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This assay supposed one kind of asymmetrical multi-level inverter that based on the topology of cells cascading, every cell in this inverter is composed of one two-levels inverter series with several three-levels H bridges, the controlling system is constructed by DSP and FPGA. This article described the topology of this inverter and its controlling methods in detail. In final, tested this inverter's...
There is a strong trend in the photovoltaic (PV) inverter technology to use transformerless topologies in order to acquire higher efficiencies. This paper presents a single-phase five-level grid connected PV inverter with a novel dual reference modulation technique. Two reference signals identical to each other with an offset equivalent to the amplitude of the rectified inverted sine carrier signal...
This project has been oriented to the development of an energy system unit for powering tramways during shorts periods of time. The aim of this work is to present the results obtained for a high frequency DC-DC converter which is included in the energy unit. The energy unit will consist on two type of energy storage devices: a battery stack and a supercapacitor stack. A comparison of the simulated...
This paper describes a new configuration of the single-phase seven-level voltage source inverter. The proposed inverter based on modified H-bridge converter. The inverter is built of conventional H-bridge inverter and two bidirectional switches and three bulk capacitor banks. To validate the proposed inverter, a low power prototype inverter has been designed and implemented; analytical, simulation...
A novel circuital model for a shunt connected RF MEMS coplanar switch, based on a fully analytical approach, is presented. The numerical simulations performed with the proposed new model are in good agreement with experimental measurements.
This paper presents the design and fabrication of fast DMTL RF MEMS phase shifters. Distributed MEMS Transmission Lines are being used with miniature RF MEMS switched capacitors (40times40 mum2), actuating at 25 V with a switching time around 1 mus. Both 90 and 180 degree phase shifters presented here operate at 20 GHz, are respectively less than 4.5 mm and 8.5 mm long. They are designed with 6 and...
A two-stage electronic ballast for metal halide (MH) lamps is presented in this paper. The front-stage is a two-output power factor correction AC-DC flyback converter. The post-stage is a half-bridge inverter, which is used to control lamp power and drives MH lamp with a low-frequency square waveform current to avoid acoustic resonance. In addition, the lamp power of steady state is maintained at...
This paper presents a high-efficiency-high power density one stage ZVS-PWM single-ended push-pull (SEPP) high frequency inverter with new PFC functional scheme. This high-frequency resonant series load resonant inverter with lossless snubbing capacitors is composed of a passive PFC converter operating at one diode conducting bridge circuit and asymmetrical ZVS-PWM high frequency resonant direct inverter...
An improved three-phase single-stage isolated power factor correction (PFC) converter topology is studied in this paper. The converter is based on full-bridge structure and operates in constant-frequency discontinuous conduction mode (DCM). Through the analysis on the working principle and mechanism of voltage spike of the original topology, a voltage-clamping circuit is proposed and added in primary...
A three-phase single-stage full-bridge power factor correction converter is presented in this paper. The converter could achieve power factor correction and AC/DC power conversion in one stage circuit. It could achieve electrical isolation between input and output sides. The voltage stress of each switch is reduced due to the adopting of the active clamp circuit. By using soft-switching techniques,...
The developed switched reluctance starter/generator system in low voltage is presented, which is made up of the three-phase 12/8 structure double salient reluctance machine, three-phase asymmetric bridge single polarity power converter and the controller. The three-phase 12/8 structure double salient reluctance machine, the three-phase asymmetric bridge single polarity power converter and the control...
Based on the working conditions and development trend of operating mechanism of high-voltage circuit breaker, this paper presented a high-load adjustment rate of portable high-frequency switching power supply designed for high-voltage circuit breakers test. The main circuit topological structure is analysed in detail, which uses the fullbridge circuit and IGBTs (insulated gate bipolar transistor)...
The conventional methods used in the isolation of the UPQC are add a isolation transformer in the point, in which series unit or parallel connection unit access the system, but owing to the non-linear of the transformer, this isolation method shall bring many baleful ingredients. In order to avoid the baleful influence of the conventional isolation transformer, the text introduces a sort of new-style...
Multilevel converters have excellent performance in power application, especially in high-power medium voltage fields. To find an effective and general strategy for multilevel and multiphase system is a challenge attracting many researchers. This paper analyses the basic analytical meaning of PWM strategy, which is to implement an analog continuous reference value by means of several available discrete...
This paper presents switched reluctance motor (SRM) torque ripple minimization based on the modified multi-level converter. The TSF control has a low torque ripple, good dynamic performance and high efficiency. And the proposed modified multi-level converter has low cost and high performance. For integrated advantages of the TSF method and the proposed modified multi-level converter, a suitable control...
This paper proposes an input-paralleled output-paralleled half-bridge converter based on single half-bridge converter, which is very suitable for the low output voltage and large output current application. All modules share a common capacitor-leg, that can reduce the number of main circuitpsilas capacitors and make topology simple. The traits and rules of combination converter are introduced and...
As an essential component in magnetic resonance imaging (MRI) systems, the gradient amplifier plays an important role for good image quality. A platform of stacked high and low level H-Bridge circuit is built to fit the high-dynamic and high-steady requirements of the gradient amplifier. Both high current slew rating and low steady ripple can be achieved by using the two H-Bridges, one with high voltage...
Through analyzing the shortcomings of the control system on the traditional cutting inverter, this paper presents the double close loop control system based on pole assignment for cutting inverter, which based on phase shift full bridge zero voltage switched (PS-FB-ZVS). This paper builds the small signal mode of PS-FB-ZVS PWM converter, and assigns the double close loop PI parameters by pole assignment...
There are demands for very large KVA switched reluctance drives (SRD) for many applications. However, one of the key issues is to ensure that the current and voltage capabilities of IGBTs are enough to safely transfer the power from the supply to the SRM. This paper extends the snubber topology of full bridge circuit to the asymmetric bridge circuit of SRDs, proposes and evaluates three different...
A novel method (AC-DC-AC)to produce symmetrical four-phase voltage is presented in this paper, The main circuit is the four-bridge topology and the control method is the three-dimensional voltage space vector control. This method has the merits of novel design, high conversion efficiency, good waveform quality and the method is easily to be realized.The power circuit topology of realizing four- phase...
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