scholarly journals Model and Topological Characteristics of Power Distribution System Security Region

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Jun Xiao ◽  
Guo-qiang Zu ◽  
Xiao-xu Gong ◽  
Cheng-shan Wang

As an important tool of transmission system dispatching, the region-based method has just been introduced into distribution area with the ongoing smart distribution grid initiatives. First, a more accurate distribution system security region (DSSR) model is proposed. The proposed model is based on detailed feeder-interconnected topology, and both substation transformer and feeder N-1 contingencies are considered. Second, generic characteristics of DSSR are discussed and mathematically proved. That is, DSSR is a dense set of which boundary has no suspension and can be expressed by several union subsurfaces. Finally, the results from both a test case and a practical case demonstrate the effectiveness of the proposed modeling approach; the shape of DSSR is also illustrated by means of 2- and 3-dimensional visualization. Moreover, the DSSR-based assessment and control are preliminary illustrated to show the application of DSSR. The researches in this paper are fundamental work to develop new security region theory for future distribution systems.

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5503
Author(s):  
Wen Fan ◽  
Ning Kang ◽  
Robert Hebner ◽  
Xianyong Feng

This paper summarizes the literature on detection of islanding resulting from distributed generating capabilities in a power distribution system, with emphasis on the rural distribution systems. It is important to understand the legacy technology and equipment in the rural distribution electrical environment due to the growth of power electronics and the potential for adding the new generations of intelligent sensors. The survey identified four areas needing further research: 1. Robustness in the presence of distribution grid disturbances; 2. the future role of artificial intelligence in the islanding application; 3. more realistic standard tests for the emerging electrical environment; 4. smarter sensors. In addition, this paper presents a synchro-phasor-based islanding detection approach based on a wireless sensor network developed by the University of Texas at Austin. Initial test results in a control hardware-in-the-loop (CHIL) simulation environment suggest the effectiveness of the developed method.


DYNA ◽  
2015 ◽  
Vol 82 (192) ◽  
pp. 141-149 ◽  
Author(s):  
Andres Felipe Panesso-Hernández ◽  
Juan Mora-Flórez ◽  
Sandra Pérez-Londoño

<p>The impedance-based approaches for fault location in power distribution systems determine a faulted line section. Next, these require of the estimation of the voltages and currents at one or both section line ends to exactly determine the fault location. It is a challenge because in most of the power distribution systems, measurements are only available at the main substation.  This document presents a modeling proposal of the power distribution system and an easy implementation method to estimate the voltages and currents at the faulted line section, using the measurements at the main substation, the line, load, transformer parameters and other serial and shunt connected devices and the power system topology. The approach here proposed is tested using a fault locator based on superimposed components, where the distance estimation error is lower than 1.5% in all of the cases. </p>


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 334
Author(s):  
Esteban Pulido ◽  
Luis Morán ◽  
Felipe Villarroel ◽  
José Silva

In this paper, a new concept of short-circuit current (SCC) reduction for power distribution systems is presented and analyzed. Conventional fault current limiters (FCLs) are connected in series with a circuit breaker (CB) that is required to limit the short-circuit current. Instead, the proposed scheme consisted of the parallel connection of a current-controlled power converter to the same bus intended to reduce the amplitude of the short-circuit current. This power converter was controlled to absorb a percentage of the short-circuit current from the bus to reduce the amplitude of the short-circuit current. The proposed active short-circuit current reduction scheme was implemented with a cascaded H-bridge power converter and tested by simulation in a 13.2 kV industrial power distribution system for three-phase faults, showing the effectiveness of the short-circuit current attenuation in reducing the maximum current requirement in all circuit breakers connected to the same bus. The paper also presents the design characteristics of the power converter and its associated control scheme.


2019 ◽  
Vol 217 ◽  
pp. 01020 ◽  
Author(s):  
Margarita Chulyukova ◽  
Nikolai Voropai

The paper considers the possibilities of increasing the flexibility of power distribution systems by real-time load management. The principles of the implementation of special automatic systems for this purpose are proposed. These systems enable some loads of specific consumers of the power distribution system switched to islanded operation to “shift” from the daily maximum to the minimum, which makes some generators available to connect certain essential consumers disconnected earlier by under-frequency load shedding system to the power system. The approach under consideration is illustrated by a power system with distributed generation.


2013 ◽  
Vol 860-863 ◽  
pp. 2007-2012 ◽  
Author(s):  
Xiao Meng ◽  
Neng Ling Tai ◽  
Yan Hu ◽  
Xia Yang

The failure current in resonant grounder power distribution system is small, so it is difficult to detect the fault feeder. This passage presents the equivalent circuit of resonant grounded system, and discusses the difference of electrical characteristics between faulty feeder and sound feeders by using shunt resistors. To reduce the influence of shunt resistors on the system and improve the detection sensitivity, it presents the method of shunting multi-level resistors, and it proves the sensitivity and reliability of this method by EMTP simulation.


Author(s):  
Reza Tajik

Nowadays, the utilization of renewable energy resources in distribution systems (DSs) has been rapidly increased. Since distribution generation (DG) use renewable resources (i.e., biomass, wind and solar) are emerging as proper solutions for electricity generation. Regarding the tremendous deployment of DG, common distribution networks are undergoing a transition to DSs, and the common planning methods have become traditional in the high penetration level. Indeed, in conformity with the voltage violation challenge of these resources, this problem must be dealt with too. So, due to the high penetration of DG resources and nonlinear nature of most industrial loads, the planning of DG installation has become an important issue in power systems. The goal of this paper is to determine the planning of DG in distribution systems through smart grid to minimize losses and control grid factors. In this regard, the present work intending to propose a suitable method for the planning of DSs, the key properties of DS planning problem are evaluated from the various aspects, such as the allocation of DGs, and planning, and high-level uncertainties. Also depending on these analyses, this universal literature review addressed the updated study associated with DS planning. In this work, an operational design has been prepared for a higher performance of the power distribution system in the presence of DG. Artificial neural network (ANN) has been used as a method for voltage monitoring and generation output optimization. The findings of the study show that the proposed method can be utilized as a technique to improve the process of the distribution system under various penetration levels and in the presence of DG. Also, the findings revealed that the optimal use of ANN method leads to more controllable and apparent DS.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
J. L. Guardado ◽  
F. Rivas-Davalos ◽  
J. Torres ◽  
S. Maximov ◽  
E. Melgoza

Network reconfiguration is an alternative to reduce power losses and optimize the operation of power distribution systems. In this paper, an encoding scheme for evolutionary algorithms is proposed in order to search efficiently for the Pareto-optimal solutions during the reconfiguration of power distribution systems considering multiobjective optimization. The encoding scheme is based on the edge window decoder (EWD) technique, which was embedded in the Strength Pareto Evolutionary Algorithm 2 (SPEA2) and the Nondominated Sorting Genetic Algorithm II (NSGA-II). The effectiveness of the encoding scheme was proved by solving a test problem for which the true Pareto-optimal solutions are known in advance. In order to prove the practicability of the encoding scheme, a real distribution system was used to find the near Pareto-optimal solutions for different objective functions to optimize.


Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 199
Author(s):  
Chengwei Lei ◽  
Weisong Tian

Fused contactors and thermal magnetic circuit breakers are commonly applied protective devices in power distribution systems to protect the circuits when short-circuit faults occur. A power distribution system may contain various makes and models of protective devices, as a result, customizable simulation models for protective devices are demanded to effectively conduct system-level reliable analyses. To build the models, thermal energy-based data analysis methodologies are first applied to the protective devices’ physical properties, based on the manufacturer’s time/current data sheet. The models are further enhanced by integrating probability tools to simulate uncertainties in real-world application facts, for example, fortuity, variance, and failure rate. The customizable models are expected to aid the system-level reliability analysis, especially for the microgrid power systems.


2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Teng ◽  
Yuejiao Wang ◽  
Shumin Sun ◽  
Yan Cheng ◽  
Peng Yu ◽  
...  

DC power distribution systems will play an important role in the future urban power distribution system, while the charging and discharging requirements of electric vehicles have a great impact on the voltage stability of the DC power distribution systems. A robust control method based on H∞ loop shaping method is proposed to suppress the effect of uncertain integration on voltage stability of DC distribution system. The results of frequency domain analysis and time domain simulation show that the proposed robust controller can effectively suppress the DC bus voltage oscillation caused by the uncertain integration of electric vehicle, and the robustness is strong.


The Indian economy has been growing at a fast pace since the beginning of this millennium. Due to constraints in the availability of fuel and environmental concerns, the power generation sector has not kept pace with other industrial sectors. One way of increasing the power availability is by reducing the high losses in the existing power transmission and distribution systems. The current increases in the motor windings when the voltages in the three phases are unbalanced. Compensation for reactive power and unbalance in the power distribution system are key factors in improving the power quality to the end user. A Distributed Static Compensator [DSTATCOM] is a custom power device, which is connected in shunt with the load in the distribution system to compensate the reactive power due unbalanced loads. The performance of the DSTATCOM is based on the control technique used for finding the voltage referred and current components to be considered. Voltage compensation is defined as the error in voltage in the grid and that the value of voltage that has to be induced in the grid. This is analyzed by using DSTATCOM for voltage compensation with series converter controller block. This paper gives the simulation of voltage compensation to rectify the issue of voltage swell/sag in order to improve the power quality in the distribution system.


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