Maximum Power Point Tracking Circuit Research Articles

Maximizing off-grid solar photovoltaic system efficiency through cutting-edge performance optimization technique for incremental conductance algorithm

The maximum power point tracking (MPPT) algorithms are required to deliver the optimal energy from solar photovoltaic cells/array (PV) under numerous weather conditions. Therefore, MPPT circuits driven by defined rules called algorithms are designed. These algorithms range from simple to complex in design and implementation and are selected based on the scenarios of the surroundings. However, the incremental conductance (InC) MPPT algorithm is one of the market's most simple, easy to implement, and demanding algorithms. The drawback associated with the InC algorithm is its tracking speed. To overcome this weakness various researchers have made multiple improvements. Although the performance became better but was not satisfied. Further, the improvements introduce steady-state oscillations of the operating point around the MPP. So, the user needs to pick and choose based on demand. Keeping the target in focus, we have introduced a couple of modifications in the structure of INC. that remain fruitful. The proposed structure named the augmented InC algorithm has shown marvelous improvement in tracking speed and steady-state oscillations. The results have been compared with the conventional InC algorithm, where the proposed augmented InC algorithm has outperformed the conventional InC algorithm in tracking speed and steady-state oscillations. We have used the MATLAB script to code the conventional InC algorithm and proposed augmented InC algorithms based on their designed flowchart. Both algorithms have been applied to the standalone solar photovoltaic system composed of a solar photovoltaic array, DC/DC boost converter, illumination and temperature inputs, MPPT algorithm, and a DC load. The model is designed in Simulink/MATLAB.

An Innovative MPPT Method Based on the Estimated Model of the Photovoltaic Cell considering the Environmental Conditions

In this paper, a novel adaptive photovoltaic maximum power point tracking (MPPT) circuit is proposed, called AT2MPPT. The AT2MPPT circuit is based on a type two fuzzy logic set and utilizes a detailed two-diode model of a solar cell, as well as an innovative hybrid algorithm for designing the MPPT circuit. The effects of environmental conditions such as azimuth, wind speed, wind direction, and irradiation, as well as the uncertainty of radiation intensity, are taken into account in the solar cell model. It is demonstrated that changes in environmental conditions can cause up to a 20% change in the PV parameters. To optimize the AT2MPPT parameters and fuzzy membership functions (MFs), a hybrid lightning search algorithm and whale optimization algorithm (hLSA-WOA) are proposed. The accuracy of the hLSA-WOA is evaluated by comparing its results with those of other optimization algorithms on 10 standard benchmarks. The simulation results indicate that the hLSA-WOA has high accuracy and is nontrapping in local optima. Finally, the proposed AT2MPPT circuit is used to track the MPPT of a PV array in partial shade, and its performance is compared with that of P&O and fuzzy MPPT circuits. The results confirm the superior performance of the AT2MPPT circuit, which produces 1.1% more power than the other two circuits. Additionally, the AT2MPPT circuit has lower power ripple and tracking time compared to perturb, observation, and fuzzy MPPT circuits.

Experimental Validation of a Fast-Tracking FOCV-MPPT Circuit for a Wave Energy Converter Embedded into an Oceanic Drifter

Wave Energy Converters (WECs) are an ideal solution for expanding the autonomy of surface sensor platforms such as oceanic drifters. To extract the maximum amount of energy from these fast-varying sources, a fast maximum power point tracking (MPPT) technique is required. Previous studies have examined power management units (PMU) with fast MPPT circuits, but none of them have demonstrated their feasibility in a real-world scenario. In this study, the performance of a fast-tracking fractional open circuit voltage (FOCV)-MPPT circuit (sampling period TMPPT of 48 ms) is compared with a commercial slow-tracking PMU (TMPPT of 16 s) in a monitored sea area while using a small-scale, pendulum-type WEC. A specific low-power relaxation oscillator circuit is designed to control the fast MPPT circuit. The results demonstrate that by speeding up the sampling frequency of the MPPT circuit, the harvested energy can be increased by a factor of three.

Maximum power point tracking for a multi-layered piezoelectric heel charger with a levered mechanism toward impact-based energy harvesting.

The piezoelectric footstep energy harvester does not always work at its maximum power point when the external load is fixed, as the optimal load changes when the walking excitation alters. Thus, the harvesting efficiency is downgraded largely in real-life scenarios compared to in-lab experiments and theoretical or numerical predictions due to the mismatch between the actual load and the optimal load. To address this issue, the concept of Maximum Power Point Tracking (MPPT) is investigated in this paper and the circuit design is implemented for a multi-layered levered piezoelectric footstep energy harvester (heel charger). The proposed event-driven MPPT circuit interface with a customized buck converter aims to maximize the power gained from daily walking using the heel charger to power a fixed load, such as smart insole or shoes. The MPPT circuit design is conceptually simulated and then tested with the heel charger to further validate if it works at its maximum power point when the frequency of the input excitation alters. Results show that the extracted power from the heel charger connected to a fixed resistance load with MPPT implementation is improved up to 300% compared to the one without MPPT implementation in simulation and up to 180% in the experiment when connected to a fixed load. The difference between simulation and experimental results is due to the optimization of using voltage sources as the heel charger and the control signals (pulse width modulation) from the microcontroller in the simulation.

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.

Analysis of Single-Diode PV Model and Optimized MPPT Model for Different Environmental Conditions

The performance of photovoltaic (PV) systems must be predicted through accurate simulation designs before proceeding to a real-time application to avoid errors. However, predicting the cohesive relationship between current and voltage and estimating the parameters of a single diode model become a perplexing task due to insufficient data in the datasheet of PV panels. This research work presents single-diode solar PV system simulation analysis under different conditions, and the performance is improved by introducing an optimization-based maximum power point tracking (MPPT) strategy. Before simulation, a mathematical model for a single diode and optimization approaches are presented in this research work. Particle swarm optimization (PSO), genetic algorithm (GA), BAT optimization, and grey wolf optimization (GWO) model-based MPPT circuits are designed, and the performances are comparatively analyzed. The simulation results identify the nonlinear relationship between current and voltage and between power and voltage as characteristic curves for different temperature and irradiance values. For maximum power (Pmax), the maximum peak point tracking power and efficiency are analyzed to verify the optimization-based MPPT system. The simulation results demonstrate that the GWO model obtains a maximum tracking efficiency (TE) of 98%, which is much better than that of other optimization techniques.

Buck‐Boost‐Type MPPT Circuit Suitable for Vehicle‐Mounted Photovoltaic Power Generation

This paper presents a buck–boost maximum power point tracking (MPPT) circuit suitable for solar cars. The MPPT controller, which consists of analog elements with a small number of complementary metal–oxide–semiconductor elements, achieved accurate tracking of the maximum power point of photovoltaic power generation and contributed to the power savings and weight reduction. A buck–boost dc–dc converter was adopted as the main power converter of the MPPT circuit to reduce the power‐conversion loss due to the wide voltage change in the battery. The 12 proposed MPPT circuits were installed in a solar car called ‘2019 Tokai Challenger’ at an international convention and were shown to successfully generate sufficient solar power. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Photovoltaic Energy Harvesting Chip With P&O Maximum Power Point Tracking Circuit and Novel Pulse-Based Multiplier

A photovoltaic (PV) energy harvesting chip with novel multiplier-based perturb and observe (P&O) maximum power point tracking (MPPT) circuit for Internet-of-Things applications is proposed, and it can be powered by only a small PV module. The proposed P&O MPPT circuit can accurately detect the maximum power point of the PV module without using a power-hungry microcontroller or inaccurate analog multiplier. Instead, a high-accuracy pulse-based multiplier is proposed. Its input signals are analog, while its output signal is digital. Moreover, a new MPPT controller based on the proposed multiplier is also presented. The chip was fabricated using a 0.18 μm 1P6M mixed-signal CMOS process. According to the measured results, the available power from the chosen PV module is 0.1-3 mW, the maximum tracking efficiency of the proposed MPPT circuit is 99.3%, and the maximum total efficiency of the proposed harvesting chip is 94.7%.

An energy harvesting system for time-varying energy transducers with FOCV based dynamic and adaptive MPPT for 30 nW to 4 mW of input power range

This article, for the first time, presents an energy harvesting system (EHS) for harvesting the energy from the continuous time-varying energy harvesters using the fractional open-circuit-voltage (FOCV) based dynamic and adaptive maximum power point tracking (MPPT). The proposed EHS includes an energy harvester, a start-up circuit, a DC-DC boost converter, a DC-DC buck converter, and a control circuit. In the FOCV based MPPT, a fraction of the open-circuit-voltage (OCV) of the energy harvester, is maintained at the output of the energy harvester (input of a DC-DC boost converter). In the proposed work, OCV of the energy harvester is dynamically and adaptively sampled depending on the ambient conditions and the maximum available power from the energy harvester. This helps in improving the tracking efficiency of the proposed MPPT circuit for the time-varying energy harvester by more than 10%. The boost converter switching time period instants are utilized for sampling the OCV of the energy harvester. A 12-stage Dickson based charge pump along with a 5-stage ring oscillator with a modified clock distribution is used for the start-up. Post-layout simulated results of the proposed EHS are presented in the 180 nm mixed-mode CMOS technology. The tracking efficiency and the boost converter efficiency for a wide range of the available input power (30 nW to 4 mW) compatible with many time-varying ambient energy harvesters in both indoor and outdoor places are presented. For a time-varying energy harvester, the tracking efficiency is more than 96%. For a source resistance of 100 kΩ, the boost converter's efficiency is 60.09% and 90.77% at available power of 56 nW and 1.6 μW, respectively.

MPPT Circuit Using Time Exponential Rate Perturbation and Observation for Enhanced Tracking Efficiency for a Wide Resistance Range of Thermoelectric Generator

The thermoelectric generator (TEG) stands out among many energy harvesters due to its simple structure, small size, rich thermal energy, and the absence of pollution and noise. However, previous studies have rarely probed into the influence of TEG internal resistances on extracting maximum power from TEGs, and the tracking of efficiency is limited. By analyzing the relationship between the tracking efficiency and the TEG internal resistances, a time exponential rate perturbation and observation (P&O) technology is proposed to achieve maximum power point tracking (MPPT) for a wide resistance range of the TEG. Using the time exponential rate P&O, the MPPT circuit observed the power change by comparing the positive-channel metal-oxide semiconductor (PMOS) on-time and perturbs the power by adjusting the negative-channel metal-oxide semiconductor (NMOS) on-time exponentially. The MPPT circuit was implemented in a 110 nm complementary metal-oxide semiconductor (CMOS) process. The tracking efficiency maintained a high level from 98.9 to 99.5%. The applicable range of the TEG resistance was from 1 to 12 Ω, which reflects an enhancement of at least 2.2 times.

An RF Energy Harvesting and Power Management Unit Operating Over −24 to +15 dBm Input Range

This paper presents the design and measurement of an RF energy harvesting and power management unit that operates across a wide range of available input power, from −24 to +15dBm. The system comprises an adaptive impedance matching network, a single-stage cross-coupled differential-drive rectifier, a start-up charge pump, an adaptive buck-boost converter, a maximum power point tracking (MPPT) circuit and a control loop to regulate the load voltage. The MPPT circuit controls the switching frequency of the buck-boost converter and configures the impedance matching network, optimizing the interfaces between the rectifier and antenna and between the rectifier and the storage capacitor, guaranteeing that the power is being harvested at maximum efficiency. To boost the rectifier output, to accumulate energy in the storage capacitor and to provide energy to the load, a single-inductor buck-boost converter that has two inputs and three outputs is used. Circuit techniques that reduce the power consumption of the control circuits and that allow for adapting the interfaces between the antenna, the rectifier and the load are presented. The peak harvesting efficiency of the system is 40.2%, when presented with an RF source of -9.1dBm available power and 403.5MHz frequency.

MPPT oscillations minimization in PV system by controlling non-linear dynamics in SEPIC DC-DC converter

Solar PV power generation has achieved rapid growth in developing countries which has many merits such as absence of noise, longer life, no pollution, less time for installation, and ease of grid interface. A maximum power point tracking circuit (MPPT) consists of DC-DC power electronics converters that are used to improve the energy attainment from solar PV array. This paper presents a detailed analysis to control of chaos, a non-linear dynamic in SEPIC DC-DC converter interfaced solar PV system, to minimize the oscillations near to MPP. In SEPIC DC-DC converter, the input inductor current is continuous and capable of sweeping the whole I-V curve of a PV module from open circuit voltage (Voc) to short circuit current (Isc) operating points. To trace the true maximum power point and to nullify the oscillations near to MPP, the yield output voltage needs to ensure period-1 operation.

An internal-resistance-adaptive MPPT circuit for energy harvesting

This paper presents a built-in input matching technique capable of handling a wide variation of multi-array thermoelectric generator (TEG) impedances, from 5 Ω to 2.7 KΩ, which is called internal-resistance-adaptive (IRA) maximum power point tracking (MPPT) technique. The IRA circuit and delay synthesis circuit in the IRA-MPPT can track the dynamic changes of the internal resistance of the energy source in real time, and transmit the optimized switching time to the switching transistor to maximize the end-to-end efficiency (ηE–E). The circuit is designed and simulated using 0.18μm technology. An improvement of 23.23%@(RS= 2.7 KΩ, VS= 0.6 V) in ηE–E is achieved with the proposed technique. Furthermore, the simulation results show that a higher than 46%@(RS=5Ω, VS= 0.03 V) efficiency can be achieved over an input resistance (RS) range of 5 Ω–2.7 KΩ and an power range of 12 μW–50 mW with a 95.52%@(RS= 100 Ω, VS= 1 V) peak efficiency.

Coordinated Power Management and Control of Standalone PV-Hybrid System With Modified IWO-Based MPPT

To augment the photovoltaic (PV) power generation conversion, a maximum power point tracking (MPPT) technique plays a very significant role. This article introduces a hybrid MPPT algorithm integrating modified invasive weed optimization (MIWO) and perturb and observe (P&O) technique under the rapid weather change and partial shading scenarios for the efficient extraction of the maximum power from the standalone PV-based hybrid system. MIWO handles the initial stages of MPPT followed by the application of the P&O algorithm at the final stages in view of acquiring the rapid global peak and maximal PV power. The studied microgrid comprises of the PV system, battery, electrolyzer, fuel cell, and load. A coordinated dc-voltage regulation and power management strategy between each subsystem of the hybrid microgrid is implemented to save the battery from the undesirable charging/discharging operation. Additionally, with the monitoring of dc voltage, the dc/dc converter associated with the battery and dc link plays as an MPPT circuit of the PV without the requirement of an extra dedicated circuit. Takagi-Sugeno (TS) fuzzy controller is adopted for suppressing/mitigating the voltage oscillations of the microgrid during the variations in the solar irradiance/temperature and power demand. The results clearly exhibit the superior performance of the proposed methodology compared with some of the existing techniques.

MPPT circuit with analog control suitable for solar cars

AbstractThis paper presents a maximum power point tracking (MPPT) circuit composed of analog circuits suitable for solar cars. The MPPT controller circuit, which consists of analog switches and two op‐amps achieved precise MPPT during solar power generation. This MPPT controller circuit was constructed using a small number of CMOS elements, and the circuit of the step‐up DC‐DC converter achieved a conversion efficiency higher than 98% as well as weight reduction. Eighteen of the proposed MPPT circuits were installed (in serial and in parallel) in a solar car called “2013 Tokai Challenger” at an international competition, and it was shown that it could generate sufficient power supply from solar power.

Novel transportation layers of NiO and ZnO for the fabrication of perovskite solar cell for e-monitoring of healthcare

Inorganic n-type NiO and p-type ZnO has been used as hole transport layers (HTL) and electron transport layers (ETL), respectively, for the fabricated perovskite solar cells. The sols of NiO and ZnO have been synthesized using sol–gel method. The structural, morphological, and optical analysis of the synthesized ZnO and NiO nanoparticles prepared from sol has been done. The spin coating technique was used for the fabrication of HTL, ETL, and perovskite layers. The thickness of the fabricated solar cell is about 2 μm. The current density versus voltage (JV) characteristics of the fabricated solar cell was investigated. The JV characteristics revealed the value of various parameters such as short-circuit current density (JSC), open-circuit voltage (VOC), fill factor (FF), power conversion efficiency, and maximum power (Pmax) is 15.90 mA/cm2, 0.93 V, 73%, 10.70%, and 10.70 W, respectively. The fabricated solar cell has been used to design a special electronic circuit with maximum power point tracker (MPPT) for monitoring of patient suffering from the heart diseases. The performance parameters of MPPT circuit have been tested under “direct sunlight” and “artificial shadow.” The energy consumption and 1-day performance load of the designed circuit is tested with the solar cell. The e-monitoring of patient suffering from heart diseases is done with the help of bluetooth low energy (BLE) to measure blood pressure (BP), heartbeat, photoplethysmography (PPG), electrocardiogram (ECG) signals.

Peripheral interface controller-based maximum power point tracking algorithm for photovoltaic DC to DC boost controller

A method of developing a maximum power point tracking (MPPT) algorithm for photovoltaic (PV) utilizing a peripheral interface controller (PIC) is presented in this paper. The efficiency and adequacy of a PV depend on the temperature and the exposed position to the sun. Thus, there is an optimum point at which the operating power is at maximum. The goal is to operate the PV module at this point (MPP). It can be accomplished by using the MPPT algorithm designed with a DC-DC boost converter. The boost converter, MPPT circuit, PIC18F4550 microcontroller and PV panel are the main components used in this design. The current and voltage produced by the solar panel are observed continuously by a closed-loop control system. The microcontroller-based control system adjusts the duty cycle of the converter to extract the maximum power. With a DC input voltage of 15 V, the boost converter is capable of generating an output voltage of an approximately 60 Vdc at a maximum power of 213.42 W with minimum voltage ripple as compared to 84 W without the MPPT. It proved the effectiveness of the developed algorithm.

A P&O MPPT With a Novel Analog Power-Detector for WSNs Applications

This brief presents a perturb and observe (P&O) maximum power point tracking (MPPT) with a novel analog power detector for wireless sensor nodes (WSNs) applications. The proposed analog power detector can judge the output power variation only by the voltage measurements, which eliminates the use of current measurements or microcontroller unit (MCU), so that its complexity and power consumption are greatly reduced. The proposed P&O MPPT circuit with the analog power detector has the advantages of simple structure, low power consumption, and high power efficiency. The proposed MPPT is used in a discontinuous conduction mode (DCM) buck-boost converter with fixed duty cycle to improve the efficiency performance. This design has been implemented in a $0.18\mu \text{m}$ CMOS process occupying an active area of $0.98\times 0.9$ mm2. The input voltage range can be from 2V to 7.2V. The peak conversion efficiency and peak tracking efficiency are 86% and 98% respectively, with power consumption about $9\mu \text{W}$ .

An efficient energy harvesting circuit for batteryless IoT devices

A new energy harvesting circuit for battery-less IoT beacon tags is developed herein to maximize power conversion efficiency as well as high throughput power with a wide input–output range. This design energy harvest (EH) circuit incorporates a charge pump (CP) with shoot-through current suppression, a body selector circuit, a maximum power point tracking circuit (MPPT), a timing control circuit, a hysteresis control circuit and a low dropout regulator. Also in this MPPT circuit is a gated clock tuned in a self-adaptive fashion to match the input impedance of the EH circuit to the output impedance of the photovoltaic (PV) panel, thus achieving successfully maximum power point. The circuit is implemented in an integrated chip in an area of 1.2 mm2 via the TSMC 0.18 process. Experiments on the chip are conducted and the results show that the input voltage range is allowed from 0.55 to 1.7 V to effectively harvest the solar power from a flexible dye-sensitized solar cell. The achieved peak power conversion efficiency (PCE) is 77% at the input power of 52 μW. For a wide range of lighting luminance (300–1300 lx,) the achieved average PCE is more than 70%. The achieved wide input–output range and the maximum throughput power of 200 μW is much larger than others reported, while the 77% of PCE is close to that best power conversion efficiency reported.

Effect of DC-DC voltage step-up converter impedance on thermoelectric energy harvester system design strategy

Conventional thermoelectric energy harvester design strategies often focus on improving the material property thermoelectric figure of merit (ZT); however, enhanced performance through improved materials cannot be achieved without optimized integration of subcomponents. The low voltage output from a thermoelectric module makes it challenging to design a practically usable wearable energy harvester. In addition to consideration of effective heat dissipation along with matching module geometry, a voltage needs to be boosted at a usable voltage value to utilize produced power. Using a DC to DC voltage step-up converter adds additional design complexity as the power cannot be harnessed at maximum power point of thermoelectric module due to input impedance requirement of the power conditioning circuit. Moreover, additional power loss occurs due to inherent voltage conversion inefficiency, which also depends on the harvesting voltage value. A recent design framework on wearable thermoelectric energy harvester assumed that a Maximum Power Point Tracking (MPPT) boost converter can be utilized for thermoelectric energy harvester systems, however it is unable to accurately determine the maximum power point during operation because of the transient nature of thermoelectric systems. Additionally, an MPPT circuit consumes power and adds complexity to the system design, which may not economically justify the use of such a circuit. This work proposes an encompassing thermoelectric system design framework for small scale energy harvesting using only state-of-the-art commercial products. Particularly, thermoelectric module geometry design is examined with the incorporation of a DC to DC voltage step-up converter without the use of MPPT. The framework can provide guidance for further development of subcomponents and materials, as well as system integration. An operational wearable energy harvester system was built using off-the-shelf components and demonstrated a usable power output which provides experimental evidence for the proposed design strategy.