Modeling and Simulation of Microgrid with Small Hydropower and Wind Generator on Island Operation Mode

2012 ◽  
Vol 614-615 ◽  
pp. 1841-1845
Author(s):  
Yong Wei Zheng ◽  
Min You Chen ◽  
Chuang Li ◽  
Rui Lin Xu ◽  
Xin Xu
Keyword(s):  
Modeling And Simulation ◽  
Distributed Generation ◽  
Power Supply ◽  
Control Strategies ◽  
Operation Mode ◽  
Wind Generation ◽  
Small Hydropower ◽  
Simulation Experiments ◽  
Load Power ◽  
Simulation Results

A microgrid model with distributed generation including small hydropower source and wind generation source is presented in this paper. The corresponding control strategies for this microgrid are developed. Simulation experiments on island operation mode using Matlab/Simulink software program have been conducted. The simulation results show that the microgrid can operate stably and reliably for load power supply.

scholarly journals An Improved Directional Relay Adapted to a Distribution Network with IIG Integration

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3345 ◽  
Author(s):  
Yifan Zhu ◽  
Tao Zheng ◽  
Minghao Wang ◽  
Hongcheng Zhao ◽  
Xingguo Wang
Keyword(s):  
Distributed Generation ◽  
Radial Distribution ◽  
Control Strategies ◽  
Distribution Network ◽  
Relay Protection ◽  
Source Distribution ◽  
Positive Sequence ◽  
Simulation Experiments ◽  
Directional Relay

The integration of distributed generation (DG) into a distribution network changes the network’s topology. Three-stage current protection for a radial distribution network cannot meet the requirements of relay protection for a distribution network with DG. A directional relay that is based on the positive sequence fault component (PSFC) can effectively identify faults in the positive and negative directions and can be used to solve the adaptability problem with three-stage current protection in a multi-source distribution network. However, DG and the traditional generators have different fault characteristics and are affected by different control strategies, which may lower the sensitivity of a directional relay based on the PSFC or even cause mal-operation. Focusing on this problem, this paper proposes an improved directional relay that is adapted to a distribution network with inverter-interfaced generation (IIG) integration. The improved scheme divides the operation zone of the directional relay based on the PSFC into sensitive and insensitive areas. If the result of a phase comparison is located in the insensitive area, further identification is needed according to a comparison of the current amplitudes. Simulation experiments are carried out based on PSCAD/EMTDC, and their results verify the correctness of the proposed scheme.

Modeling and Simulation of Motor Discrete Variable Frequency Soft Starting Based on the Variable Reactance

2014 ◽  
Vol 571-572 ◽  
pp. 930-933
Author(s):  
Xing Yu Song ◽  
Jing Chen ◽  
Shi Jie Deng ◽  
You Xin Yuan ◽  
Qing Wang
Keyword(s):  
Modeling And Simulation ◽  
Power Supply ◽  
Topological Structure ◽  
Variable Frequency ◽  
Discrete Variable ◽  
Working Principle ◽  
Simulation Results ◽  
Save Energy ◽  
Heavy Loads ◽  
Set Up

The started motors are characterized by the low staring torque and large currents when the motors draw the heavy-loads. Therefore, a method of motor discrete variable frequency soft starting based on the variable reactance is presented in this paper [1,2]. According to the topological structure and working principle of motor discrete variable frequency soft starting based on the variable reactance, the simulation model of the system has been set up by the Matlab/Simulink tool. Simulation results show that the motor starters developed with this method have been successfully applied to the loads of the drive equipment in the kiln, coal grinding mill or the mine. It can improve the starting performance when the motors draw the heavy-loads., save energy, stabilize the voltage of the power supply network.

scholarly journals Intending Island Service Restoration Method With Topology-Powered Directional Traversal Considering the Uncertainty of Distributed Generations

2021 ◽  
Vol 9 ◽  
Author(s):  
Chun Chen ◽  
Yitong Wu ◽  
Yijia Cao ◽  
Shengpeng Liu ◽  
Qingbo Tan ◽  
...  
Keyword(s):  
Distributed Generation ◽  
Power Supply ◽  
Power Loss ◽  
Power Flow ◽  
Distribution Systems ◽  
Load Capacity ◽  
Recovery Method ◽  
Load Power ◽  
Service Restoration ◽  
Restoration Method

The intending island service restoration method is one of the core technologies of self-healing control for smart distribution systems, which aims to maximize the restoration of the out-of-service loads in the out-of-service area without faults quickly. For this reason, a topology-weighted directional traversal intending island recovery method considering the uncertainty of distributed generation sources is proposed. First, divide the network level of the power-loss feeder and calculate the interval power flow of the feeder before the fault, and obtain the power flow direction when the active and reactive power of the faulted branch is the smallest so as to determine whether the distributed generation supply in the non-faulty power-loss area can restore all load power supply. If not, to determine the island recovery plan, continue to compare the distributed generation supply and the load capacity at all levels, and give priority to recovering loads with higher importance levels and smaller network levels. The traversal of the topological authority and direction effectively reduces the island recovery time and can make full use of the distributed generation output to maximize the recovery of the non-faulty power-loss area. Taking the PG&E 69-node system as an example and using the BFGS trust region algorithm to calculate the island power flow without unbalanced nodes for verification, the results show that this method consumes less time and can restore more load power supply than the existing island recovery method, which verifies the method’s effectiveness and reasonability.

Island Configuration for Service Restoration of the Smart Distribution System

2013 ◽  
Vol 325-326 ◽  
pp. 586-589
Author(s):  
Xu Dong Wang ◽  
Wei Liang
Keyword(s):  
Distributed Generation ◽  
Knapsack Problem ◽  
Power Supply ◽  
Distribution System ◽  
Operation Mode ◽  
Total Power ◽  
Power Balance ◽  
Service Restoration ◽  
Configuration Problem

sland operation is a special operation mode for service restoration for the smart distribution system with distributed generation. In this paper, a model of island reconfiguration of the smart distribution system is proposed. The objection of this model is maximizing the total power supply profit. Meanwhile, load priority, controllable and uncontrollable load, and the restrictions of power balance, voltage and equipment capability are all taken into account. The island configuration problem is first simplified as a special knapsack problem, and based on the solution of this knapsack problem an initial island scheme is gained. By feasibility checking and adjusting, a island configuration is finally proposed. The results of the samples demonstrate that the model and method presented in this paper is feasible and valid.

Comprehensive Analysis for Influence of Controllable Damper Time Delay on Semi-Active Suspension Control Strategies

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Yechen Qin ◽  
Feng Zhao ◽  
Zhenfeng Wang ◽  
Liang Gu ◽  
Mingming Dong
Keyword(s):  
Time Delay ◽  
Dynamic Characteristics ◽  
Ride Comfort ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Active Suspension ◽  
Test System ◽  
Suspension Control ◽  
Simulation Results

This paper presents a comprehensive comparison and analysis for the effect of time delay on the five most representative semi-active suspension control strategies, and refers to four unsolved problems related to semi-active suspension performance and delay mechanism that existed. Dynamic characteristics of a commercially available continuous damping control (CDC) damper were first studied, and a material test system (MTS) load frame was used to depict the velocity-force map for a CDC damper. Both inverse and boundary models were developed to determine dynamic characteristics of the damper. In addition, in order for an improper damper delay of the form t+τ to be corrected, a delay mechanism of controllable damper was discussed in detail. Numerical simulation for five control strategies, i.e., modified skyhook control SC, hybrid control (HC), COC, model reference sliding mode control (MRSMC), and integrated error neuro control (IENC), with three different time delays: 5 ms, 10 ms, and 15 ms was performed. Simulation results displayed that by changing control weights/variables, performance of all five control strategies varied from being ride comfort oriented to being road handling oriented. Furthermore, increase in delay time resulted in deterioration of both ride comfort and road handling. Specifically, ride comfort was affected more than road handling. The answers to all four questions were finally provided according to simulation results.

scholarly journals Cheating at Craps

2021 ◽  
Vol 48 (4) ◽  
pp. 53-61
Author(s):  
Andrea Marin ◽  
Carey Williamson
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Modeling And Simulation ◽  
Analytical Model ◽  
Quantitative Evaluation ◽  
Mathematical Analysis ◽  
Simulation Modeling ◽  
Analytical Modeling ◽  
The World ◽  
Simulation Results

Craps is a simple dice game that is popular in casinos around the world. While the rules for Craps, and its mathematical analysis, are reasonably straightforward, this paper instead focuses on the best ways to cheat at Craps, by using loaded (biased) dice. We use both analytical modeling and simulation modeling to study this intriguing dice game. Our modeling results show that biasing a die away from the value 1 or towards the value 5 lead to the best (and least detectable) cheating strategies, and that modest bias on two loaded dice can increase the winning probability above 50%. Our Monte Carlo simulation results provide validation for our analytical model, and also facilitate the quantitative evaluation of other scenarios, such as heterogeneous or correlated dice.

scholarly journals Over/Undervoltage and Undervoltage Shift of Hybrid Islanding Detection Method of Distributed Generation

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Manop Yingram ◽  
Suttichai Premrudeepreechacharn
Keyword(s):  
Control System ◽  
Distributed Generation ◽  
Hybrid Method ◽  
Detection Method ◽  
System Simulation ◽  
Detection Methods ◽  
Islanding Detection ◽  
Active Method ◽  
Passive Method ◽  
Simulation Results

The mainly used local islanding detection methods may be classified as active and passive methods. Passive methods do not perturb the system but they have larger nondetection zones, whereas active methods have smaller nondetection zones but they perturb the system. In this paper, a new hybrid method is proposed to solve this problem. An over/undervoltage (passive method) has been used to initiate an undervoltage shift (active method), which changes the undervoltage shift of inverter, when the passive method cannot have a clear discrimination between islanding and other events in the system. Simulation results on MATLAB/SIMULINK show that over/undervoltage and undervoltage shifts of hybrid islanding detection method are very effective because they can determine anti-islanding condition very fast.ΔP/P>38.41% could determine anti-islanding condition within 0.04 s;ΔP/P<-24.39% could determine anti-islanding condition within 0.04 s;-24.39%≤ΔP/P≤ 38.41% could determine anti-islanding condition within 0.08 s. This method perturbed the system, only in the case of-24.39% ≤ΔP/P ≤38.41% at which the control system of inverter injected a signal of undervoltage shift as necessary to check if the occurrence condition was an islanding condition or not.

Sign in / Sign up

Export Citation Format

Share Document