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In the last decade, Bayesian Networks have become more and more popular in solving statistical problems. This method also attracts a lot of attention in reliability analysis community. In this paper, a time-varying Dynamic Bayesian Network modeling framework which is extended from basic Dynamic Bayesian Network model is proposed to analyze the non-stationary failure process. And the model is illustrated...
A much nonlinear and sensitive photovoltaic array system , which is used in a hybrid electric generation system is depicted in this paper. The purpose of the operation for this nonlinear system is to use the advance control algorithm to regulate the voltage output to reach the maximum output power under ever-changing atmosphere. In order to do the upper work best, the analysis on the effect of critical...
Photovoltaic (PV) systems are growing popular nowadays due to the incessant demand for power. This has resulted in increased awareness and interest among the engineering students to learn these systems. However, PV related laboratory courses have ceased to exist due to the cost of PV panels and the relevant equipment required as well as the complexity involved in handling and testing of such systems...
Although photovoltaic (PV) systems are generally based on Maximum Power Point Tracking (MPPT), many situations such as stand-alone systems or microgrids increasingly require the PV system to operate below maximum power. The problem here is that the power regulation becomes unstable when the MPP power is lower than the reference power as a result of a decrease in irradiance. This paper proposes a control...
A common critique of photovoltaic energy is the susceptibility of the systems to high variability— passing clouds can affect a site's day-to-day energy production substantially. This research developed a tool to simulate photovoltaic energy systems in several scenarios throughout the state of Florida and quantifies the hour-to-hour impact of these systems on the statewide generation mix using 11 years...
In the last decades, growing environmental concerns have driven investments in electricity generation projects based on Renewable Energy Sources (RESs) such as Photovoltaic (PV) systems.
The equivalent power of feeder, as one of the inputs of chronological simulation of a power network in presence of a large scale photovoltaic power plant, needs some preprocessing in order to reduce simulation time. The Fuzzy C-means, Gustafson Kessel, K-means and K-medoid methods are applied to find a few numbers of representatives for the equivalent power of feeder. The proposed techniques are validated...
Single-phase current controlled, voltage source inverters are commonly used to feed unity power factor sinusoidal current into the distribution network from PV sources. A large 50 Hz transformer is often used at the inverter output for galvanic isolation and to prevent dc current injection into the distribution network. This transformer increases cost, size and overall power losses of the system....
In this paper we discuss the simulation of a solar powered air compressor comprising a cylinder and a compressor coupled to a vector controlled induction motor which is fed from a photovoltaic array with maximum power point tracking (MPPT). The induction motor speed is controlled to maintain a constant pressure in the cylinder. In the model, the effect of temperature difference between the inside...
This study seeks to quantify how much insolation varies over the span of a typical photovoltaic (PV) array. A solar sensor array was constructed and deployed at three locations where environmental conditions vary from full sun to highly restricted sunlight. Data was recorded at each location and then analyzed to find the effects of shading. In traditional series-parallel photovoltaic systems the total...
Performance of Photovoltaic (PV) system is greatly dependent on the solar irradiation and operating temperature. Due to partial shading condition, the characteristics of a PV system considerably change and often exhibit several local maxima with one global maxima. Conventional Maximum Power Point Tracking (MPPT) techniques can easily be trapped at local maxima under partial shading. This significantly...
Analytic hierarchy process (AHP) was performed on decision-making of PV modules for very large scale photovoltaic systems using sc-Si, mc-Si, a-Si, CdTe and CIS from both economic and environmental viewpoints. The amount of module, land requirement, transportation, array support and foundation varies depending on the type of PV module because of the differences of price and efficiency. In order to...
Aimed at the shortcomings that traditional fuzzy logic control method for solar LED illumination system maximum power point tracking (MPPT) control system, a novel solar LED illumination control strategy based on variable univers adaptive fuzzy PID controller is proposed.The controller can automatically adjusts the variable univers with the change of photovoltaic output power deviation, to realize...
Recently, maximum power point trackers (MPPTs) that based on single variable (IPV or VPV) have a great attention. That is due to their simplicity and easiness in implementation, when compared to the other tracking techniques. In this paper, two methods have been proposed to design a variable step size MPPT using only a single current sensor for stand-alone battery storage PV systems. These methods...
This paper proposes a general method of sizing the inverter for a PV system. The method evaluates effects of PV incentive policies, inverter efficiency curves, and inverter protection schemes on optimum inverter sizing through system-level cost analysis. Specifically, different scenarios of PV incentives are discussed and compared to show that the optimal inverter size varies notably by location and...
A passively cooled Fresnel lens concentrating photovoltaic module (FLCPM) was made and its performance was tested and analyzed. The module consists of a 0.480 m×0.480 m Fresnel lens array of 16 Fresnel lens with the size of each being 0.120 m×0.120 m, and the sunlight was concentrated onto 16 silicon solar cells with the size of each being 0.025 m×0.025 m that were placed at the focuses of the lenses...
A Versatile simulation model for photovoltaic array is developed based on the DC physical model of photovoltaic (PV) module under PSIM environment. The I-V, P-V characteristics of photovoltaic array with different combinations can be simulated by the model. In addition, the model includes the function of Maximum Power Point Tracking (MPPT) and completes the simulation of the perturbation and observation...
Solar energy is developing fast recently. Solar energy has the feature of intermittent, fluctuation and random, and it has serious harms on large scale photovoltaic grid-connected generation. This paper proposes a method to predict daily total solar-radiation and photovoltaic generation using wavelet-neural network. This method uses wavelet function to substitute the transfer function of neural-network...
As primary energy source such as coal and oil has been dried up and has bad influence on environment, human urgently need renewable energy which is friendly to environment. So in the future, solar energy will be very important energy source. It is noticeable that the output characteristics of a PV array are influenced by the environment factors, and the conversion efficiency of PV arrays is very low...
Solar photovoltaic(PV) array power generation, as a utilization form of solar energy, has been widely applied in solar generator systems throughout the world. Effective guarantee of PV array normal power generation, rapid and accurate detection of fault location and the prediction of fault occurrence are of great significance. This paper, based on the analysis of solar photovoltaic power generation...
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