standalone system since solar irradiance is unpredictable and in order to provide continuous stable power to electrical loads during no irradiance. Therefore, a battery bank is connected to a standalone unit via a DC to DC bidirectional circuit. The maximum power point tracking converter, in conjunction with the perturbed and observe algorithm, is employed to optimize the operation of the PV system and enhance the overall efficiency of the system. Neuro-Fuzzy controller based novel controller is designed for both inverter as well as bidirectional circuit to supply quality power to both single and three phase loads. Comprehensive findings have been showcased and accessed via hardware-in-loop testing on the OPAL-RT platform to optimize the suggested controller for a 1MW standalone system in various scenarios. Keywords PV, Neuro-Fuzzy, MPPT, HIL, Standalone System, Power Quality.

Simulation Study of a Single-Phase Induction Machine as a Water Pump System Utilizing Photovoltaic

This paper presents a simulation study of using a single-phase induction machine as a solar PV powered water pump system equipped with Maximum Power Point Tracking (MPPT) on the boost converter. Inverters are used to convert DC voltage stored in batteries to drive single-phase induction machines. The simulation was carried out to analyze the system's performance in generating electrical power from solar panels and using it to operate the water pump. This research also considers variables such as fluctuations in sunlight intensity, as well as the dynamic response of induction machines and MPPT converters. From the simulation test results, it was found that the system as a whole will work well if it uses a radiation input that is more significant than 750 W/m2. The load in the form of a single-phase induction motor, which is inductive, influences variations in the output power produced by the solar PV at the boost converter.

IoT based battery energy monitoring and management for electric vehicles with improved converter efficiency.

Given the recent trends in the MPPT converters in PV systems, which have been researched extensively to improve design, modified closed-loop converter technology based on SoC is presented here. This paper aims to provide detailed information on the modern-day solar Maximum Power Point Tracking (MPPT) controller and Battery Management System (BMS). Most MPPT controller examination researched in the past is suitable only for fixed-rated battery capacity, which limits the converter capability and applications. The proposed paper uses the distributed energy management control technique to dispatch multi-battery charging based on the State of Charge (SoC). The converter construction is modified here as per the prerequisite of the model. The system hardware is developed and tested using Atmega2560 low power RISC based high-performance microcontroller. The batteries' SoC level and State of Health (SoH) are calculated using embedded sensors and communication platforms through the IoT platform and Global System Monitoring (GSM) technology. The GSM and IoT technology ensure that the different batteries are monitored periodically, and any irregularities are immediately addressed through the distributed energy management control technique. This ensures a safe, reliable, and effective charging of multiple batteries with increased accuracy, thereby maximizing battery life and reducing operational costs.

A Solar Photovoltaic Array and Grid Source-Fed Brushless DC Motor Drive for Water-Pumping Applications

This article presents a brushless DC motor drive using a solar photovoltaic (PV) array and grid. Solar PV array-fed drive systems typically need a DC–DC converter stage in order to optimize the solar PV array-generated power utilizing a maximum power point (MPP) tracking technique. In this work, a boost DC–DC converter is used for MPP tracking purposes. This work utilizes an incremental conductance (INC) MPP-tracking algorithm. A bridgeless asymmetrical converter without a bridge rectifier is used at the grid side to improve power quality at supply mains. The presented asymmetrical converter is an amalgamation of a second order (buck boost) with a fourth-order (Cuk) converter, which lowers the net system’s order. The input inductor of the Cuk converter manages the input current profile and, thus, eradicates the need for the filter at the grid mains. The bridgeless asymmetrical converter comes with several advantages, such as rectifier removal, component reduction, and input filter elimination. The performance of the brushless DC motor is examined in this article in all three scenarios: first, when grid and solar energy are both present; second, when solar energy is the only source of energy; and third, when grid energy is the only source of energy. The dual-source-based brushless DC motor drive system has been developed on matrix-laboratory/Simulink. The results are deployed and discussed to verify the drive-system performance. The article also presents a detailed stability analysis and mathematical modeling of the presented power-quality converter and MPP tracking converter to verify different converters’ stability using a bode diagram and a pole-zero plot.

Optimum sizing of components for photovoltaic maximum power point tracking buck converter

A photovoltaic (PV) maximum power point tracking (MPPT) converter consists of MPPT algorithm and converter. Although there has been a lot of improvement for MPPT algorithm, there is still much to improve for the converter. This paper proposed optimum sizing for the ideal PV MPPT buck converter with resistive and battery loads. The optimum sizing ensures the MPPT converter operates in the continuous current mode (CCM) operation and within the defined output voltage ripple for the specified range of irradiance. These conditions are achieved by deriving the equations of the inductances and capacitances required for the MPPT buck converter. The CCM operation is designed to be closed to the DCM to ensure a small inductance value. The specified output voltage ripple ensures the quality of the output of the MPPT buck converter. The verification of the derivation is done using MATLAB/Simulink circuit simulation. The conventional single diode PV model and perturb and observe (PnO) MPPT is used in the system. The result shows that the range of output resistance is highly affecting the duty cycle range, which leads to MPPT failure if the output resistance is not calculated properly. The converters for both resistive and battery loads can operate in the CCM and close to the DCM operation based on the proposed design. These converters also maintain output voltage ripple factor at 1% or lower, which the proposed derivation follows the specification. In conclusion, the proposed derivation of the MPPT buck converter is accurate.

Generalized Cost-effective Converter for Solar Street Lighting featuring Averaged State-space Model-based Sensorless MPPT

Decentralized solar street lighting is an economical solution in remote areas. However, non-uniform conditions mandates an efficient maximum power point tracking (MPPT) process. Meanwhile, implementing a less-sophisticated MPPT algorithm on a cost-effective converter is preferable to reduce system cost. In this paper, a current sensorless MPPT approach, based on converter state-space model, is proposed reducing the MPPT controller cost. Moreover, it compromises between tracking accuracy, time and implementation simplicity owing to the applied variable-step perturb and observe algorithm. Regarding the MPPT converter, D1 is selected as it overcomes the discontinuous input current limitation featured by conventional buck/boost converters. Consequently, PV power fluctuations are diminished at minimum converter component-count, enhancing tracking efficiency. Moreover, the large PV output capacitor is eliminated, increasing system reliability. Simulation and experimental results of the developed prototype validate the proposed sensorless approach. Finally, a market-survey verifies the proposed MPPT unit cost-effectiveness when compared to others in literature.

Adaptive High-Power Laser-Based Simultaneous Wireless Information and Power Transfer System With Current-Fed Boost MPPT Converter

A laser beam is an effective power and data carrier that offers inherent advantages in terms of the simultaneous transfer of wireless information and power, which is widely used in both the Internet of Things and the Internet of Energy. This paper proposes an adaptive high-power and high-efficiency laser-based simultaneous wireless information and power transfer system. This is achieved through the use of adjusted and modulated laser diode systems at the transmitter and multiplexed photovoltaic cells, a coupler, a filter, and a maximum power point tracking (MPPT) converter at the receiver. The interaction between the converter and the communication component is investigated theoretically and experimentally using a current-fed boost MPPT converter with the MPPT algorithm of perturbation and observation. The results indicate a maximum DC output power of 7.3 W at the receiver and a maximum MPPT converter efficiency of 84%. Additionally, at a data rate of 495 kbit/s, with a DC output power of 5.11 W, the bit error ratio is 2.62 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> for the binary amplitude shift keying modulation format, the MPPT converter efficiency is 88%, and the corresponding loss of communication is about 1% of the total transmitted power.

Alternating multi‐stage maximum power point tracking controlled parallelled photovoltaic systems for “solar cooker”

AbstractIn this paper we propose the control of a parallel multi‐stage photovoltaic (PV) system using a reliable and precise Maximum Power Point Tracking (MPPT) control strategy. This technique is based on the acquisition of the electrical output quantities (voltage, current, and power), common to DC/DC converters, and the control of the power switches, in alternation. In the case of two stages, during the time ti, converter 1 is regulated in real time by the MPPT control, and the second converter keeps the previous MPPT optimization parameters (ti − 1). During the following time ti + 1, converter 1 retains the previous MPPT optimization parameters (ti) and converter 2 is regulated in real time by the MPPT controller. The proposed technique is experimented on a photovoltaic system that feeds a solar cooker. This system is formed by a thermal resistance, two types of PV panels (200 and 230 W) and two DC/DC converters. Compared to the classical technique (instantaneous control), the results obtained show a significant performance and improvements: Convergence speed towards the maximum power point PPM of 48%, variations the electrical quantities gaps (current, voltage, power) at the input and output of the DC/DC converters by a factor of 2.46, electrical energy production of 4%, plate heating temperature of 27.3%, and an efficiency of 5%. The temperatures of the thermal resistances are validated by the thermal models established during this work. The improvements in DC/DC converter performance and solar cooker heating temperature are attributed, on the one hand, to the nature of the proposed MPPT control, which reduces the dispersion of electrical quantities at the input and output of the DC/DC converters, and, on the other hand, to the rapid heating of the solar cooker by the electrical energy produced by the photovoltaic panels.

An Improved Control Technique for Grid Interactive 4-Phase SRM Driven Solar Powered WPS Using Three-Level Boost Converter

This article aims to develop a unique configuration of a solar-powered water pumping system (SPWPS), which ensures an uninterruptable water supply along with the earning possibility for the consumer. This water pumping system utilizing the switched reluctance motor drive, needs no current sensor on the motor side to run the system. The concept of integrating the grid to the SPWPS as an electrical energy storage device, provides assistance against the fluctuations in power, minimum electricity cost and earns from excess of photovoltaic power. An efficient control logic for grid-side voltage source converter is developed in this article. It has multiple intends like to regulate the desired dc-link voltage, to maintain the power quality and to improve the dynamic responses. This controller incorporates the second- and third-order generalized integrator-based filter for fundamental component extraction of grid voltage and has the benefits of both the filters. Moreover, the new control logic for dual output boost converter as a maximum power point tracking converter is also proposed in this article. It helps to simultaneously maximize the solar power as well as to nullify the voltage asymmetry across both dc-link split capacitors of a mid-point converter under all operating modes. The applicability of the developed arrangement with designed control logic is verified by experimental results.

A Fast-Dynamic Control Scheme for a Power-Electronics-Based PV Emulator

The dynamic performance of a photovoltaic (PV) emulator is critical for testing applications with fast maximum power point tracking (MPPT) algorithms. In this article, a power-electronics-based PV emulator (PVE) is proposed to achieve fast-dynamic response, as well as, to emulate accurately in all regions of the current-voltage (I-V) characteristic curve. The control scheme of the proposed PVE consists of an instantaneous output impedance matching (IOIM) controller based on load resistance feedback to generate the voltage reference signal and an inner boundary control (BC) scheme to regulate the converter at a given reference within a short period of time. The IOIM controller overcomes the drawback of conventional PVEs that suffer from oscillating reference signal in a certain region of the I-V characteristic curve. Moreover, use of load resistance feedback in the reference generation algorithm allows the decoupling of the reference signal generator from the inner control loop. The BC scheme adapts a corrected second-order switching surface to achieve a faster response time and robust operation with switching converter loads. Detailed small signal model of the PVE is derived to design the IOIM control loop and to ensure a stable and fast convergent emulation in the entire I-V characteristic curve. Experimental results of a 130 W (VMPP = 35.2 V, IMPP = 3.69 A) prototype are presented with both resistive loads and an MPPT converter to verify its performance under fast varying irradiance and load conditions.

CCGPA‐MPPT: Cauchy preferential crossover‐based global pollination algorithm for MPPT in photovoltaic system

AbstractIn general, the photovoltaic (PV) is considered as the best selection among renewable energy resources due to its nonpolluted operation and good flexibility condition. The PV system is affected because of the partial shading conditions (PSCs), which reduce the generated power. During steady‐state operating conditions, there occurs a time delay in tracking the Global maximum power point (GMPP) and Local maximum power point (LMPP) under PSCs using the perturb and observe (P&amp;O) method. In order to overcome such shortcomings, this paper proposed a hybrid algorithm with a P&amp;O technique to improve the maximum power point tracking (MPPT) for the PV system under PSC. In addition to this, the P&amp;O technique is utilized to achieve the LMPP in the first section, and the hybrid algorithm is utilized to achieve the GMPP in the second section. Here, the hybrid technique is the integration of Cauchy preferential crossover (CC) with the flower pollination algorithm (FPA). Furthermore, the exploitation ability of the FPA is enhanced by the CC, and the combined hybrid algorithm has the ability to produce the optimal duty cycle for the DC–DC boost converter for MPPT. Then the proposed method will be executed in MATLAB/Simulink model, and it is contrasted with the existing methods such as CC, current sensorless (CS), and FPA, respectively. The experimental results and analysis reveal that the proposed approach provides better performances when compared with several other metaheuristic algorithms.

A New Adaptive Maximum Power Point Controller for a Photovoltaic System

Controlling extraction of maximum power from photovoltaic (PV) panels is very important for an efficient PV power system. This maximum power control can be performed by using a maximum power point tracking (MPPT) algorithm. We propose anew self-tuning based adaptive MPPT algorithm that is designed with an incremental-proportional-integral-derivative (IPID) controller. Power extraction from a PV panel is greatly influenced by external weather conditions. The IPID-controller monitors the rate of change in control signal during rapid variation in input weather conditions for maintaining stability of a PV system. The proposed adaptive MPPT controller is comprised of two components, namely, parameter estimation of the MPPT converter system and control design strategy for tuning the IPID-controller. In this paper, a recursive least square algorithm and incremental generalized minimum variance (IGMV) control law have been used for parameter estimation and tuning the gains of the IPID-controller, respectively. The efficacy of the proposed MPPT algorithm is verified on comparing its performance with that of the Perturb and observe (P&O) algorithm. From the simulation and experimental results, it is envisaged that the efficacy of the proposed adaptive MPPT control scheme exhibits superior performance as compared to P&O MPPT algorithm.

Computation of current-resistance photovoltaic model using reverse triangular number for photovoltaic emulator application

PV emulator (PVE) is a power supply that produces similar current‑voltage (I‑V) characteristic as the PV module. It simplifies the testing of the PV system during the development phase. Since the output voltage and current of the PVE change based on various factors (load, irradiance and temperature), the computation of the operating point for the PVE is crucial. The resistance feedback control strategy is a robust and fast approach to find the operating point for the PVE. Nonetheless, it uses an uncommon current‑resistance PV model, which cannot be computed using the conventional approach. This work introduces the reverse triangular number to compute the PV model and obtained the operating point of the PVE. The reverse triangular number is based on the variable step sizes that allow fast computation of the PV model. The operating point is then used by the PI controller and the buck converter to produce the output voltage and current similar to the PV module. The results show that the reverse triangular number is able to compute the PV model accurately. In addition, the proposed PVE not only works well with resistive load but adapts accurately under the integration with maximum power point tracking converter.

Computation of current-resistance photovoltaic model using reverse triangular number for photovoltaic emulator application

PV emulator (PVE) is a power supply that produces similar current‑voltage (I‑V) characteristic as the PV module. It simplifies the testing of the PV system during the development phase. Since the output voltage and current of the PVE change based on various factors (load, irradiance and temperature), the computation of the operating point for the PVE is crucial. The resistance feedback control strategy is a robust and fast approach to find the operating point for the PVE. Nonetheless, it uses an uncommon current‑resistance PV model, which cannot be computed using the conventional approach. This work introduces the reverse triangular number to compute the PV model and obtained the operating point of the PVE. The reverse triangular number is based on the variable step sizes that allow fast computation of the PV model. The operating point is then used by the PI controller and the buck converter to produce the output voltage and current similar to the PV module. The results show that the reverse triangular number is able to compute the PV model accurately. In addition, the proposed PVE not only works well with resistive load but adapts accurately under the integration with maximum power point tracking converter.

Fixed- and variable-frequency sliding mode controller–maximum power point tracking converter for two-stage grid-integrated photovoltaic system employing nonlinear loads with power quality improvement features

This article presents a reliable and efficient photovoltaic sliding mode voltage-controlled maximum power point tracking DC-DC converter–active power filter integration system to supply real power to grid. This integrated active power filter system performs power quality enhancement features to compensate current harmonics to make distortion-free grid supply current and reactive power employing nonlinear loads. The proposed proportional–integral–derivative–based sliding mode controller is designed with fixed-frequency pulse-width modulation based on equivalent control approach. The main objective of this paper is to design a photovoltaic system with a new sliding surface to force the photovoltaic voltage to follow the reference maximum power point voltage with the alleviation of slow transient response and disadvantages of chattering effects of variable-frequency hysteresis modulation sliding mode controller–maximum power point tracking. The perturbations caused by the uncertainties in climatic conditions and converter output bulk oscillations during grid integration are also mitigated. The features of the proposed photovoltaic–active power filter integration system are confirmed at different operating conditions through PSIM simulation software, and its performance is also compared with a conventional variable-frequency sliding mode-controlled maximum power point tracking. The obtained simulation and experimental results give good dynamic response under various operating conditions of environmental and local load conditions.

High performance of three-level T-type grid-connected photovoltaic inverter system with three-level boost maximum power point tracking converter

A three-phase three-level transformerless T-type grid-connected inverter system with three-level boost maximum power point tracking converter is introduced in this article for high-voltage high-pow...

A non-iterative approach for maximum power extraction from PEM fuel cell using resistance estimation

A primary challenge towards the adoption of Polymer Electrolyte Membrane Fuel Cell (PEMFC) on a wider scale involves the extraction of maximum power irrespective of variation is source and loading condition, commonly referred to as Maximum Power Point Tracking (MPPT). The non-linear voltage current relationship and dynamic variation of maximum extractable power with change in operating parameters makes MPPT task quite challenging. Motivated by the need to achieve MPPT over a wider operating range with reduced computational burden, this paper proposes a non-iterative approach for maximum power extraction from PEMFC. Continuous estimation of resistance across the source and load by monitoring the voltage and current, allows reducing the deviation between equivalent resistance across the PEMFC terminals and its internal resistance by regulating the Pulse Width Modulated DC-DC converter. The power converter for MPPT is designed with the objective of simultaneously minimizing the ripple content and achieving faster dynamic response. The proposed approach is compared with the Incremental Resistance Method (INR), in terms of simplicity, MPP efficiency and better dynamic response for both source and load perturbations. The effectiveness of the proposed scheme has been validated experimentally.

Operating principles and practical design aspects of all SiC DC/AC/DC converter for MPPT in grid-connected PV supplies

A 20 kW, 20 kHz high frequency (HF) link maximum power point tracking (MPPT) converter for a grid-connected PV supply, based on all silicon carbide (SiC) power semiconductors, is presented. In the developed converter, SiC power MOSFETs are used in the low-voltage PV panel side and SiC Schottky diodes on the high-voltage DC output, in order to maximize the power conversion efficiency and the power density. Operating principles of the resulting dual H-bridge MPPT converter and the practical aspects of the converter design and its circuit layout, are described in detail. The implemented converter performance is compared with that of a classical Si-IGBT and hybrid-IGBT based MPPT converter in terms of efficiency. This configuration can compete with the non-isolated MPPT converter topologies, such as the boost converter commonly used in grid-connected PV systems, since it allows the possibility of using a conventional two-level, three-phase grid-connected inverter. This is due to the enhanced common-mode EMI performance as compared to non-isolated MPPT topologies, resulting in a competitive high efficiency PV converter design with galvanic isolation. It has been shown that the converter size can be shrinked up to a power density of 1.6 kW/lt, with a DC-DC converter full-load efficiency of 98%. The resulting compact and highly efficient SiC power MOSFET based HF link MPPT converter is suggested to be a part of grid-connected, multi-string PV supplies with simple inverter topologies in the future.

A novel hysteresis power point optimizer for distributed solar power generation

Abstract This paper proposes a new photovoltaic panel maximum-power-point optimizer based on a buck converter. It can be connected to the DC-link distributed energy harvesting system that should perform the true maximum-power-point tracking algorithm based on maintaining a constant DC link voltage. The algorithm is based on the sensorless hysteresis control and ensures high efficiency. Three different realizations of proposed hysteresis optimizers have been analyzed in the paper, including operation principle and adjustment of hysteresis intervals. An experimental study has been performed for a portable low-power photovoltaic system in case of different loads and irradiance levels. The efficiency of maximum power point tracking has been calculated analytically for different hysteresis intervals and validated by experiment, which proved a 97-98 % efficiency of tracking for different PV panel temperatures. The proposed solution is recommended to be used in small- and medium-sized power systems where the price of the conventional maximum power point tracking converter is very high and is comparable to the cost of the individual panel

Maximum power point tracking using Hill Climbing and ANFIS techniques for PV applications: A review and a novel hybrid approach

The development of Maximum Power Point Tracking (MPPT) techniques is continuing in order to increase the generated energy from photovoltaic (PV) generators. A variety of MPPT techniques have been proposed and classified based on three main categories: offline, online and hybrid techniques. This paper presents a review of the most popular techniques for offline and online tracking of the Maximum Power Point (MPP), which are the Adaptive Neuro-Fuzzy Inference System (ANFIS) and Hill Climbing (HC) techniques, respectively. This is in addition to a review for all hybrid techniques reported in the literature demonstrating their main merits and shortcomings. Moreover, the present paper combines the ANFIS and HC as a hybrid technique for the first time. The proposed technique involves the features of the ANFIS and HC techniques and mitigates their shortcomings in order to increase the generated PV electrical energy. The proposed technique is a combination of two stages to assess the duty ratio (control signal) being applied to a boost converter for MPP tracking. The first stage includes a set point calculation loop to estimate the duty ratio. The second stage involves a fine tuning loop to determine the exact duty ratio corresponding to the MPP. This achieves maximum power transfer to the load even under nonuniform climatic conditions using a relatively simple control system. The proposed technique has been simulated in MATLAB/SIMULINK environment and compared with some other MPPT techniques (the Constant Voltage (CV), ANFIS, HC, Incremental Conductance (IncCond) techniques) for steady state and rapidly changing climatic conditions (Ropp and sine radiation tests) as well as load variations. The results reveal that the proposed hybrid MPPT technique outperforms other MPPT techniques in term of performances indicators, which include the tracking speed, tracking accuracy and energy gain factor.