1,721,076 research outputs found
A simple control technique for series resonant converters
No full textA simple control strategy for series resonant converters, based on the control of the state space trajectory, is proposed. The control technique, suitable also for high frequency applications, only implies a linear combination of the converter state variables, maintaining quite linear and load independent control characteristics. Simulated dynamic response and experimental results are reporte
Mechanical motion induced EMI on mobile synchronous generators
No full textThis paper presents the results of some experimental EMC tests performed on different mobile synchronous generators. These results show that, besides normal EMI generated by rectifying diodes in the field current circuit, additional noise raises from mechanical vibration of electric connection devices and friction between different insulating materials. Further investigations demonstrate that such vibration-derived EMI depends on connectivity of both of inner and outer wire connectors, where load and field currents are flowing. The experiments reveal these additional EMI generating mechanisms by comparing the synchronous generator EMI before and after proper modifications of the power cable connection and layout. Also rubbing different insulating materials can produce static electricity discharge, which results in additional EMI source. Further suggestions for EMI reduction are also discussed
A simple control technique for series resonant converters
No full textA control strategy for series resonant converters, based on the control of the state space trajectory, is proposed. Its simple implementation allows high frequency applications and requires only resonant current sensing. Quite linear and load independent control characteristics are obtained. Simulated and experimental results show good steady-state stability, fast dynamic response for wide reference step variations, and well-controlled converter start-u
Series Resonant Converter with Wide Load Range
No full textA modification of the series resonant converter topology is presented which extends converter operation from no-load to full-load. This result is accomplished by adding two switches at the secondary-side bridge rectifier, thus improving output voltage control. The resonant inverter can be operated either at constant switching frequency, even for the half-bridge topology, or at variable switching frequency. With constant switching frequency, the output voltage is regulated by controlling the switches of the rectifier stage. Soft-switching commutations of all switches are maintained in any operating condition, thus optimizing overall efficiency. The secondary-side control of the output voltage adds another interesting feature to the basic converter, i.e. the step-up and step-down regulation capability which allows the use of this topology in high power factor rectification, too. Simulated and experimental results confirm proper converter operation in the range from no-load to full-load
Design Considerations on Current-Mode and Voltage-Mode Control Methods for Half-Bridge Converters
No full textThe instability of the input capacitors midpoint voltage in the half-bridge topology observed using peak current-mode control is investigated and a simple solution, which does not require any modification of the converter power stage, is proposed. As far as voltage-mode control is concerned, a novel multi-loop control allows synthesis of the desired regulator transfer function by using only low-pass filters, thus reducing the high-frequency noise coupling typical of standard PID regulators and reducing the dependency of crossover frequency and phase margin on output capacitor ESR. In the paper, useful design considerations are given and verified with an experimental prototype
Digitally-Controlled Single-Phase AC/DC Integrated PWM Converter
No full textThe paper presents the implementation of a fully digital controller for a boost type integrated AC/DC PWM converter. The considered converter has the following basic features: high power factor, full control of the output DC voltage, high-frequency line filter inductor and insulation transformer. Its main advantage is the complete integration of a rectifier and an inverter stage requiring only four IGBTs and six diodes. The converter is described in detail and the structural limitations of its operation are highlighted. The paper focuses on the converter control strategy describing in detail the implementation, by means of the TMS320F240 digital signal processor, of a fully digital predictive input current control technique. An application specific modulation strategy is also developed that allows simultaneous input current and output voltage control. The control system is finally tested on a 0.5 kVA laboratory converter prototype, so as to validate the design procedure and illustrate the achievable converter performance
AC/DC PWM converter with sinusoidal AC currents and unity power factor for DC motor drives
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