JournalTOCs

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

[228 journals]

Comparisons and Improvements of Key Operating Characteristics of Current
Source Converter Applied in HVDC System
- Authors: Wenwen Zhang;Longlong Chen;Xiaoguang Wei;Guangfu Tang;Lei Qi;Chong Gao;Zhiyuan He;
  Pages: 1601 - 1612
  Abstract: Because of its controlled power factor and no commutation failure, current source converter (CSC) made up of reverse-blocking IGCTs (RB-IGCTs) offers broad application prospects in the field of HVDC system. Valve voltage and power operating range as the most important operating characteristics should be paid attention to but they are always contradictory. First, the relationship between valve voltage and modulation index is obtained. In particular, valve voltage of converter under the three typical modulation methods is compared, analyzed, and verified. Second, with the help of the independent control strategy and coordinated control strategy of both ends, power operating ranges of the three modulation methods are comprehensively analyzed and compared. Third, in order to solve power coupling at a low active power, the improved coordination control strategy at both ends in this paper is proposed and the relationships among active power, reactive power, DC current and phase angle difference are given in detail. Finally, a 500 kV/3 kA simulation system was built in PSCAD/EMTDC to obtain comparison results of the key operating characteristics of CSC under different modulation methods and the converter can realize unity power operation under random active power after adopting the improved coordinated control strategy, and DC current does not decrease to zero, verifying effectiveness of the coordinated control strategy.
  PubDate: TUE, 27 JUN 2023 10:01:26 -04
  Issue No: Vol. 9, No. 5 (2023)
Synchrophasor-based Online State Estimated in Large-scale Power Grid
- Authors: Junjie Lin;Chao Lu;Wenchao Song;Yingduo Han;Yinsheng Su;He Huang;Licheng Li;
  Pages: 1613 - 1622
  Abstract: With integration of a larger amount of clean power sources and power electronic equipment, operation and dynamic characteristics of the power grid are becoming more and more complicated and stochastic. Therefore, it is necessary and urgent to obtain accurate real-time states, which is difficult from traditional state estimation. This paper systematically develops a phasor measurement unit (PMU) based real-time state estimator for a realistic large-scale power grid for the first time. The estimator mainly relies on three refined algorithms, i.e., an improved linear state estimation algorithm, a practical bad data identification method and a distributed topology check technique. Furthermore, a novel system architecture is designed and implemented for the China Southern Power Grid. Numerical simulations and extensive field operation results of the state estimator recorded under both normal and abnormal situations are presented. All the tests and field results demonstrate the advantages of the proposed algorithms in terms of online system monitoring and feasibility of refreshing the states of the whole system at intervals of tens of milliseconds.
  PubDate: WED, 25 JAN 2023 10:01:00 -04
  Issue No: Vol. 9, No. 5 (2023)
Edge Intelligence for Smart Grid: A Survey on Application Potentials
- Authors: Hoay Beng Gooi;Tianjing Wang;Yong Tang;
  Pages: 1623 - 1640
  Abstract: With the booming of artificial intelligence (AI), Internet of Things (IoT), and high-speed communication technology, integrating these technologies to innovate the smart grid (SG) further is future development direction of the power grid. Driven by this trend, billions of devices in the SG are connected to the Internet and generate a large amount of data at network edge. To reduce pressure of cloud computing and overcome defects of centralized learning, emergence of edge computing (EC) makes the computing task transfer from the network center to the network edge. When further exploring the relationship between EC and AI, edge intelligence (EI) has become one of the research hotspots. Advantages of EI in flexibly utilizing EC resources and improving AI model learning efficiency make its application in SG a good prospect. However, since only a few existing studies have applied EI to SG, this paper focuses on the application potential of EI in SG. First, the concepts, characteristics, frameworks, and key technologies of EI are investigated. Then, a comprehensive review of AI and EC applications in SG is presented. Furthermore, application potentials for EI in SG are explored, and four application scenarios of EI for SG are proposed. Finally, challenges and future directions for EI in SG are discussed. This application survey of EI on SG is carried out before EI enters the large-scale commercial stage to provide references and guidelines for developing future EI frameworks in the SG paradigm.
  PubDate: TUE, 27 JUN 2023 10:01:25 -04
  Issue No: Vol. 9, No. 5 (2023)
Impact of Frequency Anti-windup Limiter on Synchronization Stability of
Grid Feeding Converter
- Authors: Junru Chen;Chenchen Ge;Di Qiang;Hua Geng;Terence O'Donnell;Federico Milano;
  Pages: 1676 - 1687
  Abstract: Loss of synchronization is one of the main issues for a grid-feeding converter in a weak grid after being subjected to a large disturbance. The synchronous transient is highly nonlinear due to phase movement and frequency limiters. However, none of the previous research has considered the anti-windup PI in the phase-locked loop, which is commonly implemented in reality and introduced as an additional nonlinear transient. This work provides a taxonomy to evaluate and compare the effect of different anti-windup PI limiters on synchronization stability, including clamping, back-calculation and combined method. Different anti-windup PI limiters allocate zeros and poles differently and have different impacts on damping and stability enhancement. A case study implemented in Matlab/Simulink serves to compare the trajectory of the converter phase and frequency using different anti-windup PI in the scenario of both with and without equilibrium points during the fault. Simulation results show that anti-windup PI limiters increase damping during the fault and thus improve the synchronization stability margin.
  PubDate: WED, 25 JAN 2023 10:01:00 -04
  Issue No: Vol. 9, No. 5 (2023)
Single-source Switched-capacitor Boost Nine-level Inverter with Reduced
Components
- Authors: Kaibalya Prasad Panda;R.T. Naayagi;Pravat Kumar Ray;Gayadhar Panda;
  Pages: 1688 - 1697
  Abstract: Increasing demands for improvement in power quality and power capacity have contributed to development of switched-capacitor multilevel inverters (SCMLIs). Recently developed SCMLIs enable single-stage voltage boosting, as well as inversion resulting in step-up ac output. Towards reduction in number of components, this paper introduces a boost type single-source nine-level (9-level) SCMLI employing two capacitors and three diodes. Owing to the series-parallel connection process, capacitor voltages are inherently balanced and assist in quadruple voltage boosting from a single-source. Maximum voltage stress across semiconductor devices is limited to twice input voltage only. Using a minimum number of components, the proposed SCMLI can be extended to increase voltage levels without additional dc input. Each extension module adds two additional voltage steps in the output while maintaining maximum voltage stress the same as 9-level circuit. Followed by in-depth analysis of circuit operation and power losses, a thorough comparison of recently developed single-phase 9-level MLIs is carried out, which verifies design superiority. Extensive simulation and experimental results are presented to verify the prominent features of the 9-level SCMLI under dynamic operating conditions.
  PubDate: THU, 20 APR 2023 10:03:20 -04
  Issue No: Vol. 9, No. 5 (2023)
An HESS Based on a Modified MMCC-TSBC Converter Integrating Energy
Storages
- Authors: Prabir Ranjan Kasari;Subhadeep Bhattacharjee;
  Pages: 1698 - 1709
  Abstract: This paper presents a modified modular multilevel cascaded converter based on a triple star bridge cell (MMCC-TSBC) for integrating different types of energy storage to form a hybrid energy storage system (HESS). The proposed HESS comprises battery energy storage, supercapacitor energy storage and a doubly-fed induction machine (DFIM) based variable speed pump storage (VSPS). Different low-rated energy storage units can be intermixed in this converter to form an HESS. This is possible due to the modular structure of the modified converter and provides an advantage in a high-power energy storage system. To validate the performance of HESS, real-time power variation data is accumulated from online sources and a weighted median filter (WMF) is employed for generating appropriate references for battery energy storage system (BESS) and supercapacitor storage to mitigate both low frequency and high-frequency power variations. Here, the control approach permits independent regulation of grid current and DFIM current through the modified MMCC-TSBC converter. The simulation and experimental results validate the effectiveness of the control scheme for the proposed HESS.
  PubDate: WED, 25 JAN 2023 10:01:00 -04
  Issue No: Vol. 9, No. 5 (2023)
Neural Network Based Fea sible Region Approximation Model for Optimal
Operation of Integrated Electricity and Heating System
- Authors: Xuewei Wu;Bin Zhang;Mads Pagh Nielsen;Zhe Chen;
  Pages: 1808 - 1819
  Abstract: This paper proposes a neural network based feasible region approximation model of a district heating system (DHS), and it is intended to be used for optimal operation of integrated electricity and heating system (IEHS) considering privacy protection. In this model, a neural network is trained to approximate the feasible region of the DHS operation and then is reformulated as a set of mixed-integer linear constraints. Based on the received approximation models of DHSs and detailed electricity system model, the electricity operator conducts centralized optimization, and then sends specific heating generation plans back to corresponding heating operators. Furthermore, subsequent optimization is formulated for each DHS to obtain detailed operation strategy based on received heating generation plan. In this scheme, optimization of the IEHS could be achieved and privacy protection requirement is satisfied since the feasible region approximation model does not contain detailed system parameters. Case studies conducted on a small-scale system demonstrate accuracy of the proposed strategy and a large-scale system verify its application possibility.
  PubDate: TUE, 27 JUN 2023 10:01:25 -04
  Issue No: Vol. 9, No. 5 (2023)
Hybrid Physics and Data-driven Contingency Filtering for Security
Operation of Micro Energy-water Nexus
- Authors: Mostafa Goodarzi;Qifeng Li;
  Pages: 1820 - 1831
  Abstract: This paper investigates a novel engineering problem, i.e., security-constrained multi-period operation of micro energy-water nexuses. This problem is computationally challenging because of its high nonlinearity, nonconvexity, and large dimension. We propose a two-stage iterative algorithm employing a hybrid physics and data-driven contingency filtering (CF) method and convexification to solve it. The convexified master problem is solved in the first stage by considering the base case operation and binding contingencies set (BCS). The second stage updates BCS using physics-based data-driven methods, which include dynamic and filtered data sets. This method is faster than existing CF methods because it relies on offline optimization problems and contains a limited number of online optimization problems. We validate effectiveness of the proposed method using two different case studies: the IEEE 13-bus power system with the EPANET 8-node water system and the IEEE 33-bus power system with the Otsfeld 13-node water system.
  PubDate: THU, 20 APR 2023 10:04:20 -04
  Issue No: Vol. 9, No. 5 (2023)
Improving Operational Flexibility of Integrated Energy Systems Through
Operating Conditions Optimization of CHP Units
- Authors: Shixing Ding;Wei Gu;Shuai Lu;Xiaogang Chen;Ruizhi Yu;
  Pages: 1854 - 1865
  Abstract: As a type of energy system with bright application prospects, the integrated energy system (IES) is environmentally friendly and can improve overall energy efficiency. Tight coupling between heat and electricity outputs of combined heat and power (CHP) units limits IES operational flexibility significantly. To resolve this problem, in this paper, we integrate operating mode optimization of the natural gas combined cycle CHP unit (NGCC-CHP) into dispatch of the IES to improve flexibility of the IES. First, we analyze operational modes of the CHP units from the perspectives of thermal processes and physical mechanisms, including the adjustable extraction mode, back-pressure mode, and switching mode. Next, we propose an explicit mathematical model for full-mode operation of the CHP units, in which the heat-electricity feasible region, switching constraints, and switching costs are all formulated in detail. Finally, a novel economic dispatch model is proposed for a heat and electricity IES, which uses the full-mode operation of CHP units to improve operational flexibility. The Fortuny-Amat transformation is used to convert the economic dispatch model into a mixed-integer quadratic programming model, which can then be solved using commercial solvers. Case studies demonstrate the proposed method can reduce operational costs and obviously promotes wind power utilization.
  PubDate: FRI, 03 MAR 2023 10:00:56 -04
  Issue No: Vol. 9, No. 5 (2023)
Electrical Tracking, Erosion and Fire Retardancy Performance of Silicone
Rubber Insulation Containing Aluminum Trihydrate, Graphene and Glass Fiber
Additives
- Authors: M. Tariq Nazir;Arslan Khalid;B. Toan Phung;Arup K. Das;Peter Cheetham;Ashish Paramane;Shakeel Akram;Khoi Loon Wong;
  Pages: 1918 - 1925
  Abstract: Silicone rubber composite is a priority electrical insulating material used in high-voltage outdoor insulation applications. Low electrical tracking/erosion and poor flame resistance performance of silicone rubber once ignited, substantially reduce its working life. This paper attempts to investigate tracking/erosion performance of room temperature vulcanized (RTV) silicone rubber along with flame retardant parameters using aluminum trihydrate (ATH), graphene nanosheets (GN) and milled glass fiber (GF) additives. The inclined plane test (IPT) was performed in line with criteria defined in IEC 60587 using step-up tracking voltage method while flame retardancy is evaluated according to ASTM E 1354.0 using a cone calorimeter. Results suggest 30% of ATH assists in improving physical tracking/erosion resistance of pristine silicone elastomer rubber by impeding development of leakage current and a great reduction in maximum average temperatures on the surface of RTV2. Further improvement in performance of RTV2 is achieved through introduction of 1% of GN and 5% of GF as seen in RTV4. Moreover, 30% of ATH reduces heat release rate and smoke production rate, and this trend is improved with the introduction of GN/GF. RTV4 has pop up as the most promising silicone rubber composite with excellent electrical tracking, erosion, and flame resistance performance relative to its counterparts in this study.
  PubDate: THU, 20 APR 2023 10:04:14 -04
  Issue No: Vol. 9, No. 5 (2023)
Surface Charge Accumulation Characteristics on DC GIL Three-post
Insulators Considering the Influence of Temperature Gradient
- Authors: Qi Hu;Qingmin Li;Zhipeng Liu;Naifan Xue;Jian Wang;Manu Haddad;
  Pages: 1926 - 1934
  Abstract: Surface charge accumulation is considered to be a critical factor in flashover failure of three-post insulators. However, surface charge accumulation characteristics on three-post insulators with complex structures and uneven electric fields are still unclear. Furthermore, the temperature gradient field makes charge accumulation more complicated. In this presentation, surface charge profiles of DC three-post insulators under electro-thermal coupling stress are studied by establishing a multi-degree-of-freedom movement measurement system. The abdominal area of the three-post insulator accumulaftes charges of identical polarity as the DC voltage, while the leg area accumulates heteropolar charges. Charge density from the bottom of the leg to the center of the abdomen presents a trimodal distribution pattern, including two homopolar charge peaks and one heteropolar charge peak. Asymmetrical surface conductance distribution arising from the temperature gradient leads to a significant increase in amplitude and distribution range of the homopolar charge peak at the legs of insulator. Increase of the temperature gradient will further magnify the homopolar charge peak at the legs. When DC voltage is 100 kV and conductive pole temperature is 70°C, surface charge density of the three-post insulator can reach 100 μC/m2. Therefore, surface conductance regulation of the leg region is the key to charge regulation and insulation optimization design of DC three-post insulators.
  PubDate: FRI, 03 MAR 2023 10:00:56 -04
  Issue No: Vol. 9, No. 5 (2023)
Insulation Properties and Degradation Mechanism for XLPE Subjected to
Different Aging Periods
- Authors: Qian Wang;Rui Liu;Sichen Qin;Xi Chen;Zicai Shen;Zhe Hou;Zeli Ju;
  Pages: 1959 - 1967
  Abstract: Due to its excellent insulation and mechanical properties, cross-linked polyethylene (XLPE) is widely used as the insulation candidate of power cables in power transmission and distribution systems. However, its performance can be affected due to various stresses, which endangers safe operation of the power system in service. In this paper, dielectric and insulation properties of XLPE materials of 110 kV cables with the service lives of 0, 15, and 30 years were tested and evaluated. Results show that with increase of service life, dielectric loss caused by the polarization process increases significantly, and dielectric strength decreases as well. Power frequency breakdown field strength and crystallinity decrease significantly, and carbonyl index increases. The degradation process of XLPE can be divided into two stages: the structure of the crystalline region of the original sample is relatively complete, and loss can be almost ignored. After long-term service, the crystallization region is destroyed, and thermal oxygen reaction occurs. Intermolecular force is weakened, which makes breakdown easier to occur. However, there is no direct relation between the carbonyl index and macroscopic characteristics. This paper reveals the deterioration law of the XLPE cable insulation, which provides a theoretical basis for evaluating cable aging condition and is of great significance to improve cable operation safety and maintenance quality.
  PubDate: FRI, 09 DEC 2022 10:03:02 -04
  Issue No: Vol. 9, No. 5 (2022)