Operation Of Solar Photovoltaic System Research Articles

Concurrent UPQC Schemes for the Power Quality Improvement in Solar Photovoltaic Systems

Aims: Aim of this research is to propose a novel concurrent UPQC scheme for improving the power quality issues in grid integrated solar photovoltaic (PV) systems. Background: The power quality is a major issue for the grid integration of renewable energy sources. Issues like voltage sag, voltage swell, harmonics & non-linear load variations are certainly observed in the distributed energy system and it is mandated that any system has to depend on advanced controllers to improve power quality and stabilize the electrical parameters. Controller related power quality improvements are a bit easier to design but the tuning of power is difficult in this aspect. Objective: In order to overcome the aforesaid limitation, this particular paper proposes a new concurrent UPQC scheme for improving the four different power quality issues in grid integrated solar photovoltaic (PV) system such as voltage sag, voltage swell, non-linear load variations and current harmonics. Methods: The operating regions of each power quality issues are examined in the I-V curves of PV specifications and the new operating modes of PV systems are mapped for every quality improvement considering the power, current and frequency of the grid and load as well. The pool of solutions is developed from the real power, reactive power and converter duty cycle and verified with the proposed solutions. Additionally, the designed switching frequency of the proposed system has a 5% variation for practical irradiance. The PV uniform irradiance profile matches the real power for various proposed concurrent UPQC schemes. Results: Finally, the simulation results are presented to validate the operation of the proposed concurrent UPQC schemes for PV system. The comparative study of the proposed concurrent UPQC scheme for PV system with appropriate literature is presented. The superiority of the proposed schemes infers studying the odd harmonic components up to 100th order after implementing the proposed concurrent UPQC scheme for PV system. Conclusion: From the measured results, it is concluded that a new concurrent optimization scheme enhances the operation of solar PV system that integrates with the grid. The power quality issues like voltage & current swell, voltage & current sag, voltage imbalance, and harmonics are reduced compared to existing methods. The validation of the schemes is achieved through the group constraints and the operating slopes in each region.

Modeling of solar photovoltaic power using a two-stage forecasting system with operation and weather parameters

ABSTRACT The integration of solar photovoltaic (SPV) system to the grid has introduced a new source of intermittency in the grid, and the grid has to react smartly to the changes that occur in the penetration of SPV power. Accurate modeling of weather-dependent SPV power will be helpful in forecasting the penetration of SPV power into the grid. An SPV power output forecasting model has been developed based on artificial neural network (ANN) approach. Two forecasters, namely ANN forecaster and two-stage hybrid-ANN forecaster, are developed with operational and weather parameters. The historical data of SPV power (P), hours of operation of SPV system (to), daily global solar radiation (H), and ambient temperature(T) are used as modeling parameters. The combination of modeling parameters {P, H, T, to} is identified as the best combination that influences the forecasting of day-ahead power output. A relative root mean square error (RRMSE) of 5.74% was obtained with the combination of {P, H, T, to}. An RRMSE of 6.04% was observed with the combination of {P, H, T} as inputs, and the hours of operation of the SPV plant could be ignored in the model. The historical power data of the SPV plant is identified as the crucial parameter in the SPV power forecast model and has given an RRMSE of 7.25%. The models developed with temperature and radiation as modeling parameters have resulted in good forecasting accuracy, which could be best suitable for feasibility studies of SPV plant at a particular location. Solar radiation prediction models are used in the development of hybrid-ANN forecaster. It has produced an RRMSE of 7.35% with four inputs. The hybrid-ANN forecaster with predicted radiations as modeling input will eliminate the need of a costly pyranometer. The models developed in the present study have utilized readily available parameters as modeling parameters, thereby cost of the forecasting system has been decreased. The developed models will be useful for energy scheduling and energy management in the smart grid. Abbreviations: GSR, Global Solar Radiation; ANN, Artificial Neural networks; SPV, Solar Photovoltaics; MAPE, Mean Absolute Percentage Error; RRMSE, Relative Root Mean Square Error; MSE, Mean Square Error.

Підвищення якості електропостачання у Energy Smart Community з джерелами розосередженої генерації

Solar photovoltaic energy is the most commercially attractive and widely used. The rapid development of the direction of renewable energy has become a prerequisite for the future change in the basic strategy for the functioning of energy systems and the energy market, the creation of new formats of interaction within the framework of "consumer — energy supply company", which are described in the concept of Energy Smart Community. The best option for building an Energy Smart Community is a mode of operation for private households, in which not only electricity is efficiently and economically consumed, but also generated into the grid. Grid connection requirements are fundamental principles in the design, management and operation of solar photovoltaic systems. These requirements are contained in the standards. The voltage (current) of photovoltaic generators is incompatible with the load in terms of amplitude and frequency, so power converters must be used. The control system of the DC/AC converter should be designed in such a way that the current is sinusoidal with low THD. The paper proposes a converter based on the developed tracking system with relay control and forced formation of sinusoidal currents consumed and generated from the network in the absence of a phase shift between voltage and current. Relay control allows you to realize the maximum speed. By digital modeling, the operating modes of the proposed converter were investigated: power supply of the load from the network and photovoltaic system (PV-system) power supply from the PV-system and power generation into the network; generating energy to the network, with the load disconnected; power supply from PV-system In all modes of operation, the current is sinusoidal. The quality of the current is analyzed using harmonic analysis. THD is 3.41 %, which meets the current quality standard. Individual harmonics do not exceed the maximum permissible values.

Study of the Operation of Solar Modules Using Holographic Thermal Protection

This paper explores the problem of overheating of solar modules as a result of exposure to sunlight. An increase in temperature above the standard leads to the degradation of solar modules and their premature decommissioning. Cooling the working surface is a key factor that must be considered in order to achieve higher efficiency in the operation of solar photovoltaic systems. Based on the considered methods of cooling and removing excess heat from the surfaces of the modules, an inexpensive and technologically advanced method for protecting solar modules from overheating using holographic films was proposed. The article presents the results of comparative laboratory tests of solar modules using such a holographic thermal protection. It is shown that when using a film, the SM performance does not change, and in some cases even gets better. The surface temperature of the module depends on the angle of its inclination to the horizon, which must be taken into account when choosing the location of installation of solar power plants. The experiments confirmed the assumption of effective protection of the modules from overheating using holographic thermal protection and showed its promise.

Single-stage sine-wave inverter for an autonomous operation of solar photovoltaic energy conversion system

This paper proposes a high performance single-stage inverter topology for the autonomous operation of a solar photovoltaic system. The proposed configuration which can boost the low voltage of photovoltaic (PV) array, can also convert the solar dc power into high quality ac power for driving autonomous loads without any filter. An MPPT circuit with parallel connection is implemented so that the part of the energy generated is processed by the dc–dc converter to supply dc loads. The line current total harmonic distortion (THD) obtained using this configuration is quite reasonable. The proposed topology has several desirable features such as low cost and compact size as number of switches used, are limited to four as against six switches used in classical two-stage inverters. In this paper analysis, simulation and experimental results are presented.