scholarly journals Design and Implementation of a Flexible Photovoltaic Emulator Using a GaN-Based Synchronous Buck Converter

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1587
Author(s):  
Chao-Tsung Ma ◽  
Zhen-Yu Tsai ◽  
Hung-Hsien Ku ◽  
Chin-Lung Hsieh

In order to efficiently facilitate various research works related to power converter design and testing for solar photovoltaic (PV) generation systems, it is a great merit to use advanced power-converter-based and digitally controlled PV emulators in place of actual PV modules to reduce the space, cost, and time to obtain the required scenarios of solar irradiances for various functional tests. This paper presents a flexible PV emulator based on gallium nitride (GaN), a wide-bandgap (WBG) semiconductor, and a based synchronous buck converter and controlled with a digital signal processor (DSP). With the help of GaN-based switching devices, the proposed emulator can accurately mimic the dynamic voltage-current characteristics of any PV module under normal irradiance and partial shading conditions. With the proposed PV emulator, it is possible to closely emulate any PV module characteristic both theoretically, based on manufacturer’s datasheets, and experimentally, based on measured data from practical PV modules. A curve fitting algorithm is used to handle the real-time generation of control signals for the digital controller. Both simulation with computer software and implementation on 1 kW GaN-based experimental hardware using Texas Instruments DSP as the controller have been carried out. Results show that the proposed emulator achieves efficiency as high as 99.05% and exhibits multifaceted application features in tracking various PV voltage and current parameters, demonstrating the feasibility and excellent performance of the proposed PV emulator.

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2308
Author(s):  
Kamran Ali Khan Niazi ◽  
Yongheng Yang ◽  
Tamas Kerekes ◽  
Dezso Sera

Partial shading affects the energy harvested from photovoltaic (PV) modules, leading to a mismatch in PV systems and causing energy losses. For this purpose, differential power processing (DPP) converters are the emerging power electronic-based topologies used to address the mismatch issues. Normally, PV modules are connected in series and DPP converters are used to extract the power from these PV modules by only processing the fraction of power called mismatched power. In this work, a switched-capacitor-inductor (SCL)-based DPP converter is presented, which mitigates the non-ideal conditions in solar PV systems. A proposed SCL-based DPP technique utilizes a simple control strategy to extract the maximum power from the partially shaded PV modules by only processing a fraction of the power. Furthermore, an operational principle and loss analysis for the proposed converter is presented. The proposed topology is examined and compared with the traditional bypass diode technique through simulations and experimental tests. The efficiency of the proposed DPP is validated by the experiment and simulation. The results demonstrate the performance in terms of higher energy yield without bypassing the low-producing PV module by using a simple control. The results indicate that achieved efficiency is higher than 98% under severe mismatch (higher than 50%).


2015 ◽  
Vol 785 ◽  
pp. 106-110
Author(s):  
M.N.M. Hussain ◽  
Ahmad Maliki Omar ◽  
Intan Rahayu Ibrahim ◽  
Kamarulazhar Daud

An identification system of multiple-input single-output (MISO) model is developed in controlling dsPIC microcontroller of positive output buck-boost (POBB) converters for module mismatch condition of photovoltaic (PV) system. In particular, the possibility of the scheme is to resolve the mismatch losses from the PV module either during shading or mismatch module occurrences. The MPPT algorithm is simplified by identification approach of indirect incorporated with a simple incremental direct method to form a combined direct and indirect (CoDId) algorithms. Irregular consumption of solar irradiation on a PV module shall step-up or step down the voltage regarding to the desired DC output voltage of POBB converter. This optimized algorithm will ensure that the PV module to kept at maximum power point (MPP), preventing power loss during module mismatch incident in PV module especially during partial shading condition. The simulation and laboratory results for PV module of polycrystalline Mitsubishi PV-AE125MF5N indicate that the proposed model and development of PV system architecture performs well, while the efficiency up to 97.7% at critical of low solar irradiance level. The controlling signal is based on low-cost embedded microcontroller of dsPIC30F Digital Signal Control (DSC).


2011 ◽  
Vol 57 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Konrad Skup ◽  
Paweł Grudziński ◽  
Piotr Orleański

Application of Digital Control Techniques for Satellite Medium Power DC-DC Converters The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter is based on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage and current mode stabilization that was implemented using VHDL. The described controllers are based on a classical digital PID controller. The converter used for testing is a 200 kHz, 750W buck converter with 50V/15A output. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.


2015 ◽  
Vol 25 (04) ◽  
pp. 1550049 ◽  
Author(s):  
Fredy Edimer Hoyos Velasco ◽  
Nicolás Toro García ◽  
Yeison Alberto Garcés Gómez

In this paper, the output voltage of a buck power converter is controlled by means of a quasi-sliding scheme. The Fixed Point Inducting Control (FPIC) technique is used for the control design, based on the Zero Average Dynamics (ZAD) strategy, including load estimation by means of the Least Mean Squares (LMS) method. The control scheme is tested in a Rapid Control Prototyping (RCP) system based on Digital Signal Processing (DSP) for dSPACE platform. The closed loop system shows adequate performance. The experimental and simulation results match. The main contribution of this paper is to introduce the load estimator by means of LMS, to make ZAD and FPIC control feasible in load variation conditions. In addition, comparison results for controlled buck converter with SMC, PID and ZAD–FPIC control techniques are shown.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1050
Author(s):  
Ferran Reverter ◽  
Manel Gasulla

Autonomous sensors that harvest energy from the environment usually employ a dc/dc converter to regulate the operating voltage of the energy transducer around its maximum power point (MPP). In this context, this work evaluates the efficiency of a buck converter when regulating the operating point of two low-power photovoltaic (PV) modules subjected to different irradiance levels. The buck converter operates in burst mode (BM) and is able to transfer the energy from the PV module to a storage unit through an optimal value of the inductor current. Experimental results show that an irradiance increase can cause either an increase or a decrease of the converter efficiency. This is because the higher the irradiance, the higher both the MPP voltage and current of the PV module, which involve opposite effects in terms of the converter efficiency.


2013 ◽  
Vol 333-335 ◽  
pp. 317-321
Author(s):  
Rong Sen Yin ◽  
Jia Qiang Yang

In order to eliminate the measurement error caused by working voltage fluctuation of weighing sensor, a dynamic voltage compensation method for improving the weighing accuracy was proposed in the paper. The method takes strain gauge type pressure sensor as the weighing sensor and corrects Wheatstone bridge circuit. By synchronously detecting output voltage signal and working voltage of the weighing sensor, the method dynamically compensates the working voltage fluctuation of the weighing sensor, corrects the measurement error caused by the voltage fluctuation of external source and calculates the weight in real time. A weighing system based on the digital signal processor (DSP) was designed. Results of simulation experiment verify the feasibility of the proposed method.


ACTA IMEKO ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 93
Author(s):  
Giovanni Bucci ◽  
Fabrizio Ciancetta ◽  
Edoardo Fiorucci ◽  
Antonio Delle Femine

<p class="Abstract">Shading is one of the most critical factors that produces a reduction in power in photovoltaic (PV) modules. The main causes of shading are related to cloud cover; local specificity; natural characteristics; building and other civil works; and the presence of the PV system itself. A reduction in overall radiation produces a consequent reduction in electric power. Another more problematic effect is associated with the partial shading of the PV modules. The shaded cell behaves as a load, dissipating energy and increasing its temperature. This effect can involve irreversible changes to the PV module, with a decrease in performance that can even cause the destruction of the shaded cell.</p><p>The main aim of this work is the development of a testing procedure for the performance evaluation of commercial PV modules in the presence of partial shading on one cell. Tests were carried out using thermographic and electric measurements and by varying the shading levels according to IEC standards. Shading up to total darkening is achieved by means of a number of filters that reduce the direct solar irradiance.</p><p>As a case study, a complete characterisation of a 180 Wp polycrystalline PV module was performed according to the proposed testing procedure, showing that high temperatures can be measured on the shaded PV module surface even if only 50 % of the surface of one cell of the PV module is darkened.</p>


2015 ◽  
Vol 10 (2) ◽  
pp. 10-17
Author(s):  
Dmitriy Senkov ◽  
Dmitriy Pureskin ◽  
Anatoliy Medvedko

There are the structure and control algorithms 10kW power source with 25 kHz converter and output synchronous rectifier shown in the article. The output voltage or current of power source has controlled waveform with 1 kHz maximal frequency. The output voltage is galvanically isolated from mains. The source design allows using the load’s energy recuperation in the power converter storage capacitor and soft switching in the synchronous rectifier. The article shows the application of power source as 400 Hz waveform regulated sinusoidal voltage generator.


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