Grid Photovoltaic System Research Articles

Modelling and simulation for installation feasibility of standalone photovoltaic system for Quetta, Pakistan

The impact and significance of renewable energy in developing countries is increasing rapidly in latest years. There is much need of energy dependence to be based on off grid photovoltaic systems in developing countries like Pakistan which are suffering from severe power shortfalls annually and load shedding concern. In this paper, a concept assessment and estimation of standalone photovoltaic system is done for the site of Quetta, Pakistan in comparison to the location of the Copiapo-Chamonate. Copiapo-Chamonate site is situated in Atacama Desert which is often labelled as the best solar irradiation receiving location in the world with maximum solar insolation reaching to 9.28 kWh/m2/day. The systems for both locations is modelled and simulated in PVSYST for a constant load of 11.9 kWh/day with seasonal tilt adjustment. According to the simulation, results of the parameters including performance ratio, solar fraction, energy supplied to the load etc. show that Quetta meet its individual household demand quite efficiently.

MPSO-MPPT based Single Phase Grid PV System for Power Enhancement

The solar power became a challenging area among other renewable energy sources (RESs) since the photovoltaic (PV) systems have the benefits of not inflicting pollution, having low maintenance, and durable operation life. Besides these benefits, a PV system has many drawbacks like significantly higher installation cost comparing some other RESs, and limited potency ranges between 9–18%. The feasibility analyses have a good role so as to work out the foremost appropriate plant site before installation. On the other hand, the operating analyses and enhancements supported maximum power point tracking (MPPT) are quite necessary to extend the harvested total energy. To maximize the performance of solar photovoltaics (PV) under dynamic climatic conditions, MPPT (Maximum Power Point Tracking) controllers are integrated into photovoltaic systems. This research presents a modified PSO algorithm based on the method of tracking the maximum global power point used for photovoltaic systems with variable co-efficient. The modified PSO (MPSO) algorithm is able to trace the maximum global power point faster. This improves the effectiveness of follow-up. Simulation results show that MPSO coordination control methods have better tracking accuracy as compared to P&O as well as PSO MPPT Technique. This also improves the energy efficiency of the photovoltaic system.

Investigation of off-grid photovoltaic systems for a reverse osmosis desalination system: A case study

There has been a great concern about shortage of potable water in many countries as well as Iran, because of the dramatic low rainfall during past few decades almost in all over the Iran. There is a great concern for implementing renewable desalination systems as it seems to be the only clean and environmental friendly source to the traditional fossil fuel powered systems. This study sought to simultaneously assess the reliability of electricity and cost in off grid photovoltaic systems for a photovoltaic reverse osmosis desalination system in 9 districts of Bushehr Province in Iran. Solar data used in this study contains indices of “Clearness Index” and “Daily Solar Radiation” over a period of 16 years from 2000 to 2016. HOMER and Excel were used for technical-economic feasibility of the proposed systems. For this study, a new model of BWRO-2S-130/75 desalination system is tested and proposed. The results indicate that the proposed photovoltaic systems are technically and economically feasible. It was also found that the reliability of off grid photovoltaic system using fuzzy time function provided better results than using the simple method. The results of the evaluation of proposed photovoltaic systems by HOMER software shows that annual electricity production for Delvar and Deylam port are 72,336 and 47,915 kWh respectively which is promising. Also, maximum of 228 m3 and a minimum of 148 m3/day of potable water can be produced with cost of 1.96 to 3.02 $/m2 for Delvar and Deylam port respectively. Results indicate that using the proposed system of desalination would be economically feasible for Delvar, since the predicted water cost is cheaper compared to existing water price of $2.5. The new model of BWRO-2S-130/75 desalination can meet the water demand of the selected city.

A rule-based energy management scheme for uninterrupted electric vehicles charging at constant price using photovoltaic-grid system

This work proposes a rule-based energy management scheme (REMS) for electric vehicle (EV) charging from photovoltaic-grid (PV-grid) system. The main feature of this scheme is that it provides uninterrupted daytime charging at a constant price. In order to simulate the system, the models of PV output power, EV power demand, state of charge (SOC) estimation of energy storage unit (ESU) and grid electricity prices are developed. The uninterrupted and constant price charging is achieved by managing the energy flow between PV, ESU and grid according to the rules defined by REMS. Furthermore, the valley-filling operation is implemented during the grid off-peak hours. The resiliency of REMS is validated under various weather conditions, different ESU prices and at grid parities. For comparison, its performance is benchmarked against the standard grid-based EV charging. The results demonstrate a decline in charging price by 16.1% besides reducing the burden on the grid by 93.7% with the implementation of REMS. In addition, the vehicle-to-grid (V2G) technology is incorporated in the charging system to improve the payback schedule of the existing PV-grid system.

Control strategy of grid-connected photovoltaic generation system based on GMPPT method

There are multiple local maximum power points when photovoltaic (PV) array runs under partial shading condition (PSC).However, the traditional maximum power point tracking (MPPT) algorithm might be easily trapped in local maximum power points (MPPs) and cannot find the global maximum power point (GMPP). To solve such problem, a global maximum power point tracking method (GMPPT) is improved, combined with traditional MPPT method and particle swarm optimization (PSO) algorithm. Under different operating conditions of PV cells, different tracking algorithms are used. When the environment changes, the improved PSO algorithm is adopted to realize the global optimal search, and the variable step incremental conductance (INC) method is adopted to achieve MPPT in optimal local location. Based on the simulation model of the PV grid system built in Matlab/Simulink, comparative analysis of the tracking effect of MPPT by the proposed control algorithm and the traditional MPPT method under the uniform solar condition and PSC, validate the correctness, feasibility and effectiveness of the proposed control strategy.

Improved grid-photovoltaic system based on variable-step MPPT, predictive control, and active/reactive control

In this paper a grid connected photovoltaic system is presented. The presented system has two stages, the first is the MPPT strategy based on variable-step with predictive current control. In the second stage an active/reactive power control is uses to control a multilevel inverter for grid connection. All the system is developed in Matlab and simulated on Simulink for validation.

Design of a solar photovoltaic system to cover the electricity demand for the faculty of Engineering- Mu’tah University in Jordan

In this study, the reduction ways of the electricity demand for Engineering Faculty at Mu’tah University were investigated. The using of the available resources efficiently and effectively to reduce energy bill is one way to reduce the energy consumption as well as the electricity generation. On grid photovoltaic system considers the most promising way to achieve the target of saving. For that, the availability of the solar photovoltaic system as an electricity generation source for Faculty of Engineering proposed to design a 56.7 kW grid-connected as a solar photovoltaic power plant to cover the electricity demand. The analysis revealed that the Engineering Faculty at Mu’tah University consumed 96 MWh annually and by installing an on-grid photovoltaic system with a capacity of 56.7 KW the electricity production to the grid will be 97.02 MWh per year, which cover the electricity demand for Engineering Faculty at Mu’tah University with a capital cost of $117,0 0 0 and payback period about 5.5 years.

Design, modelling and optimal power and hydrogen management strategy of an off grid PV system for hydrogen production using methanol electrolysis

Hydrogen used as an energy carrier and chemical element can be produced by several processes such as gasification of coal and biomass, steam reforming of fossil fuel and electrolysis of water. Each of these methods has its own advantage and disadvantage. Electrolysis process is seen as the best option for quick hydrogen production. Hydrogen generation by methanol electrolysis process (MEP) gained much attention since it guarantees high purity gas and can be compatible with renewable energies. Furthermore, due to its very low theoretical potential (0.02 V), MEP can save more than 65% of electrical energy required to produce 1 kg of hydrogen compared to water electrolysis process (WEP). Electrolytic hydrogen production using solar photovoltaic (PV) energy is positioned to become as one of the preferred options due to the harmful environmental impacts of widely used methane steam reforming process and also since the prices of PV modules are more competitive.In this paper, hydrogen production by MEP using PV energy is investigated. A design of an off grid PV/battery/MethElec system is proposed. Mathematical models of each component of the system are presented. Semi-empirical relationship between hydrogen production rate and power consumption at 80 °C and 4 M concentration is developed. Optimal power and hydrogen management strategy (PHMS) is designed to achieve high system efficiency and safe operation. Case studies are carried out on two tilts of PV array: horizontal and tilted at 36° using measured meteorological data of solar irradiation and ambient temperature of Algiers site. Simulation results reveal great opportunities of hydrogen production using MEP compared to the WEP with 22.36 g/m2 d and 24.38 g/m2 d of hydrogen when using system with horizontal and tilted PV array position, respectively.

Design of a solar photovoltaic system to cover the electricity demand for the faculty of Engineering- Mu'tah University in Jordan

Abstract In this study, the reduction ways of the electricity demand for Engineering Faculty at Mu'tah University were investigated. The using of the available resources efficiently and effectively to reduce energy bill is one way to reduce the energy consumption as well as the electricity generation. On grid photovoltaic system considers the most promising way to achieve the target of saving. For that, the availability of the solar photovoltaic system as an electricity generation source for Faculty of Engineering proposed to design a 56.7 kW grid-connected as a solar photovoltaic power plant to cover the electricity demand. The analysis revealed that the Engineering Faculty at Mu'tah University consumed 96 MWh annually and by installing an on-grid photovoltaic system with a capacity of 56.7 KW the electricity production to the grid will be 97.02 MWh per year, which cover the electricity demand for Engineering Faculty at Mu'tah University with a capital cost of $117,000 and payback period about 5.5 years.

Modeling and simulation of photovoltaic systems and responsive loads in smart grid

In this paper, the methods of forecasting output at different times and applications within the smart grid photovoltaic system (PV) systems will be investigated method of calculations used in this short amount of solar radiation to consider the reduction in average for a few hours to compensate for power fluctuations and power reserve or battery operation and supply and demand balance is forecast. In this paper, the Monte Carlo simulation is used to predict the long-term average. Usually the use of the smart grid PV system problems and even load variation problems within the system are accountable in this study, and surpassed Weather amount of output power into a smart grid system used pv is the case in the field of innovation and new research in this paper uses three software HOMER, GAMS and MATLAB simulation of photovoltaic systems within a network smart look and accountability in the network will be supplied by the PV system will be examined.

Design of an Off Grid Photovoltaic System for a Three Bedroom Flat in Makurdi, Benue State, Nigeria

Design of an Off Grid Photovoltaic System for a Three Bedroom Flat in Makurdi, Benue State, Nigeria

A Novel Single Phase Grid Connected Five Level Inverter for high Power Multi Level Applications

This paper presents a single phase five level photovoltaic (PV) inverter method for grid PV system with a novel modulated Sine pulse width modulation (SPWM). The multi-level inverters are used in high power and medium voltage applications, such as common mode voltage, operation at both fundamental and high switching frequency, drawing input current with low distortion, reduced harmonic distortions. It utilizes two reference signals and a carrier signal to generate PWM switching signals. The proposed five level inverter is designed with lesser number of switches (four) which in reduces the circuit and control loop complexity efficiently. it can produce a high quality output voltage wave with a good harmonic characteristic. Finally, it reduces stresses on power switching devices, resulting in low audio and Radio Frequency (RF) noise and Electromagnetic Interference (EMI), and fewer Electromagnetic Compatibility (EMC) problems, since multilevel inverter operates with a low switching frequency and voltage switching is done for relatively lower voltage levels. The proposed system is verified through simulation and is implemented in a prototype.

The Least Action Solving Method of MPPT for Micro-Inverter in Distributed PV Grid

The solar radiation conditions and environmental factors on the shadow of the power generation resulted in loss of efficiency. In this paper, a simple structure with interleaved isolation converter according to the characteristics of the hardware circuit is proposed in order to improve the conversion efficiency of photovoltaic grid system. First, the hot spot effect and discretization of solar panels according to the characteristics of the microinverter with a lot of promotion is analyzed. The least action recursive method is involved, which has high computing precision, and therefore is more suitable for distributed microinverter system. The PC56F8245 chip is chosen to overcome the loss of photovoltaic energy and improve the conversion efficiency. The stability and high accuracy has been proved through the related experiments.

Simulation of solar off- grid photovoltaic system for residential unit

The aim of this study is to design a solar off-grid PV system to supply the required electricity for a residential unit. A simulation model by MATLAB is used to size the PV system. The solar PV system is simulated with the case of maximum solar radiation on a sunny day. The results show that the average daily load requirement of the selected residential unit is 36 kWh/day. This load requirement can be meet by using an array of 44 solar panels. During the day time, the PV system supplies the desired 12.4 kWh of energy. During the night time, a battery storage system of 23.6 kWh (48V, 350 Ah) is used to meet the night load.

Study on Automatic Control Method of Photovoltaic Power Systems

Maximum power point tracking (MPPT) algorithm directly affect the conversion efficiency of photovoltaic power generation system independent of energy, the thesis of common strengths and weaknesses of the MPPT algorithm to summarize, the traditional method of perturbation and observation maximum power point tracking algorithm is improved and build a simulation model, the simulation model are direct and network controllers and input grid and grid-independent photovoltaic power generation system model of network simulation, and network time from both the grid conditions, and the impact of current network waveforms and grid voltage waveform analyzed. Simulation results observed with the conventional perturbation method were compared and analyzed to verify the effectiveness of the improved method.

An Islanding Detection Method for Photovoltaic Power Generation System Using Fluctuation Characteristic of PCC Harmonic Voltage

In the photovoltaic power generation system, the harmonic voltage of the point of common coupling (PCC) is determined by system disturbance, local load and photovoltaic power generation system itself together. Based on the fluctuations of this harmonic voltage, a new islanding detection method for the PV system is proposed. By extracting the higher harmonic components from the wavelet transformation of point of common coupling (PCC) voltage, and then taking its fluctuations as the islanding identification and detection index, non-detection zone (NDZ) can be eliminated, without a plus disturbance. According to IEEE Std.1547, simulated verification of the proposed method is accomplished in the ideal photovoltaic grid system. When the PCC voltage and frequency are within the normal range, it can not only give a fast and accurate detection to the occurrence of islanding, but also identify the false islanding, such as voltage dips and switching loads, effectively avoiding false detection caused by the false islanding.

Green building design solution for a kindergarten in Amman

Abstract Buildings in Jordan consume a significant amount of energy for heating, cooling and lighting purposes. Therefore, improving energy performance of the existing building in Jordan will significantly reduce national electrical consumption. In this work, an existed kindergarten in Amman was redesigned moving toward low energy performance, in doing so, the proposed design studied the use of applying lighting saving lamps, adding thermal insulation for walls, solar water heater for domestic hot water, on grid photovoltaic system as a source of electrical power to generate free solar electricity to cover the electrical load demand of the kindergarten, and finally a heat recovery system for the exhaust air in air conditioning and ventilation. Also, a suitable economic evaluation criterion was used to estimate the payback period of all systems applied. The results showed energy saving fluorescent lamps can reduce the energy use by about 15%, and reduce the heating load up to 10%, achieved by using thermal insulation and 61.3% by using exhaust air heat recovery system. Furthermore, suitable energy conversion using solar systems were sufficient to cover the domestic hot water heating demand to reach zero of domestic hot water heating energy during sunshine days. The annual reduction achieved in carbon dioxide (CO2) emission was 11.7 ton.

The Study of the Digital Three-Phase Phase-Locked Loop in the Photovoltaic Grid System

In order to track the phase of the voltage of the grid quickly and accurately in the photovoltaic grid system, a digital three-phase phase locked loop optimization method that can be completed by FPGA, which can lock the in a short time and adjust the power system voltage phase to the synchronization with the grid voltage. This design consists of three-phase phase detector, comparator and bit phase locking circuit. The principle of synchronous rotating coordinate transformation and lookup table of RAM are used to adjust the phase error more and more fine-tune. The adjustment of the phase is controlled by the waveform output of driver without analog circuit, besides the ability of anti-jamming is improved by the full digital designation and the dynamic characteristics is better. The system is simulated with MATLAB/Simulink and the given results show that this method greatly shorten the time needed for adjusting the phase difference. Obviously the precision of the system has been improved and then the effectiveness of the proposed method was verified.

A Phase Locked Loop Method for Low Voltage Ride-Through Control in Three-Phase Three-Wire Photovoltaic Grid System

Low voltage ride through (LVRT) is regarded as one of the biggest challenges in photovoltaic grid equipments designing, manufacturing and control technology. The fast and accurate automatic phase locked control is the premise to achieve photovoltaic grid low voltage ride through. Considering that the traditional phase locked loop method is difficult to adapt the performance requirements of low voltage ride through (LVRT) in three-phase three-wire photovoltaic grid system, this paper presents a new three-phase unbalanced phase locked loop method. Improved second order generalized integral orthogonal signal generator (SOGI-OSG) is used for line voltage detection; Synchronous reference frame for phase locked loop (SRF-PLL) is used for line voltage phase locked and phase angle detection; Heron formula and Sine theorem is adopted to calculate the three-phase phase voltage amplitude and phase angle. Research results show that when grid voltage dips, this phase locked loop method can detect the fault signal accurately. It provides a technical support for photovoltaic grid low voltage ride through system.

First results of incentives policy on grid interconnected photovoltaic systems development in Greece

Abstract The present study provides insights into how the national legislation affected the development of connected to the grid Photovoltaic (PV) systems in Greece from January 2007 to June 2012. It analyses the evolution of PV systems installed capacity in Greece, compared to the targets set, as well as the PV electricity production and CO 2 emissions reduction. Moreover the geographical and the size distribution of installed capacity are examined. Up to June 2012, more than 820 MW p had been installed, covering 55% of the 2014 national PV target capacity of 1500 MW p . The majority of installed and licensed PV systems is in the class of 20–150 kW p , while the share of PV systems larger than 150 kW p is increasing steadily. The majority of installed capacity is located in southern Greece regions, where the solar potential is higher, with Peloponnesus having 15.4% of the total. The total licensed PV capacity, which is more than 2.400 MW p exceeding not only the national 2014 target but also the 2020 target of 2200 MW p for PV plants, together with the accelerated construction rate, which during 2012 is 49 MW p per month, allow the save prediction that the 2014 target will be overcome.