Two-dimensional optical orthogonal codes have important applications in code division multiple access networks. In this paper, a generic construction of two-dimensional with at most one pulse per wavelength (AM-OPPW 2D OOCs) is proposed. As result, some optimal AM-OPPW OOCs new parameters can be yielded. The OOC may support more subscribers and heavier asynchronous traffic compared known constructions.

At present, the accuracy rate of single-phase grounding fault disposal column circuit breaker with primary and secondary integration is low, so it urgent to carry out assessment verification disposal. The test in operation site subject influence safety risk user power supply reliability. It not easy many times. In this paper, through establishment real distribution network system, achieve rapid access objects, flexible reproduction ground fault, put forward a complete set on fusion columns...

As an environmental insulating medium, natural ester fluid has many advantages such as renewable, biodegradable, fireproof and heat resistance. In order to master the ester's insulation properties of long-term high temperature operation, electrical — paper under thermal aging condition, especially partial discharge characteristic test research is very necessary. this paper, mineral oil composite sample were processed after same treatment. Long-term experiments performed 110 Ό 130 compare...

Understanding the oxidative mechanism of natural ester based insulating oils will benefit seeking antioxidants for their long time service in a transformer. The present studies introduced comprehensive investigation on soybean oil under accelerated aging conditions through 1H, 13C, DEPT-135 NMR, GPC, ICP, viscosity analysis, and chemical scavenger tests. It was found that superoxide radical, generated by copper wire activated oxygen, played significant role aging. Capturing radical...

Gas insulated transmission line (GIL) is widely used for power in special geographical environment such as river crossing, mountain crossing and city tunnel scenarios. Because of its totally enclosed structure, it difficult to locate the fault position when internal breakdown discharge occurs. Fault location by using ultrasonic wave aroused an efficient method GIL maintenance. This paper reports experimental theoretical results attenuation propagation law signal GIL. An ultra-high voltage...

UHV AC transformer is one of the most difficult equipment in transportation electric power large equipment. Its weight and dimension have reached limit highway transportation. At present, it impossible to transport by railway, very coordinate It often necessary reconstruct roads, strengthen bridges so on. There are many factors that affect transportation, not only period safety risk control difficult, but also cost high. Limited conditions some areas, location substation directly affected....

With the two-carbon goal and new power system advancing, grid structure, supply structure load are facing profound changes, which brings great challenges to distribution equipment, fault self-healing technology non-power outage maintenance. At same time, due gradual acceleration of county's rooftop photovoltaic pilot, anti-island overvoltage protection strategies devices not perfect. Large-scale wind farms, stations supporting energy storage centrally connected regional substations, coupling...

Frequency-hopping sequences (FHSs) with low Hamming correlation are essential for synchronization and multiple-access communication systems. In this paper, we propose a novel construction of FHSs using generalized cyclotomy. Our results reveal that the constructed exhibit one-coincidence property, meaning smallest between different FHSs, aside from trivial case, is minimized. Additionally, new sets achieve an optimal size in relation to known theoretical bound.

In order to study the method of analysis dissolved gas for natural ester insulating oil transformer, test model was built according common types electrical failures oil-filled transformers. The discharge experiment (Soybean and camellia seed oil) mineral carried out analyze compare type percentage generated under typical faults different paper insulation. results show that main productions oils were CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Three-phase load imbalance in low-voltage distribution network is inevitable and exists for a long time. And lot of devices are developed to solve the problems. However, current national standards trade standards, there only clear provisions on three-phase voltage imbalance, test methods relatively vague, compensation effect above cannot be effectively judged. From perspective above, this paper establishes 400V true platform, analyzes determines key parameters influencing unbalanced ability...

In order to improve safety and economy of the power transformer operation, guide operator deal with abnormal condition, as well how find out fault causes malfunction quickly, this paper, a new diagnosis expert system was established. The first uses rough set method experience simplify knowledge sample database, eliminate redundant information, form refined rules input them into base system. During reasoning, or corresponding processing scheme are obtained by analyzing matching between...

Through the study on countermeasures against abnormal conditions of transformer and some key technologies including insulation state service life evaluation transformer, paper develops intelligent module for basis integrating sensor technology, technology communication as a whole makes prototype, initially realizing operation transformer. The online monitoring device is developed in this includes oil chromatogram, distributed temperature sensing, leak current insulating casing, dielectric...

At present, ground faults are a hot research topic at home and abroad. As many scientific institutions manufacturers continue to deepen single-phase faults, they have proposed new type of environmentally friendly primary secondary fusion pole-mounted circuit breaker ZW68. However, the manufacturer' s products vary from good bad, so 10kV distribution network true platform is used screen quality products. same time, grounding fault tests with different transition resistances intermittent...

In the construction of Ultra High Voltage (UHV) AC project in china, UHV transformer is very difficult to transport. Disintegrating transportation and on-Site assembly an effective way reduce weight, solve problems costs. China's Yuheng-Weifang transmission project, auto-transformer with disintegrating on-site used Jinzhong substation by Sate Grid Corp. China for first time. It also engineering application 1000kV class at home abroad. Compared conventional Transformer, design manufacture...

The frequency-hopping sequence(FHS) plays a crucial role in achieving the anti-jamming capability of FH communication system. Therefore, it is necessary to try ensure that wide-gap between two adjacent frequency slots larger enough and number collisions small enough. In this paper, we present new class one-coincidence FHS set. Such WG-OC-FHS set optimal with respect WG-Peng-Fan Bound. And each sequence WG-Lempel-Greenberger Compared previous construction, construction has good randomness use...

For a long time, there has been no consensus on what grounding method should be used for the neutral point of distribution network. Especially when single phase-to-earth fault occurs in network, is great controversy over whether to use ground through arc suppression coil or low resistance, which not only involves reliability power supply, but also personal safety issues. However, most handling devices can obtain characteristic data simulation some line waveforms. And lack comparative...