Traveling wave method has been proved to be effective in fault line selection of power distribution system with the neutral non-effectively grounded. However, it can be easily disturbed by non-faulty traveling wave wh...
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ISBN:
(数字)9781728117225
ISBN:
(纸本)9781728117232
Traveling wave method has been proved to be effective in fault line selection of power distribution system with the neutral non-effectively grounded. However, it can be easily disturbed by non-faulty traveling wave when selecting the line. For this reason, this paper proposes a new traveling wave line selection method based on sparse representation, in which current traveling wave signals are measured for the selection task. The algorithm of selection is based on the idea that all non-zero terms in the sparse coefficients of the measured signal are found to be associated with training samples from a single class, and the test samples can be easily assigned to the class. This makes it possible to distinguish between the non-faulty traveling wave and the real fault traveling wave.
We constructed a frequently updated, near-real-time global powergeneration dataset: Carbon Monitor-power since January, 2016 at national levels with near-global coverage and hourly-to-daily time resolution. The data ...
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The cumulative installed capacity of wind power worldwide has grown rapidly in recent years. Fixed reactive powercontrol is adopted by wind turbines (WTs) to receive cycle instruction of wind farm (WF) automatic volt...
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Continuous-time random disturbances (also called stochastic excitations) due to increasing renewable generation have an increasing impact on powersystem dynamics;However, except from the Monte Carlo simulation, most ...
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In recent years, human electric shock accident caused by line fault of distribution system has happened all over the world. This kind of problem of high resistance grounding fault safety is becoming more and more the ...
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ISBN:
(数字)9781728117225
ISBN:
(纸本)9781728117232
In recent years, human electric shock accident caused by line fault of distribution system has happened all over the world. This kind of problem of high resistance grounding fault safety is becoming more and more the attention of the researchers. In this paper, typical arc high resistance grounding fault model is established to simulate the human electric shock accident and the line fell to the ground condition. The transient- state and steady-state fault characteristics of high resistance grounding fault are analyzed in the neutral point grounded through a small resistance grounding system and the resonant grounding system. The above analysis has laid a good foundation for the establishment of an effective fault detection method for high resistance grounding and the realization of human electric shock protection.
Because the fault characteristics is not obvious, the high resistance grounding fault feeder selection in a resonant grounding system has always been a hot and difficult problem in the field of powersystem protection...
ISBN:
(数字)9781839531248
ISBN:
(纸本)9781839531255
Because the fault characteristics is not obvious, the high resistance grounding fault feeder selection in a resonant grounding system has always been a hot and difficult problem in the field of powersystem protection. To solve this problem, the expressions of the transient zero sequence current of each feeder under over-damping and under-damping conditions are obtained based on the transient equivalent circuit of high resistance grounding fault in a resonant grounding system. The correlation degree of the transient zero sequence current between any two feeders is analysed by using the correlation coefficient method, so as to realize the fault feeder selection for high resistance grounding fault. simulation results of PSCAD software show that this method is not affected by transition resistance, initial phase angle of fault, and has high accuracy and reliability.
The beat frequency characteristic of the recovery voltage of fault phase in the case of single-phase grounding transient fault happening to line with the shunt reactors is analyzed. Besides, the paper analyzes the rea...
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ISBN:
(数字)9781728117225
ISBN:
(纸本)9781728117232
The beat frequency characteristic of the recovery voltage of fault phase in the case of single-phase grounding transient fault happening to line with the shunt reactors is analyzed. Besides, the paper analyzes the reason of no beat frequency phenomenon of transient fault happening to line without shunt reactor. The AC power networks with metallic grounding fault and arc grounding fault are analyzed by simulation. The recovery voltage of single-phase grounding fault in AC/DC hybrid power grid is studied by PSCAD. The new problems of the adaptive re-closure in AC-DC hybrid powersystem are discussed. Then the follow-up ideas to solve several existing problems are also presented.
Imbalance of generation and load caused by volatile generations poses challenges on frequency regulation. AGC is required to respond to the generation fluctuations without violating operational and security constraint...
Imbalance of generation and load caused by volatile generations poses challenges on frequency regulation. AGC is required to respond to the generation fluctuations without violating operational and security constraints. While explicit model predictive control (EMPC) provides an approach, the partition number of the piecewise affine control laws grows exponentially with the number of constraints and prediction/control horizons, which hinders its application in large systems. In this paper, we propose an EMPC approach for AGC by approximating the control laws using Legendre polynomial series expansions, thus entirely eliminating the partition issue. Galerkin method is applied to the KKT conditions of EMPC's multiparametric quadratic programming (mp-QP) problem to compute the approximations. Case study in New England 39-bus system verifies the performance and efficiency of the proposed controller.
The battery differences not only affect the reliability and security of battery packs but also accelerate the decline of the packs' life. Although battery management systems (BMS) and equalization circuit can be u...
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ISBN:
(纸本)9781728149318
The battery differences not only affect the reliability and security of battery packs but also accelerate the decline of the packs' life. Although battery management systems (BMS) and equalization circuit can be used to balance the differences, only the whole battery pack can be protected with high-cost and complex circuits. Dynamic reconfigurable battery management system (DRBMS) based on networked control has a simple principle and can shield the differences of battery cells. This paper designs experiments for the dynamic reconfigurable battery network technology and makes a contrast with the traditional BMS. Through the analysis of voltage, SOC difference and dynamic resistance during charging and discharging, the results show that DRBMS has better voltage and capacity equalization effect than BMS. The cells of paralleled battery packs can be fully charged/released in DRBMS. It is also verified that DRBMS is applicable on decommissioned bus battery packs which are of larger differences and the ladder utilization.
With the implementation of the "coal to electricity" project, the heat pump load in the distribution network increases significantly. Standing in the point of heat pump users, cooperative game mode is used f...
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