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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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.
Wind-photovoltaic-energy storage (ES) hybrid generating system has numerous reactive power sources. It is crucially important for coordinated control of these reactive power sources. According to the test results, the...
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With the rapid development of distributed energy resources (DERs), it is of vital importance to develop a well-designed transmission cost allocation scheme to reflect the contributions of DERs to the powersystem. In ...
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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...
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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.
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.
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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The prediction method based on the partition of weather types has been widely used in photovoltaic prediction. Here, the temporal characteristics of PV data is studied, the physical meaning of the sequential differenc...
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The prediction method based on the partition of weather types has been widely used in photovoltaic prediction. Here, the temporal characteristics of PV data is studied, the physical meaning of the sequential difference sequences is analysed, and a characteristic index system including sequential characteristics index is proposed. The weather types are partitioned based on self-organising map neural network algorithm. Case study shows that the partition method is helpful to improve the discrimination of weather types and to improve prediction accuracy.
Considering the effect of LNG supplying risk on the combined gas and electricity system's operation under the multi-gas-source supply background, the optimization planning model of the combined system's LNG re...
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Considering the effect of LNG supplying risk on the combined gas and electricity system's operation under the multi-gas-source supply background, the optimization planning model of the combined system's LNG reserve is developed in this paper. The optimization objective of this model is minimizing the annual cost of combined system, considering operation simulation of several typical scenarios along 52 weeks in a whole year and the annualized investment of LNG tanks. The operation objective of each scenario is determined by LNG's arrival and the operation mode of LNG terminals. A test system of IEEE-39 test system and Belgian 20-node system is formulated. The optimal LNG reserve of the test system is solved, and the effect of load level and operation mode on the reserve planning is also analyzed.
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