Power converting device

Abstract

Disclosed is a power conversion device that does not generate ripples, including a control circuit that generates a switching signal at a timing capable of realizing soft switching. The first main switch (Q1) and the second main switch (Q2) connected in series are connected to the positive terminal of the DC power supply at the end of the first switch, and connected to the negative terminal of the DC power supply at the end of the second main switch. Diodes (D1, D2) are connected in parallel on each main switch to make it reverse biased relative to the DC power supply. On each main switch, the main switch buffer capacitors (C1, C2) are connected in parallel. The connection point of the circuit is connected to the load, and the output is generated by controlling the on and off of the main switch according to the switching signal from the control circuit. The first auxiliary resonant circuit composed of the first auxiliary switch and the second auxiliary switch (Q3, Q4, Q5, Q6) connected in series and the resonant inductor (L1) connected in series on the second auxiliary switch is connected to the positive terminal of the DC power supply Between its connection point and the two main switches, connect diodes to the first and second auxiliary switches so that they are reverse biased relative to the DC power supply. The control circuit takes the voltage signals from the voltage detection part representing the voltages at both ends of the main switch and the above-mentioned auxiliary switch as input, and supplies the first and second auxiliary switches with an on-signal as a switch signal before supplying the first main switch Turn on the signal.

Description

technical field [0001] The present invention generally relates to current conversion devices. More specifically, the present invention relates to a power conversion device including a control circuit capable of realizing soft switching of switching elements. Background technique [0002] In power conversion devices such as converters and inverters, circuits including soft switching functions are being developed for the purpose of reducing switching losses of switching elements and increasing switching frequencies. [0003] For example, in U.S. Patent No. 5,047,913, a converter with the following structure is disclosed: the voltage of the DC power supply is divided into a voltage of 1 / 2 by two capacitors connected in series, and the connection point of the capacitor is passed through a bidirectional switch and an inductor. connected to the connection point of two series-connected main switches. The load is connected to the connection point of the mai...

AI Technical Summary

Problems solved by technology

This control method is accompanied by the problem that ripple voltage is generated in the case of causing the power conversion device to perform inverter operation

If a capacitor is used for downsizing the device, a ripple voltage of the same cycle as the inverter output voltage occurs between the first potential and the second potential, causing the same problem as the circuit described in the aforementioned U.S. patent

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