The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
At present, voltage regulation of no load distribution transformer is not flexible and failure rate of mechanical on-load tap-changers is high. To solve these problems, a scheme of automatic on-load voltage regulation system designed via thyristor for distribution transformer was proposed. The system improved the existing topology of on-load voltage regulation system via power electronic device and...
Particle Swarm Optimization (PSO) has been widely used in the reactive power optimization of distribution networks, and the basic PSO algorithm takes too long time to solve the reactive power optimization problem of low voltage distribution network with multiple constraints. To solve this problem, a scheme of reactive power optimization for low-voltage distribution network using improved particle...
Libraries play an important role at the intersections of government, universities, research institutes, and the public since they are storing and managing digital assets. The large amount of data and those data in library need to be transformed into information or knowledge which then be used by researchers or users. Librarians might need to understand how to transform, analyze, and present data in...
Although a lot of researches have been carried out to evaluate efficiency and effectiveness of different testing techniques there is still lacking of experimental work on functional testing, particularly for black-box testing on open-source software. In this work, four black-box testing techniques were chosen to test on two open source applications. The results have confirmed some conclusions which...
Condition assessment of gas-insulated switchgear (GIS) is an important approach to provide decision-making for condition maintenance which improves the operation reliability of power systems. Indices system of operation condition assessment for GIS is established according to its operation condition which is related to quite a few factors. A part of the factors is vague. Constant weight is determined...
In this paper, an intellectual technology for transformer noise reduction using radial basis wavelet neural network is investigated. The noise reduction technique proposed in this paper enhances noise reduction capability and improves the adaptability of the noise reduction system. The data required for the proposed method is transformer noise obtained during steady state operation. The data is then...
This paper introduces an advanced monitoring and diagnosis technique for the detection of incipient stator electrical faults in doubly-fed induction generators (DFIG) used in wind turbines. Thanks to the measurability of DFIG rotor side electrical characteristics, a new diagnostic method based on the frequency analysis of rotor instantaneous power spectrum is proposed. Theoretical analysis shows that,...
There have been some software tools of managing references when researchers prepare for their research publications, such as zotero and endnote. During last several years, developers of these kinds of tools tried to design a new feature or interface that can be used to visualize the “reference relations” between scientific articles. However, probably because of the complexity of formatting reference...
The effectiveness of on-line advertising is the key to the success of e-commerce. This paper discussed current status and new opportunities for online advertising, one of critical factors for successful e-commerce. With in-depth discussions and our working experience in a US based company, we also proposed a new advertising platform, Cicadida.com, which implemented a few new ideas we discussed.
The converter transformer is one of the most significant components of a HVDC station. And the parameters of the converter transformer play an important role in the operation performance, technical and economic index in HVDC system. According to the valve's surge current level, in combination with ac maximal short-circuit capacity of three phase, rated dc voltage and dc current, this paper describes...
With the increasing requirements of power quality, adjusting voltage frequency and cumulative voltage regulation frequency are increasing for on-load tap-changing transformer, which makes the fault rate of on-load tap-changers(OLTC) in power transformer constantly raise. Contact loosing fault is a common fault for OLTC, which has been paid more attention in recent years. But so far, no effective diagnostic...
Contact burning is one of the main faults of transformer on-load tap changers (OLTC). If contact burning fault diagnosis is not timely, the decreasing contact area, increasing contact resistance and the increasing arc and heat during the witching processes will cause further burning. Researches on contact burning failure were done and a feature analysis method based on wavelet packet energy entropy...
The biggest difference between wind turbine generating units and other traditional ones (hydro and thermal generating sets) is its frequent variation of the prime mover output power and difficulties in control, due to the volatility and the uncontrollability of wind speed. In consideration of the characteristics of wind power system and Direct Current (DC) generator, a wind power generation system...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.