It is very difficult to correctly identify single-phase-to-ground fault (SFG) in distribution system with neutral non-effectively grounded (NNG). A novel travelling wave based singlephase-to-ground protection is propo...
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ISBN:
(纸本)9781849198349
It is very difficult to correctly identify single-phase-to-ground fault (SFG) in distribution system with neutral non-effectively grounded (NNG). A novel travelling wave based singlephase-to-ground protection is proposed in the paper. The polarity of initial transient current and voltage travelling waves are used to identify the fault direction, and power frequency voltages are used to distinguish SFG from phaseto- phase fault to ensure the reliability of the protection. In the paper, wavelet transforms and module maxima theory was adopted to represent the polarity of travelling waves effectively and construct protection algorithm,. The analysis and simulation demonstrate that the protection is valid.
Fault diagnosis plays an important role in improving power network troubleshooting capability. Conducting local fault diagnosis in substations can make full and quick use of abundant local information. A substation fa...
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This paper describes several methods for condition-based maintenance, introduced CBM, RCM development process, the main theoretical logic, techniques and practices. Focuses on the health index based on equipment maint...
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ISBN:
(纸本)9789881532329
This paper describes several methods for condition-based maintenance, introduced CBM, RCM development process, the main theoretical logic, techniques and practices. Focuses on the health index based on equipment maintenance strategies, namely CBRM. Focused on the development of narrative context, theoretical foundation, model healthy index. And for its application in power transformers were introduced.
Online partial discharge monitoring for powerequipments is useful to improve the capacity of the power supply. Main technology for PD testing is introduced in this paper. Advantages and disadvantages of pulse current...
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ISBN:
(纸本)9789881532329
Online partial discharge monitoring for powerequipments is useful to improve the capacity of the power supply. Main technology for PD testing is introduced in this paper. Advantages and disadvantages of pulse current, UHF, ultrasonic and TEV method are present. The status quo of online PD monitoring is analyzed, and the detection effect of online PD monitoring is not good. Opinions to improve the effect are given. They include built-in sensors, increasing sensitivity and sample rate. Analysis of the state quo indicates that the relevant technical standards and specifications must be revised to improve the normalization and standardization.
This paper presents a new control strategy for three-level neutral point clamped (NPC) pulse width modulated (PWM) rectifier without power source voltage sensors. The relationship between instantaneous power and volta...
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For the simulation of large-scale AC/DC hybrid systems, both the precision of the DC parts and the efficiency of the whole system should be considered. Thus a real-time hybrid transient simulation platform is proposed...
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For the simulation of large-scale AC/DC hybrid systems, both the precision of the DC parts and the efficiency of the whole system should be considered. Thus a real-time hybrid transient simulation platform is proposed by combining the real-time digital simulator (RTDS) and a transient stability analysis (TSA) program. A latest GTFPGA card is used to realize the high speed digital communication between RTDS and the computer deploying TSA program. Moreover, the frequency dependent network equivalent (FDNE) is implemented in this simulation platform to improve the accuracy of simulation results. By simulating a modified New England 39-bus test system incorporating high-voltage direct current (HVDC) components, the validity of the proposed simulation platform is verified.
Look-ahead generation dispatch is a critical measurement to accommodate large-scale integration of wind powergeneration. In real application, the model for conventional generators should involve generation regulation...
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Look-ahead generation dispatch is a critical measurement to accommodate large-scale integration of wind powergeneration. In real application, the model for conventional generators should involve generation regulation constraints including regulation frequency constraints and discrete output constraints. Look-ahead generation dispatch with regulation constraints is a large-scale nonlinear mixed-integer programming problem, and it could be hardly solved strictly within acceptable time. An efficient three-stage method for solving this problem is developed, together with a forward-backward-pass dynamic programming approach for handling generation regulation constraints. Numerical tests are taken on IEEE 31-bus systems and a large-scale 264-bus power system to verify the high efficiency and practicability of the proposed method.
With the ever-increasing size of the power grid and the large-scale integration of stochastic renewable energy, the conventional active power dispatch method has become inapplicable. Therefore, a model predictive cont...
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With large-scale electric vehicles (EVs) integrated into the power system, how to optimize EV charging power in real time to avoid incremental peak load and achieve valley-filling will be important. The regular real-t...
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Energy management system (EMS), known as the brain of power grid, utilizes information flow to control energy flow so as to keep power grid operation efficient and secure. Conventionally, the EMS is a centralized one ...
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