Modeling Of Photovoltaic System Research Articles

Optimization of fractional order PI controller to regulate grid voltage connected photovoltaic system based on slap swarm algorithm

Problems with voltage and stability have arisen as a result of the dramatic development in renewable energy generating units, notably solar energy systems linked to low and medium voltage networks, and the influence of active loads that vary rapidly from time to time during the day. Because reactive power is directly proportional to voltage, its use to renewable energy producing units can only improve their efficiency. Better performance for these controllers is possible via the usage of several controller types. In this paper, we use a salp swarm optimization algorithm (SSA) to design fractional order proportional-integral (FO-PI) controllers, whose job it is to regulate the active and reactive power of solar inverters by compensating for the overvoltage and undervoltage presented by the inverters' ability to absorb and produce reactive power. After that, we compared the FO-PI controller's results to those of the standard PI controller. Grid-connected photovoltaic (PV) system modeling and simulation were performed using the MATLAB/ Simulink modeling and simulation tools. After that, the full PV system was simulated in the most likely situations across a range of grid and weather conditions. We may infer from the simulation results that this model is credible, reliable, and applicable to the analysis of grid-connected PV systems.

Transient modeling of photovoltaic system (PV) to investigating the peak of transient voltage generated by direct and indirect lightning strikes

Transient modeling of photovoltaic system (PV) to investigating the peak of transient voltage generated by direct and indirect lightning strikes

Design of Photovoltaic Power Generation Servo System Based on Discrete Adaptive Network Dynamic Surface Control Technology

In recent years, under the development of the dual carbon goal, the energy crisis has become increasingly serious, and China has also experienced serious power rationing. However, the research on dynamic surface control technology in solar tracking systems in nonlinear control systems is mostly based on continuous-time systems, while adaptive dynamic surface control based on discrete-time nonlinear control systems can describe an actual control system more accurately in the production process. It can effectively suppress interference with extremely high stability and safety. To solve the problem of low efficiency in photovoltaic power generation, this research first built a photovoltaic power generation servo system model based on the parameter of uncertainty. Then, a discrete adaptive neural network dynamic surface (DANNDS) controller was designed to solve the problems in the design of the traditional backstepping method. Finally, based on the designed method of a dynamic surface controller, a discrete adaptive neural network quantization controller (DANNQC) for the photovoltaic power generation servo system was designed by introducing external disturbance. The control parameters and their studied ranges were as follows: The reference signals were or1=sin(0.1t) and or2=cos(0.1t). The parameters of the virtual control law and the final control law were m11=0.01, m22=0.01, m12=0.02, m13=0.02, and m23=0.02. The time constant of the low-pass filter was ζ12=ζ13=ζ22=ζ23=0.005. The parameters of the parameter regulation law were ρ12=ρ13=ρ22=ρ23=0.0005 and a12=a13=20, a22=a23=22. The research results show that the MTE, RMSTE, and 2NTE scores of the height angle servo motor of the DANNDS control method were 0.0026, 7.0279 × 10−4, and 0.3552, respectively. The scores for each index of the azimuth servo motor were 0.0028, 8.9237 × 10−4, and 0.4511, respectively. The height angle tracking error for the DANNQC control method was [−0.02,0.022]. The azimuth tracking error was [−0.03,0.03]. In summary, the photovoltaic power generation servo system based on the DANNQC has a better control performance. By controlling the height angle and azimuth angles, it can better track the position of the sun and adjust the position of the photovoltaic panel in real time. The sun’s rays illuminate the photovoltaic panel at an appropriate angle to achieve maximum power generation efficiency, which is of great practical significance for the development of solar technology.

Modeling of Solar Photovoltaic System Assisted Water Cooling System

Modeling of Solar Photovoltaic System Assisted Water Cooling System

Model construction and electro-thermal-hydrogen co-generation performance for multi-section compound parabolic concentrator

Non-imaging solar concentrator has many applications in solar thermal conversion and photovoltaic power generation because of its performance characteristics such as no tracking, stable light concentration, compact structure and easy integration. For this purpose, this paper conducts a study on the non-imaging concentrator based on the optimized design of the concentrating surface structure for photovoltaic electric generation, thermal energy recovery and direct-drive hydrogen production. Firstly, a theoretical construction of a mathematical model of the solar Concentrating Photovoltaic and Photo-thermal (CPV/T) system with electricity-thermal-hydrogen co-generation and a numerical solution path for the Current and Voltage (I-V) characteristic curve is presented. Moreover, an integrated CPV/T system experimental setup is constructed outdoors and its power generation, heat collection and hydrogen production processes are measured. Finally, it is found that the average electrical efficiencies of the CPV/T system are 13.03 % and 13.29 % for theory and experiment, respectively. The theoretical and experimental average thermal efficiencies are 27.47 % and 27.24 %, respectively. The theoretical and experimental average hydrogen production rates based on Maximum Power Point Tracking (MPPT) control are 19.47 ml/min and 16.11 ml/min, respectively. The research results also show that the integrally constructed CPV/T system not only achieves effective conversion of solar energy into electrical and thermal energy, but also can directly convert electrical energy into clean, stable and easily stored hydrogen energy, which has potential application prospects.

Modelling of an off-grid roof-top residential photovoltaic nano grid system for an urban locality in India

In modern era of energy self-sufficiency and its personal preference, an off-grid rooftop solar photovoltaic nanogrid for private use in a single household or among limited number of households poses a promising futuristic prospect. However, several critical aspects need investigation to realize its viability. The present work investigates the techno-economic-space feasibility of an off-grid rooftop photovoltaic nanogrid for residential sector of a cosmopolitan urban locality with unreliable electricity in India. A novel combination of RAMP for load modelling, HOMER PRO for techno-economic analysis and an innovative technique for space feasibility analysis was implemented. 269 houses were surveyed and innovatively classified, based on number of dwelling rooms and demand profile similarity. Correlation and sensitivity analysis were conducted to understand the impact of individual and grouped load profiles, plinth area per household, number of dwelling rooms, climatic conditions, building types and component specification availability in market on the overall cost, configuration and feasibility of the system. Sharing of photovoltaic nanogrids and higher durations of daily occupancy in houses reduce the Levelized Cost of Energy (LCOE) from the system due to reduction in percentage variations of load. The LCOE of shared nanogrids ranged between 0.151 $/kWh to 0.195 $/kWh in India. The study recommends 50 % subsidy on system capital cost against grid prices. Batteries operated at higher depth of discharge (DOD) and having longer life at higher DOD reduce the system LCOE. Apartments in locations with high annual solar radiation, low annual temperatures, large plinth area, low monthly demand and unobstructed rooftops are good candidates for PV nanogrids. In India, high-rise buildings with monthly loads up to 30 kWh/household, mid-rise buildings with loads up to 50 kWh/household, low-rise buildings with loads up to 100 kWh/household and double-storey buildings with loads up to 200 kWh/household can successfully adopt autonomous rooftop PV nanogrids.

Harmonic Suppression Strategy of LCL Grid-Connected PV Inverter Based on Adaptive QPR_PC Control

To reduce the influence of voltage harmonics on the grid current, a control strategy based on adaptive quasi-proportional phase compensated resonance (QPR_PC) is proposed. Firstly, the LCL grid-connected photovoltaic inverter system model is established, and the stability performance of the three-level inverter system under double closed-loop control is analyzed using the output impedance model of the inverter. Then, a QPR regulator for the zero steady-state error tracking of AC signals is studied. To solve the problem that the system has poor robustness against frequency changes when the traditional QPR regulator is used in the static coordinate system, this paper improves the traditional QPR regulator to optimize the response characteristics of the closed-loop system. Based on the QPR regulator, a phase margin compensation structure is introduced to form QPR_PC control. Then adaptive frequency design is added to ensure good control even when the power grid frequency drifts, which is the control strategy proposed in this paper. Verification shows that the proposed method improves the phase margin of output impedance at a specific frequency, restrains the interference of the 3rd, 5th, and 7th harmonics of grid voltage, and improves the dynamic performance of the system and the quality of grid-connected current. Finally, the simulation results show that the total harmonic distortion rate of grid-connected current is reduced by 1.03% after adopting this strategy, which verifies the effectiveness and correctness of the proposed method.

Buildings with Photovoltaic Glazing System Using IoT

Buildings with photovoltaic glazing systems using IoT (BIPV) is an innovative technology that has the potential to not only generate electricity but also reduce energy consumption. BIPV systems are integrated into the building envelope, which means they serve the dual purpose of generating power and acting as a structural element of the building. This article is explaining the working and IoT-based control mechanism of a prototype model of Buildings with photovoltaic glazing systems, also called BIPV (Building-integrated photovoltaics). BIPV is an innovative technology that can reduce energy consumption apart from electricity production. As the population is increasing there is also an increase in the usage of electricity. To accommodate easy access to electricity, we designed a prototype model of photovoltaic glazing system using IoT. The integration of photovoltaic (PV) systems into buildings has gained significant attention due to the increasing demand for renewable energy sources and the need for sustainable building practices. IoT-enabled PV systems utilize smart sensors, data analytics, and automation to monitor and optimize solar energy’s generation, consumption, and storage, resulting in improved energy management and cost savings. The future of PV glazing systems looks promising with potential advancements in efficiency, integration, aesthetics, energy storage, smart connectivity, cost reduction, and sustainable building certifications.

Technical modelling of solar photovoltaic water pumping system and evaluation of system performance and their socio-economic impact

Water is a precious resource for agriculture and most of the land is irrigated by tube wells. Diesel engines and electricity-operated pumps are widely used to fulfill irrigation water requirements; such conventional systems are inefficient and costly. With rising concerns about global warming, it is important to choose renewable energy source. In this study, SPVWPS has been optimally designed considering the water requirement, solar resources, tilt angle and orientation, losses in both systems and performance ratio. A PVSyst and SoSiT simulation tools were used to perform simulation analysis of the designed solar photovoltaic WPS. After designing and performance analysis, farmers were interviewed during fieldwork to assess socioeconomic impacts. In the result section, performance of PV system is analyzed at various tilt angles and it is established that system installed at a 15° tilt angle is more efficient. The annual PV array virtual energy at MPP of designed photovoltaic system is 33342 kWh and the annual energy available to operate the WPS is 23502 kWh. Module array mismatch and ohmic wiring losses are 374.16 kWh and 298.83 kWh, respectively. The total annual water demand of the selected site is 80769 m³ and designed SPWPS pumped 75054 m³ of water, supplying 92.93% of the irrigation demand. The normalized values of the effective energy, system losses, collection losses and unused energy in the SPVWP system are 2.6 kW/kWp/day, 0.69 kW/kWp/day, 0.72 kW/kWp/day and 0.48 kW/kWp/day, respectively. The annual average performance ratio of the proposed system is 74.62%. The results of the interviews showed that 70% of farmers are extremely satisfied with the performance of SPVWPS and 84% of farmers indicated that they did not incur any operating costs. The unit cost of the SPWPS is 0.17 €/kWh, which is 56.41% and 19.04% less expensive than the cost of diesel and grid electricity.

Modelling of Large-Scale Photovoltaic Power Generation System Based on PSCAD and Analysis of Its Stability

In this paper, based on the study of PV power generation principles and mathematical models of PV cells, PSCAD simulation modelling is performed for a large-scale PV plant with required output over 100 MW, and its operational characteristics are analysed. An improved Newton iteration, conductance increment method and semi-aggregate equivalent control algorithm are used to achieve maximum power point tracking (MPPT) for large-sized photovoltaic electricity plant. Finally, the simulation analysis of the large-scale photovoltaic electricity generation system under normal operation and light disturbance is conducted to validate the validity and stability of the model.

Detection and Location of Series DC Arc Fault in Photovoltaic System Based on VMD

A large number of connecting wires and electrical contact points exist in large photovoltaic power generation systems, which can easily cause the occurrence of an arc fault. Failure to detect and isolate faults in time will result in serious fire hazards. In the document, a new approach to fault arc monitoring and positioning built on variational mode decomposition is presented for a variety of series DC arc faults in photovoltaic systems. The time and frequency-domain properties of signals collected under different working conditions are obtained by the use of variational mode decomposition (VMD), and the detection of faults by matching changes in features under the same sub-mode. Finally, a 400KW photovoltaic system model is built by Matlab/Simulink for simulation verification. The outcome indicated that the technique is capable of accurately detecting and locating series DC arc faults.

Optimal ground coverage ratios for tracked, fixed-tilt, and vertical photovoltaic systems for latitudes up to 75°N

General guidelines for determining the layout of photovoltaic (PV) arrays were historically developed for monofacial fixed-tilt systems at low-to-moderate latitudes. As the PV market progresses toward bifacial technologies, tracked systems, higher latitudes, and land-constrained areas, updated flexible and representational guidelines are required. Using our 3D view-factor PV system model, DUET, we provide formulae for ground coverage ratios (GCRs –i.e., the ratio between PV collector length and row pitch) providing 5%, 10%, and 15% shading loss as a function of mounting type and module type (bifacial vs monofacial) between 17-75°N. Fixed-tilt arrays span a wide range of GCR (0.15–0.68, 5% loss) compared to single-axis tracked arrays (0.17–0.32) and vertical east–west arrays (0.11–0.16). We additionally optimize fixed-tilt module tilt, finding that the optimum tilt can vary from 7° above latitude-tilt to 60° below latitude-tilt in certain cases. We demonstrate that tracked and fixed-tilt PV arrays should have similar GCRs >55°N, but tracked systems are more sensitive to row-to-row shading losses <55°N. The GCR of fixed-tilt arrays at lower latitudes can reach 0.55 without introducing >2.5% shading loss, whereas tracked and vertical arrays reach 2.5% shading loss by GCRs <0.22 and <0.10, respectively. We additionally find that bifacial PV arrays require GCRs up to 0.03 lower than monofacial GCRs. These results can inform future deployment designs for latitudes >15°N.

Influence of off-grid/grid-connected operation on stability of large-scale photovoltaic system

Off-grid or grid-connected operation of large-scale photovoltaic system may cause stability problems. When the system performs off-grid operation, energy storage, as balance node, regulates power and frequency, then also influences stability. Under grid-connected operation, the external power system balances power and frequency regulation, and energy storage only equilibrium wave power. Although a detailed model for a single photovoltaic generation system has been established, the connection of numerous photovoltaic units is difficult to model and simulate, and it can easily cause dimension disaster. In order to analyze stability effectively of off-grid/grid-connected operation of large-scale photovoltaic system, we first establish the equivalent model of a photovoltaic farm through the method of dynamic aggregation of wind turbines, and then obtain indicators affecting the stability considering the reactance matrix of the transmission line. When the real part of the oscillation mode sensitivity index is greater than zero, oscillation mode approaches the imaginary axis, indicating that the PV system stability deteriorates. Conversely, the PV system is regionally stable. Finally, the effects of the number of photovoltaic units and transmission line length on stability are theoretically analyzed, and the theoretical derivation is validated through simulations. More PV units and a longer transmission line increase the likelihood of instability through the sensitivity of the oscillation mode.

A simplified model of flexible power point tracking algorithms in double-stage photovoltaic systems

Traditionally, photovoltaic (PV) systems have been operated using maximum power point tracking algorithms, which force the PV arrays to produce the maximum available power at all times. Nevertheless, distribution system operators are increasingly asking for flexible power point tracking (FPPT) algorithms, which allow the regulation of the PV power to a predefined reference value. FPPTs are difficult to tune and often have non-linear behavior. It complicates the modeling of PV systems for power system stability studies. This paper proposes a simplified model that reproduces the dc-side dynamics of a double-stage FPPT-controlled PV system. In addition to its simple tuning, the key advantage of the proposed model is that it can be easily translated into differential equations, which can be used in stability analyses. The proposed model is validated on a temporal simulation as well as a small-signal stability study.

Design and Optimization of Photovoltaic System in Full-Chain Ground-Based Validation System of Space Solar Power Station

In the face of the increasing depletion of non-renewable energy sources and increasingly serious environmental problems, the development of green and environmentally friendly renewable energy sources cannot be delayed. Because of the far-reaching development potential of solar energy, solar power has become an important research object for power development. The available solar energy in space is several times greater than that on Earth. Solar energy from space can be collected by a space solar power station (SSPS) and transmitted to the ground by wireless power transfer. In the full-chain ground-based validation system of SSPS-OMEGA, the spherical concentrator is used, and the light intensity distribution on the solar receiver is non-uniform. The non-uniform light intensity makes the output current of each photovoltaic (PV) cell on the solar receiver greatly different, and causes power losses, known as the mismatch problem. This paper proposes a simple, efficient and easy-to-implement method to optimize the structure of PV arrays to reduce the effect of non-uniform light on the output performance of each PV cell, which is beneficial to the topology of PV arrays and also effectively improves the layout rate. Then, a differential power processing (DPP) converter with a simple structure and easy control is designed to further deal with the power mismatch problem between series-connected PV modules. Finally, a simulation circuit model and a physical hardware model of the differential power processing PV system are built and used in the full-chain ground-based validation system of SSPS-OMEGA. The results demonstrate that the influence of non-uniform lighting on PV cells is effectively reduced, the output power of PV modules connected in series under non-uniform light distribution is substantially increased, and the photoelectric conversion efficiency is significantly improved.

Development of a day-ahead solar power forecasting model chain for a 250 MW PV park in India

Due to the steep rise in grid-connected solar Photovoltaic (PV) capacity and the intermittent nature of solar generation, accurate forecasts are becoming ever more essential for the secure and economic day-ahead scheduling of PV systems. The inherent uncertainty in Numerical Weather Prediction (NWP) forecasts and the limited availability of measured datasets for PV system modeling impacts the achievable day-ahead solar PV power forecast accuracy in regions like India. In this study, an operational day-ahead PV power forecast model chain is developed for a 250 MWp solar PV park located in Southern India using NWP-predicted Global Horizontal Irradiance (GHI) from the European Centre of Medium Range Weather Forecasts (ECMWF) and National Centre for Medium Range Weather Forecasting (NCMRWF) models. The performance of the Lorenz polynomial and a Neural Network (NN)-based bias correction method are benchmarked on a sliding window basis against ground-measured GHI for ten months. The usefulness of GHI transposition, even with uncertain monthly tilt values, is analyzed by comparing the Global Tilted Irradiance (GTI) and GHI forecasts with measured GTI for four months. A simple technique for back-calculating the virtual DC power is developed using the available aggregated AC power measurements and the inverter efficiency curve from a nearby plant with a similar rated inverter capacity. The AC power forecasts are validated against aggregated AC power measurements for six months. The ECMWF derived forecast outperforms the reference convex combination of climatology and persistence. The linear combination of ECMWF and NCMRWF derived AC forecasts showed the best result.

A strategic review: the role of commercially available tools for planning, modelling, optimization, and performance measurement of photovoltaic systems

Abstract Solar power and photovoltaic (PV) systems have become crucial components of the world’s energy portfolio. The PV systems may be engineered in a number of ways, including off-grid, on-grid, and tracking. Incorporating PV systems with traditional sources of power like diesel generators (DGs) or other renewable sources, like windmills, is possible. In this situation, developers, investigators, and experts are striving to create the best design that accommodates the load demand in regards to technological, financial, ecological, and social aspects. To assist in figuring out the best PV size and design, numerous tools, models, and heuristics were created and rolled out. The majority of the tools, models, and techniques used to build PV systems over the past 70 years were described, assessed, and evaluated in this article. It was observed that methods for optimising PV system designs evolved with time and demand. Tool design is often divided into segments such as artificial and classical, solo and hybrid approaches, and others. Hybrid approaches, nevertheless, gained prominence to become the most popular approach because of its adaptability and capacity for handling challenging issues. This paper’s evaluation also helps the readers choose a PV system design tool (approximately 46) that is suited for their needs.

Reliability and Criticality Analysis of a Large-Scale Solar Photovoltaic System Using Fault Tree Analysis Approach

Solar Photovoltaic (PV) systems typically convert solar irradiance into electricity, thereby helping to reduce the need for fossil fuels and the amount of greenhouse gases released. They provide a reliable and continuous renewable source of energy. However, PV systems are continuously exposed to diverse and changing environmental conditions, such as temperature, humidity, dust, and rain. Exposure to such conditions creates electrical and visible faults in the PV systems. These faults may reduce the PV system’s performance, reliability, and lifetime. In this regard, this paper aims to propose a framework/methodology for reliability modeling and assessment of large-scale grid-connected PV systems using a Fault Tree Analysis (FTA) approach. Specifically, an exhaustive literature survey is carried out to acquire the failure rates of different components/faults existing on the DC side of the PV system. Then, the Fussel-Vesely (F-V) importance measure is employed to identify critical faults and their criticality ranking. Results showed that solder bond failure, broken cell, broken interconnect (finger interruption), rack structure, grounding/lightning protection system, delamination, discoloration, and partial shading are the most critical faults which severely degrade the performance of the PV systems. The recommendations and scope for further study are provided to optimize operations and maintenance costs.

Performance analysis of a novel model of photovoltaic PV-TEGs system enhanced with flat plate mirror reflectors

Recently, the combination of photovoltaic (PV) modules and thermoelectric generators (TEGs) have shown optimal models of energy harvesting from solar photovoltaic/thermal systems. In this regard, the design of solar collectors with simpler models and compatible with TEGs attract attention. The following article is a report on the simulation of a simple new model of photovoltaic PV-TEGs system enhanced with flat plate mirror reflectors. The energy output of the system is hot water flowing in aluminum tubes with a rectangular cross-section connected to the cold surfaces of the series TEGs. Arranged experimental results were used for the power and efficiency relationships of the series of TEGs in the simulation. The results showed that the difference in electrical energy produced by PV module and TEGs due to the presence and absence of reflectors are equal to 1095.448 (kJ) and 80.874 (kJ), respectively. Also, the daily thermal efficiency of the system was about 42%.

Improved variable-step incremental conductance MPPT algorithm applied to photovoltaic storage systems

For the traditional PV maximum power tracking control method in terms of tracking speed and stability, proposed an improved variable-step incremental conductance method. The method first speeds up the tracking speed by the constant voltage coefficient method to quickly locate around the MPP(Maximum power point,MPP) and dynamically adjusts the step size using the inverse tangent function value when the operating point is located to the left of the maximum power point, and dynamically adjusts the step size using the exponential function value when the operating point is located to the right. Given the characteristics of photovoltaic power generation, it usually constitutes a light storage system with an energy storage battery. To verify the effectiveness, the simulation experiments are carried out in Matlab/Simulink to build a photovoltaic energy storage system model, which contains an energy storage battery. Results indicate that the proposed new method achieves the optimization of tracking precision and speed according to the nature of the function and can make the energy storage battery charge and discharge stably, which verifies the practicality of the proposed improved algorithm.