Subjects -> ENERGY (Total: 414 journals)
    - ELECTRICAL ENERGY (12 journals)
    - ENERGY (252 journals)
    - ENERGY: GENERAL (7 journals)
    - NUCLEAR ENERGY (40 journals)
    - PETROLEUM AND GAS (58 journals)
    - RENEWABLE ENERGY (45 journals)

ELECTRICAL ENERGY (12 journals)

Showing 1 - 12 of 12 Journals sorted alphabetically
CES Transactions on Electrical Machines and Systems     Open Access   (Followers: 1)
CPSS Transactions on Power Electronics and Applications     Open Access   (Followers: 3)
CSEE Journal of Power and Energy Systems     Open Access   (Followers: 1)
Electrical Engineering and Power Engineering     Open Access   (Followers: 3)
Electrochemical Energy Reviews     Hybrid Journal   (Followers: 3)
IEEE Open Journal of Power Electronics     Open Access   (Followers: 11)
IEEE Power and Energy Technology Systems Journal     Open Access   (Followers: 4)
IEEE Transactions on Transportation Electrification     Hybrid Journal   (Followers: 3)
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal   (Followers: 3)
Journal of Power Electronics     Hybrid Journal   (Followers: 6)
Journal of Power Sources Advances     Open Access   (Followers: 1)
KnE Energy     Open Access  
Similar Journals
Journal Cover
CSEE Journal of Power and Energy Systems
Number of Followers: 1  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2096-0042
Published by IEEE Homepage  [228 journals]
  • Pilot Protection Based on Amplitude Comparison for Renewable Power Teed
           Lines

    • Authors: Ke Jia;Zhe Yang;Yu Fang;Zhengxuan Zhu;Liming Zheng;Tianshu Bi;Ali Hooshyar;
      Pages: 1519 - 1529
      Abstract: Fault behaviors of inverter-interfaced renewable energy generators (IIREGs) are quite diverse from those of synchronous generators (SGs). They show the variable system impedance, the limited current and low inertia, so the proportional brake differential protection installed on the transmission line has a high risk of failure for phase-phase failures. To cope with this adaptive problem, a new pilot protection is proposed considering the huge differences in both current amplitudes. Also, an improved criterion is presented for a scenario with a teed line. The existing protection principles focus excessively on the fault current characteristics of IIREGs, so they cannot operate correctly once IIREGs do not output their fault current. This happens when IIREGs produce no power or the circuit breakers exactly reclose on permanent failures. However, the proposed method has good performance for the above cases. The proposed method only requires current amplitude information, and in this case the strict synchronizing measurement is not necessary. Case studies are performed under different fault conditions, and they confirm the proposed method has good performance under different fault conditions. Furthermore, it is also verified using field-testing data.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Modeling and Stability Issues of Voltage-source Converter-dominated Power
           Systems: A Review

    • Authors: Liansong Xiong;Xiaokang Liu;Yonghui Liu;Fang Zhuo;
      Pages: 1530 - 1549
      Abstract: With the substantive increase in the proportion of voltage-source converter (VSC)-based equipment, traditional power systems that primarily constituted of synchronous generators (SGs) gradually evolved into VSC-dominated ones. At the same time, there is an urgent need for modeling and stability assessment of such systems, since low inertia and weak damping features impair the ability of the systems to resist random disturbances. Existing works model the system dynamic processes from various domains (i.e., time, frequency and energy), and analyze/determine the system stability under small or large disturbances. Among them, small-signal stability assessments mainly adopt the time-domain analysis based on the state-space model while frequency-domain methods include the impedance model, phase-amplitude dynamics model, and static synchronous generator model. Large-signal stability assessments mainly exploit the time-domain simulation with detailed models (i.e., continuous/discrete-time mixed model with differential-difference-algebraic equations), and the energy-domain analysis is based on energy function models. This paper presents a comprehensive review of existing modeling and stability analysis methods for VSC-dominated power systems, including their basic principles, key features, application scenarios and development tendencies. Key technical issues related to modeling and stability analysis are also summarized.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Graph Computing and Its Application in Power Grid Analysis

    • Authors: Mike Zhou;Jianfeng Yan;Qianhong Wu;
      Pages: 1550 - 1557
      Abstract: Approaches to apply graph computing to power grid analysis are systematically explained using real-world application examples. Through exploring the nature of the power grid and the characteristics of power grid analysis, the guidelines for selecting appropriate graph computing techniques for the application to power grid analysis are outlined. A custom graph model for representing the power grid for the analysis and simulation purpose and an in-memory computing (IMC) based graph-centric approach with a shared-everything architecture are introduced. Graph algorithms, including network topology processing and subgraph processing, and graph computing application scenarios, including in-memory computing, contingency analysis, and Common Information Model (CIM) model merge, are presented.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Proportional Current Sharing Based on Periodic Dynamic Event-driven
           $H_{infty}$ Consensus in DC Microgrids with Power Coupling

    • Authors: Rui Wang;Qiuye Sun;Lei Liu;Li Zhang;Peng Wang;Huaguang Zhang;
      Pages: 1558 - 1568
      Abstract: Although the proportional current sharing has been widely studied, the heterogeneous characteristic of the different interfaced converters and power coupling terms among distributed generators (DGs) are rarely considered. Therefore, this paper proposes a secondary $H_{infty}$ consensus method with a periodic dynamic event-driven scheme for dc microgrids with power coupling to accomplish the precise proportional current-sharing. It is useful for reducing carbon. First, a generalized converter is constructed through equivalent transformation between rectifier and boost converter. Moreover, the heterogeneous characteristic of the interfaced converters regarding different DGs, such as wind and solar generators, is embedded into controller design. Furthermore, the standard linear heterogeneous multi-agent system with power coupling term is built. On this basis, the problem of proportional current sharing is modified into the output consistency problem of multi-agent systems. Furthermore, the $H_{infty}$ consensus approach is proposed to accomplish the precise proportional current sharing. Meanwhile, to shorten communication bandwidth, the periodic dynamic event-driven communication strategy is designed. Compared with traditional event-driven communication schemes, a lower communication frequency has been obtained through the proposed communication scheme. In addition, this communication scheme not only avoids Zeno-behavior, but also acquires the smallest sampling time interval. Finally, effectiveness of the proposed approach is verified by two test systems.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Operational Control of Low-voltage MTDC Systems in a Cyber-physical
           Environment

    • Authors: Wei Deng;Wei Pei;Ningning Li;Xue Zhang;Yin Yi;Li Kong;
      Pages: 1569 - 1582
      Abstract: Based on the standardized cyber-physical modeling and communication system - IEC 61850, this paper establishes the operational control architecture of a low-voltage multi-terminal DC (LV-MTDC) system. The coordinated operational control strategies, including power electronic transformer (PET), and voltage source converter (VSC), are proposed. Then a cyber-physical model of the system based on IEC 61850 is built, according to the application requirements of operational control in the LV-MTDC system. On this basis, the implementation method of system operational control based on IEC 61850 is proposed, including the software/hardware design of the intelligent electronic device (IED), dispatching operations and uninterrupted power supply. The simulation environment is further built to verify the system operational control technology, and the test platform is used to carry out the actual tests. The research results show that the operational control technology for the LV-MTDC system proposed in this paper is feasible, which can guarantee the rapid and accurate information exchange of control commands and settings, and thus effectively realize the operational control of the LV-MTDC system under complex conditions.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Effective Control of Smart Hybrid Power Systems: Cooperation of Robust LFC
           and Virtual Inertia Control Systems

    • Authors: Gaber Magdy;Hossam Ali;Dianguo Xu;
      Pages: 1583 - 1593
      Abstract: A modern power system is expected to consist primarily of renewables, which either lack or have less rotating masses (i.e., source of inertia) compared to the traditional generation sources. However, the growth of renewables generation, based on power electronics, can substantially decrease the inertia levels of renewable power grids, which can create several frequency stability issues, resulting in power system degradation. To address this issue, this paper presents a recent virtual inertia scheme predicated on electric vehicles (EVs) to mimic the necessary inertia power in low-inertia smart hybrid power systems (SHPSs), thus regulating the system frequency and avoiding system instability. Moreover, to guarantee robust performance and more stability for SHPSs against multiple perturbations, system uncertainties, and physical constraints, this paper also proposes a robust control strategy relying on a coefficient diagram method (CDM) for the load frequency control (LFC) of SHPSs considering high renewables penetration and EVs. The efficacy of the proposed system (i.e., robust LFC with the proposed VIC strategy) is validated by comparison with a conventional LFC with/without the proposed VIC system. In addition, the simulation outcomes show that the proposed system can considerably support smart low-inertia hybrid power systems for many different contingencies.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • TS Fuzzy Prediction-based SVC Compensation of Wind Farms Flicker: A
           Dual-UKF Approach

    • Authors: Saeedeh Ketabipour;Haidar Samet;Navid Vafamand;
      Pages: 1594 - 1602
      Abstract: Fast fluctuations in wind farm power produce voltage flicker in the network. One way to mitigate the flicker is to place a static VAr compensator (SVC). Due to the operating delay of SVCs, it is essential to predict the wind farm reactive power. Here, a novel fuzzy nonlinear modeling approach is suggested and used in the one-step-ahead prediction of the power characteristics. The base of the developed fuzzy modeling is the Takagi-Sugeno fuzzy representation and a dual-unscented Kalman filter (D-UKF). In other words, a nonlinear TS fuzzy system is trained online via the D-UKF. The forecasted value is used as the SVC's reference signal. A large amount of actual data gathered from a wind farm is used for the performance evaluation. This data is collected in winter and summer for different climate situations. Using the actual data, a current source with changing amplitude and phase which is updated every half-cycle, is used to model the wind farm. Numerical results, including the flicker indices, confirm the improvement in the SVC's performance.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Integrated Configuration and Control Strategy for PV Generation in Railway
           Traction Power Supply Systems

    • Authors: Peng Cheng;Huiwen Kong;Chao Wu;Jing Ma;
      Pages: 1603 - 1612
      Abstract: Recently, electric railways have experienced a rapid development causing an increasing power demand. Due to the flexible installation available at trackside land along railways, photovoltaic (PV) generation is suggested as an extension to the traction power supply system (TPSS) in railways. First, this paper proposes a three-phase integrated configuration for PV generation connected to a two-phase traction network and the on-site consumption of solar resources alongside railways. In this configuration, another inverse V/V transformer is used to maintain a balanced three-phase low voltage (LV) AC bus from a two-phase traction network. It is more convenient for accessing PV generation units. Then, in order to mitigate the negative sequence currents caused by electric trains, an individual phase current (IPC) control strategy for PV converters is developed for power quality improvement. It can not only supply the locomotive with asymmetrical currents, but also provide feedback to the grid through symmetrical currents. All the implementation and calculations are conducted in the three-phase stationary reference frame without any sequence extracting and power compensations. Finally, simulation results are presented to validate the effectiveness of the proposed IPC control strategy.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Coordinated Optimization of Multi-energy Generation Systems Considering
           the Health Damages of Coal-fired Pollutant Dispersion

    • Authors: Suhua Lou;Yinhao Yang;Yanjie Liang;Yaowu Wu;
      Pages: 1613 - 1622
      Abstract: Pollutants emitted from coal-fired power plants lead to the deterioration of air quality in developing countries, and contribute to both mortality and morbidity. To improve air quality from power generation, new dispatch strategies incorporated with air pollution dispersion models should be considered. This paper takes into account the impact of meteorological variations on spatio-temporal dispersion of pollutants. Depending on the coal-fired pollutant concentration estimated by the Gaussian plume dispersion model, exposure-response functions are used to quantify the resulting health effects. Furthermore, the corresponding economic costs of health damages are incorporated to penalize the power dispatch. Considering generation costs and economic costs of health damages, this paper formulates a two-stage stochastic optimization model of a multi-energy generation system including coal units, gas units, and photovoltaic stations. Finally, numerical studies based on a modified IEEE 14-node system are performed for illustration and validation.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Bi-objective Layout Optimization for Multiple Wind Farms Considering
           Sequential Fluctuation of Wind Power Using Uniform Design

    • Authors: Yinghao Ma;Kaigui Xie;Yanan Zhao;Hejun Yang;Dabo Zhang;
      Pages: 1623 - 1635
      Abstract: The fluctuation of wind power brings great challenges to the secure, stable, and cost-efficient operation of the power system. Because of the time-correlation of wind speed and the wake effect of wind turbines, the layout of wind farm has a significant impact on the wind power sequential fluctuation. In order to reduce the fluctuation of wind power and improve the operation security with lower operating cost, a bi-objective layout optimization model for multiple wind farms considering the sequential fluctuation of wind power is proposed in this paper. The goal is to determine the optimal installed capacity of wind farms and the location of wind turbines. The proposed model maximizes the energy production and minimizes the fluctuation of wind power simultaneously. To improve the accuracy of wind speed estimation and hence the power calculation, the time-shifting of wind speed between the wind tower and turbines' locations is also considered. A uniform design based two-stage genetic algorithm is developed for the solution of the proposed model. Case studies demonstrate the effectiveness of this proposed model.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Droop Control Method to Achieve Maximum Power Output of Photovoltaic for
           Parallel Inverter System

    • Authors: Wei Zhang;Zhong Zheng;Hongpeng Liu;
      Pages: 1636 - 1645
      Abstract: In general, the power distribution of a parallel inverter is achieved by the use of droop control in a microgrid system, which consists of PV inverters and non-regeneration energy source inverters without energy storage devices in an islanded mode. If the shared load power is no more than the available maximum PV inverter output power, then there is a power waste for the PV inverter. In addition, due to the intermittency of PV sources, the system may become unstable if the shared load power is more than the available maximum power output of the PV (MPO-PV) inverter. Therefore, in order to avoid power waste and potential instability caused by insufficient PV power by traditional droop control, this paper recommends an improved droop control scheme to maximize the power output of PV units. As required by the load, the remaining power is composed of the other inverters, which can effectively improve the utilization rating of renewable energy sources and system stability. At the same time, according to the system stability analysis based on small signal modeling, it has been designed around the droop coefficients of the improved droop control loop. In the end, the simulation and experimental results show that the suggested scheme has a varied validity and robustness.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Power Quality Dectection and Classification in Active Distribution
           Networks Based on Improved Empiricial Wavelet Transform and Disperson
           Entropy

    • Authors: Yanchun Xu;Shirong Fan;Shasha Xie;Mi Lu;
      Pages: 1646 - 1658
      Abstract: In this paper, a model including wind power generation, photovoltaic power generation and electric vehicle for high permeability active distribution network (ADN) is established. The power quality (PQ) disturbance signals in the high permeability are extracted, and the characteristics of disturbance signals are analyzed in the situation of grid connection, interruption and islanding. The multi-scale fluctuation dispersion entropy (MFDE) initialized by the improved empirical wavelet transform (IEWT) is utilized to detect and classify the disturbance signals in the high permeability ADN. First, the eigenvectors of the disturbance signals are obtained by using the multi-scale fluctuation dispersion entropy initiated by the IEWT, and then the reduced eigenvectors are put into the support vector machine to classify the PQ disturbances caused by the access of the different distributed generators accessed. The classification results are compared with that in the traditional methods and other similar ways; the effectiveness of the IEWT-MFDE system is verified.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Composite Model-free Adaptive Predictive Control for Wind Power Generation
           Based on Full Wind Speed

    • Authors: Shuangxin Wang;Jianshen Li;Zhongsheng Hou;Qingye Meng;Meng Li;
      Pages: 1659 - 1669
      Abstract: Aiming at the problem that the existing model-based control strategy cannot fully reflect stochastic fluctuations of wind power, this paper presents a model-free adaptive predictive controller (MFAPC) for variable pitch systems with speed disturbance suppression. First, an improved small-world neural network with topology optimization is used for 15-second-ahead forecasting of wind speed, whose rolling time is 1s, and the predicted value serves as a feedforward to obtain the early compensation variation of the pitch angle. Second, a function of the multi-objective optimization at full wind speed with optimal power point tracking and minimum control variation is constructed, and an advanced one-step adaptive predictive control algorithm for wind power is proposed based on the online estimation and prediction of the time-varying pseudo partial derivative (PPD). In addition, the compound MFAPC framework is synthetically obtained, whose closed-loop effectiveness is verified by a BP-built pitch system based on the SCADA data with all working conditions. Robustness of the schemes has been analyzed in terms of parametric uncertainties and different operating conditions, and a detailed comparison is finally presented. The results show that the proposed MFAPC can not only effectively suppress the random disturbance of wind speed, but also meet the stability of wind power and the security of grid-connections for all operating conditions.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Modeling and Analysis of PV Configurations to Extract Maximum Power Under
           Partial Shading Conditions

    • Authors: Aditi Atul Desai;Suresh Mikkili;
      Pages: 1670 - 1683
      Abstract: Photovoltaics (PV) are widely used as renewable energy sources for standalone and grid connected PV systems. But these PV systems face major reduction in output power and efficiency due to Partial Shading Conditions (PSCs). This research paper focuses on the different choices of optimum PV Configuration under a given shading pattern to extract maximum power by mitigating mismatching loss. Various PV configurations, such as Series (S), Series Parallel (SP), Total Cross Tied (TCT), Bridge Linked (BL), Honey Comb (HC) and Alternate Total Cross Tied – Bridge Linked (A-TCT-BL) are modeled and analyzed under PSCs. Nine shading patterns, such as center, diagonal, corner, L-shaped, short and narrow, short and wide, long and narrow, long and wide and random, are considered to study the behavior of a $6times 6$ array form of a PV Configuration. Their performances are compared based on open circuit voltage, short circuit current, global maximum power point (GMPP), maximum voltage, maximum current, shading loss, fill factor, mismatching loss and efficiency. A novel Hybrid Configuration called A-TCT-BL PV Configuration is proposed to generate maximum power under PSCs and to minimize the number of cross ties and wiring complexities. This Configuration is an integration of TCT and BL PV Configuration and the simulation results prove the capability of this proposed PV Configuration to generate maximum power, fill factor, efficiency and minimum mismatching loss compared to S, SP, BL and HC PV Configurations under a majority of the PSCs investigated. A Canadian Solar CS5P-200M PV module is considered for simulation and is simulated using Matlab/Simulink software.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Online Monitoring Method for Insulator Self-explosion Based on Edge
           Computing and Deep Learning

    • Authors: Baoquan Wei;Zhongxin Xie;Yande Liu;Kaiyun Wen;Fangming Deng;Pei Zhang;
      Pages: 1684 - 1696
      Abstract: Aiming at the problems of traditional centralized cloud computing which occupies large computing resources and creates high latency, this paper proposes a fault detection scheme for insulator self-explosion based on edge computing and DL (deep learning). In order to solve the high amount of computation brought by the deep neural network and meet the limited computing resources at the edge, a lightweight SSD (Single Shot MultiBox Detector) target recognition network is designed at the edge, which adopts the MobileNets network to replace VGG16 network in the original model to reduce redundant computing. In the cloud, three detection algorithms (Faster-RCNN, Retinanet, YOLOv3) with obvious differences in detection performance are selected to obtain the coordinates and confidence of the insulator self-explosion area, and then the self-explosion fault detection of the overhead transmission line is realized by a novel multimodel fusion algorithm. The experimental results show that the proposed scheme can effectively reduce the amount of uploaded data, and the average recognition accuracy of the cloud is 95.75%. In addition, it only increases the power consumption of edge devices by about 25.6W/h in their working state. Compared with the existing online monitoring technology of insulator selfexplosion at home and abroad, the proposed scheme has the advantages of low transmission delay, low communication cost and high diagnostic accuracy, which provides a new idea for online monitoring research of power internet of things equipment.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • A Hybrid Method for False Data Injection Attack Detection in Smart Grid
           Based on Variational Mode Decomposition and OS-ELM

    • Authors: Chunxia Dou;Di Wu;Dong Yue;Bao Jin;Shiyun Xu;
      Pages: 1697 - 1707
      Abstract: Accurate state estimation is critical to wide-area situational awareness of smart grid. However, recent research found that power system state estimators are vulnerable to a new type of cyber-attack, called false data injection attack (FDIA). In order to ensure the security of power system operation and control, a hybrid FDIA detection mechanism utilizing temporal correlation is proposed. The proposed mechanism combines Variational Mode Decomposition (VMD) technology and machine learning. For the purpose of identifying the features of FDIA, VMD is used to decompose the system state time series into an ensemble of components with different frequencies. Furthermore, due to the lack of online model updating ability in a traditional extreme learning machine, an OS-extreme learning machine (OS-ELM) which has sequential learning ability is used as a detector for identifying FDIA. The proposed detection mechanism is evaluated on the IEEE-14 bus system using real load data from an independent system operator in New York. Apart from detection accuracy, the impact of attack intensity and environment noise on the performance of the proposed method are tested. The simulation results demonstrate the efficiency and robustness of our method.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Economy Analysis of Flexible LCC-HVDC Systems with Controllable Capacitors

    • Authors: Nan Chen;Kunpeng Zha;Haitao Qu;Fangling Li;Ying Xue;Xiao-Ping Zhang;
      Pages: 1708 - 1719
      Abstract: Commutation failure (CF) is a frequent dynamic event at inverter of LCC-HVDC systems caused by AC side faults which can lead to inverter blocking, interruption of active power transfer, and even system blackout. To eliminate CFs and improve system performance, new Flexible LCC-HVDC topologies have been proposed in previous research but with limited analysis on its economic performance. Therefore, to further validate the applicability of Flexible LCC-HVDC topologies, this paper utilizes Life-Cycle Cost Analysis model to analyze the life-cycle cost of inverter stations for conventional LCC-HVDC, Capacitor Commutated Converter based HVDC (CCC-HVDC) topology and Flexible LCC-HVDC topologies including Controllable Capacitor based Flexible LCC-HVDC, AC Filterless Controllable Capacitor based Flexible LCC-HVDC and improved Flexible LCC-HVDC. Through a case study based on a 500 kV, 1000 MW LCC-HVDC scheme, comparison results show that the AC Filterless Controllable Capacitor based Flexible LCC-HVDC topology and the improved Flexible LCC-HVDC topology have lower cost than the conventional LCC-HVDC and CCC-HVDC topologies, which proves that the elimination of CFs can be achieved with reduced cost.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Grid Voltage Sensor-less Protection Scheme for One Cycle-Controlled
           Single-phase Photovoltaic Inverter Systems

    • Authors: Venkata R. Reddy;E. S. Sreeraj;
      Pages: 1720 - 1729
      Abstract: One-cycle-controlled (OCC) inverters are suitable for small single-phase photovoltaic distributed-generator systems because of their simplicity, phase-locked-loop free structure, grid voltage sensor-less operation, and cost-effectiveness. Grid voltage sensor-less control helps reduce cost and increases reliability in operation. However various sensors are used for implementation of a protection mechanism. In this paper, a grid voltage sensor-less protection scheme for OCC based single-phase inverter systems is proposed. The estimated value of voltage at point of common coupling (VPCC) is used for protecting the system during over/under voltage conditions of the grid, implementing of voltage ride through conditions, and for disconnecting the grid during islanded conditions. The VPCC is estimated from the measured inverter current, switching pulses, and the measured dc-link voltage using a second-order filter. Simulation and experimental studies are performed to verify the efficacy of the proposed voltage sensor-less protection mechanism triggered using estimated VPCC.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Scenario Generation for Cooling, Heating, and Power Loads Using Generative
           Moment Matching Networks

    • Authors: Wenlong Liao;Yusen Wang;Yuelong Wang;Kody Powell;Qi Liu;Zhe Yang;
      Pages: 1730 - 1740
      Abstract: Scenario generations of cooling, heating, and power loads are of great significance for the economic operation and stability analysis of integrated energy systems. In this paper, a novel deep generative network is proposed to model cooling, heating, and power load curves based on generative moment matching networks (GMMNs) where an auto-encoder transforms high-dimensional load curves into low-dimensional latent variables and the maximum mean discrepancy represents the similarity metrics between the generated samples and the real samples. After training the model, the new scenarios are generated by feeding Gaussian noises to the scenario generator of the GMMN. Unlike the explicit density models, the proposed GMMN does not need to artificially assume the probability distribution of the load curves, which leads to stronger universality. The simulation results show that the GMMN not only fits the probability distribution of multi-class load curves very well, but also accurately captures the shape (e.g., large peaks, fast ramps, and fluctuation), frequency-domain characteristics, and temporal-spatial correlations of cooling, heating, and power loads. Furthermore, the energy consumption of generated samples closely resembles that of real samples.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Distributed DC-Bus Signaling Control of Photovoltaic Systems in Islanded
           DC Microgrid

    • Authors: Noushin Poursafar;M. J. Hossain;Seyedfoad Taghizadeh;
      Pages: 1741 - 1750
      Abstract: The stability of an islanded DC microgrid (DCMG) is highly dependent on the presence and performance of the backup energy storage system (BESS), due to the lack of main grid support. This condition makes the DCMG vulnerable to the critical situation of absence of the BESS, which could be caused by a fault or being fully charged or flat. This paper presents an enhanced distributed DC-bus signaling control strategy for converters of photovoltaic systems (PVs) to make the islanded DCMG less dependent on the BESS. Unlike a conventional control approach that utilizes PVs to operate in maximum power point tracking (MPPT) mode and the BESS solely regulating DC-bus voltage, the proposed control method maintains DC-bus voltage via intelligently managing output powers of the PVs. The proposed control method continuously monitors DC-bus voltage and regulates the output powers of all the PVs via switching between MPPT mode and voltage regulating mode. Accordingly, if the DC-bus voltage level is less than a predefined maximum level, the PVs work in MPPT mode; otherwise, the PVs work in voltage regulating mode to maintain DC-bus voltage at an acceptable range. Such switching between MPPT and voltage regulating control operations results in protecting the DCMG from unavoidable shutdowns conventionally necessary during the absence of the BESS unit. Moreover, the proposed control method reduces oscillations on the DC-bus voltage during existence of the BESS. The performance and effectiveness of the proposed control strategy are validated through different case studies in MATLAB/Simulink.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Data Completion for Power Load Analysis Considering the Low-rank Property

    • Authors: Chijie Zhuang;Jianwei An;Zhaoqiang Liu;Rong Zeng;
      Pages: 1751 - 1759
      Abstract: With large-scale applications, the loss of power load data during transmission is inevitable. This paper proposes a data completion method considering the low rank property of the data. According to the low-rank property of data and numerical experiments, we find either the linear interpolation (LI) or the singular value decomposition (SVD) based method is superior to other methods depending on the smoothness of the data. We construct an index to measure the smoothness of data, and propose the SVDLI algorithm which adaptively selects different algorithms for data completion according to the index. Numerical simulations show that irrespective of the smoothness of data, the data complementing results of SVDLI are comparable to or better than the best of SVD or LI algorithms. The present study is verified using the measurements in China, and the public data of the Australian electricity distribution company and Lawrence Berkeley National Laboratory.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Hierarchical Multi-objective Planning for Integrated Energy Systems in
           Smart Parks Considering Operational Characteristics

    • Authors: Weijie Dong;Limei Zhang;Dongxia Zhang;Quansheng Cui;
      Pages: 1760 - 1771
      Abstract: An integrated energy system (IES) is considered to be an important supporting technology for emission reduction because it can effectively improve the efficiency of energy utilization and promote its sustainable development. Considering the uncertainties and operational conditions, this paper establishes a bilevel multi-objective optimization model for IES for the Smart Park from the standpoint of economy, technology and environment. The upper level with one objective reflects the economic cost composed of investment, operating and maintenance, etc. The lower level constructs three objectives, including pollution emission, operation costs and renewable energy utilization. Simultaneously, various equality and inequality constraints are addressed to satisfy the technical requirements. In addition, an improved MOEA/D-MC-DC algorithm (Multi Objective Evolutionary Algorithm through Decomposition Based on Monte Carlo and Decoupled Coding, MOEA/D-MC-DC) is presented for handling the complex and nonlinear bilevel multi-objective optimization problems with constraints. A genetic algorithm (GA) is used to solve the upper single objective, while MOEA is employed to cope with the multi-objectives of the lower level. Using three typical IESs in the Smart Park as examples, several simulations are carried out to verify the efficiency, applicability and universality of the proposed model and optimization algorithm. The results show that the proposed method can effectively optimize the configuration of an IES in various Smart Parks.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • A Reliability Assessment of an Integrated Energy System Based on Coupling
           Energy Flow and Thermal Inertia

    • Authors: Wenxia Liu;Tie Ma;Yue Yang;
      Pages: 1772 - 1783
      Abstract: With the wide application of integrated energy systems (IES), the degree of coupling between different types of energy sources is further strengthened, and the mechanism of fault development tends to be complicated. Therefore, in order to improve the accuracy and practicability of the reliability assessment of IESs, a sequential simulation reliability assessment method considering multi-energy flow and thermal inertia is proposed in this paper. In this method, the IES structure model is constructed with the combined cooling, heating and power (CCHP) unit as the core equipment, combining with the new energy source to realize the comprehensive energy power flow calculation considering any loss. Then, a load reduction optimization model is established, considering the importance of load and operational economy, in the system status analysis. Furthermore, the heat supply reliability index is corrected taking into account the transmission delay characteristics and terminal thermal inertia. A case study based on the 20-node and the analysis of the influence factors demonstrates the validity of the proposed method.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • An Improved Power Flow Method to Cope with Non-smooth Constraints of
           Integrated Energy Systems

    • Authors: Yuntao Ju;Jiankai Wang;Zifeng Zhang;
      Pages: 1784 - 1793
      Abstract: Integrated energy system applications can significantly improve energy efficiency. In this paper, we establish an integrated energy system containing heat, electricity and gas. The existing power flow (PF) calculation method applied to integrated energy systems (IESs) does not consider non-smooth constraints, such as the piecewise pipeline friction coefficient and generator buses reactive power limits, etc. Mixed integer nonlinear programming (MINLP) is conventionally used to deal with piecewise pipeline friction coefficients in gas network parts, but it is both complex and inefficient. Hence, we develop a piecewise linear function-based fitting method that can reduce the number of integer variables and enhanced the computational efficiency. In the electric network part, if the reactive power of the PV bus violates limits, it will be converted into a PQ bus, which is a non-differentiable and non-smooth constraint. Mixed complementarity problems are conventionally introduced to represent the PV-PQ buses type switching relationship and are addressed by the Newton-Raphson (NR) method. However, the above method is sensitive to the initial point. Here, we introduce a robust projected Levenberg-Marquardt (PLM) algorithm to cope with this issue. We demonstrate the advantages of our method and validate it both in a small-scale system and large-scale network test cases.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
  • Enhancement of Soil Discharge Channels on Potential Surrounding Buried
           Cables Under Impulsive Currents

    • Authors: Wenxia Sima;Xiaochuan Li;Tao Yuan;Ming Yang;Donghui Luo;Jialun Li;
      Pages: 1794 - 1803
      Abstract: Substations have a large number of signal transmission cables beneath the ground. Both the insulation safety and signal reliability of the cables are affected severely by the electromagnetic field. Under high-amplitude impulsive currents, the dispersion of currents can cause soil discharge and thus cause unexpected distortions in an electromagnetic field. This paper focuses on the distortions of the electric field. In general, soil discharge channels occur in the vicinity of the independent rod. Closer development of the channel might enhance the electric field distribution and the potential surrounding the outer insulation of the cables (i.e. the surface potential on the cable). Therefore, this paper establishes a platform for observing the soil discharge channel and measuring the surface potential. Direction characteristic of the channel is extracted from the captured image of soil discharge channels and the surface potential is obtained by the measured coupling capacitive current on the shield experimentally. This paper also presents an improved model considering a dynamic growing discharge channel for the transient analysis of the grounding electrode. Study results show the surface potential increases as the discharge channel approaches the cable. To quantify this enhancement effect, the ratio of the highest to the lowest value of surface potential in different directions is taken as the multiple of the surface potential increase. The calculated multiples of the surface potential increase are in the range of 1 to 1.64 times under different conditions by the improved model. Therefore, taking the soil discharge channel into account is helpful to accurately analyze the impulsive interference of buried cables.
      PubDate: November 2022
      Issue No: Vol. 8, No. 6 (2022)
       
 
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