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The main objective of this paper is to increase the power conversion efficiency by effective solar spectral band splitting. This is attained here by cascading semiconductor materials of varying energy band gap arranged in the decreasing order. In addition, an efficiency of a multijunction solar cell can be improved by current and lattice constant matching of the cells. Accordingly, a multijunction...
In order to improve the efficiency of high voltage power supply for electron beam welder, the characteristics of LCC series parallel resonant converter with capacitive filtering are studied in this paper, and the circuit model of LCC resonance in discontinuous current mode(DCM) is established. The working mode of the converter is analyzed by mathematical time domain analysis method, and the mathematical...
In this paper, the effect of changes in the width of teeth and yoke on stator temperature characteristics was analyzed. An initial model of fill factor 45% was produced. The validity of the temperature analysis using the thermal equivalent circuit method was experimentally verified. A basic model was selected as the initial model. Also, a temperature characteristic analysis was performed for various...
The energy conservation of motors becomes one of the most important areas of industrial energy saving. At present, the majority of motors in industrial applications is induction motors (IMs) which has huge potential for the efficiency improvement. The IMs are nowadays widely used in transportation fields as traction motors or for other electrical devices such as compressors, integrated starter generator,...
Intermediate coils are used in wireless power transfer to improve system performance, such as power transfer capability and efficiency. However, they can have adverse effects if used improperly. This paper focuses on the coil coupling stage of three-coil series-compensated wireless power transfer systems and analyses the effects of the intermediate coil under different conditions. When the coupling...
Spoke type is one of the most popular rotor configurations in ferrite interior permanent magnet synchronous machines. In such configuration, the focusing factor of permanent magnet flux is of essential importance to achieve high performance. Large number of rotor poles is usually preferred to boost the air-gap flux density from the low-energy ferrite permanent magnets. Besides, multi-layer magnet...
For many transport systems a necessity of performing in time a set of heterogeneous repair work exists. Several works should be performed by one repair brigade in crossed time. And conditions for performing different repair works are characterized by uncertainties. There exists given term for each work and possible damages or the missed benefit if the performance of works isn't well-timed. Taking...
The switched reluctance motor (SRM) is suitable for high-speed driving and enables high output. However, it is less efficient than other motors. This is due to an increase in iron loss caused by high speed operation. Therefore, in this paper, we adjusted firing angle and verified that firing angle realizing maximum efficiency exists by changing current waveform and loss. It was confirmed that the...
In recent years, Most of countries think to combine between existing electrical grid and a smart grid using renewable resources as solution with the intention of achieving 100% of green power in the future, The objective is to decrease costs of production and importation of energy, protecting environment and citizens health by closing all power plants like nuclear plant. The process of delivering...
GaN RF technology has continued to demonstrate state-of-the-art power, efficiency, linearity, and low-noise performance in RF and mm-wave band. Here, we report on a multi-octave (100 MHz–8 GHz), linear nonuniform distributed amplifier (NDPA) in a MMIC architecture using scaled 120-nm short-gate-length GaN HEMTs. The linear NDPAs were built with six sections in a nonuniform distributed amplifier approach,...
The concept of Smart City IoTisa comprehensive and layered framework that caters to the needs of multiple facets of projects related to smart city and thus allowing cities to utilise urban networking in order to increase economic prowess, and build more efficient, unique technological solutions to deal with the numerous challenges of the city. Smart City is the product of advanced development of the...
At present, the SiC devices have been widely concerned with the excellent characteristics of low switching losses, which can significantly improve the frequency of power electronic converters, and also have broad application prospects in the field of rail transportation. In this paper, through the establishment of 1500V powered subway auxiliary inverter loss model, the author estimated loss and efficiency...
In this paper, a 400kHz high-frequency dual-buck inverter is fabricated for the applications of small scale renewable energy generation. A systematic calculation method for the converter's loss distribution is proposed to evaluate the efficiency. This method concerns the impacts caused by the high frequency on the loss distribution, which are always neglected by the traditional method. In the last,...
Renew able energy sources have gained momentum in the current trends of effective power generation to overcome global warming due to the pollution caused by existing power generating system. The renewable power will also meet the future demand when existing fuel will be exhausted. Solar power is considerably preferred on account of its easy availability all year round. In this paper, a very efficient...
Exhaust emissions from motor vehicles have become hot issues due to their toxicities and their effects on health adverse. To reduce the emission, people have to develop a filtering system. This study developed a filtering system based on electrostatic principle and taken an advantage on motor battery for the electricity to reduce the PM2.5 exhaust emissions. The filter consists of a set of aluminum...
This paper investigates different methods for improving the power efficiency of Class-D audio amplifier output stages. A standard half-bridge design is analysed and the effects of using Gallium Nitride (GaN) and Silicon Carbide (SiC) devices are considered. A new 2-phase interleaved output stage is proposed, and the advantages of this are discussed. The effect of the output low-pass filter parameters...
In this paper, the misalignment property of the Conformal Strongly Coupled Magnetic Resonant (CSCMR) system is studied and applied to power multi-device simultaneously. A planar CSCMR WPT system shows excellent misalignment in azimuth plane compared to traditional SCMR system. The Receiving (RX) resonator can be moved around the Transmitting (TX) resonator in the same plane without scarifying efficiency...
Two wearable sensor applications by using Conformal Strongly Coupled Magnetic Resonance (SCMR) wireless power transfer (WPT) system is presented. SCMR system was used to replace the battery system in these wearable sensors. The advantage of removing battery system with a WPT system is presented. Design of different shape SCMR transmitter/receiver is also discussed and demonstrated in this paper.
A Z-source boost dc-dc converter along with a multilevel inverter is proposed. In this work, the modified converter with conventional Z-source network has high voltage gain compared to the traditional boost dc-dc converters. It gives a common ground between the dc supply source and load output. The impedance network acts as a bridge connecting the source and the converter. It does not require any...
This paper uses Data Envelopment Analysis (DEA) to empirically analysis the efficiency of Beijing-Tianjin-Hebei traffic integration and the results are as follows. Firstly, the railway network is running well while the difficulties to alleviate the contradiction between supply and demand of the highway transport has existed for a long time, and the homogenization of competition in the port construction...
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