This paper basically investigates the enhancement of a modified non-square direct matrix converters (MC) for renewable microgrid applications using generative adversarial networks (GAN). Such a deep ...learning technique which benefits from two multi-layer adversary perceptions is used to enhance the security of the data in the microgrid. This paper also provides a new application of the non-square direct MC in the microgrid system which is able to provide balanced output with any desired amplitude and frequency under unbalanced condition specifically in the case of using renewable energy sources such as photovoltaics (PVs) and wind turbines. In addition, a new modified social spider optimization (MSSO) algorithm is introduced to help improving the training process of GAN. Simulation results show that matrix converter based on GAN makes it possible to convert any input voltage to the desired output voltage which leads to the elimination of the back to back converter of wind turbine.
Microgrid Protection Hooshyar, Ali; Iravani, Reza
Proceedings of the IEEE,
07/2017, Letnik:
105, Številka:
7
Journal Article
Recenzirano
The proliferation of distributed energy resources is setting the stage for modern distribution systems to operate as microgrids, which can avoid power disruptions and serve as resources for fast ...recovery during macrogrid disturbances. Microgrids are, therefore, major assets to improve the grid resilience. However, the offered resilience is seriously undermined if microgrids are not properly protected in the event of faults within their own boundaries. Distribution protective devices cannot reliably protect microgrids due to the variable and often limited short-circuit capacities of microgrids. Moreover, the research on microgrid protection has not led to a commercially available microgrid relay to date and has little prospect of reaching that level in the near future. As a result, the existing options for reliable microgrid protection remain effectively the subtransmission and transmission system protective devices, e.g., directional overcurrent, distance, and differential relays. Although years of operation in macrogrids support these relays, their performance for microgrids is yet to be analyzed. This paper presents such analysis for different relay types by considering various fault and generation conditions in a microgrid. Time-domain simulations are used to identify the scenarios where the relays function correctly as well as the problematic conditions, on which future research should focus. This paper also presents a short review on direct current (dc) microgrids and their protection requirements.
For those in developed nations, suddenly being without electricity is a disaster: power cuts have us fretting over the food stored in the freezer, and even a few hours without lights, televisions, or ...air conditioning is an ordeal. However, for an estimated 1.6 billion people worldwide, the absence of electricity is their daily experience. An untold number of others live with electricity that is erratic and of poor quality. How can electric power be brought into their lives when the centralized utility models that have evolved in developed nations are not an economically viable option? Poor, rural communities in developing nations cannot simply be 'plugged in' to a grid. Small-scale Distributed Generation (DG), ranging from individual solar home systems to village level grids run off diesel generators, could provide the answer, and this book compares around 20 DG enterprises and projects in Brazil, Cambodia and China, each of which is considered to be a 'business model' for distributed rural electrification. While large, centralized power projects often rely on big subsidies, this study shows that privately run and localized solutions can be both self-sustaining and replicable. Its three sections provide a general introduction to the issue of electrification and rural development, set out the details of the case studies and compare the models involved, and discuss the important thematic issues of equity, access to capital and cost-recovery. Hisham Zerriffi shows that in each case, it is not simply a matter of matching a particular technology to a particular need. Numerous institutional factors come into play including the regulatory regime, access to financial services, and government/utility support or opposition to the DG alternative. Despite this, in many countries, the question is not whether DG has a role to play. Rather it is a question of how it will play a role.
Abstract In order to mitigate the volatility and randomness caused by the switching processes in a photovoltaic storage microgrid, and to enhance its stability, in this paper, the utilization of the ...PQ+PQ control strategy is proposed for grid-connected operation and the V/f+PQ integrated control strategy is proposed for off-grid operation. Through this approach, a smooth transition from the PQ control of the master inverter to the V/f control is achieved, enabling seamless switching between grid-connected and off-grid modes in the photovoltaic storage microgrid. The proposed integrated control strategy is validated for feasibility and accuracy using a simulation platform built in Matlab/Simulink.
The scope of this study is the optimal siting and sizing of distributed generation within a power distribution network considering uncertainties. A probabilistic power flow (PPF)-embedded genetic ...algorithm (GA)-based approach is proposed in order to solve the optimisation problem that is modelled mathematically under a chance constrained programming framework. Point estimate method (PEM) is proposed for the solution of the involved PPF problem. The uncertainties considered include: (i) the future load growth in the power distribution system, (ii) the wind generation, (iii) the output power of photovoltaics, (iv) the fuel costs and (v) the electricity prices. Based on some candidate schemes of different distributed generation types and sizes, placed on specific candidate buses of the network, GA is applied in order to find the optimal plan. The proposed GA with embedded PEM (GA–PEM) is applied on the IEEE 33-bus network by considering several scenarios and is compared with the method of GA with embedded Monte Carlo simulation (GA–MCS). The main conclusions of this comparison are: (i) the proposed GA–PEM is seven times faster than GA–MCS, and (ii) both methods provide almost identical results.
Abstract
A distributed autonomous economic control strategy is proposed to realize the economic operation of the DC microgrid in the islanded state. The control strategy first introduces incremental ...cost in primary control, but due to the influence of line impedance, it is not possible to precisely achieve the consensus of incremental cost at each unit, and it generates a steady-state error. To overcome this problem, a distributed secondary control based on a dynamic consensus algorithm is designed on the basis of primary control, which makes each distributed generator operate under equal incremental cost. The two layers of control strategies cooperate work together to realize the hierarchical-distributed autonomous economic operation of the DC microgrid. Finally, the simulation model of the DC microgrid is constructed, which verifies the effectiveness of the proposed method.
Since the global warming and climate change are recognized as real concerns, attention of power system planners and operators, energy policy makers and regulators as well as developers around the ...world including Australia is focused on using alternative and low emission energy technologies for electric power production.
Renewable energy and energy efficient technologies have many advantages including reducing climate change, increasing sustainability in power sector, and increasing security of power supply.
This paper presents an overview on both current electricity grid and future grid. Experts believe that in future more distributed generation (DG) will be integrated into the low to medium electricity grid. This paper will also review the key drivers in relation to integration of increased DG technologies in general and the renewable energy-distributed generation (RE-DG) technologies in particular, into the electric power system and the opportunities and challenges linked to these technologies. This paper also reviews possible connection location of RE-DG into the grid and its impact on system voltage.
Power demand in the current days is increasing more and more where the conventional power generation systems are failing to meet these power demands due to less availability of non-renewable ...resources. Hence, many of the researchers are working on the distributed generation (DG) by using renewable resources like wind and solar. The penetration towards wind, solar DG faced challenging situations during power generation due to uncertainty in the wind speed and solar radiation. Recent studies have predicted that the combination of both solar and wind can lead to better performance. However, the sizing and placement of DG systems is necessary to achieve efficiency otherwise the systems may lead to adverse effects in distribution networks. This paper introduced the solar DG, wind DG and hybrid (solar and wind) DG system. The particle swarm optimization technique is used to size and place the DG because of its parallel search capability. Also, the combination of wind-solar DG gives better DG sizing in the respective DG location. The voltage profile of these DG systems has shown better results for the efficient power system. In comparison to conventional DG systems, the suggested hybrid DG system is capable of minimizing power loss and maintaining voltage profile.
Grid-connected inverters are key components of distributed generation systems (DGSs) and micro-grids (MGs), because they are effective interfaces for renewable and sustainable distributed energy ...resources (DERs). Recently, multi-functional grid-connected inverters (MFGCIs) have attracted more and more attention for their benefits on auxiliary services on power quality enhancement in DGSs and MGs. These kinds of converters can not only achieve the power generation of DERs, but also can perform as power quality conditioners at their grid-connected points. It should be noted that these functionalities are optimally organized in the same device, which can significantly enhance the cost-effective feature of the grid-connected inverter, as well as can decrease the investment and bulk compared with multiple devices with independent functionalities. MFGCIs are especially suitable for DGSs and MGs application due to their good performances and benefits. Topologies and control strategies of MFGCIs are comprehensively reviewed in this paper. Additionally, detailed explanation, comparison, and discussion on MFGCIs are achieved. Furthermore, some future research fields on MFGCIs are well summarized.
