The stability and reliability of the intelligent terminal's receiving information affects its control of intelligent switch in operation directly. To achieve reliable intelligent communications terminals, with tec...
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The stability and reliability of the intelligent terminal's receiving information affects its control of intelligent switch in operation directly. To achieve reliable intelligent communications terminals, with techniques and methods of IEC61850 modeling, the paper completed the 126KVGIS intelligent terminal information model based on the analysis of its information characteristics, and established the hardware platform with data model and logical nodes provided by IEC61850. Thus it has a certain practical significance to promote the standard construction, operation and management of intelligent substation, and lead the digital process of process layer devices.
Multi-bay information sharing has very important significances for the the enhancing of the relay characteristics and improving of the system control methods. With the summary of distribution substation busbar protect...
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Multi-bay information sharing has very important significances for the the enhancing of the relay characteristics and improving of the system control methods. With the summary of distribution substation busbar protection, small current grounding fault line selection, non-communication double-circuit line protection, reactive power and voltage control, low frequency load shedding control programmes, It analyse the needs of the information sharing among multiple bays and the application of integrated protection.
The development of high voltage direct current (HVDC) grid is an effective approach to implement the large-scale long-distance power transmission, the large-scale renewable energy integration and accommodation, and th...
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Ultra-high-voltage (UHV) transmission lines (over 750 kV) normally have larger shunt capacitance and longer transmission radius, which impose limitations of direct application of traditional impedance algorithm. A nov...
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Ultra-high-voltage (UHV) transmission lines (over 750 kV) normally have larger shunt capacitance and longer transmission radius, which impose limitations of direct application of traditional impedance algorithm. A novel impedance fault location algorithm is proposed for UHV transmission lines with single-line-to-ground faults due to higher voltage level than 750 kV. It is based on the precondition that the negative sequence current phase at meter location can precisely describe the phase information of negative current in fault path or fault voltage. The algorithm is immune to the influence of shunt capacitance with distributed parameters modeling for transmission line, and is not disturbed by fault resistance with fault location calculation at zero-crossing point of voltage at fault point. Theoretical analysis and simulation prove that the proposed method can guarantee good fault location accuracy, and fulfill the requirements in the field.
As the energy scarcity and environment problems become more and more severe, promoting renewable energy has become an important task and thus energy storage draws increasing attention for integrating renewable energy....
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ISBN:
(纸本)9781839533907
As the energy scarcity and environment problems become more and more severe, promoting renewable energy has become an important task and thus energy storage draws increasing attention for integrating renewable energy. Among many availab.e options, advanced adiabatic compressed air energy storage (AA-CAES) are considered mature and affordable options for gridscale applications. However, the relatively high capital cost hinders the development of AA-CAES system. As a result, the cost-benefit analysis of AA-CAES application is studied in this paper. The thermodynamic characteristics of AA-CAES system are carefully studied and modeled. An optimal configuration method of AA-CAES capacity considering energy arbitrage is proposed and the optimal capacity of each component of AA-CAES is demonstrated. simulation results indicate that the application of AA-CAES in arbitrage market is profitable but the payback period is long. The profit estimations are more realistic compare to conventional battery model. Profitable cost range of AA-CAES is found through sensibility analysis. Augmenting electricity price to improve economic of AA-CAES is discussed at the end.
Polyethylene (PE) is a major kind of internal insulating material. With great progresses of space charge measurement technologies in the last three decades, lots of researches are focused on space charge in PE. The he...
Polyethylene (PE) is a major kind of internal insulating material. With great progresses of space charge measurement technologies in the last three decades, lots of researches are focused on space charge in PE. The heat pressing and annealing condition of polyethylene affect its morphology obviously. During the heat pressing, the surface of PE forms different surface topographies because of different substrate materials. Surface topography has great relation to the epitaxial crystallization layer and influences the space charge characteristic of PE dramatically. This paper studied the formation process of different surface topographies and their micrographic characters in low density polyethylene (LDPE). pulsed electro-acoustic (PEA) method was used to measure the space charge distribution of samples with different surface topographies and morphologies in LDPE. The effect of surface topography and morphology to space charge packet were studied. The surface topography has great influence on space charge packet polarity and morphology has influence on both movement speed rate and polarity of space charge packet.
In this paper, the characteristics of electrical tree ageing in silicone rubber (SIR) under AC voltage were studied. The electrical tree initiation rate is 20% after the application of 6 kV AC voltage for 1000 hours. ...
In this paper, the characteristics of electrical tree ageing in silicone rubber (SIR) under AC voltage were studied. The electrical tree initiation rate is 20% after the application of 6 kV AC voltage for 1000 hours. Samples are separated into three kinds according to processes of electrical tree formation: virgin samples without voltage application, non-treed samples without electrical tree formation after 1000 hours and treed samples with electrical tree formation after 1000 hours. Certain physicochemical diagnostic tests were carried out to understand the degradation of material, ascribed to long-time voltage application, using differential scanning calorimetry (DSC) and thermogravimetric-differential thermal analysis (TG-DTA). Physicochemical analyses, especially the DSC results, show that no additional phases are formed in the processes of electrical tree ageing in SIR. Reduction of the melting point and crystallinity of SIR is observed in the sequence of virgin samples, non-treed samples and treed samples. The activation energy values were calculated from the TG-DTA data. Compared to virgin samples, obvious reduction of activation energy value is observed in non-treed samples. Degradation in SIR has already occurred before electrical tree formation and charge injection and extraction by high field electrode under AC voltage is regarded as the reason.
With the construction of Global Energy Internet, Intelligent distribution network has more and more characteristics of multi scene, multi service and changeable measurement and control objects. In order to realize dat...
With the construction of Global Energy Internet, Intelligent distribution network has more and more characteristics of multi scene, multi service and changeable measurement and control objects. In order to realize data collection and information exchange among the intelligent terminal and energy, power grid, load, energy storage and other control resources in distribution network, we should research an architecture which can adapt to various data sources Based on dynamic self describing protocol.
Introduce the IoT platform technology based on SDN (Software Defined Network), cloud-based, flexible management and configuration of smart terminals, and support access to millions of terminal devices and smart operat...
Introduce the IoT platform technology based on SDN (Software Defined Network), cloud-based, flexible management and configuration of smart terminals, and support access to millions of terminal devices and smart operation and maintenance management. The traditional monitoring system is integrated with the Internet of Things platform, and on the basis of realizing the general SCADA system monitoring function, through the side-cloud collab.ration, the lean management of the distribution station area is realized.
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