grid connected PV inverters Research Papers (original) (raw)

A training Report on Two weeks training program on Solar Rooftop Grid Engineer Course.
Report contains major outcomes of course also experience of author.

Plug and play solar photovoltaic (PV) systems are affordable, easy to install and portable grid-tied solar electric systems, which can be purchased and installed by an average prosumer (producing consumer). The combination of recent technical/safety analysis and trends in other advanced industrialized nations, indicate that U.S. electrical regulations may allow plug and play solar in the future. Such a shift in regulations could radically alter the current PV market. This study provides an estimate of this new U.S. market for plug and play PV systems if such regulations are updated by investigating personal financial decision making for Americans. The potential savings for the prosumer are mapped for the U.S. over a range of scenarios. The results show the total potential U.S. market of over 57 GW, which represents an opportunity for sales for retailers from 14.3–14.3–14.3–71.7 billion depending on the capital cost of plug and play solar systems ($0.25-$1.25/W). These systems would generate ∼108,417,000 MWh/year, which is 4 times the electricity generated from U.S. solar in 2015. This distributed solar energy would provide prosumers approximately $13 billion/year in cost savings, which would be expected to increase by about 3% per year over the year lifetime of the systems.

- by Joshua Pearce and +1
- •
- Electrical Engineering, Photovoltaics, Renewable Energy, Energy

Solar power technology is developing rapidly in Vietnam and investors are interested in developing the solar power plant. Comparison of the choice of grid-tie inverter technology between central inverter and string inverter can affect the change of investment cost, operation and maintenance costs, and operation efficiency of solar power plants in the real condition. However, most of solar power plants in Vietnam are currently in the design stage, so experience in selection of technology, design, construction, and operation of solar power plants in general and the inverter is very limited. In this study, the advantages and disadvantages of grid-tied inverter technology for solar power plants in Vietnam are analyzed. Besides, the research results using the PVSYST program showed that generated electricity and the performance of a typical solar power plant in Vietnam using string inverter would be slightly higher than the case of using central inverter.

- by Le Hang
- •
- Solar Power, grid connected PV inverters, Solar PV, Solar Inverter

This paper describes a granular approach for investigating
the impacts of very high photovoltaic (PV) generation penetration.
Studies on two real-world distribution feeders connected
to PV plants are presented. The studies include both steady-state
and time-series power flow analyses, which include the effects of
solar variability. The goal of the study is to predict the effects of increasing
levels of PV generation as it reaches very high penetration
levels. The loss and return of generation with and without regulation
is simulated to capture short-term problems such as voltage
fluctuations. Impact results from the analyses are described along
with potential mitigations

- by Danling Cheng and +2
- •
- Photovoltaics, Power System, Electric Power Systems, grid connected PV inverters

This paper provides a smart photovoltaic (PV) inverter control strategy. The proposed controllers are the PV-side controller to track the maximum power output of the PV array and the grid-side controller to control the active and reactive power delivered to the electric grid through the inverter. A Volt-VAR regulator is proposed for controlling the reactive power exchange with the grid according to the voltage at the point of common coupling (PCC). The gains of the proposed proportional-integral (PI) controllers are optimized using a genetic algorithm (GA) via adaptive online tuning. The control methodology is then tested to a 33-bus radial distribution network under MATLAB/SimPowerSystem environment to prove the validity of the proposed control methodology and to analyze the interactions between the PV-based distributed generation (DG) and the power network. The optimal control of PV inverters demonstrated that the optimized Volt-VAR control strategy is both efficient and effective. The optimization of the PI controller parameters resulted in a good dynamic response under varying climatic conditions. The proposed control method enables the most efficient utilization of PV-DG systems by extracting maximum power and contributing to grid voltage support.

- by Girish Gowd Talapur
- •
- grid connected PV inverters

PV inverters have been tested according the procedure defined in the EN 50530 standard-overall efficiency of grid connected photovoltaic inverters. Maximum power point tracking efficiency, static and dynamic, power electrical conversion and overall efficiencies are measured. Results for two models of microinverters and for one string inverter for comparison purposes are presented in this work.

An obvious device for the utilization of renewable energy sources is inverter and Pulse Width Modulation technique is widely used method for voltage source inverters. This paper deals with the generation of PWM signals by analog circuit, where the comparison of sine wave and sawtooth wave for the operation of power circuit takes place. The above mentioned technique is studied and verified by Simulating the circuit. The prototype of PWM based, single phase, full bridge inverter is developed and the results are verified for the nominal voltage and frequency with the help of simulation and hardware is designed.

Dans cet article, nous allons définir
un modèle simple et applicable aux cellules photovoltaïques. L’objectif est de trouver un modèle simple et adaptable avec différents modules des constructeurs. Ce modèle doit être modélisé de telle façon que tous les paramètres sont facilement calculés et en évitant le plus possible les équations complexes. Pour développer un circuit équivalent précis pour une cellule PV, il est nécessaire de comprendre la configuration physique des éléments de la cellule aussi bien que les caractéristiques électriques de chaque élément. Selon cette philosophie plusieurs modèles électriques dans la littérature ont été développés, dont le but est l’obtention d’une caractéristique I(V) plus performante et pratique. Ces modèles sont différents entre eux par la procédure et le nombre de paramètres pris en compte.

- by Reda Merahi
- •
- grid connected PV inverters, Photovoltaic Power Systems

— A DC-DC converter is an important constituent of a photovoltaic(PV) power system. Power generated by the PV system is a function of solar insolation, and temperature. Power-voltage (P-V) characteristic of a PV module exhibits a single power peak. A maximum power point tracking algorithm is required to operate the PV array at its maximum power point. The DC-DC converter works as an impedance matching circuit in between the PV array and load. A suitable selection of DC-DC converter is an important decision according to the application. In this study, a comparative analysis of different DC-DC converter is discussed in terms of efficiency, computational time, and complexity. A widely adopted Incremental conductance (INC) MPPT algorithm is used to evaluate the performance of each DC-DC converter. Performance of each converter in MPPT application is simulated using MATLAB/SIMULINK

- by Tadiparthi Ramki
- •
- grid connected PV inverters

Bài báo phân tích động học và đưa ra phương pháp điều khiển số cho mạch vòng khóa pha với kỹ thuật bắt điểm không ứng dụng cho điều khiển nối lưới hệ thống điện mặt trời. Trên cơ sở nghiên cứu đó, bài báo đưa ra một mô hình thực nghiệm được nhóm tác giả thiết kế. Mô hình được kiểm chứng qua các kết quả đo và cho thấy hệ thống đã đạt được các yêu cầu điều khiển đặt ra.

- by Phung Quangkhai
- •
- grid connected PV inverters

L’utilisation des énergies renouvelables connaît une croissance significative dans le monde. Devant la demande croissante d’énergie électrique.
On abordera dans cet article l'optimisation de la production d’un GPV par différant techniques MPPT.
Divers point maximum de puissance (MPPT) basées sur
le nombre de sondes exigées, la vitesse de la convergence, la capacité d'exécuter dans des conditions bruyantes et ambiant variables a été simulées et discutées.
Amélioration de La stabilité du point maximal par
contrôleur floue a été décrite.

The prospective spread of Electric vehicles (EV)
and plug-in hybrid electric vehicles arises the need for fast
charging rates. High required charging rates lead to high power
demands, which may not be supported by the grid. In this paper,
an optimal power flow technique of a PV-battery powered fast
EV charging station is presented to minimize the operation cost.
The objective is to help the penetration of PV-battery systems
into the grid to support the growing need for fast charging of
EVs. An optimization problem is formulated along with the
required constraints and the operating cost function is chosen as
a combination of electricity grid prices and the battery
degradation cost. In the first stage of the proposed optimization
procedure, an offline particle swarm optimization (PSO) is
performed as a prediction layer. In the second stage, dynamic
programming (DP) is performed as an online reactive
management layer. Forecasted system data is utilized in both
stages to find the optimal solution for the power management. In
the reactive management layer, the outputs of the PSO are used
to limit the available state trajectories used in the DP and,
accordingly, improve the system computation time and
efficiency. Online error compensation is implemented into the DP
and fed back to the prediction layer for necessary prediction
adjustments. Simulation and experimental results are
successfully implemented to validate the effectiveness of the
proposed management system.

- by Mohamed Badawy
- •
- Electric Vehicles, Solar Energy, grid connected PV inverters, Optimal Power Flow

The book is organized through seven chapters. The first chapter is intended as an introduction to the subject. It defines the photovoltaic process, introduces the main meteorological elements, the solar irradiance and presents an overview of PV systems (stand alone systems and grid connected systems). This chapter also includes pre-sizing and maintenance of PV systems.
Chapter 2 focuses on an explicit modeling of solar irradiance and cells. Different models describing the operation and the behavior of the photovoltaic generator are presented. Some programs are given under MATLABTM/SIMULINKTM.
Chapter 3 is devoted to power electronics modeling. The different structures of converters used in PV systems are presented.
In Chap. 4, a detailed review on the most used algorithms to track the maximum power point is presented. Some simple MATLABTM/SIMULINKTM examples aregiven.
In Chap. 5, a description and modeling of the storage device is showed. The study describes a usual battery bank and provides an explicit modeling and experimental scheme of the lead-acid battery.
Chapter 6 fulfils these tasks for a photovoltaic pumping system based on both DC and AC machines. Each component is modeled individually before connecting subsystems for simulation. Several control algorithms such as scalar, vector and direct torque control are well described. In addition, classic optimization algorithms are applied and an analysis of economic feasibility of PV pumping system in comparison with systems using diesel generators is presented. This chapter includes also environmental aspects of PV power pumping system.
The Chap. 7 is devoted to hybrid photovoltaic systems. The chapter describes the different configurations and the different combinations of hybrid PV systems.
Different synoptic schemes and simulation applications are also presented.

- by Anass Ait Laachir
- •
- Photovoltaics, Fuzzy Logic, Renewable Energy Systems, Electric Power Systems

The stability of dc and ac bus voltage is of the most important issues in all microgrids including ac, dc or ac/dc hybrid microgrids. In this paper, a hybrid ac/dc microgrid is proposed to reduce processes of multiple reverse conversions in an ac or dc microgrid and to facilitate the connection of various renewable ac and dc sources and loads to power system. Also, all control schemes used among all converters are developed in order to improve the voltage stability of the dc grid. Results are achieved considering the uncertainty of the generators and loads existed in microgrid verifying the robustness of the controllers to restore and stabilize quickly the voltage of the dc grid.

The concept of feeding photovoltaic power to the grid has gained widespread acceptance in these days of renewable energy generation and distribution. In this work, all areas including standards and specifications of single-phase and three-phase grid-connected inverter, classification of inverter types, historical overview of inverter technologies, classifications of inverter topologies are to be covered. The information will include details not only on the topologies commercially available but also on the switching devices employed and the associated switching frequencies, efficiency etc. Also advantages & Disadvantages of various topologies are to be included in the thesis. Finally being an M.Tech student of Renewable Energy Science & Technology, I am going to do my Master degree project on Study of Power conditioning Unit of Photovoltaic Power System & so this paper is being submitted as my Term Paper. This paper includes different types of solar PV system, standards, and specifications of single-phase grid-tied PV inverter, single-phase grid-tied PV inverter topologies, and development of various types of single-phase grid-tied PV inverters

The following research proposal is presented as a technological solution focused on the design of a current controller for a grid-connected photovoltaic (PV) inverter. In order to achieve a suitable grid-connection, it is required a filter interface between the voltage source inverter (VSI) and the electrical grid. In the earlier times, the interface was composed of a single inductor. A single inductor filter (L filter) has the disadvantage of not fully eliminating switching harmonics. To overcome this issue, LCL filters have gained preference over L filters. Systems based on LCL filters produce less switching harmonics and have reduced size inductors. However, LCL filters present an undesired resonance, and are more sensitive to electric grid harmonics. Due to these drawbacks, it is necessary to design more sophisticated controllers to guarantee stability and good performance. Generally, the knowledge of the state variables in the LCL filter is required to solve the instability problem associated to the overall system. Nevertheless, measurement of all state variables is an expensive solution because of the quantity of required sensors. In this paper it is proposed a current controller based on a reduced-order observer to reduce the number of measured state variables.

- by Josue Alonzo
- •
- Photovoltaics, Solar Energy, grid connected PV inverters, Solar PV

This paper presents a new islanding detection strategy for low-voltage (LV) inverter-interfaced microgrids based on adaptive neuro-fuzzy inference system (ANFIS). The proposed islanding detection method exploits the pattern recognition capability of ANFIS and its nonlinear mapping of relation between inputs. The ANFIS monitors seven inputs measured at point of common coupling (PCC), namely root-mean square (RMS) of voltage and current (RMSU and RMSI), total harmonic distortion (THD) of voltage and current (THDU and THDI), frequency (f), and also active and reactive powers (P, Q) that are experimentally obtained based on practical measurement in a real-life microgrid. The proposed method is composed of passive monitoring of the mentioned inputs and therefore, does not influence power quality (PQ); but considerably decreases non detection zones (NDZs). In order to cover as much situations as possible, minimizing false tripping and still remaining selective, type and number of samples are introduced. Here, one of the main goals is reducing NDZ by still keeping PQ in order. Based on the sampled frequency and number of samples, we find that the proposed method has less detection time and better accuracy, compared to the reported methods. Simulations performed in MATLAB/Simulink software environment and several tests performed based on different active load conditions and multiple distributed generation (DG)s, prove the effectiveness, authenticity, selectivity, accuracy and precision of the proposed method with allowable impact on PQ according to UL1741 standard.

- by Srete Nikolovski and +1
- •
- Renewable energy resources, grid connected PV inverters, ANFIS Etc.), Islanding Detection

While substantial research covers current control and synchronization of grid-connected photovoltaic (PV) inverters, issues concerning control of the PV input voltage deserve more attention, as they equally affect the reliable and stable operation of the system. Hence, this paper analyses the PV voltage regulation in the single-stage single-phase PV inverter. In contrast to previous work, the PV source influence on the input voltage dynamic is analytically formalized, exposing a potential instability when the PV source is operating in its constant current region. A traditional proportional-integral PV voltage controller fails to ensure a consistent and stable voltage regulation. On the other hand, this issue is resolved by the proposed feedback linearization based controller. The new controller is validated on a test setup comprising of a PV source emulating a 1.2 kW PV array, interfaced to a single-phase inverter connected to a grid emulator. Confirming the issues predicted by the theoretical analysis, the experiments subsequently prove two main advantages of the proposed controller. Firstly, PV voltage regulation instability is eliminated when the PV array operates in its constant current region. Secondly, the PV voltage transient behavior is now independent from the operating point of the PV source.

Electrical energy consumption has been increasing in recent years and the technology moves towards On-Site power generation for mainly to reducing the transmission losses and gaining some benefits such as high reliability, modularity, high power quality. But unfortunately due to uncontrolled use of individual DG units can cause various problems thereby compromising their benefits. To improve performance the micro grids in integrated with main grid or standalone operations by using an efficient controllers and with high efficient converters/inverters. The paper introduces a residential micro grid with a new topology. These paper proposes i) a DC-DC converter along with regenerative clamping circuit, ii) Constant current controller for grid integrated power generation, iii) Constant voltage current controller standalone DG units. The residential grid performance is evaluated under grid connected and islanding conditions and performance is evaluated by using MATLAB tool.

A shortage of energy reserves in power electronic based (active) microgrids (distributed generation) is not able to accommodate the load dynamics and is a major cause for the frequency stability problem. The work proposed in this paper aims to efficiently stabilize the frequency of grid feeding active distributed generators (GF-ADG) by controlling the stored energy in the dc link capacitor. In particular, an active damping control method is proposed to help GF-ADG to withstand larger power disturbances. The proposed method increases the stability margins by reducing frequency overshoot and improves the frequency profile when the system interfaces a weak grid. The method uses enhanced capabilities of dc link synthetic inertia controlled by the instantaneous energy mismatch between the supply and the load. The proposed method is verified with the simulation results developed for a PV connected microgrid system.

- by Salman Harasis
- •
- Microgrid, grid connected PV inverters

The photovoltaic panel not only generates low DC voltage but also DC voltage which varies with time and environmental condition. Therefore design of electrical energy system with constant output voltage is a big challenge to designer. This project deals with the development of electrical energy system which consists of Z-source based high step up chopper. The chopper is basically based on coupled inductor which provides high voltage gain and physical isolation between input and output with small turn ratio. It also provides a low voltage stress on active components and small conduction losses due to low duty cycle. Due to the usage of a single switch, the control circuitry is less complex. The proposed chopper recycles the energy of leakage inductance hence enhancing system efficiency. This report consists of mathematical modelling and designing of proposed chopper circuit. The MATLAB simulation of proposed chopper circuit is to convert 25 volts dc to 400 volts dc with 300 watts power. The simulation results validate the theoretical results. The H-Bridge inverter circuit is used at the end of proposed chopper for converting DC voltage into AC voltage.

— This paper describes the design and evaluation of high current toroidal Printed Circuit Board (PCB) embedded inductor applicable for high frequency DC/AC converters (lower than 10MHz). The equivalent circuit model of the inductor is presented and the filtering effectiveness is verified by testing three different geometries with its own characteristics and function through a GaN converter. Besides, the temperature rise analysis is provided for all the prototypes by using finite element methods, and the obtained results are also verified by experiments. The reason behind asymmetric trend of temperature rise for the toroidal PCB embedded inductor is also discussed through both simulation and experiment, and the capability of using a heat sink to lower the temperature increment for different geometries is explained. Keywords— air-core PCB embedded inductor; temperature rise analysis; high frequency; GaN

- by Mehrdad Biglarbegian
- •
- Power Electronics, PCB Design, High Frequency, Wide Band-gap Semiconductor

Sizing of PV panel, wind turbine and storage batteries in hybrid energy systems is the most important research topic for a system design. There are many studies in the literature, using different approaches about sizing of hybrid renewable energy systems. In this study, experimental and simulation performance differences of the installed hybrid system are presented. The system that is installed in Yildiz Technical University, has 600 W wind turbine, 2x320 W photovoltaic (PV) panel group and 4x210 Ah batteries. A maximum power point tracking (MPPT) controller, a hybrid controller and an inverter are utilized to control the panels, wind turbine and power flow. A weather station is used to measure the weather conditions such as wind speed, temperature, radiation, and electrical quantities are recorded by a data logger. The system is modelled depending on the datasheets of the components, and the modelling results are compared with experimental results.

This paper presents a grid connected multilevel topology for photovoltaic (PV) systems. Usually, multilevel converters for PV application suffer from a distorted output current and voltage when the submodules are not subjected to an even solar irradiance. The difference in submodules irradiance results in different submodules duty cycles when maintaining the maximum power point tracking (MPPT). The distortion of the output current is proportional with the difference of the cells duty cycles. To this regard, a multilevel topology for PV applications is proposed along with a control and modulation strategy. In this proposed topology, H6 bridge-based cell is used instead of an H-bridge one. In case of solar irradiance mismatch, the proposed converter injects power with less voltage from the shaded cells without altering the PV voltage, and hence, the MPPT. This modification allows retaining a tantamount duty cycle in all cells whatever the meteorological conditions are present. To test the effectiveness of the proposed idea, a detailed simulation model was set up. The results show that the proposed concept provides a significantly improved output current quality compared to the cascaded H-bridge topology.

— This paper proposes an integrated common and differential mode filter with passive damping for single-phase grid-connected transformerless photovoltaic (PV) microinverters, employing the full-bridge voltage source inverter (VSI) topology with continuous unipolar modulation. This strategy achieves low current distortion, low leakage current and high efficiency. A design procedure for the proposed filter is presented including the passive damping components. The effectiveness of the proposed solution is confirmed by simulation and experimental results. Additionally, discussions about safety standards, analysis of leakage current production mechanism and some common mode (CM) filter implementations found in the literature are presented.

- by ricardo souza
- •
- Power Electronics, grid connected PV inverters

In this paper the issue of control strategies for single-stage photovoltaic (PV) inverter is addressed. Two different current controllers (the classical proportional-integral (PI) and the novel proportional-resonant (PR) controllers) have been implemented and an experimental comparison between them has been made. A complete control structure for the single- phase PV system is also presented. The superiority of the PR controller is demonstrated with respect to the PI controller in terms of harmonic current rejection and the capability to remove the steady-state error without using the voltage feed-forward (VFF). The control strategy was successfully tested on a real 1.5 kW PV inverter.

—With increasing levels of small-scale distributed generation (DG) systems connecting into the electrical grid, there is a growing awareness of potentially adverse interactions between these systems and the grid because of their differing responses to steady state and transient network events. To study these issues, it is important to use simulation models of both the grid network and the DG inverter systems that are sufficiently detailed to realistically represent their real world physical system behaviours. However, inverter systems are usually simulated in detail using specialist packages, which are not particularly suited to modelling larger scale power systems. Similarly, power system simulation packages typically represent inverter systems using simpler averaged models, which do not adequately reflect the inverter's real dynamic response to transient events. This paper addresses this issue, by presenting a detailed power inverter model developed within the DigSILENT power network simulation package, which is sufficiently detailed to represent the inverter operation up to the PWM switching frequency, but is still computationally viable for use with larger scale system studies.

- by Suwicha Sokul
- •
- grid connected PV inverters

This paper presents new alternatives of design and control for three-phase grid connected photovoltaic systems GCPS. In this work, the photovoltaic generation source PVG is connected to the main electric grid via two power electronics stages. The first stage consists on a buck-boost dc-dc converter that insures impedance adaptation between the PVG and the grid. This converter is controlled by the sliding mode control SMC to track the dc reference voltage required by the main grid. The second stage is composed by a dc-bus and a three-phase voltage inverter used to interface the PVG with the grid utility. The inverter is controlled by the Direct Power Control DPC in order to inject the PV power into the main grid with a high quality power factor. The model of the GCPS has been implemented in the Matlab/Simulink software and simulation studies have been presented to demonstrate the effectiveness of the proposed study.

- by S.m. Ferdous
- •
- grid connected PV inverters

The coordination of charging and discharging between plugged electric vehicles and main electrical grid/microgrid is very important to maintain good performance from both vehicle and grid side. As of now several controllers are proposed for energy management between grid/microgrid and electric vehicles. In this paper, presenting an aggregator based controller which is helpful for better energy management in the charging and discharging mode of electric vehicle in coordination with charging technologies. The proposed controller is having the technical capability of load assessment, optimal charging/discharging capability, load shedding, and demand side management. The proposed controller is feasible to solve the charging/discharging issues with EV’s and energy management issues with the main grid. This controller also helpful to improve the overall system performance with the help of bidirectional converter and reduce the overloading on the system improves power quality and reduces power loss of the system.

- by IAEME Publication
- •
- Power Quality, Electric Vehicles, grid connected PV inverters, Aggregator

Grid-connected photovoltaic (PV) inverter technology has advanced since it first attracted the attention of policy makers. The objective of this article is to present a survey of grid-connected PV inverters and their present technology in Malaysia. Surveyed here are 186 PV inverter products from 22 manufacturers, their power factors, system THDs, efficiencies, power inputs (from PV array), costs, sizes, and protections investigated, and their datasheets collected from various manufacturers in Europe, North America, and Asia. The data are compared within regions and subject headings. Discussed are the lowering of cost, the raising of efficiency levels, and reliability improvement.

The demand of energy increases as the civilization increase around the world on the same ratio. As compared to load demand the generation of electrical power is very less because of limited available of resources. The problem arises when potency of them is far smaller than load demand and the high difference between wind velocity profile and solar radiant intensity and load profile is happened. Its make excess electricity to be higher so the electrical production cost to be higher too. The purpose of this research is designing optimal configuration of microgrid PV-Wind turbine-Grid-Battery through optimization of load capacity to reduce excess electricity. Hybrid system are environmental friendly and can be installed at remote location were the supply of electrical power through grid is difficult. In this paper we have proposed a hybrid system cost analysis which has wind turbine generation, solar system, and storage battery system and diesel generator. We use an efficient optimization tool HOMER for obtain the optimal cost of the hybrid plant. The main aim of this paper is to find out the optimal cost of the hybrid plant in such a way to fulfill the load demand and minimized the cost.

- by Gorakh Mishra
- •
- Homer, Renewable Energy, Wind Energy, grid connected PV inverters
- by Prof. Dr. Saad Mekhilef
- •
- Engineering, Power Electronics, Topology, Electric motor drives

Solar power industry in the country is growing rapidly. As of last month (September 2017), the country’s aggregate solar capacity is 16.20 GW. The country increased its solar power production capability to about fourfold from 2650 MW in the month of May 2014 to 12,289 MW in the month of March 2017. The paper aims to offer tools along with strategy so as to ascertain that solar PV power systems are correctly specified and installed, giving an efficient arrangement which works to its rated capacity. The paper addresses solar PV systems set up on rooftop that are interconnected to grid. Statistical data studies reveal that about 10–20% of recently set-up solar PV systems have major drawbacks in installation which has led to performance deterioration, significantly reducing output. Proper sizing and orientation of the solar PV panel to obtain maximum electrical power and energy output are important. Poor public opinions resulting from improperly installed solar PV system will adversely ...

- by Sheeba Babu
- •
- Renewable Energy, grid connected PV inverters, solar PV power plants, Net Metering

Microgrid is cluster of distributed generation sources, storage systems and controllable loads. Microgrid can provide quality and reliable supply of energy to consumer. Microgrid can operate in both modes of operations that is grid connected mode and islanded mode. This implementation poses technical challenge of protecting the micro grid. Power quality, energy management, stability, power flow control, protection system and integration of various distributed generators are the major issues in the microgrid operation. This paper reviews various protection issues in micro grid, various protection schemes to overcome the protection issues are also discussed. Implementation of adaptive protection system using digital relaying and advanced communication is most successful method of the protection of micro grid.

—This research paper presents the reasons for most inverter project failures. Most of the projects which are based on inverter hardware design are failed due to switching spikes and malfunction of IGBT/MOSETs. Not only in demonstration but also in testing level, those inverter circuits burned out or malfunction. This research project is carried out to identify and mitigate the problems in an inverter circuit due to switching spikes and malfunctioning of IGBT/MOSFETs.

Bu makalede, fotovoltaik (PV) panel, DC/DC
dönüştürücüler, Maksimum Güç Noktası Takibi (MPPT),
lityum-iyon akü ve PID kontrolcüler içeren ve çıkışta sabit bir
DC gerilim elde etmek amacı güden bir fotovoltaik sistemin
tasarımı ve simülasyonu üzerinde durulmaktadır. İlk olarak
genel sistem modellenmiş ve bu tür sistemlerin simülasyonu
için geliştirilmiş MATLAB/Simulink-SimPowerSystems aracı
ile benzetimleri gerçekleştirilmiştir. MATLAB programında
yaygın olarak kullanılan standart doğrusallaştırma yöntemleri,
bu şekilde doğrusal olmayan bir sisteme yönelik kontrolcü
tasarımında yeterli değildir. Çünkü sistemde DC/DC
dönüştürücülerin anahtarlaması için PWM sinyalleri
kullanılmakta ve bu da MATLAB tarafından
doğrusallaştırılamayan bir yapı oluşturmaktadır. Bu nedenle
sistem giriş/çıkışlarının simüle edilmesine dayalı alternatif bir
yöntem kullanılmıştır. Tasarlanan PV sistemi, değişken
sıcaklık ve ışınım düzeyleri ile simüle edilmiş, sistem
performansı ve verimliliği değerlendirilmiş ve tasarlanan
kontrolcülerin farklı atmosferik koşullarda maksimum güç
noktasında PV panelini çalıştırma, sabit bir çıkış DC gerilimi
sağlama ve panelin ürettiği ve yükten arta kalan güçle aküyü
şarj etme konusunda yeterli olduğu görülmüştür.