scholarly journals Influence of Parasitic Parameters on DC–DC Converters and Their Method of Suppression in High Frequency Link 35 kV PV Systems

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3743
Author(s):  
Rui Li ◽  
Fangyuan Shi ◽  
Xu Cai ◽  
Haibo Xu
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
Pv System ◽  
Zero Voltage Switching ◽  
Pv Systems ◽  
Magnetic Inductance ◽  
Parasitic Parameters ◽  
Saturable Inductor ◽  
Secondary Side ◽  
Pv Power Generation

Photovoltaic (PV) power generation has shown a trend towards large-scale medium- or high-voltage integration in recent years. The development of high-frequency link PV systems is necessary for the further improvement of system efficiency and the reduction of system cost. In the system, high-frequency high-step-up ratio LLC converters are one of the most important parts. However, the parasitic parameters of devices lead to a loss of zero-voltage switching (ZVS) in the LLC converter, greatly reducing the efficiency of the system, especially in such a high-frequency application. In this paper, a high-frequency link 35 kV PV system is presented. To suppress the influences of parasitic parameters in the LLC converter in the 35 kV PV system, the influence of parasitic parameters on ZVS is analyzed and expounded. Then, a suppression method is proposed to promote the realization of ZVS. This method adds a saturable inductor on the secondary side to achieve ZVS. The saturable inductor can effectively prevent the parasitic elements of the secondary side from participating in the resonance of the primary side. The experimental results show that this method achieves a higher efficiency than the traditional method by reducing the magnetic inductance.

scholarly journals Deep Learning with Loss Ensembles for Solar Power Prediction in Smart Cities

Smart Cities ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 842-852
Author(s):  
Moein Hajiabadi ◽  
Mahdi Farhadi ◽  
Vahide Babaiyan ◽  
Abouzar Estebsari
Keyword(s):  
Power Generation ◽  
Deep Learning ◽  
Large Scale ◽  
Smart Cities ◽  
Energy Generation ◽  
Loss Functions ◽  
Support Vector ◽  
Pv System ◽  
Pv Systems ◽  
Pv Power Generation

The demand for renewable energy generation, especially photovoltaic (PV) power generation, has been growing over the past few years. However, the amount of generated energy by PV systems is highly dependent on weather conditions. Therefore, accurate forecasting of generated PV power is of importance for large-scale deployment of PV systems. Recently, machine learning (ML) methods have been widely used for PV power generation forecasting. A variety of these techniques, including artificial neural networks (ANNs), ridge regression, K-nearest neighbour (kNN) regression, decision trees, support vector regressions (SVRs) have been applied for this purpose and achieved good performance. In this paper, we briefly review the most recent ML techniques for PV energy generation forecasting and propose a new regression technique to automatically predict a PV system’s output based on historical input parameters. More specifically, the proposed loss function is a combination of three well-known loss functions: Correntropy, Absolute and Square Loss which encourages robustness and generalization jointly. We then integrate the proposed objective function into a Deep Learning model to predict a PV system’s output. By doing so, both the coefficients of loss functions and weight parameters of the ANN are learned jointly via back propagation. We investigate the effectiveness of the proposed method through comprehensive experiments on real data recorded by a real PV system. The experimental results confirm that our method outperforms the state-of-the-art ML methods for PV energy generation forecasting.

scholarly journals Analysis and Design of a Multi-Port DC-DC Converter for Interfacing PV Systems

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1943
Author(s):  
Bader N. Alajmi ◽  
Mostafa I. Marei ◽  
Ibrahim Abdelsalam ◽  
Mohamed F. AlHajri
Keyword(s):  
High Frequency ◽  
Computer Aided Design ◽  
Electromagnetic Transients ◽  
Pv System ◽  
Analysis And Design ◽  
Pv Systems ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
Aided Design

A high-frequency multi-port (HFMP) direct current (DC) to DC converter is presented. The proposed HFMP is utilized to interface a photovoltaic (PV) system. The presented HFMP is compact and can perform maximum power point tracking. It consists of a high-frequency transformer with many identical input windings and one output winding. Each input winding is connected to a PV module through an H-bridge inverter, and the maximum PV power is tracked using the perturb and observe (P&O) technique. The output winding is connected to a DC bus through a rectifier. The detailed analysis and operation of the proposed HFMP DC-DC converter are presented. Extensive numerical simulations are conducted, using power system computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) software, to evaluate the operation and dynamic behavior of the proposed PV interfacing scheme. In addition, an experimental setup is built to verify the performance of the HFMP DC-DC converter.

scholarly journals Large Photovoltaic Power Plants Integration: A Review of Challenges and Solutions

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3798 ◽  
Author(s):  
Mansouri ◽  
Lashab ◽  
Sera ◽  
Guerrero ◽  
Cherif
Keyword(s):  
System Integration ◽  
Power Plants ◽  
Large Scale ◽  
System Stability ◽  
Pv System ◽  
Pv Systems ◽  
Large Scale Integration ◽  
Voltage Limit ◽  
The Stability ◽  
Scale Integration

Renewable energy systems (RESs), such as photovoltaic (PV) systems, are providing increasingly larger shares of power generation. PV systems are the fastest growing generation technology today with almost ~30% increase since 2015 reaching 509.3 GWp worldwide capacity by the end of 2018 and predicted to reach 1000 GWp by 2022. Due to the fluctuating and intermittent nature of PV systems, their large-scale integration into the grid poses momentous challenges. This paper provides a review of the technical challenges, such as frequency disturbances and voltage limit violation, related to the stability issues due to the large-scale and intensive PV system penetration into the power network. Possible solutions that mitigate the effect of large-scale PV system integration on the grid are also reviewed. Finally, power system stability when faults occur are outlined as well as their respective achievable solutions.

scholarly journals The Technical Challenges Facing the Integration of Small-Scale and Large-scale PV Systems into the Grid: A Critical Review

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1443 ◽  
Author(s):  
Abdullah Alshahrani ◽  
Siddig Omer ◽  
Yuehong Su ◽  
Elamin Mohamed ◽  
Saleh Alotaibi
Keyword(s):  
Large Scale ◽  
Distribution Network ◽  
Small Scale ◽  
Energy Access ◽  
Solar Pv ◽  
Pv System ◽  
Pv Systems ◽  
Technical Challenges ◽  
Technical Solutions ◽  
The Impact

Decarbonisation, energy security and expanding energy access are the main driving forces behind the worldwide increasing attention in renewable energy. This paper focuses on the solar photovoltaic (PV) technology because, currently, it has the most attention in the energy sector due to the sharp drop in the solar PV system cost, which was one of the main barriers of PV large-scale deployment. Firstly, this paper extensively reviews the technical challenges, potential technical solutions and the research carried out in integrating high shares of small-scale PV systems into the distribution network of the grid in order to give a clearer picture of the impact since most of the PV systems installations were at small scales and connected into the distribution network. The paper reviews the localised technical challenges, grid stability challenges and technical solutions on integrating large-scale PV systems into the transmission network of the grid. In addition, the current practices for managing the variability of large-scale PV systems by the grid operators are discussed. Finally, this paper concludes by summarising the critical technical aspects facing the integration of the PV system depending on their size into the grid, in which it provides a strong point of reference and a useful framework for the researchers planning to exploit this field further on.

scholarly journals ANN Fed High Gain Luo Converter based Reduced Switch Multilevel Inverter for Single Phase Network Bridged PV Arrangement

2019 ◽  
Vol 9 (2S4) ◽  
pp. 604-610
Keyword(s):  
High Frequency ◽  
Single Phase ◽  
Closed Loop ◽  
High Gain ◽  
Maximum Energy ◽  
Multilevel Inverter ◽  
Solar Irradiation ◽  
Pv System ◽  
Pv Systems ◽  
Grid Synchronization

In the present scenario photovoltaic (PV) systems feature resonant interest in the recent researches. The amount from the PV frame is highly oscillated due to temperature variation. In this proposed work, the ANN based MPPT algorithm extracts maximum energy from the PV system by benefit of high gain DC-DC Luo converter, the Luo converter produced voltage is given to the single phase grid through reduced switch seven level inverter. The proposed seven level inverter is controlled by high frequency technique multicarrier modulation technique. The PI controller based closed loop grid synchronization is implemented for solving the power quality issues. The multilevel inverter reduce the total harmonics distortion in the output AC voltage waveform. The developed work is carried out using Matlab software-based simulation with various solar irradiation and degree. Keywords: Artificial Neural Network

Stability Analysis of Grid-Connected Photovoltaic Systems

2012 ◽  
pp. 254-270
Author(s):  
M. A. Mahmud ◽  
M. Jahangir Hossain ◽  
H. R. Pota
Keyword(s):  
Feedback Linearization ◽  
Single Phase ◽  
Pv System ◽  
Maximum Power Point ◽  
Linearization Technique ◽  
Pv Systems ◽  
Current Controller ◽  
Power Point ◽  
The Stability ◽  
Pv Power Generation

This chapter presents an overview Photovoltaic (PV) power generation and integration of PV systems with power grid. This chapter also presents a Feedback Linearizing Current Controller (FBLCC) to synchronize the PV system with the grid. This controller is designed based on the feedback linearization technique. The reference current for the controller is generated from the Maximum Power Point Tracker (MPPT). The stability of a single-phase grid connected PV system is analyzed through the Lyapunov function. To do these things, a suitable mathematical model of grid-connected PV system is also presented in this chapter. The performance of the designed controller is tested on a single-phase grid-connected PV system.

scholarly journals Investigating the Impact of Shading Effect on the Characteristics of a Large-Scale Grid-Connected PV Power Plant in Northwest China

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yunlin Sun ◽  
Siming Chen ◽  
Liying Xie ◽  
Ruijiang Hong ◽  
Hui Shen
Keyword(s):  
Power Distribution ◽  
Large Scale ◽  
Northwest China ◽  
Pv System ◽  
Shading Effect ◽  
Pv Systems ◽  
Large Scale Grid ◽  
Feasible Solutions ◽  
The Impact ◽  
Scale Grid

Northwest China is an ideal region for large-scale grid-connected PV system installation due to its abundant solar radiation and vast areas. For grid-connected PV systems in this region, one of the key issues is how to reduce the shading effect as much as possible to maximize their power generation. In this paper, a shading simulation model for PV modules is established and its reliability is verified under the standard testing condition (STC) in laboratory. Based on the investigation result of a 20 MWp grid-connected PV plant in northwest China, the typical shading phenomena are classified and analyzed individually, such as power distribution buildings shading and wire poles shading, plants and birds droppings shading, and front-row PV arrays shading. A series of experiments is also conducted on-site to evaluate and compare the impacts of different typical shading forms. Finally, some feasible solutions are proposed to avoid or reduce the shading effect of PV system during operation in such region.

scholarly journals An Investigation into the Potential of Hosting Capacity and the Frequency Stability of a Regional Grid with Increasing Penetration Level of Large-Scale PV Systems

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1254
Author(s):  
Abdullah Alshahrani ◽  
Siddig Omer ◽  
Yuehong Su
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Frequency Stability ◽  
Electricity Production ◽  
Generation System ◽  
Pv System ◽  
Pv Systems ◽  
Significant Change ◽  
Grid Operators ◽  
Net Load

It is widely believed that the incorporation of renewable energy to the current power grid is the way forward in achieving sustainable power generation. Currently, with the reduction of PV prices, many countries have started connecting PV systems into their grid network, hence leading to a sharp increase of the penetration levels of renewable electricity production. This will bring significant change in the load pattern and the ramping requirements of the grid’s conventional generation system due to the varying nature of the renewable energy generation. This significant change affects the stability of the grid frequency because it becomes more challenging for the system operators to maintain the equilibrium between the generation and load. Additionally, this significant change affects the PV system potential hosting capacity of the traditional grid because of the PV system’s curtailment in order to comply with the constraints of the grid’s conventional generation system. In this paper, the net load, grid frequency stability, and grid potential hosting capacity are evaluated in the situation of increasing the penetration level of large-scale PV systems generation into the grid. The results show that the grid operators will face increasingly variable net load patterns and steeper ramping events as the PV system penetration level increases. Additionally, the results show the requirement of having flexibility measures that target each grid constraint as the PV system penetration level increases.

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