3,619 research outputs found
Small-signal modelling of maximum power point tracking for photovoltaic systems
In grid connected photovoltaic (PV) generation systems, inverters are used to convert
the generated DC voltage to an AC voltage. An additional dc-dc converter is usually
connected between the PV source and the inverter for Maximum Power Point Tracking
(MPPT). An iterative MPPT algorithm searches for the optimum operating point of PV cells
to maximise the output power under various atmospheric conditions. It is desirable to be able
to represent the dynamics of the changing PV power yield within stability studies of the AC
network. Unfortunately MPPT algorithms tend to be nonlinear and/or time-varying and
cannot be easily combined with linear models of other system elements.
In this work a new MPPT technique is developed in order to enable linear analysis of
the PV system over reasonable time scales. The new MPPT method is based on interpolation
and an emulated-load control technique. Numerical analysis and simulations are employed to
develop and refine the MPPT. The small-signal modelling of the MPPT technique exploits
the fact that the emulated-load control technique can be linearised and that short periods of
interpolation can be neglected. A small-signal PV system model for variable irradiation
conditions was developed. The PV system includes a PV module, a dc-dc boost converter, the
proposed controller and a variety of possible loads. The new model was verified by
component-level time-domain simulations.
Be
cause measured signals
in PV systems contain noise, it is important to assess the
impact of that noise on the MPPT and design an algorithm that operates effectively in
pr
esence of noise. For performance assessment of the new MPPT techniques, the efficiencies
of
various MPPT techniques
in presence of noise were compared. This comparison showed
superiority of the interpolation MPPT and led to conclusions about effective use of existing
MPPT methods.
The new MPPT method was also experimentally tested.Open Acces
Cakar ayam shaping machine
Cakar ayam (Figure 7.1) is one of the Malay traditional cookies that are made from sliced sweet potatoes deep-fried in the coconut candy. In current practice of moulding the cookies, the fried sweet potatoes are molded using traditional manual tools, which are inefficient and less productive for the mass production purposes. âKuih cakar ayamâ associated with the meaning of the idiom means less messy handwriting has a somewhat negative connotation .This cookies may just seem less attractive in shape but still likeable . In fact, this cookie is considered a popular snack even outside the holiday season. The choice of the name of this cookie is more to shape actually resembles former chicken scratches made by the paw the ground while foraging. The value of wisdom, beauty and creativity of the Malays is clearly evident through the Malay cookie. Although it is attacked by the invention of modern cakes that look far more interesting, these cakes will be able to survive a long time until now
Modeling a Grid-Connected PV/Battery Microgrid System with MPPT Controller
This paper focuses on performance analyzing and dynamic modeling of the
current grid-tied fixed array 6.84kW solar photovoltaic system located at
Florida Atlantic University (FAU). A battery energy storage system is designed
and applied to improve the systems stability and reliability. An overview of
the entire system and its PV module are presented. In sequel, the corresponding
I-V and P-V curves are obtained using MATLAB-Simulink package. Actual data was
collected and utilized for the modeling and simulation of the system. In
addition, a grid- connected PV/Battery system with Maximum Power Point Tracking
(MPPT) controller is modeled to analyze the system performance that has been
evaluated under two different test conditions: (1) PV power production is
higher than the load demand (2) PV generated power is less than required load.
A battery system has also been sized to provide smoothing services to this
array. The simulation results show the effective of the proposed method. This
system can be implemented in developing countries with similar weather
conditions to Florida.Comment: 6 pages, 14 figures, PVSC 201
Modeling and Control for Smart Grid Integration of Solar/Wind Energy Conversion System
Performance optimization, system reliability and operational efficiency are key characteristics of smart grid systems. In this paper a novel model of smart grid-connected PV/WT hybrid system is developed. It comprises photovoltaic array, wind turbine, asynchronous (induction) generator, controller and converters. The model is implemented using MATLAB/SIMULINK software package. Perturb and observe (P&O) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The dynamic behavior of the proposed model is examined under different operating conditions. Solar irradiance, temperature and wind speed data is gathered from a grid connected, 28.8kW solar power system located in central Manchester. Real-time measured parameters are used as inputs for the developed system. The proposed model and its control strategy offer a proper tool for smart grid performance optimization
Solar array fed synchronous reluctance motor driven water pump : an improved performance under partial shading conditions
An improved performance of a photovoltaic (PV) pumping system employing a synchronous reluctance motor (SynRM) under partial shading conditions is proposed. The system does not include the dc-dc converter that is predominantly being utilized for maximizing the output power of the PV array. In addition, storage batteries are also not contained. A conventional inverter connected directly to the PV array is used to drive the SynRM. Further, a control strategy is proposed to drive the inverter so that the maximum output power of the PV array is achieved while the SynRM is working at the maximum torque per Ampere condition. Consequently, this results in an improved system efficiency and cost. Moreover, two maximum power point tracking (MPPT) techniques are compared under uniform and partial shadow irradiation conditions. The first MPPT algorithm is based on the conventional perturbation and observation (P&O) method and the second one uses a differential evolution (DE) optimization technique. It is found that the DE optimization method leads to a higher PV output power than using the P&O method under the partial shadow condition. Hence, the pump flow rate is much higher. However, under a uniform irradiation level, the PV system provides the available maximum power using both MPPT techniques. The experimental measurements are obtained to validate the theoretical work
Integrated series transformer in cascade converters for photovoltaic energy systems
This paper proposes a novel configuration for photovoltaic applications based on a cascade converter topology. The series connection between modules is achieved through the magnetic core of the integrated series transformer, therefore an inherent isolation is provided without the requirement of a dc-dc conversion stage. Such isolation approach between each module allows operation at high voltage levels without harming the PV panel insulation. The main principles that support this proposal, as well as, simulation results are presented to validate the configuration.Peer ReviewedPostprint (author's final draft
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