Peng Han^1,*, Xinchen Zhao¹, Yannan Wu¹, Zhiyu Zhou², Qi Qi³

Energy Engineering, Vol.120, No.5, pp. 1271-1285, 2023, DOI:10.32604/ee.2023.027489

Abstract The hybrid dc circuit breaker (HCB) has the advantages of fast action speed and low operating loss, which is an ideal method for fault isolation of multi-terminal dc grids. For multi-terminal dc grids that transmit power through overhead lines, HCBs are required to have reclosing capability due to the high fault probability and the fact that most of the faults are temporary faults. To avoid the secondary fault strike and equipment damage that may be caused by the reclosing of the HCB when the permanent fault occurs, an adaptive reclosing scheme based on traveling wave injection is proposed in this… More >

Wen Long^*, Bin Zhu, Huaizheng Li, Yan Zhu, Zhiqiang Chen, Gang Cheng

Energy Engineering, Vol.120, No.5, pp. 1253-1269, 2023, DOI:10.32604/ee.2023.026395

Abstract There is instability in the distributed energy storage cloud group end region on the power grid side. In order to avoid large-scale fluctuating charging and discharging in the power grid environment and make the capacitor components show a continuous and stable charging and discharging state, a hierarchical time-sharing configuration algorithm of distributed energy storage cloud group end region on the power grid side based on multi-scale and multi feature convolution neural network is proposed. Firstly, a voltage stability analysis model based on multi-scale and multi feature convolution neural network is constructed, and the multi-scale and multi feature convolution neural network… More >

Yuhan Liu, Yuqiao Zheng^*, Zhuang Ma, Cang Wu

Energy Engineering, Vol.120, No.5, pp. 1223-1237, 2023, DOI:10.32604/ee.2023.026329

Abstract An operating condition recognition approach of wind turbine spindle is proposed based on supervisory control and data acquisition (SCADA) normal data drive. Firstly, the SCADA raw data of wind turbine under full working conditions are cleaned and feature extracted. Then the spindle speed is employed as the output parameter, and the single and combined normal behavior model of the wind turbine spindle is constructed sequentially with the pre-processed data, with the evaluation indexes selected as the optimal model. Finally, calculating the spindle operation status index according to the sliding window principle, ascertaining the threshold value for identifying the abnormal spindle… More >

Chao Zhu¹, Zhuopei Liu², Hao Chen^2,3, Yangyang Li^2,3,*

Energy Engineering, Vol.120, No.5, pp. 1081-1105, 2023, DOI:10.32604/ee.2023.026000

Abstract Experiments were conducted on a diesel-methanol dual-fuel (DMDF) engine modified by a six-cylinder, turbo-charged, inter-cooled diesel engine. According to the number of diesel injection, the experiments are divided to two parts: the single injection mode and double injection mode. The results show that, at the double injection mode, the maximum of pressure rise rate is small and the engine runs smoothly, however, knock still occurs when the co-combustion ratio (CCR) is big enough. Under knock status, the power density of the block vibration concentrating at some special frequencies rises dramatically, and the special frequency of single injection mode (about 4.1… More >

Feng Zhao^1,2, Di Liao^1,*, Xiaoqiang Chen^1,2, Ying Wang^1,2

Energy Engineering, Vol.120, No.5, pp. 1133-1148, 2023, DOI:10.32604/ee.2023.025900

Abstract Aiming at the problems of multiple types of power quality composite disturbances, strong feature correlation and high recognition error rate, a method of power quality composite disturbances identification based on multi-resolution S-transform and decision tree was proposed. Firstly, according to IEEE standard, the signal models of seven single power quality disturbances and 17 combined power quality disturbances are given, and the disturbance waveform samples are generated in batches. Then, in order to improve the recognition accuracy, the adjustment factor is introduced to obtain the controllable time-frequency resolution through multi-resolution S-transform time-frequency domain analysis. On this basis, five disturbance time-frequency domain… More >

Fuyin Ni^1,2, Kai Li^2,*

Energy Engineering, Vol.120, No.5, pp. 1203-1221, 2023, DOI:10.32604/ee.2023.025796

Abstract Unified power quality conditioner (UPQC) with energy storage is commonly based on conventional capacity configuration strategy with power angle control. It has problems such as phase jumping before and after compensation. DC-link cannot continuously emit active power externally. Therefore, this paper presents the compensation strategy of full load voltage magnitude and phase in capacity configuration of UPQC. The topology of UPQC is integrated a series active power filter (SAPF), a shunt active power filter (PAPF) and a photovoltaic-battery energy storage system (PV-BESS). The principle of full load voltage compensation is analyzed based on the PV-BESS-UPQC topology. The magnitude constant of… More >

Jinrui Tang^*, Ganheng Ge, Jianchao Liu, Honghui Yang

Energy Engineering, Vol.120, No.5, pp. 1107-1132, 2023, DOI:10.32604/ee.2023.025666

Abstract Electric vehicle (EV) charging load is greatly affected by many traffic factors, such as road congestion. Accurate ultra short-term load forecasting (STLF) results for regional EV charging load are important to the scheduling plan of regional charging load, which can be derived to realize the optimal vehicle to grid benefit. In this paper, a regional-level EV ultra STLF method is proposed and discussed. The usage degree of all charging piles is firstly defined by us based on the usage frequency of charging piles, and then constructed by our collected EV charging transaction data in the field. Secondly, these usage degrees… More >

Yuqian Qi^*, Mingshui Li, Yu Lu, Baitong Li

Energy Engineering, Vol.120, No.5, pp. 1185-1201, 2023, DOI:10.32604/ee.2023.025574

Abstract In view of the problem of power quality degradation of port distribution network after the large-scale application of shore power load, a method of power quality management of port distribution network is proposed. Based on the objective function of the best power quality management effect and the smallest investment cost of the management device, the optimization model of power quality management in the distribution network after the large-scale application of large-capacity shore power is constructed. Based on the balance between the economic demand of distribution network resources optimization and power quality management capability, the power quality of distribution network is… More >

Jingjing Bai^*, Hongyi Zhou, Zheng Xu, Yu Zhong

Energy Engineering, Vol.120, No.5, pp. 1163-1183, 2023, DOI:10.32604/ee.2023.025553

Abstract The current electricity market fails to consider the energy consumption characteristics of transaction subjects such as virtual power plants. Besides, the game relationship between transaction subjects needs to be further explored. This paper proposes a Peer-to-Peer energy trading method for multi-virtual power plants based on a non-cooperative game. Firstly, a coordinated control model of public buildings is incorporated into the scheduling framework of the virtual power plant, considering the energy consumption characteristics of users. Secondly, the utility functions of multiple virtual power plants are analyzed, and a non-cooperative game model is established to explore the game relationship between electricity sellers… More >

Li Xiao^1,2, Xu Yang^1,2,*, Guozhi Zhang^1,2, Lin Cheng^1,2, Yi Jiang^1,2, Chuanxian Luo^1,2, Jing Zhang^1,2

Energy Engineering, Vol.120, No.5, pp. 1239-1252, 2023, DOI:10.32604/ee.2023.025530

Abstract In view of the effective perception demand of PD (Partial Discharge) insulation defect of in-service GIS (Gas Insulated Switchgear), the external UHF (Ultra High Frequency, 0.3−3 GHz) sensing technology for GIS PD insulation defect from resin hole is studied in this paper. Firstly, rectangular waveguide theory is used to analyze the electromagnetic wave propagation characteristics from rectangular resin hole in GIS disc insulator. It is found that the energy of leaked electromagnetic wave mainly concentrates in the frequency band above 1 GHz. Then based on this frequency band characteristics, a cavity-backed bowtie sensor for GIS PD external detection is designed… More >