scholarly journals Integration of Photovoltaic Power Units to Power Distribution System through Modular Multilevel Converter

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2753 ◽  
Author(s):  
Seyed Hakimi ◽  
Amin Hajizadeh
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Lyapunov Theory ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Power Distribution System ◽  
Grid Voltage

With the growing of using photovoltaic (PV) units in power distribution systems, the role of high-performance power electronic converters is increasing. In this paper, modelling and control of Modular Multilevel Converter (MMC) are addressed for grid integration of PV units. Designing a proper controller for MMC is crucial during faulty conditions to make the converter stable and provide proper dynamic performance. To achieve this goal, a dynamic model of MMC is presented which it includes symmetrical components of voltage and current. Then, adaptive robust current controllers are developed based on sliding mode and fuzzy controllers for MMC and then the robustness and stability of the controllers are proved by the Lyapunov theory. To implement the proposed controllers under unbalanced grid voltage fault, positive and negative sequences current controllers are implemented to compensate the effect of grid voltage fault and load power variation. Finally, numerical results are shown to evaluate the performance of MMC. In the end, the experimental results are given to prove the controller performance. The outcome indicates that the proposed current controllers are more effective under voltage disturbance conditions and could satisfy the stability of MMC.

scholarly journals Complete power distribution system representation and state determination for fault location

DYNA ◽  
2015 ◽  
Vol 82 (192) ◽  
pp. 141-149 ◽  
Author(s):  
Andres Felipe Panesso-Hernández ◽  
Juan Mora-Flórez ◽  
Sandra Pérez-Londoño
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Fault Location ◽  
Estimation Error ◽  
Distance Estimation ◽  
Power Distribution Systems ◽  
Line Load ◽  
Power Distribution System ◽  
Line Section

<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>

scholarly journals Active Reduction of Short-Circuit Current in Power Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 334
Author(s):  
Esteban Pulido ◽  
Luis Morán ◽  
Felipe Villarroel ◽  
José Silva
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Power Converter ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
In Series

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.

scholarly journals A Single-Phase Buck-Boost Matrix Converter with Low Switching Stresses

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Naveed Ashraf ◽  
Tahir Izhar ◽  
Ghulam Abbas
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Single Phase ◽  
Low Voltage ◽  
Sliding Mode ◽  
Low Frequency ◽  
Matrix Converter ◽  
Power Distribution System ◽  
Selective Approach ◽  
Switching Devices

The suggested single-phase ac-to-ac matrix converter operated with inverting and noninverting characteristics may solve the grid voltage swell and sag problem in power distribution system, respectively. It is also employed as a direct frequency changer for domestic induction heating. The output voltage is regulated through duty cycle control of high frequency direct PWM (DPWM) and indirect PWM (IDPWM) switching devices. The DPWM control switches control the switching states of IDPWM switching devices. The inverting and noninverting characteristics are achieved with low voltage stresses and hence low dv/dt across the high and low frequency-controlled switches. This reduces their voltage rating and losses. The high voltage overshoot problem in frequency step-up operation is also analyzed. The sliding mode (SM) controller is employed to solve this problem. Pulse selective approach determines the power quality of load voltage. The validity of the mathematically computed values is carried out by modelling the proposed topology in MATLAB/Simulink environment and through hardware results.

scholarly journals Flexibility Enhancement in an Islanded Distribution Power System by Online Demand-Side Management

2019 ◽  
Vol 217 ◽  
pp. 01020 ◽  
Author(s):  
Margarita Chulyukova ◽  
Nikolai Voropai
Keyword(s):  
Power System ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Load Shedding ◽  
Load Management ◽  
Daily Maximum ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Islanded Operation

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.

scholarly journals Islanding Detection in Rural Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5503
Author(s):  
Wen Fan ◽  
Ning Kang ◽  
Robert Hebner ◽  
Xianyong Feng
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Islanding Detection ◽  
Distribution Grid ◽  
Power Distribution System ◽  
University Of Texas ◽  
Intelligent Sensors ◽  
Detection Approach ◽  
The University

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.

Shunt Petersen-Coil with Resistor for Single Phase Fault Detection in Resonant Grounded Power Distribution Systems

2013 ◽  
Vol 860-863 ◽  
pp. 2007-2012 ◽  
Author(s):  
Xiao Meng ◽  
Neng Ling Tai ◽  
Yan Hu ◽  
Xia Yang
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Single Phase ◽  
Detection Sensitivity ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Multi Level ◽  
The Difference ◽  
Petersen Coil

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.

Planning of Distribution System with High Penetration Level for Distributed Generation in Smart Grid

2018 ◽  
Vol 8 (3) ◽  
Author(s):  
Reza Tajik
Keyword(s):  
Smart Grid ◽  
Power Systems ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Distribution Networks ◽  
Planning Problem ◽  
Renewable Energy Resources ◽  
Power Distribution System ◽  
High Penetration

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.

scholarly journals An Encoding Technique for Multiobjective Evolutionary Algorithms Applied to Power Distribution System Reconfiguration

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
J. L. Guardado ◽  
F. Rivas-Davalos ◽  
J. Torres ◽  
S. Maximov ◽  
E. Melgoza
Keyword(s):  
Evolutionary Algorithms ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Pareto Optimal ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Power Distribution Systems ◽  
Encoding Scheme ◽  
Power Distribution System

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.

scholarly journals Probability-Based Customizable Modeling and Simulation of Protective Devices in Power Distribution Systems

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 199
Author(s):  
Chengwei Lei ◽  
Weisong Tian
Keyword(s):  
Power Systems ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Current Data ◽  
System Level ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Protective Devices

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.

scholarly journals Robust Stability Control for Electric Vehicles Connected to DC Distribution Systems

2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Teng ◽  
Yuejiao Wang ◽  
Shumin Sun ◽  
Yan Cheng ◽  
Peng Yu ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Stability Control ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Dc Power ◽  
Dc Distribution

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.

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