Micro-dc grid is a novel power system focused on the development of renewable resources. However, two-wire transmitting mode generally accepted in micro-dc grid, which usually not suitable for requirements input voltage levels different converters and loads. In order to meet requirements, half-bridge balancer was introduced can convert into three-wire via neutral line. shoot-through problem existing bridge-type degrades reliability balancer. this paper, dual-buck control strategy are...

This paper studies a three-level dc converter for balancing the input voltage, which has similar topology with conventional converter. It can easily build neutral line changing voltage source into two voltage-level sources. A control strategy of conducting time extension partial switch devices is also presented achieving states each power switch. The operating principle analyzed in detail based on strategy. small-signal model and effects proposed are driven. Finally, prototype fabricated...

In view of the characteristics greenhouse environment monitoring system , a scheme based on wireless sensor network (WSN) is presented, which adopts Atmega128L chip and CC2530 that low power RF from TI to design sink node nodes in WSN. The management center can control temperature humidity greenhouse, measure carbon dioxide content, collect information about intensity illumination, so on. And multilevel energy memory. It combines with transfer, makes collected by solar batteries be used...

Abstract—This paper introduces display design process about hardware and software based on AT89C52 single chip microcomputer. We use a simple external circuit to control the screen, which size is 32 × 192. The screen also can of six dot matrix Chinese characters by dynamic scan mode, be divided into two small twenty-four whose 16×16. modify code change content display, subtitles achieve scrolling function scroll speed adjusted according requirements, pause function. character stored in data...

Non-grid-connected wind power theory, which is defined as the optimized integration of grid-connected and standalone generation forms, avoids technical issue integrating into utility, creates a new solution for generation. In this paper, droop control strategy, namely current feed forward adopted dc grid based multi-terminal non-grid-connected system consists several turbines, high-energy-consuming (HEC) loads, energy storage devices, port. The decoupling different terminals achieved with...

This study proposes a three-level dual-buck voltage balancer, which consists of two buck circuits. It can split DC input source into output sources. The sources may have the same levels or different based on applications, while sum voltages is always equal to level. To achieve states, control strategy introducing an extra freewheeling time presented by adding small bias in loop. operation principles are analysed detail. In addition, small-signal model also given design parameters. Finally,...

Abstract In this paper, a low elastic modulus, non-cytotoxic Ti-10Ta-2Nb-2Zr titanium alloy was prepared by selective laser melting additive manufacturing. The effect of annealing and solution heat treatment on the structure, mechanical properties, tribological behavior were investigated. results show that microstructure composed main α′ phase small amount β phase. Heat improved strength elongation. ultimate tensile ( UTS ) elongation deposited specimen 807 ± 8.74 MPa 6.6 0.75 %,...

In order to accurately determine the growth of greenhouse crops, system based on AVR Single Chip microcontroller and wireless sensor networks is developed, it transfers data through transceiver devices without setting up electric wiring, structure simple. The monitoring management center can control temperature humidity greenhouse, measure carbon dioxide content, collect information about intensity illumination, so on. addition, adopts multilevel energy memory. It combines with transfer,...

Reliability is an important performance indicator of wireless sensor network, to some application fields, which have high demands in terms reliability, it particularly ensure reliability network. At present, the research findings network are much more at home and abroad, but they mainly improve from networks topology, reliable protocol layer fault correction so on, comprehensive considered hardware software aspects less. This paper adopts bionic implement reconfigurable nodes, as nodes able...

Focusing on the applications of wireless sensor networks in marine environment monitoring, a localization algorithm underwater with self-healing (SHLA) was proposed.The adopt k-node overlay to elect some nodes as anchors, so make maximum com mon covered by four anchor nodes. The normal location coordinate node locate position, and then transmit monitored environmental information their surface buoy. In order avoid reducing coverage accuracy due failure network, remedial positioning measures...

In this paper, a 3-phase 4-wire star-connected three phase three-switch three-level rectifier (VIENNA) with unity power-factor-correction (PFC) based on one cycle control (OCC) is presented. The technology does not require multipliers to scale the current reference and only need integrators. advantage of that switch voltage stress half total output it doesn't three-phase sensors. can be decoupled in topology single PFC parallel-connected. Even if lacks input, still has excellent...

A novel control strategy for three-phase combined inverters is proposed based on phase-locked loop (PLL) technology. Phase synchronous signal easily disturbed in the process of transmission conventional with control-wire connection, which solved by demodulation a certain output voltage. The concept simple, and easy to implement. And good symmetrical voltage could be achieved under unbalanced loads, even different topologies controllers together. It demonstrates almost same high performance...

In this paper, a novel hysteresis current control method based on the phase of output voltage loop by using single LEM sensor is proposed. Because having two filter inductors, Dual Buck Half Bridge Inverter has bridge arm shoot-through problem. Each inductor can be independently controlled, so power switches and free wheeling diodes optimally chosen, efficiency inverter will increased. So promise high practical value in engineering application. Finally, verified simulation experimental results.

Boost single-phase active power factor correction (APFC) is widely used to reduce input current harmonics. In this paper, distortion in the vicinity of voltage zero crossing APFC high line frequency studied. Current loop model and admittance based on one cycle control (OCC) presented. It pointed out that its equivalent stage a 1st order system, pure resistive around low domain capacitive since 1 kHz around. However, it does not matter aero ac system with 400Hz or 360~800Hz frequency,...

In this paper, first, a new type of DC/DC converter which is composed by variable winding DC transformer as its front-end and back-end converter, combined four buck converters interleaved with 90 degree phase shift to each other (the output voltage about 25 V uncontrolled for there are several batteries connected it) designed produced on the existing wind power testing experimental integration system. This not only has merits ultra-wide range input voltage, high-precision control current...

Abstract In order to reliable data transmission of wireless sensor network (WSN) in indoor environment, the field intensity distribution and characteristics electromagnetic wave were researched. First all, 3D model specific environment was built by finite difference time domain method (FDTD).Then, layout room, different furniture, position source frequency had an influence on that studied, simulated MATALAB. According simulation three dimensional distribution, it directly shown various...