Traditional operation rules depend on human experience, which are relatively fixed and difficult to fulfill the new demand of the modern power grid. In order to formulate suitable and quickly refreshed operation rules...
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Traditional operation rules depend on human experience, which are relatively fixed and difficult to fulfill the new demand of the modern power grid. In order to formulate suitable and quickly refreshed operation rules, a method of linear decision tree based on support samples is proposed for rule extraction in this paper. The operation rules extracted by this method have advantages of refinement and intelligence, which helps the dispatching center meet the requirement of smart grid construction.
IPS has many special characteristics, such as using multi-phase, multi-frequency and hybrid AC/DC devices. As a result, existing electromagnetic transient simulators developed for powersystems on land do not apply to...
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In order to maintain the separability of different fault onsets, more characteristic parameters need to be used to establish the feature space with multiple possible faults. Usually, the dimensions of feature space ha...
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In order to maintain the separability of different fault onsets, more characteristic parameters need to be used to establish the feature space with multiple possible faults. Usually, the dimensions of feature space have a positive correlation with the number of faults. Describing multiple faults in visualization is more difficult and the classification bounds with hyperplanes are less convenient to realize. Therefore implementing dimensionality reduction approaches in original feature space is beneficial for fault diagnosis and prognostics. Multidimensional Scaling (MDS) has been widely studied and used for dimensionality reduction as well as Principal Component Analysis (PCA). When these methods are applied in the prognostics process, the effectiveness needs validation with the reason that the deterioration features in degradations are different from the faults onsets that in diagnostics. The paper analyzes the nonlinear dimensionality reduction methods including Self-Organizing Map (SOM) and Isometric feature mapping (Isomap). Based on the deterioration data in an engine, the effects of these methods are analyzed.
Aimed at power system large-scale blackouts, the paper firstly analyzes the existing problems of current protective relaying and emergency control in power grid. A novel system protection based on local information, p...
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power grid and communication network, which depends on each other to provide proper functionality, are becoming more and more coupled together. Failure of a fraction of nodes in communication networks may lead to a fa...
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Electro-Geometric Model (EGM) has been applied widely all over the world to evaluate the lightning shielding failure of transmission *** with the increase of operation voltage to 1000 kV and tower height to more than ...
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Electro-Geometric Model (EGM) has been applied widely all over the world to evaluate the lightning shielding failure of transmission *** with the increase of operation voltage to 1000 kV and tower height to more than 100 meters, some shortcomings of the traditional EGM model were found by many *** Progression Model (LPM) was proposed to solve these *** some fundamental works, such as when the upward leader initiates and how it propagates, is still *** experiment was designed and implemented in this paper to simulate the electric field circumstance near the test transmission line while the lightning downward leader *** upward leader from the test transmission line was clearly *** inception voltage and characteristics was *** streamer and leader initiated from the ground wire and conductor bundle were *** experiment results show that the leader initiating from the ground wire is more active in the inception *** velocity of the upward leader acquired is about 1.2-3.0 cm/μs.
Travelling-wave starting element is an integral part of the ultra high-speed protection. Existing design method depends on engineering experience, low accuracy in travelling-wave signal recognition, easy to trip frequ...
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With high speed data sampling technology development, fault generated high-frequency signals can be got, in which fault generated traveling waves reflects fault location, fault type and faulted equipment so on from di...
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The Electromagnetic Compatibility (EMC) is a major issue for the truck crane designing, due to the large dimension. The conducted disturbance sources of truck crane was measured under stable conditions, the time domai...
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ISBN:
(纸本)9781467307185
The Electromagnetic Compatibility (EMC) is a major issue for the truck crane designing, due to the large dimension. The conducted disturbance sources of truck crane was measured under stable conditions, the time domain characteristics of possible conducted disturbance sources was analyzed, and typical waveforms were concluded to solve the EMC (Electromagnetic Compatibility) issue. The electromagnetic disturbance characteristics at different test points under different operation conditions were compared, and the influence of different factors was studied. The amplitude and frequency parameters of the major disturbance sources were compared with the standard immunity test pulses suggested by ISO7637-2. The differences between them indicate that the extant standard might not apply to the test of the truck crane. The presented results could form a basis for the development of a special standard for the EMC test of the truck crane and further relevant EMC research.
Standardization is the development tendency of information exchange among control centers. Based on the standard in IEC 61970, an information exchange model suitable for coordinated automatic voltage control (CAVC) am...
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Standardization is the development tendency of information exchange among control centers. Based on the standard in IEC 61970, an information exchange model suitable for coordinated automatic voltage control (CAVC) among multi control centers is proposed. Firstly, the contents of information flow of CAVC is analyzed and the definition of coordinated control model for information exchange is given;then the common information model is extended and a standardized information model for CAVC is designed;and then based on component interface specification, a standardized information exchange interface for CAVC is designed and its architecture for information exchange as well as its information exchange procedure are given. The presented information exchange model possesses wide application prospect in the implementation of information exchange among multi CAVC control centers for future smart grids.
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