Regarding the power transmission mode from energy base to load center as the heart of the matter, a joint optimal operating model for both sending- and receiving- end power grids is established. In this model, the car...
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Wind power planning aims at optimally locating and sizing wind ***,it tends to choose the wind farms with the richest wind resource in order to maximize the energy ***, the capacity benefit of wind power should also b...
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Wind power planning aims at optimally locating and sizing wind ***,it tends to choose the wind farms with the richest wind resource in order to maximize the energy ***, the capacity benefit of wind power should also be considered in the large-scale clustered wind farm planning since the correlation among the wind farms performs an obvious influence on the capacity benefit brought by the whole wind *** paper proposes a planning model considering both energy and capacity benefit of the wind ***, the capacity benefit is evaluated by wind power capacity *** Ordinal Optimization (OO) theory, capable of handling problems with non-analytical forms, is applied to address the *** verify its feasibility and advantages, the proposed model is compared with widely-used genetic algorithm (GA) via a modified IEEE RTS-79 system and a real world case of Ningxia, *** results show that the diversity of wind farm enhances the capacity credit of wind power.
With the continuous growth of the installed capacity of wind power in China, the ability of integrating wind power becomes the bottleneck of its development. The electricity generation is determined by the heat supply...
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Due to the physical limitations of the generator, the vibrations in a shaft bearing may be amplified at a certain operation regimes, the prohibited zones are needed which leads to a disjoint powergeneration instead o...
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Surge Impedance Relay(SIR) is applied to DC system. Characteristics of SIR in DC line are analysed. A DC SIR algorithm implementing wavelet transform applied to HVDC line protection is proposed. The feasibility of DC ...
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ISBN:
(纸本)9781849198349
Surge Impedance Relay(SIR) is applied to DC system. Characteristics of SIR in DC line are analysed. A DC SIR algorithm implementing wavelet transform applied to HVDC line protection is proposed. The feasibility of DC SIR is verified and the performance of DC SIR is simulated and analysed.
The signal of travelling wave has the merit of immunity to system oscillation, transition resistance, CT saturation and the neutral point operation modes;it has been widely applied in field of fault detection and prot...
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ISBN:
(纸本)9781849198349
The signal of travelling wave has the merit of immunity to system oscillation, transition resistance, CT saturation and the neutral point operation modes;it has been widely applied in field of fault detection and protection. Especially in isolated neutral grounded wind farm distribution network, the algorithm using multiple-bay travelling wave's information can exclusively achieve the fast fault feeder selection and tripping. However, travelling wave sampling frequency tends to reach 500 to 1000 times of that in algorithms with power frequency signal. The direct of travelling wave sampling data sharing in process bus would produce the communication block, and weaken the security of whole substation automation. To solve this problem, the performance of communication in process bus is theoretically analyzed and simulated in this paper, the communication requirement of travelling waves is quantified, and then a feasible scheme is proposed with data pre-processing and fault characteristic abstraction moving forward into the merging unit. simulations prove its validity. The work in paper can promote the wide application of travelling waves in substation based on IEC61850.
The distribution network detection devices are generally using two kinds of instrument current transformer (ICT), of which one is used to transform the travelling wave and transient signals, while the other is used to...
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ISBN:
(纸本)9781849198349
The distribution network detection devices are generally using two kinds of instrument current transformer (ICT), of which one is used to transform the travelling wave and transient signals, while the other is used to transform the power frequency signals. Such scheme is neither necessary nor economical. This paper analyses the influences of sampling resistance, stray capacitance and magnetizing inductance on the frequency characteristic of ICT. Considering that fault zero sequence transient current has big transient component and small power frequency component, an ICT with wide band frequency accuracy has been chosen. Practical experiments have been done. The technical parameters given by the instrument factory are only within 20-20kHz. The characteristics in higher frequency are seldom reported due to the lack of test means. The experiments in this paper is based on the transient tester instrument and current amplifiers developed by our laboratory, which can output wide frequency band current within 20Hz-100kHz up to 50A. Experiment shows that, the predicted results were in good agreement with the measured ones.
In deregulated electricity markets, generation companies with the aim of maximum revenue need to provide trading strategies to the electricity trading market, which contributed to a self-scheduling model. When conside...
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A novel protection scheme for two-phase faults in power distribution system with neutral ungrounded is presented. The feasibility of tripping single-phase circuit when a phase-tophase or two-phase-to-ground fault occu...
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ISBN:
(纸本)9781849198349
A novel protection scheme for two-phase faults in power distribution system with neutral ungrounded is presented. The feasibility of tripping single-phase circuit when a phase-tophase or two-phase-to-ground fault occurs is studied with induction motor loads as the focus. The paper at first analyses the effect of a induction motor runs with one phase cut off theoretically. And then a real power distribution system model with 110kV, 35kV and 6kV voltage levels is built in PSCAD/EMTDC. Three feasibility criteria are proposed for motors in continuous operation with single-phase opened. At last, the novel protection scheme is testified in simulation with protection time and reclosing time as variables respectively. The results verify that the scheme is feasible and power supply reliability is improved.
For PD pattern recognition, six kinds of typical cable fault models are made and tested. Characteristics are calculated from test data. Multiple statistical characteristics of PD distribution map are calculated and pa...
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