Papers by Keyword: Inverter Circuit

Abstract: The work process of medium-frequency power supply is complicated .Its waveform is complex and can not be measured conveniently. Therefore,This paper focuses on the analysis of operating principles and control methods of medium-frequency power supply, to determine its basic structural units.A simulation model of medium-frequency power supply which is controlled by pulse width modulation (PWM) is built with the electromagnetic transient analysis software PSCAD. The simulation and analysis of the medium-frequency power supply circuit are performed on the basis of the model.The simulation waveform can reflect the working process of medium-frequency power supply accurately. So this paper will provide a reliable basis for further research of medium-frequency furnace.

Abstract: By recycling the kinetic energy in gyms, a generating system is closely related to this design, in which a perfect output circuit has been used so as to output a constant voltage no matter how variable the power of the kinetic energy is. Consequently, a continuing and constant current will be output when an electrical storage device is equipped. Based on a systematic analysis of the generator, accumulator and loading equipment, this thesis would grasp the variation tendency of each variable in the generating system, thus to realize the grid-connected operation of the existing alternating current and the generating system built-up by the fitness equipment.

Abstract: In order for wide bandgap semiconductor power devices to be practical use in various power electronics applications, a 2in1 600V75A power package with a 200 degree Celsius heat resistance was newly developed on the premise of mass production. This package designed to specify a low inductance of less than 24nH enables SiC and GaN-based devices to be driven with a high slew rate up to 5kA/us under hard-switching condition. Furthermore, this package encapsulated by a epoxy resin of a high heat resistance and equipped with thick Cu heat spreader allow these power devices to be driven up to 200 degree Celsius and dissipate heat in large quantities (thermal resistance R_th,jc: 0.6K/W), which is found to make cooling heat sink simplified. We introduced 50ASiC-MOSFET in this package, and verified the operation on a power conditioner for Solar Photovoltaic cells up to 4kW output. A high power conversion efficiency of 97.7% was measured by our SiC power packages on downsized cooling heat sink in 1/4 volume, which was more efficient than Si-IGBT module by 1.5%.

Abstract: A simulation model was built based on the Simulink module in the Matlab to study the effect of DC power harmonics to hysteresis current control performance. The DC power supply in the hysteresis current control circuit was obtained by a three-phase rectifier circuit, and the harmonics of DC power supply vary with the value of the capacitor which was in parallel to the rectifier circuit output. The result of experiment shows that the harmonics cause the inverter output waveform distortion, even cause hysteresis current control tracking failure.

Abstract: According to the special requirements of power supply for seismic station, a new single-phase emergency power supply control system is proposed in this paper. The principle and structure diagram of the system is illustrated. The control strategies of the system and hardware design of key circuits are discussed in detail. The emergency power supply control system adopts high-property C8051F310 single chip micro-computer. According to the monitoring value of input voltage, the system switches between charging and inverting. Main circuit of inverting uses single-phase full-bridge topology. To correct a power factor, charging system applies boost circuit to make input current follow to a given current reference. Experiments validate the feasibility of the proposed design.

Abstract: IGCT is a kind of new type power electronic device which developed from GTO and IGBT . In this paper, Author based on analysis of the internal structure of GTO, shows how GTO development IGCT through technical methods.Through simulation of its off and on performance, the work curve and comparing results of the two devices are given. Then on two components of the inverter circuits are analyzed and compared. Thinking in large power AC drive locomotive, IGCT inverter is greatly simplifier than GTO inverter circuit, and superior performance,it will become the main converter for AC driving locomotive.