The fault of transmission line is mostly caused by lightning,and a ground lightning stroke process is often accompanied by multiple *** duration of ground lightning stroke are also *** this paper,a method for evaluati...
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The fault of transmission line is mostly caused by lightning,and a ground lightning stroke process is often accompanied by multiple *** duration of ground lightning stroke are also *** this paper,a method for evaluating the reclosing time of reclosure based on lightning parameters is *** addition,this paper also gives an expression for the cumulative rate of the duration of ground lightning stroke,and an expression for probability distribution of the amplitude of lightning current in Guangdong *** also proposed a method for calculating the probability of tripping of *** this calculating method,the average probability of tripping of reclosure is less than 1/10000 during a ground lightning stroke process,when the reclosing time t0 is greater than 1.012 s.
With the development of smart grid, the self-healing ability of protection device becomes much more important. Pilot protection is of good selectivity, but it needs a highly reliable communication network. Once the co...
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ISBN:
(纸本)9781785618260
With the development of smart grid, the self-healing ability of protection device becomes much more important. Pilot protection is of good selectivity, but it needs a highly reliable communication network. Once the communication line between two devices is out of work, pilot protection will be forced out of operation. Since there are many ring structures in communication network, circuitous routes can be found to help pilot protection remain operational. In this paper, ant colony algorithm (ACA) are used to find the optimal circuitous route, and simulation results show the method is fast and accurate. To the actual communication network of powersystem, each node is just connected to a few other nodes, so the search process often come to dead ends. Use penalty functions can reduce the probability of coming to a dead end and improve the algorithm efficiency. The whole route accelerating penalty function is most efficient.
Insufficient power capacity for peak load regulation has caused loss of wind power accommodation in China.A regulation capacity market is under consideration to encourage more peak regulation service,thus how much the...
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Insufficient power capacity for peak load regulation has caused loss of wind power accommodation in China.A regulation capacity market is under consideration to encourage more peak regulation service,thus how much the market would be is important for each participant.A new peak-load regulation capacity planning method is proposed for long-term market based on the wind power curtailment evaluation model using probabilistic production *** method is suitable for the situation in the planning stage without the knowledge of detailed sequences of load and renewable power,and includes modeling of two peak load regulation measures,increasing the adjustable capacity and to shift some long-lasting units to on/off cycling units.A typical area in China is studied in the paper to evaluate the actual effects of different measures.
The unavoidable wind power forecast error results in the pervasive uncertainty in powersystem economic *** order to solve optimization problem such as economic dispatch with random variables,the commonest and simples...
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The unavoidable wind power forecast error results in the pervasive uncertainty in powersystem economic *** order to solve optimization problem such as economic dispatch with random variables,the commonest and simplest method is using a deterministic value to replace this random *** kinds of predictions are used such as maximumlikelihood approximation,expectation and *** study analyses the effect of these prediction choices on uncertainty of powersystem via comparing their statistical *** is shown that when the wind power output is very volatile,the quality of these prediction choices is not ***,a simplified three-unit thermal system and a tenunit system are studied for illustrating the consequence of statistical inconsistency.
Parallel gaps,as a new mode of "channel" type lightning protection,can do it with the sub insulator arc distance to effectively protect the insulator,but the corresponding line tripping rate will be affected...
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Parallel gaps,as a new mode of "channel" type lightning protection,can do it with the sub insulator arc distance to effectively protect the insulator,but the corresponding line tripping rate will be affected because of this;Development method based on the leader in this paper the calculation method of the lightning path,the typical used tower of guangzhou trip rate change after the application of parallel gap situation has carried on the analysis,got a short distance and adopt reasonable reinforced insulation,the trip rates did not rise significantly.
As a new kind of lightning protection, parallel gaps have simple structure, easy installation, good economy, and many other advantages. The traditional parallel gap due to the large short distance, can lead to lightni...
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As a new kind of lightning protection, parallel gaps have simple structure, easy installation, good economy, and many other advantages. The traditional parallel gap due to the large short distance, can lead to lightning trip-out rate increases. Based on arc movement characteristics this paper presents a design of new type of parallel gaps and the analysis of the surface field strength, and the verification test, design a new kind of parallel gap are obtained.
In this paper, the reliability of the rolling bearing fault feature extraction based on casing vibration signals is discussed. Through the fault simulation experiment of rolling bearing, the vibration data of the oute...
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Travelling wave (TW) differential protection fully utilizes the fault information contained in TW at both terminals of a transmission line, so it's a protection with high reliability and high selectivity. However,...
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ISBN:
(纸本)9781785618260
Travelling wave (TW) differential protection fully utilizes the fault information contained in TW at both terminals of a transmission line, so it's a protection with high reliability and high selectivity. However, because TW differential protection needs a large amount of communication, it cannot be put into practical use. This paper proposes a TW differential protection which is based on equivalent travelling wave (ETW). Fault information is not lost during the process of getting ETW, so the proposed protection has the same reliability and selectivity with traditional TW differential protection. Because only several modulus maxima are needed to be sent to the opposite terminal, the traffic is largely reduced and the protection can operate much more rapidly. Extensive simulations validate the proposed protection.
By calling MATlab calculation engine function library,associated simulation between powersystem Analysis Software Package(PSASP) and MATlab can be realized in parallel and serial *** could use different timing sequen...
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By calling MATlab calculation engine function library,associated simulation between powersystem Analysis Software Package(PSASP) and MATlab can be realized in parallel and serial *** could use different timing sequence from PSASP,and mixed step simulation can be *** calculation method was used in a 10-nodes powersystem case for the modeling and simulation of Automatic Voltage Regulator(AVR),and the correctness of the proposed approach is *** this foundation,the electromechanical transient model of Static Var Generator(SVG) was founded with MATlab/Simulink,and it is of universal applicability and *** inner inverter model can also be used in general grid-connection simulating models of wind power generator,photovoltaic generation,energy storage,***,simulation and analysis for grid-connected wind farm by introducing the SVG model into PSASP were carried out via the proposed associated simulation method above,and the correctness of the model is verified via the calculation *** research results can be used to do assistant analysis for reactive voltage of grid-connected new energy powergeneration.
Aiming at the characteristics of the casing vibration acceleration signal of rotating machinery with rubbing fault, a diagnosis method based on EMD (empirical mode decomposition) and Hilbert envelop spectrum is put fo...
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