Selection of the Filter Capacitor for Power Supplies using 1-Phase Diode Rectifier
Diode bridge rectifiers with capacitor-input filters are commonly used at the input stage for power supplies operating from the single phase mains input, as they provide a cost effective solution in the lower power range. However, as there is no simple design rule existing in published literature that gives a reasonable prediction based on real-life conditions, the design of the rectifier-capacitor stage is still a trial and error or based upon experience. This paper presents an approximate (but simple) solution based upon empirical relations, for the prediction of the currents involved and specifies the capacitor, so that it can be selected.
Input-Series Output-Equivalent-Parallel Multi-Inverter System for High-Voltage and High-Power Wireless Power Transfer
This article presents an input-series output-equivalent-parallel (ISOEP) multi-inverter system for high-power wireless power transfer (WPT), where preisolation dc/dc converter is concealed to achieve higher efficiency, and the number of inverter modules is allowed to be flexibly adjusted to satisfy different voltage and power requirements. The main contribution of this article is to analyze the possible factors that may lead to voltage unbalance in the series inverters of the proposed ISOEP multi-inverter topology. At the same time, the dividing capacitor suppression and duty cycle adjustment are adopted to achieve input voltage sharing. To confirm and validate the effectiveness and merit of the proposed WPT system, a prototype consisting of three inverters connected in series was designed, built, and tested. Experiments show that the proposed topology achieved both high-power output and effective input voltage sharing. The maximum output power is 38.37 kW with an efficiency of 89.31%.
Analysis of rectifier filter circuits
The analysis of wave norms in circuits containing rectifiers is in reality a study of transient conditions which repeat cyclically. This paper presents a method of solution for such circuits by means of Fourier series, assuming initially a perfect rectifier with sinusoidal applied voltage. It shows, for cases in which the rectifier conducts current continuously, that the curve of voltage output from rectifier to d-c load consists of sinusoidal segments, and that the series for this voltage can be used, term by term, to find the current series. In some circuits the rectifier conducts current for only a portion of the cycle; in such cases the voltage curve consists of sinusoidal parts joined by sections of other forms. Wave forms are found by computation for several typical circuits, and verified by oscillograms.