Simulation Of Distribution Network Research Articles

Simulation and Measurement of Power Distribution Networks (PDN)

Abstract In this publication, signal integrity issues of Power Distribution Networks (PDNs) are addressed (to insure acceptable quality of signals within); Transmission line effects, Crosstalk, and Impedance mismatch. Power Integrity issues of PDNs are also addressed (to insure acceptable quality of power delivery within); Voltage drop, High impedance, Parasitic Via inductances, and Noise coupling. In this work, ANSYS™ HFSS 2013 FEM simulation techniques development, adaptive meshing, and convergence to S-parameters, Differential S-parameters, and Z-parameters to design and simulate PDNs under different conditions and the results are compared to measurements performed in our laboratories.

Modeling and Simulation of Distribution Network with the Integration of Distribution Generator using Matlab

Background: Due to increasing power demand across the country, the usage of renewable systems is being increased. One such efficient and compactly available renewable energy is solar power. In this paper, a clear view of harnessing maximum DC solar power output and converting it to AC is discussed. Methods: A method of grid interconnection of solar powered inverter is presented with IEEE-15 bus system as an example model using Matlab simulation. Findings: A detailed analysis of bus voltage, load current and line current is made with the simulated model. Applications/Improvements: The data obtained could be used for fine optimization of the position in which the distribution generator interconnection is to be made.

Real-Time Simulation of Distributed Energy Systems and Microgrids

Abstract: This paper describes the challenges met in real-time simulation of modern power systems, explains various methods to address these challenges and solve the problems they impose. This is detailed and demonstrated through a case study - real time simulation of a micro-grid connected to a large distribution network containing 615 single-phases nodes. The contribution of this work relies in solving two major challenges in real-time simulation of micro-grids and distribution networks: the distribution of large grids over several processors, and the accuracy in simulating fast switching power converters applied to and demonstrated by a case study of a micro-grid connected to a distribution network.

Energy Efficient Dynamic Content Distribution

Consider a network of prosumers of media content in which users dynamically create and request content objects. The request process is governed by the objects’ popularity, which may vary across network regions and over time. In order to meet user requests, content objects can be stored and transported over the network, characterized by the capacity and efficiency of its storage and transport resources. The energy-efficient dynamic content distribution problem aims at finding the evolution of the network configuration, in terms of the placement and routing of content objects over time, that meets user requests, satisfies network resource capacities and minimizes overall energy use. We present 1) an information-centric linear programming formulation for the energy efficient dynamic content distribution problem that captures multicasting and caching over the network, per-object system dynamics, and delivery deadlines; 2) an offline solution that characterizes the minimum energy use achievable with global knowledge of user requests and network resources; and 3) an efficient distributed online solution that allows network nodes to make caching decisions based on their local estimate of the global energy benefit. Using a custom-built content distribution network simulator as well as a real prototype implementation in an information-centric networking testbed, we show the significant energy savings that can be obtained via the efficient and lightweight cache cooperation induced by our service and energy aware distributed online solution with respect to state of the art approaches.

Identification of Design Criteria for District Cooling Distribution Network with Ice Thermal Energy Storage System

Two (2) distribution network models of district cooling system with ice thermal energy storage system are presented in which the theoretical system pressure drop, system flow rate and flow rate requirements in each energy transfer station were determined. The hydraulic calculation and system simulation of distribution networks with and without secondary lines are evaluated based on system temperature difference set-point of 11°C. Variable primary flow pumping system arrangement was used to improve energy usage and to eliminate the need for a distribution pump in the network. The system of nonlinear equations was solved using multivariable Newton-Raphson method. The linearized equations revealed that coefficient matrices formed between the two networks were different from each other which suggested that different decomposition algorithms must be used to properly determine the solution vectors. Optimization technique such as exhaustive search method was adopted to identify the piping network design criteria that could yield minimum overall cost.

A unified framework for spiking and gap-junction interactions in distributed neuronal network simulations.

Contemporary simulators for networks of point and few-compartment model neurons come with a plethora of ready-to-use neuron and synapse models and support complex network topologies. Recent technological advancements have broadened the spectrum of application further to the efficient simulation of brain-scale networks on supercomputers. In distributed network simulations the amount of spike data that accrues per millisecond and process is typically low, such that a common optimization strategy is to communicate spikes at relatively long intervals, where the upper limit is given by the shortest synaptic transmission delay in the network. This approach is well-suited for simulations that employ only chemical synapses but it has so far impeded the incorporation of gap-junction models, which require instantaneous neuronal interactions. Here, we present a numerical algorithm based on a waveform-relaxation technique which allows for network simulations with gap junctions in a way that is compatible with the delayed communication strategy. Using a reference implementation in the NEST simulator, we demonstrate that the algorithm and the required data structures can be smoothly integrated with existing code such that they complement the infrastructure for spiking connections. To show that the unified framework for gap-junction and spiking interactions achieves high performance and delivers high accuracy in the presence of gap junctions, we present benchmarks for workstations, clusters, and supercomputers. Finally, we discuss limitations of the novel technology.

Residential electrical vehicle charging strategies: the good, the bad and the ugly

In recent years, a wide variety of centralised and decentralised algorithms have been proposed for residential charging of electric vehicles (EVs). In this paper, we present a mathematical framework which casts the EV charging scenarios addressed by these algorithms as optimisation problems having either temporal or instantaneous optimisation objectives with respect to the different actors in the power system. Using this framework and a realistic distribution network simulation testbed, we provide a comparative evaluation of a range of different residential EV charging strategies, highlighting in each case positive and negative characteristics.

Model order reduction for transient simulation of active distribution networks

With the increasing penetration of distributed generation, distribution networks are evolving from passive to active. New transient simulation methods are required to study the detailed dynamic characteristics of large-scale active distribution networks. A model order reduction method based on Krylov subspace theory is introduced in this study to reduce the overall model scale of active distribution networks for transient simulations. A modified state-space model of linear distribution networks is developed to replace the conventional models for improvement in model reduction efficiency, while guaranteeing the passivity and stability of the reduced models. The proposed model order reduction method is validated with the IEEE 123-node test network. The results prove that the proposed method is effective for different applications to improve the simulation efficiency of large-scale active distribution networks.

Optimization of Wireless Ad-hoc Networks using an Adjacent Collaborative Directional MAC (ACDM) Protocol

In this paper we designed a modern Medium access control (MAC) protocol for wireless ad-hoc network that focuses on neighbor node information availability and uses directional antenna. MAC protocol coordinates different users to share the wireless channel fairly and resourcefully in the wireless networks. However, using directional antennas in ad-hoc networks causes new challenges such as new hidden terminal, deafness problems, unnecessary blocking of nodes etc. The problems arise mostly due to lack of information of the neighbor node’s activities. Thus, we proposed a new directional MAC protocol name Adjacent Collaborative Directional MAC Protocol (ACDM) for wireless ad-hoc networks. The objective is to improve the throughput and delay performance together with overhead reduction of the wireless network. In addition, the integrity of the ACDM has been verified using the distributed network simulator tool NS3. The simulation results have shown that the ACDM protocol outperforms the existing protocols of wireless networks using directional antennas by minimizing the depressing effect of hidden-terminal, deafness and head of line blocking problems that also avoids asymmetry-in-gain problem. The performance of ACDM protocol shows that it improves the throughput and reduces the overhead from the state-of-art works.

EMTP-type program realization of Krylov subspace based model reduction methods for large-scale active distribution network

Effective model reduction methods are required to deal with new challenges in active distribution network simulations that are on a large scale and have complicated structures. In the development of advanced electromagnetic transient simulation programs, automated model reduction plays an important role. This paper proposes an automated realization algorithm for the Krylov subspace based model reduction methods of an active distribution network with which the reduced model can be automatically established according to a given threshold of reduction error. The combined state-space nodal analysis framework is employed to apply the automated model reduction algorithm in popular EMTP-type simulation programs. Simulations are performed using PSCAD and a self-developed program to show the feasibility and validity of the proposed methods.

Efficient Preconditioned Iterative Methods for Hydraulic Simulation of Large Scale Water Distribution Networks

In this paper, we consider the use of an efficient null space algorithm for hydraulic analysis that employs preconditioned conjugate gradient (PCG) methods for solving the Newton linear equations. Since large water network models are inherently badly conditioned, a Jacobian regularization is employed to improve the condition number to some degree, this resulting in an inexact Newton method whose analyses is presented. Based on this analysis, constraint preconditioners are used to improve the condition number further for more efficient use of CG solvers. Operational networks are used to study the computational properties of the various approaches.

Simulation Study on Series Capacitor Compensation to Improve the Voltage Quality of Rural Power Distribution Network

In order to improve the voltage quality of rural power distribution network, the series capacitor in distribution lines is proposed. The principle of series capacitor compensation technology to improve the quality of rural power distribution lines voltage is analyzed. The real rural power distribution network simulation model is established by Power System Power System Analysis Software Package (PSASP). Simulation analysis the effect of series capacitor compensation technology to improve the voltage quality of rural power distribution network, The simulation results show that the series capacitor compensation can effectively improve the voltage quality and reduce network losses and improve the transmission capacity of rural power distribution network.

Implementation of DEVS Based Distributed Network Simulator for Large-Scale Networks

Implementation of DEVS Based Distributed Network Simulator for Large-Scale Networks

Real-Time Simulation of Pipe Network Based on EPANET

Hydraulic simulation models of water pipe networks (WPN) are routinely used for operational investigations and network design purposes. However, their full potential is often never realized because in the majority of cases, they have been calibrated with data collected manually from the field during a single historic time period and reflects the network operational conditions that were prevalent at that time. They were then applied as part of a reactive investigation. An urban water distribution network real time simulation system based on EPANET system using OPC (object linking and Embedding for Process control) communication was built in this paper. In order to make real-time simulation of water distribution network, the real-time data was collected every 15 minutes, the real time data were received and sent into water distribution network simulation model by OPC communication of EPANET system. The real-time data included total head of reservoir, flow rate, pressure, pump operation information. The real-time simulation system can give timely warning of changes for normal network operation, providing capacity to minimize customer impact and comparing the simulation results with the real-time data collected. The real time simulation system of urban water pipe network solved the problem of data input and user interaction compare to traditional network model. It offers a way for the development of intelligent water network.

Simplification of Water Distribution Network Simulation by Topological Clustering – Investigation of its Potential Use in Copenhagen's Water Supply Monitoring and Contamination Contingency Plans

Topological clustering was investigated to simplify a complex water distribution network of Copenhagen, Denmark, into recogniz- able water movement patterns. This made it possible to assess the general transport of the water and to suggest strategic sampling locations. Through a topological analysis, the network model was divided into strongly and weakly connected clusters within selected time periods. Steady connected clusters were found by conducting a cluster analysis over all chosen selected time periods. We identified sampling locations with steady hydraulic conditions, increasing the samples’ comparability over time, and locations, where samples represent the distributed and consumed water in the Nørrebro district.

Water distribution network simulation by optimization approaches

When a fire-flow condition occurs and a nodal demand is excessive or when a pipe breaks, a water distribution system (WDS) may temporarily become deficient and unable to satisfy all nodal demands. Thus, estimation of the influences of failure conditions on the network is needed. A method for analyzing the hydraulic condition of the network in such a situation is proposed. The method, which is constructed based on the amount of supply on each consumption node, is called node flow analysis (NFA). Given the limitations of the NFA method proposed earlier for determining optimal solutions, such as inflexibility of the approach toward more complicated problems and its time-consuming process, this paper presents the honey-bee mating optimization (HBMO) algorithm for maximizing the total supply of the Two-loop and Hanoi water distribution networks (WDNs) under a failure condition. The proposed method is much faster and simpler to use than the NFA method. Consequently, obtained results confirm the higher accuracy of the proposed method to conditions of WDNs under local pipe breakage. In addition, results make one aware of the effects of each pipe breakage on consumption nodes and in the entire network under two scenarios for maximizing total supply in the network.

Modeling Local Water Storages Delivering Customer Demands in WDN Models

Water distribution network (WDN) models account for customer-demands as water withdrawals concentrated in nodes. Customer- demands can be assumed to be constant or varying with nodal head/pressure entailing demand-driven or pressure-driven simulation, respec- tively. In both cases, the direct connection of customer properties to the hydraulic system is implicitly assumed. Nonetheless, in many technical situations, the service pipe fills a local private storage (e.g., a roof tank or a basement tank) from which the water is actually delivered to customers by gravity or pumping systems. In such contexts, the service pipe fills the local tank by means of a top orifice. Consequently, what is really connected to the hydraulic system is a tank, which is subject to a filling/emptying process while supplying water to customers. Therefore, since modeling this technical situation in WDN analyses is necessary, the paper develops a formulation for nodal water withdrawals in WDN models accounting for the filling/emptying process of inline tanks between the hydraulic network and customers. The formulation is also introduced in a widely used method for steady-state WDN modeling, the global gradient algorithm, and its effectiveness to increase the hydraulic accuracy of results is discussed using a simple case study and a small network. DOI: 10.1061/(ASCE) HY.1943-7900.0000812. © 2014 American Society of Civil Engineers. Author keywords: Tank modeling; Water distribution networks; Hydraulic network modeling; Water distribution network simulation; Extended period simulation.

Three-Dimensional Distribution Operation Simulation Training System

The training of distribution operators is an important link to ensure the safe operation to effectively enhance the training effect,the paper put forward a new teaching form that combining the line operation and simulation training. It firstly analyzes the distribution network simulation training function demand, then designs training simulation system structure,extracts simulation training process,introduces the key technology:three-dimensional simulation technology,then simulation training process,finally gives the system development example. The application result shows the power line operation simulation training system can effectively guarantee the operation training effect,has a great practical significance.

Dynamic state estimation for distribution networks with renewable energy integration

The massive integration of variable and unpredictable Renewable Energy Sources (RES) and new types of load consumptions increases the dynamic and uncertain nature of the electricity grid. Emerging interests have focused on improving the monitoring capabilities of network operators so that they can have accurate insight into a network’s status at the right moment and predict its future trends. Though state estimation is crucial for this purpose to trigger control functions, it has been used mainly for steady-state analysis. The need for dynamic state estimation (DSE), however, is increasing for real-time control and operation. This paper addresses the important role of DSE over conventional static-state estimation in this new distribution network context. Computational burden mitigates the state-of-the-art utilizations of DSE in real large-scale networks, although DSE was introduced several decades ago. This paper the unscented Kalman filter (UKF) to alleviate computational burden with DSE. The UKF-based approach does not use a linearization procedure and thus outperforms the conventional Extended Kalman Filter based approach to cope with non-linear models. The performance of the UKF method is investigated with a simulation of an 18-bus distribution network on the real-time digital simulator (RTDS) platform. A distribution network with considerable integration of renewable energy production is used to evaluate the UKF-based DSE approach under different types of events.

Modeling Simulation Technology Research for Distribution Network Planning

This paper proposes to use the power system simulation software CYME to plan, model and simulate for an actual distribution network for improving the reliability and efficiency, enhancing the efficiency and capacity, simulating the abnormal condition of distribution network, and presenting operation program of safe, reliable and having simulation record statements. The modeling simulation results show that the software module has lots of advantages including high accuracy, ideal reliability, powerful practicality in simulation and analysis of distribution network, it only need to create once model, the model can sufficiently satisfy multifarious types of simulation analysis required for the distribution network planning.