Showing papers in "Electric Power Components and Systems in 2017"
TL;DR: In this paper, a microgrid concept has been widely adopted by power and energy community to boost the resilience and enhance the economics of the energy system, stability control and economic control are two main f...
Abstract: Microgrid concept has been widely adopted by power and energy community to boost the resilience and enhance the economics of the energy system. Stability control and economic control are two main f...
68 citations
TL;DR: In this paper, the authors present the concept of a universal DC distribution system, as envisioned by the authors, which could be implemented in various use cases, but could also completely replace AC distribution grids.
Abstract: Due to an increasing number of power generation units and load devices operating with direct current (DC) at distribution level, there is a potential benefit of leading efforts toward building a DC distribution system. However, the implementation of DC distribution systems faces important challenges, including the market inertia of AC systems and standardization. Many of the benefits that are attributed to DC can only be realized if a complete DC system is developed, and not if only a few components are replaced. This paper presents the concept of a universal DC distribution system, as envisioned by the authors. The universal DC distribution system could be implemented in various use cases, but could also completely replace AC distribution grids. The paper covers the possibilities of having DC nanogrids inside buildings, DC microgrids in neighborhoods, and the connection to AC and DC medium voltage grids. Furthermore, considerations regarding flexibility, electricity market design, control, and pr...
65 citations
TL;DR: In this article, the authors review the availability of fault location techniques in traditional distribution networks and present a review of the availabability of these techniques with satisfactory accuracy for the last two decades.
Abstract: Electricity customers are usually connected to the power system networks through distribution grids, and any interruption in these grids causes customer minute loss (CML). Most of the CMLs are caused due to different types of faults sustained for a longer period of time. Therefore, rapid fault location techniques are very necessary in order to restore the power supply quickly by reducing outage durations and revenue losses. To expedite restoration process and to ensure reliable power supply in traditional distribution networks, many fault location techniques were presented by researchers with satisfactory accuracy for last two decades. However, the recent trends of adopting distributed generators (DGs) to distribution grids are disturbing grid protection schemes by changing their technical parameters and direction of current/power flows. Additionally, the accuracy of traditional fault lactation techniques is also being affected significantly. The aim of this research paper is to review the availab...
54 citations
TL;DR: An efficient methodology based on the Grey Wolf Optimizer (GWO) to determine the optimal size and location of ESSs in a distribution network so as to minimize the total annual cost of system comprising the cost of energy not supplied (ENS), the ESS's investment costs and operating costs is proposed.
Abstract: One of the most important issues that must be taken into consideration during the operation of distribution network is improving the network reliability. This objective can be achieved by connecting energy storage systems (ESSs) to the network; the correct size and location of these ESSs cause enhancing of the system reliability. This paper proposes an efficient methodology based on the Grey Wolf Optimizer (GWO) to determine the optimal size and location of ESSs in a distribution network so as to minimize the total annual cost of system comprising the cost of energy not supplied (ENS), the ESSs' investment costs and operating costs. The proposed methodology is applied to two radial distribution systems, a 30-bus, 11-kV system and a 69-bus, 12.6-kV system. The results obtained via the proposed GWO are compared to those obtained via classical approaches, dynamic programming (DP), and meta-heuristic algorithms (PSO). In the case of a 30-bus network, the total cost is saved by 14.12% from the base cas...
44 citations
TL;DR: In this article, a robust proportional integral derivative (PID) load frequency controller is designed, through the H∞ performance analysis and the particle swarm optimization (PSO) searching algorithm, to deal with the load disturbances and multiple delays in the LFC loop and the DDC loop.
Abstract: Communication networks are used in load frequency control (LFC) for transmitting remote measurements and control commands, and in demand side response (DSR) for aggregating small-scale controllable loads. This paper investigates modeling and controller design for LFC together DSR in a deregulated environment, considering multiple time delays introduced by the usage of communication channels. Time delay model of the deregulated multi-area LFC with dynamic demand control (DDC) is obtained at first, in which a typical thermostatically controlled appliance, air conditioner, is used for DDC. A robust proportional integral derivative (PID) load frequency controller is designed, through the H∞ performance analysis and the particle swarm optimization (PSO) searching algorithm, to deal with the load disturbances and multiple delays in the LFC loop and the DDC loop. Case studies based on a three-area deregulated LFC system demonstrate the effectiveness of the proposed load frequency controller and the perfo...
40 citations
TL;DR: An optimal control design for minimization of the power flow in tie-lines and frequency deviations in the microgrid, which will lead to power balance between the generation and load demand of the system.
Abstract: Active power balance and frequency control are important tasks in the daily management of a power system. With the integration of several microgrids in the modern power system, the balancing of sou...
39 citations
TL;DR: In this article, optimal single and multiple installations of different types of distributed generation (DG) units are used to handle annual growth in system load, while satisfying system operational constraints.
Abstract: In power distribution network, the gradual increase in system load is a natural process, and it results in increased real and reactive power losses and reduced voltage profile. In this paper, optimal single and multiple installations of different types of distributed generation (DG) units are used to handle annual growth in system load, while satisfying system operational constraints. For load growth study, a predetermined growth in system annual load is considered. Minimization of system total real power loss is taken as the main objective, and optimal location and sizing of different DG types are determined using a hybrid configuration of weight-improved particle swarm optimization (WIPSO) with gravitational search algorithm (GSA) called hybrid WIPSO-GSA algorithm. The effect of load growth is studied using standard 33-bus radial distribution system, and the results illustrate significant reduction in system real and reactive power losses, enhancement in system voltage profile, and improvement i...
38 citations
TL;DR: In this paper, a heuristic approach for the planning of distributed generator (DG) to minimize annual system energy loss has been proposed, where the particle-swarm optimization-based method has been used as an optimization tool for determining the optimal size and allocating the DGs to minimize energy loss.
Abstract: This research work proposes a heuristic approach for the planning of Distributed Generator (DG) to minimize annual system energy loss. The particle-swarm-optimization-based method has been used as an optimization tool for determining the optimal size and allocating the DGs to minimize energy loss. In this approach, time-varying characteristics of electrical load demand have been considered to mimic real load scenario in the electrical distribution system. The proposed approach is generic and simple. It can provide optimal solutions to the distribution utilities to select multiple DGs in stages under various constraints. The effectiveness of the proposed approach is validated on 16-, 33-, and 69-bus radial distribution networks. The results are compared with those of already existing methods as suggested in the literature.
34 citations
TL;DR: A novel hybrid algorithm–chaotic artificial bee colony differential evolution (CABC-DE) algorithm, which improves the DE algorithm based on Artificial bee colony algorithm and ideas of chaotic search, which can save the search time greatly and get a better solution for optimization, thus making it suitable for solving reactive power optimization problems.
Abstract: Reactive power optimization is closely related to voltage quality and network loss, and it has great significance for the safety, reliability, and economical operation of the power system. Differential evolution (DE) algorithm has been currently applied to reactive power optimization. In order to mitigate the shortcomings of poor local search ability and premature convergence in DE, this paper presents a novel hybrid algorithm–chaotic artificial bee colony differential evolution (CABC-DE) algorithm, which improves the DE algorithm based on artificial bee colony algorithm and ideas of chaotic search. It introduces the observation bees' acceleration operation and the detective bees' chaotic search operation into CABC-DE. The validity of the proposed method is examined using IEEE-14 and IEEE-30 bus system. The experimental results show that CABC-DE algorithm is more effective than regular DE algorithm for reactive power optimization. The algorithm can save the search time greatly and get a better sol...
33 citations
TL;DR: The dynamic performance of the system is observed in terms of settling time, peak overshoot and peak undershoot, which reveals the adaptability of the proposed method in multi-area interconnected power system.
Abstract: This paper deals with an optimal hybrid fuzzy-Proportional Integral Derivative (fuzzy-PID) controller optimized by hybrid differential evolution–Grey Wolf optimization algorithm for automatic gener...
33 citations
TL;DR: In this article, a hybrid algorithm to identify the islanding has been proposed based on the passive parameters (ROCOV and ROCORP) and capacitor bank connection strategy.
Abstract: Nowadays, penetration of DG resources into the power systems due to their advantages is rapidly increasing. Islanding performance is one of the most disadvantages of using DGs, which should be considered, because this option may lead to negative effects on the protection, performance, and operation management of distributed systems implementation. An island must be detected in less than 2 sec based on IEEE STD 1547-2003 standard, and DG resources must be disconnected from distribution network immediately. In this paper, a novel hybrid algorithm to identify the islanding has been proposed based on the passive parameters (ROCOV and ROCORP) and capacitor bank connection strategy. In the incompatibility conditions of the large-scale power, by combining two parameters i.e. ROCOV and ROCORP and investigating their changes, the islanding is carefully and quickly identified. This strategy is completely verified in the mismatch conditions of small-scale power by applying the capacitor bank connection strat...
TL;DR: In this article, the authors developed coordinated EV charging strategies for renewable energy powered charging stations in parking lots to maximize the profits for parking lot operators by taking advantage of time-varying electricity pricing while satisfying system constraints.
Abstract: Electric vehicles (EVs) are increasing in popularity because of their low operating cost and environmental friendly operation. The anticipated rise in EV usage, along with the increased use of renewable energy sources and smart storage devices for EV charging, presents opportunities as well as challenges. Time-varying electricity pricing and day-ahead power commitment add another dimension to this problem. In this research, we develop coordinated EV charging strategies for renewable energy powered charging stations in parking lots. This work maximizes the profits for parking lot operators by taking advantage of time-varying electricity pricing while satisfying system constraints. We propose a linear programming-based strategy for EV charging, and we specifically derive a centralized linear program that minimizes the charging cost for parking lot operator while satisfying customers’ demand in available time.
TL;DR: The proposed method uses only demand profile information and ESS parameters to achieve load-leveling and peak demand reduction and also considers the entire optimization time horizon.
Abstract: A method for applying combinatorial optimization algorithms to Energy Storage System (ESS) scheduling is presented in this paper. Scheduling is essential for the integration of ESS in electrical ne...
TL;DR: An energy management technique for isolated DC microgrids for academic readers, as well as provides an introduction to not-familiarized readers for understanding the common design challenges for implementing off-grid power systems.
Abstract: Recent times have witnessed a significant positive trend in adoption of renewable energy sources and DC-based loads, which questions the efficiency and reliability of existing structure of electric...
TL;DR: In this paper, a new Switched DC-Link Capacitor Multi-Level Converter (SDC2MLC) with considerably few numbers of power electronics switches (IGBTs) is proposed, where keeping the total harmonic distortion of the output voltage waveforms as low as possible is desired.
Abstract: At present, one of the most common techniques for high power conversion in medium-voltage applications is the use of cascaded multi-level converters. In this article, a new Switched DC-Link Capacitor Multi-level converter (SDC2MLC) with considerably few numbers of power electronics switches (IGBTs) is proposed, where keeping the total harmonic distortion of the output voltage waveforms as low as possible is desired. The proposed topology is configured using two separate basic units. Each unit consists of four switches with a series-parallel combination of isolated DC sources. The performance of the presented topology for both configurations is described. The required number of switches, power diodes, gate driver circuits, and voltage stresses across the switches are compared with those of other recently published techniques. Furthermore, the operation and performance of the proposed SDC2MLC are illustrated with the aid of experimental results of a single-phase 11-level converter to clarify the via...
TL;DR: In this paper, a less conservative stability criterion is presented to ascertain delay-dependent stability of such network-controlled LFC systems with two additive time-varying delays in the feedback path in the presence of uncertain load disturbance conditions.
Abstract: In deregulated power system scenario coupled with smart grid technology, for networked load frequency control (LFC), an open communication structure, owing to low cost and flexibility, is preferred over dedicated networks in the feedback control loop for transmitting/receiving the data between the geographically displaced power system and the control center. In such a control scheme, closing the feedback loop through an open communication channel, in turn, introduces two additive time-varying delays of dissimilar characteristics in the feedback path. These delays degrade the performance of the closed-loop system, and exert a destabilizing effect on the overall system. In this paper, using Lyapunov-Krasovskii functional approach, a less conservative stability criterion is presented to ascertain delay-dependent stability of such network-controlled LFC systems with two additive time-varying delays in the feedback path in the presence of uncertain load disturbance conditions. Unlike the existing resul...
TL;DR: In this article, the authors proposed a computationally efficient direct model predictive control (DMPC) scheme for doubly-fed induction generators (DFIGs) based on variable speed wind turbine systems (WTSs).
Abstract: In reality, heavy calculation burden is an obstacle for applying direct model predictive control (DMPC) schemes in industrial applications. To resolve this problem, this paper proposes a computationally efficient DMPC scheme for doubly-fed induction generators (DFIGs) based on variable-speed wind turbine systems (WTSs). The procedure of selecting the optimal switching vector is enhanced by calculating the reference voltage vector (VV) directly from the reference current. Then, the sector where this reference VV is located is identified. Finally, the cost function is evaluated only for three times to get the best switching action. Consequently, the necessity to test all candidates VVs will be avoided, which reduces the calculation burden of the conventional DMPC method. Control performance of the proposed efficient DMPC method is compared with the conventional DMPC by simulation results for all operation conditions. Furthermore, the performance of the proposed efficient DMPC is investigated under variations of the DFIG parameters and in case of unbalanced grid conditions.
TL;DR: The widespread proliferation of electric vehicles (EVs) can have a transformative effect on the electric power system as mentioned in this paper, and the power and energy consumed by EVs when charging is substantial.
Abstract: The widespread proliferation of Electric Vehicles (EVs) can have a transformative effect on the electric power system. The power and energy consumed by EVs when charging is substantial, which has c...
TL;DR: The feedback linearization technique is employed to obtain the control laws, which simplifies the original dynamical models and decouples different components in the form of several subsystems to achieve the desired control objectives.
Abstract: This paper aims to design decentralized controllers for different components in islanded DC microgrids. The major components in the DC microgrid as considered in this paper include a fuel cell, sol...
TL;DR: In this article, a photovoltaic (PV) array interfaced with a DC-DC boost converter feeding three-phase grid-tied voltage source converter is designed and modeled, and its performance is verified through simulation in MATLAB/Simulink.
Abstract: This paper deals with the design, modeling, and implementation of a photovoltaic (PV) array interfaced with a DC–DC boost converter feeding three-phase grid-tied voltage source converter. The system uses an Instantaneous Reactive Power Theory-based control algorithm and is operated in unity power factor mode. This three-phase shunt-connected solar PV energy conversion system is also used for load currents harmonics elimination, power factor correction, reactive power compensation, and grid currents balancing in a three-phase distribution system. A Perturb and Observe-based maximum power point tracking algorithm is used to generate maximum power from the PV array. This system is designed and modeled, and its performance is verified through simulation in MATLAB/Simulink. A prototype of the proposed renewable energy system is developed in the laboratory using a digital signal processor to validate its design and control.
TL;DR: A Binary Gravitational Search Algorithm methodology for the optimal placement of Phasor Measurement Units (PMUs) to achieve full and maximum observability of the power system and case studies reveal that the lower number of PMUs or equal number ofPMUs has been produced by the proposed method compared to methods reported in the literature.
Abstract: This paper presents a Binary Gravitational Search Algorithm (BGSA) methodology for the optimal placement of Phasor Measurement Units (PMUs) to achieve full and maximum observability of the power sy...
TL;DR: In this article, the authors exploited the utilization of photovoltaic (PV) energy system with highvoltage (HV) output DC-DC converter to maximize the PV power generation.
Abstract: This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power generation. The proposed power circuitry substantially improves the output power gain transfer ratio and a prototype hardware module is implemented using industrial standard DSP TMS 320F2812. Numerical simulation development followed by an experimental prototype implementation is carried out in this investigation. A set of numerical and experimental results is provided in this paper, which show close conformity with...
TL;DR: In this paper, an application of teaching-learning-based optimization method for the optimal allocation of Distributed Generations (DGs) in radial distribution systems is addressed, where the problem is formulated to maximize annual energy loss reduction while maintaining better node voltage profiles using penalty function approach.
Abstract: This paper addresses an application of Teaching-Learning-Based Optimization method for the optimal allocation of Distributed Generations (DGs) in radial distribution systems. The problem is formulated to maximize annual energy loss reduction while maintaining better node voltage profiles using penalty function approach. A piecewise linear multi-level load pattern is considered, and the distribution network is reconfigured after optimal placement of DGs in the distribution network. A probability-based heuristic intelligent search (IS) is suggested to enhance the accuracy and convergence of the optimization techniques. IS directs optimization techniques to efficiently scan the problem search space in such a way that a fair candidature is available to all decision variables of the problem. It virtually squeezes the search space while maintaining adequate diversity in population. The proposed method is investigated on the benchmark IEEE 33-bus, 69-bus test distribution systems, and 83-bus real distrib...
TL;DR: In this paper, an optimal bidding strategy for price-taker generation companies (GenCos), which participate in a day-ahead joint energy and reserve market, is presented, and the problem is formulated as a Mixed-Integer Quadratic Constrained Program (MIQCP) to maximize the profit.
Abstract: This paper presents an optimal bidding strategy for price-taker generation companies (GenCos), which participate in a day-ahead joint energy and reserve market. Moreover, this problem is formulated as a Mixed-Integer Quadratic Constrained Program (MIQCP) to maximize the profit. Also, the price uncertainties of energy and reserve markets prices have direct impacts on the expected profit and bidding curves. This optimization problem is modeled with utilization of information gap decision theory (IGDT) for optimizing robustness to failure—or opportunity to windfall—under uncertainty conditions. IGDT assesses the robustness/opportunity of bidding strategy in the face of price uncertainties to determine whether a decision is risk-averse or risk-taking. Correlations among the prices of energy and reserve markets are properly modeled based on the concept of weighted average squared error using a variance–covariance matrix. It is shown that the risk-averse decisions, as well as risk-taking decisions, will...
TL;DR: Simulation results show that the proposed control strategy can effectively improve the performance of wind power fluctuation smoothing and ensure that the HESS works within a reasonable range to guarantee the long-term stable operation of the Hess.
Abstract: For the purpose of smoothing wind power fluctuations by using a battery–supercapacitor hybrid energy storage system (HESS), this paper designs a novel control strategy based on a self-adaptive wavelet packet decomposition technique and a two-level power reference signal distribution method. According to the fluctuation characteristics of wind power in different output scenarios, and considering the grid regulations on wind power volatility, the proposed technique can yield wind power grid-connected values adaptively. Then, the HESS power reference signals will be given by a two-stage reasonable distribution method based on the performance characteristics and the state of charge of the HESS. Simulation results show that the proposed control strategy can effectively improve the performance of wind power fluctuation smoothing and ensure that the HESS works within a reasonable range to guarantee the long-term stable operation of the HESS.
TL;DR: The experimental results are found to closely match with the theoretical values, indicating that MEMS accelerometers can be successfully employed for the detection of stator winding inter-turn short circuit fault in induction motors.
Abstract: This paper presents a novel method for detecting stator winding inter-turn short circuit fault in a three-phase induction motor by vibration signature analysis using non-electrical contact type mic...
TL;DR: In this paper, the authors proposed a robust protection scheme to alleviate some problems associated with topology selection for DC microgrid topologies, which uses continuous finite-time convergent differentiator to estimate the derivative of line currents.
Abstract: Various topologies of the Direct Current (DC) microgrid have been proposed in the literature by considering practical requirements. One of the important criteria in topology selection is the availability of a well-functioning protection scheme. A significant part of the DC microgrid protection system literature considers differential protection schemes for various topologies. However this scheme doesn’t work satisfactorily with noisy measurements. Noisy measurements are a reality and can not be avoided for any real engineering system. This article proposes a robust protection scheme to alleviate some problems associated with topology selection. The proposed scheme considers noisy current measurements and works by estimating the time derivative of line currents. The proposed approach uses continuous finite-time convergent differentiator to estimate the derivative. The gains of the differentiator were tuned through Firefly algorithm-based optimization technique. Matlab/Simulink ®-based simulations v...
TL;DR: Simulation results show Antlion algorithm optimized Fuzzy PID supervised on-line recurrent fuzzy neural network based controller has proved to be superior than other considered controllers in all aspects.
Abstract: In this paper, Antlion algorithm optimized Fuzzy PID supervised on-line Recurrent Fuzzy Neural Network based controller is proposed for the speed control of Brushless DC motor. Learning parameters ...
TL;DR: In this article, the authors describe the development of high-frequency air-gap windings for a 1 MW, 96% efficient permanent magnet (PM) motor, targeted at 13 kW/kg.
Abstract: This paper describes the development of high-frequency air-gap windings for a 1 MW, 96% efficient permanent magnet (PM) motor, targeted at 13 kW/kg. Due to the power level and high-specific power requirements, special attention has to be paid to the electromagnetic, thermal, and mechanical performance for the high-frequency coils. Specifically, AC losses have to be minimized while fill factor and thermal conductivity of the assembly are maximized. The paper presents analytical and finite element-based AC loss studies along with experimental validation by indirect balanced calorimetry, and shares the results which should be scalable for other large machines. Hardware development and corresponding manufacturing process are also described.
TL;DR: Simulation results on the modified IEEE 30-bus test system indicate that SWTC_NSPSO can provide a lower and wider Pareto front than non-dominated sorting genetic algorithm II and a stochastic weight trade-off non- dominated sorting particle swarm optimization in a less computation effort, leading to a lower generator fuel cost and a higher system reliability trade-offs solution.
Abstract: In this paper, a stochastic weight trade-off chaotic non-dominated sorting particle swarm optimization (SWTC_NSPSO) is proposed for solving multi-objective economic dispatch considering win...