A Combined AC+DC Distribution Network Interconnected with Renewable Energy

2014 ◽  
Vol 960-961 ◽  
pp. 676-679
Author(s):  
Dong Xin Hao ◽  
Li Zhang ◽  
Meng Qi Liu ◽  
Pan Ting Dong ◽  
Hao Wu
Keyword(s):  
Renewable Energy ◽  
Reactive Power ◽  
Voltage Drop ◽  
Electrical Power ◽  
Distribution Network ◽  
Transient State ◽  
Transient Effects ◽  
Line Voltage ◽  
Dc Power ◽  
Dc Distribution

The combined AC+DC distribution network in this study provides a coupling and decoupling strategy of renewable energy in DC mode by using zig-zag transformer, which makes each line transmit AC electrical power and DC power simultaneously. The proposed scheme is digitally simulated with the help of Simulink software package. Simulation results indicate lower line voltage drop and less active and reactive power loss in steady state; almost similar or even better transient effects in transient state, which demonstrates the feasibility of combined AC+DC distribution network of single line interconnected with renewable energy.

scholarly journals Voltage Stability of Power Systems with Renewable-Energy Inverter-Based Generators: A Review

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 115
Author(s):  
Nasser Hosseinzadeh ◽  
Asma Aziz ◽  
Apel Mahmud ◽  
Ameen Gargoom ◽  
Mahbub Rabbani
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Voltage Stability ◽  
Reactive Power ◽  
Power Grid ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
System Stability ◽  
Special Issue ◽  
Synchronous Generators

The main purpose of developing microgrids (MGs) is to facilitate the integration of renewable energy sources (RESs) into the power grid. RESs are normally connected to the grid via power electronic inverters. As various types of RESs are increasingly being connected to the electrical power grid, power systems of the near future will have more inverter-based generators (IBGs) instead of synchronous machines. Since IBGs have significant differences in their characteristics compared to synchronous generators (SGs), particularly concerning their inertia and capability to provide reactive power, their impacts on the system dynamics are different compared to SGs. In particular, system stability analysis will require new approaches. As such, research is currently being conducted on the stability of power systems with the inclusion of IBGs. This review article is intended to be a preface to the Special Issue on Voltage Stability of Microgrids in Power Systems. It presents a comprehensive review of the literature on voltage stability of power systems with a relatively high percentage of IBGs in the generation mix of the system. As the research is developing rapidly in this field, it is understood that by the time that this article is published, and further in the future, there will be many more new developments in this area. Certainly, other articles in this special issue will highlight some other important aspects of the voltage stability of microgrids.

scholarly journals Numerical and experimental investigations of the impacts of the integration of wind energy into distribution network

2021 ◽  
Author(s):  
◽  
Ramesh Kumar Behara
Keyword(s):  
Renewable Energy ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Power ◽  
Distribution Systems ◽  
Electrical Power ◽  
Distribution Network ◽  
Experimental Investigations ◽  
Doubly Fed ◽  
The Impact

The growing needs for electric power around the world has resulted in fossil fuel reserves to be consumed at a much faster rate. The use of these fossil fuels such as coal, petroleum and natural gas have led to huge consequences on the environment, prompting the need for sustainable energy that meets the ever increasing demands for electrical power. To achieve this, there has been a huge attempt into the utilisation of renewable energy sources for power generation. In this context, wind energy has been identified as a promising, and environmentally friendly renewable energy option. Wind turbine technologies have undergone tremendous improvements in recent years for the generation of electrical power. Wind turbines based on doubly fed induction generators have attracted particular attention because of their advantages such as variable speed, constant frequency operation, reduced flicker, and independent control capabilities for maximum power point tracking, active and reactive powers. For modern power systems, wind farms are now preferably connected directly to the distribution systems because of cost benefits associated with installing wind power in the lower voltage networks. The integration of wind power into the distribution network creates potential technical challenges that need to be investigated and have mitigation measures outlined. Detailed in this study are both numerical and experimental models to investigate these potential challenges. The focus of this research is the analytical and experimental investigations in the integration of electrical power from wind energy into the distribution grid. Firstly, the study undertaken in this project was to carry out an analytical investigation into the integration of wind energy in the distribution network. Firstly, the numerical simulation was implemented in the MATLAB/Simulink software. Secondly, the experimental work, was conducted at the High Voltage Direct Centre at the University of KwaZulu-Natal. The goal of this project was to simulate and conduct experiments to evaluate the level of penetration of wind energy, predict the impact on the network, and propose how these impacts can be mitigated. From the models analysis, the effects of these challenges intensify with the increased integration of wind energy into the distribution network. The control strategies concept of the doubly fed induction generator connected wind turbine was addressed to ascertain the required control over the level of wind power penetration in the distribution network. Based on the investigation outcomes we establish that the impact on the voltage and power from the wind power integration in the power distribution system has a goal to maintain quality and balance between supply and demand.

Loss Minimization in Active Distribution Network

2020 ◽  
pp. 119-135 ◽  
Author(s):  
Bawoke Simachew
Keyword(s):  
Power Loss ◽  
Reactive Power ◽  
Electrical Power ◽  
Distribution Network ◽  
Optimization Method ◽  
Energy Utilization ◽  
Optimal Size ◽  
Loss Reduction ◽  
Voltage Profile ◽  
Power Sources

Power loss reduction is an important problem that needs to be addressed with respect to generating electrical power. It is important to reduce power loss using locally generated power sources and/or compensations. This chapter brings a method of presents a method of maximizing energy utilization, feeder loss reduction, and voltage profile improvement for radial distribution network using the active and reactive power sources. Distributed Generation (DG) (wind and solar with backup by biomass generation) and shunt capacitor (QG) for reactive power demand are used. Integrating DG and QG at each bus might reduce the loss but it is economically unaffordable, especially for developing countries. Therefore, the utilization optimization method is required for finding an optimal size and location to feeders for placing QG and DG to minimize feeder loss.

scholarly journals Study on the Key Problems of UHVAC/DC Power Grids with New Generation Large Synchronous Condenser

2018 ◽  
Vol 57 ◽  
pp. 03003
Author(s):  
Xiao Fan ◽  
Zhou Kunpeng ◽  
Wang Tao ◽  
Cao Kan ◽  
Rao Yuze
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Reactive Power ◽  
Power Transmission ◽  
Excitation Control ◽  
Synchronous Condenser ◽  
Dc Power ◽  
Ac Power ◽  
New Generation ◽  
Dc Power Transmission

In order to cope with the great pressure caused by the gradually exhaustion of fossil energy and environmental protection and climate warming, the development and application of the renewable energy has become an important foundation and development direction in the field of energy. However, due to the impact of energy and resource endowment, China’s load center and renewable energy base into the characteristics of long-range reverse distribution, the use of long-distance large-capacity transmission potential is necessary. With the “strong DC system and weak AC system” problem of the company power grid is increasingly prominent, the higher demand of dynamic reactive power support is put forward in the UHV DC power transmission project. Then, the large-capacity dynamic reactive power of new generation synchronous condenser is large-scale built up in the UHV DC/AC power system. Due to the high requirement of response speed and capacity in the UHV DC power transmission, the structure, dynamic characteristics, excitation control and relay protection and other aspects of the large synchronous condenser are different from generators and traditional synchronous condenser. Based on this, the dynamic reactive power demand of UHV DC power system is analyzed in this paper. Then, the main situation of large synchronous condenser is considered. In addition, the key points of the excitation control system and protection system are also discussed in this paper. There are important theoretical and practical significance for the safe and reliable operation of the UHV DC/AC power system.

scholarly journals A Mutual Technique for Reconfiguration of Feeder Network by Optimal Locating and Sizing of Distribution Generator

2019 ◽  
Vol 63 (4) ◽  
pp. 320-331
Author(s):  
Kothuri Ramakrishna ◽  
Basavaraja Banakara
Keyword(s):  
Radial Distribution ◽  
Reactive Power ◽  
Electrical Power ◽  
Distribution Network ◽  
Pso Algorithm ◽  
Optimization Techniques ◽  
Optimum Location ◽  
Algorithm Optimization ◽  
Electrical Power System ◽  
Comparison Results

Common technique has been discussed in this paper for the reconfiguration of feeder network by optimal location and measuring of Distribution Generator (DG) in electrical power system. The consolidated execution of both Biography Based Optimization (BBO) and Particle Swarm Optimization (PSO) strategies are the curiosity of the proposed strategy. The optimization techniques are utilized for optimizing the optimum location and DG capacity for radial distribution network. The BBO algorithm requires radial distribution network voltage, real and reactive power for deciding the optimum location and capacity of the DG. Here, the input parameters of BBO are classified into sub parameters and permitted as the PSO algorithm optimization process. The PSO develops the sub solution with the assistance of sub parameters by issue synthesis. For identifying the optimum location and capacity of DG the BBO movement and mutation process is applied for the sub solution of PSO. At that point the proposed mutual technique is actualized in the MATLAB/simulink platform and by contrasting it with the BBO and PSO systems the effectiveness is scrutinized. The comparison results demonstrate the predominance of the proposed approach and affirm its capability to comprehend the issue.

scholarly journals Two-Stage Stochastic Programming Scheduling Model for Hybrid AC/DC Distribution Network Considering Converters and Energy Storage System

2019 ◽  
Vol 10 (1) ◽  
pp. 181
Author(s):  
Peng Kang ◽  
Wei Guo ◽  
Weigang Huang ◽  
Zejing Qiu ◽  
Meng Yu ◽  
...  
Keyword(s):  
Wind Power ◽  
Reactive Power ◽  
Distribution Network ◽  
Stochastic Scheduling ◽  
Second Order ◽  
Mixed Integer ◽  
Two Stage ◽  
Dc Distribution ◽  
Scheduling Model ◽  
Second Order Cone

The development of DC distribution network technology has provided a more efficient way for renewable energy accommodation and flexible power supply. A two-stage stochastic scheduling model for the hybrid AC/DC distribution network is proposed to study the active-reactive power coordinated optimal dispatch. In this framework, the wind power scenario set is utilized to deal with its uncertainty in real time, which is integrated into the decision-making process at the first stage. The charging/discharging power of ESSs and the transferred active/reactive power by VSCs can be adjusted when wind power uncertainty is observed at the second stage. Moreover, the proposed model is transformed into a mixed integer second-order cone programming optimization problem by linearization and second-order cone relaxation techniques to solve. Finally, case studies are implemented on the modified IEEE 33-node AC/DC distribution system and the simulation results demonstrate the effectiveness of the proposed stochastic scheduling model and solving method.

Reliability Evaluation of Mid-Voltage DC Distribution Network with Multiple Topologies

2014 ◽  
Vol 666 ◽  
pp. 112-118 ◽  
Author(s):  
Jia Si Zeng ◽  
Yi Bo Gao ◽  
Feng Yang ◽  
Xi Dong Xu ◽  
Peng Qiu ◽  
...  
Keyword(s):  
Power Electronics ◽  
Sequential Monte Carlo ◽  
Reactive Power ◽  
Transmission Loss ◽  
Distribution Network ◽  
Reliability Evaluation ◽  
Power Electronic ◽  
Electronic Components ◽  
Reliability Models ◽  
Dc Distribution

With the development of power electronics, DC distribution network has advantages in power supplying for DC loads, saving transmission loss of reactive power and improving power quality, when compared with traditional AC distribution network. Since DC distribution network has several multiple topologies, lots of power electronic components and DGs, the traditional reliability evaluation methods aren’t applicable any more. Hence, the reliability models of power electronics and DGs are built in this paper, and a hybrid method combining minimum-cut with non-sequential Monte Carlo is presented. Moreover, three topologies of mid-voltage DC distribution network are designed based on IEEE RBTS bus6, by which the feasibility of the method is validated. Results show that two-terminal network is more reliable than radial and looped network.

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