- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- rural electrification
- optimised renewable energy utilisation
- power sharing
- micro grid
- community development
- grid interconnection
- IoT based data acquisition system
- Grid tie solar PV system
- IoT
- Losses in Solar PV plant
- Electrical Engineering and Automation
- Amrita School of Engineering
- Zeal College of Engineering and Research
-
Nonlinear Analysis Methods Applied on Grid-Connected Photovoltaic (PV) Systems Driven by Power Electronic Converters
摘要： A novel method of analysis is deployed in detail on the basis of nonlinear systems theory with aim to design suitable controllers with guaranteed stability for grid-connected photovoltaic (PV) systems driven by power converters. By this method, all the system nonlinearities are taken into account to allow a reliable analysis in a wide range of operation and to avoid instabilities that as shown in the paper can be occurred by inappropriate design. To this end, firstly a detailed accurate nonlinear dynamic model is presented for the PV system by including a cascade-mode control scheme. Then, taking into account the closed-loop system and incorporating the concept of input-to-state stability (ISS), a rigorous novel stability analysis is developed which achieves to prove asymptotic stability of the desired equilibrium point. A multi-step process is deployed in which the control loops operating in cascade-mode are involved. However, since the cascaded-mode control scheme and analysis is based on the time-scale separation principle, a systematic tuning method is conducted for the accurate gain selection of both inner-loop and outer-loop controllers which is based on the construction of suitable Lyapunov functions. To further validate the overall analysis, experimental results are carried out.
关键词： nonlinear analysis,grid-interaction,Photovoltaic systems,stability,power converter control design
更新于2025-09-23 15:21:01
-
Islanding detection for grid connected photo-voltaic systems for excess generation and under generation
摘要： Islanding occurs mostly in wide areas. The Dc-link-voltage method gives the effective results when compared to the Under/over Fre- quency/Voltage method and Rate of Change of Frequency (ROCOF) method. This paper describes the islanding detection based on ob- servation of the DC-Link-Voltage Source Converter (VSC) and also proposes a method for detecting islanding for Grid-connected Photo- Voltaic system based on rise or fall of DC-Link-Voltage for excess generation and under generation conditions. The proposed technique is validated through experimental results.
关键词： Grid-Connected,PV systems,Islanding,Anti-islanding,DC-Link-Voltage
更新于2025-09-23 15:21:01
-
[IEEE 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE) - Cochin, India (2020.1.2-2020.1.4)] 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE2020) - Power Optimized Architecture based Converter and Its Control for Single Phase Grid-Tied Solar Photovoltaic System
摘要： This paper proposes a power optimized based converter and its control for low voltage solar photovoltaic (PV) modules. For the grid tied solar PV system, the dc-bus voltage must be maintained more than a minimum level for its satisfactory working. In optimized architecture, each PV module is connected with a non isolated high gain DC-DC converter. These converters boost up the PV voltage as well as harvest the maximum solar energy. In the case of shadow, aging and fast change in solar insolation profile on each PV modules; it is able to harvest the maximum power. For maximum power harvesting, fuzzy logic control (FLC) is used. Each PV module with high gain DC-DC converter is connected at the common DC link. The DC power is converted into AC power by using voltage source Inverter (VSI). The VSC is controlled to stabilize dc-link voltage, synchronize with grid supply and to achieve low total harmonic distortion (THDs) in grid current under feeding non linear loads. For switching of a VSC, hysteresis control is used. Proposed model is developed using MATLAB 2015a and results are obtained under various operating conditions.
关键词： single phase grid,voltage source inverter (VSI),DC-DC converter,photovoltaic (PV) system,point of common coupling (PCC),high gain,maximum power harvesting (MPH)
更新于2025-09-23 15:21:01
-
An Improved Frequency Measurement Method from the Digital PLL Structure for Single-Phase Grid-Connected PV Applications
摘要： The Phase Locked Loop (PLL) technique has been studied to obtain the phase and frequency information in grid-connected distributed generations for the sake of synchronizing the grid voltage and the inverter output current. In particular, the line frequency information, such as the anti-islanding function, is very important for the grid connection requirement. This paper presents a novel frequency measurement method from the digital PLL control structure for single-phase grid-connected PV applications. The conventional PLL controller uses the phase information to calculate the frequency of PV inverter output voltage after every line cycle and has shown a relatively low accuracy. This paper uses the angular frequency to directly measure the frequency after every line cycle. To verify the validity of the proposed method compared with the conventional method, a simulation was conducted. According to the simulation results, the measurement error of the proposed method is 80 times lower than the conventional one.
关键词： phase locked loop,frequency measurement,photovoltaic generation,grid-connection,PV inverter
更新于2025-09-23 15:21:01
-
Dependence of the Optimization of the Front Grid Design in Passivated Emitter and Rear Contact c-Si Solar Cells on the Finger Width and the Aspect Ratio
摘要： In this research, modeling was performed to optimize the grid of the front surface of a solar cell with the passivated emitter and rear contact (PERC) structure by considering the recombination characteristics. The front surface recombination velocity can be reduced in two main ways. The first method is to reduce the emitter Auger recombination by lowering the surface doping concentration during emitter formation, and the second method is to reduce the recombination that occurs at the surface when the electrode and the silicon are in contact, which is called metal-induced recombination and is represented by J0.metal. Because J0.metal increases in proportion to the area of the front electrode, minimizing the finger width and number by optimizing the electrode design is important. Therefore, the front electrode grid should be designed considering the emitter characteristics, J0.metal, according to the number of fingers and the resistance. In this research, the front grid of the solar cell was optimized via modeling using equations to calculate the number of fingers and the resistance. According to the finger width, the number of busbars, the sheet resistance, the aspect ratio, and the number of fingers corresponding to the maximum efficiency were identified. As a result, this modeling enabled us to optimize the front grid to the desired conditions, and we found that an increase in the number of busbars plays an important role in improving the efficiency of solar cells. In addition, the efficiency change with increasing number of busbars can be seen to be affected by the width of the finger and the resolution of the printed finger rather than the aspect ratio.
关键词： Aspect ratio,Finger width,Resistance,Front grid optimization,Crystalline silicon solar cells
更新于2025-09-23 15:21:01
-
Macroscopic Nonuniformities in Metal Grids Formed by Cracked Film Lithography Result in 19.3%-Efficient Solar Cells
摘要： Cracked film lithography (CFL) is an emerging method for patterning transparent conductive metal grids. CFL can be vacuum- and Ag-free, and it forms more durable grids than nanowire approaches. In spite of CFL’s promising transmittance/grid sheet resistance/wire spacing tradeoffs, previous solar cell demonstrations have had relatively low performance. This work introduces macroscopic nonuniformities in the grids to improve the short-circuit current density/fill factor tradeoff in small area Cu(In,Ga)Se2 cells. The performance of optimized baseline grids is matched by CFL grids with microscopic openings and macroscopic patterns, culminating in a 19.3%-efficient cell. Simulations show that uniform CFL grids are enhanced by patterning because it leads to better balance among shadowing, grid resistance and transparent conductive oxide resistance losses. Thin-film module efficiency calculations are performed to highlight the performance gains that metal grids can enable by eliminating the transparent conductive oxide losses and widening monoliths. Adding the patterned CFL grids demonstrated in this work to CIGS modules is predicted to reach 0.7% higher efficiency (absolute) than screen-printed grids.
关键词： transparent conductive,solar cell,lithography,photovoltaics,metal grid
更新于2025-09-23 15:21:01
-
Harmonic detection method based on adaptive noise cancellation and its application in photovoltaic - active power filter system
摘要： The adaptive harmonic detection method based on the adaptive noise cancellation principle has the advantages of strong adaptability and good robustness. However, when the step size of the algorithm is selected, there is a conflict between the convergence speed and the steady-state accuracy. To solve this problem, this paper proposes an improved variable step size adaptive harmonic detection method. The algorithm uses the sliding integrator to find the feedback that can truly reflect the tracking situation, and substitutes it into the step size iteration formula based on L2 norm to achieve the step size adjustment. In order to further verify the superiority and practicability of the improved algorithm, the algorithm is applied to the photovoltaic-active power filter (PV-APF) system, and simulation verification is performed in MATLAB. The simulation results show that under the same simulation conditions, the convergence speed of the improved algorithm is half a cycle faster than that of the traditional method, and the steady-state error is smaller. In the application of PV-APF system, under normal light, the dual functions of grid-connected photovoltaic system and harmonic compensation are realized. The total harmonic distortion (THD) of the system is 2.09%, which effectively improves the power quality of photovoltaic system.
关键词： Photovoltaic grid-connected,Adaptive noise cancellation,Harmonic detection,Active power filter,Photovoltaic-active power filter system
更新于2025-09-23 15:21:01
-
Fabrication of large-scale freestanding THz wire grid polarizers by femtosecond laser micromachining
摘要： High-performance THz polarizers, as a quasi-optical device to manipulate THz waves, are highly demanded for THz spectroscopy and imaging applications. In this work, we have employed the femtosecond laser micro-machining technique to fabricate freestanding THz wire grid polarizers with two kinds of reinforced line structures which weaken the e?ects of gravity sagging and entanglement of long free wires, thus enabling large-scale processing. The e?ect of the reinforced lines on the polarizers were simulated by the Finite-Di?erence Time-Domain (FDTD) method, and the performances of the polarizer were characterized by THz time-domain spectroscopy and compared with that of a commercial wire gird polarizer. The calculated transmittance is in good agreement with the FDTD results. The degree of polarization and the extinction ratio of the polarizer with discontinuous reinforced lines are better than those of a commercial wire grid polarizer.
关键词： Time-domain THz spectroscopy,THz,Femtosecond laser micro-machining,Wire grid polarizer
更新于2025-09-23 15:21:01
-
Modeling of photovoltaic power uncertainties for impact analysis on generation scheduling and cost of an urban micro grid
摘要： In electrical systems, the main objective is to satisfy the load demand at the least cost without having imbalance between generation and consumption. Thus, the uncertainty of photovoltaic (PV) power production must be considered in generation planning of a power system. In this paper, we develop a modeling method of this uncertainty to consider it into the generation scheduling. The optimal generation scheduling in an urban microgrid is made by taking in consideration the operating reserve provision under stochastic characteristics of PV power prediction. By considering a prescribed risk level of unbalancing, a dynamic programming algorithm sets the operational planning of conventional generators by solving a non-convex mixed-integer nonlinear programming model, so that the operational cost and available operating reserve can be calculated. Then, the effect of PV power uncertainty into the unit commitment is analyzed by considering PV forecast intervals with a 95 % confidence level. The unit commitment is then recalculated with new generator set points and the same criteria. Finally, variations of the targeted minimized costs and obtained OR is analyzed according to the uncertainty.
关键词： Dynamic programming,Micro grid,Uncertainty,Unit commitment,Operating reserve
更新于2025-09-23 15:21:01
-
Solar Power Plant Grid Interactive and Building Integration Photovoltaic
摘要： With the development of technology, the need for electricity is increasing. In terms of Indonesia's topology, the Solar Power Plant is most suitable for use in rural (remote) areas, known as the Solar Home System (SHS). This system is preferred because it is small in scale and uses a direct current (DC) system. This system can reduce costs because it does not use an inverter. But the weakness of this system is the difficulty of finding home electronic equipment such as TV, Radio / Tape and others that use DC, so the SHS system is not attractive to use. PLTS connected to PLN's electricity network, Interactive Grid, BIPV (Building Integration PV) is a hybrid application between the electricity network (PLN) and PLTS that are already widely used. Thus, PV-Genset Hybrids can reduce the inefficiency of operations and maintenance and reduce large initial investment costs
关键词： grid,interactive,photovoltaic,integration
更新于2025-09-23 15:21:01