Two-way DC-DC converter

Abstract

The invention allows DC power supply systems efficiently accommodate each other for electric power, with a simple control system with no fear of a large current flowing a switching element at turning on / off, with less switching loss.A rectification element is connected parallel to each of switching elements 4-1 to 4-4 of a low-voltage side switching part 4, while a rectification element is connected parallel to each of switching elements 5-1 to 5-4 of a high-voltage side switching part 5. By performing switching control either or both of the low-voltage side switching part 4 and the high-voltage side switching part 5 at the same time, an electric power is traded between DC power sources through a transformer 3. An LC resonance circuit 6 is provided between a high-voltage side coil 3-2 of the transformer 3 and the high-voltage side switching part 5, or between a low-voltage side coil 3-1 of the transformer 3 and the low-voltage side switching part 4, so that the current flowing a primary side and secondary side is made to be sine wave, for switching near its zero crossing point.

Description

technical field [0001] The invention relates to a bidirectional direct current-direct current converter, in particular to a bidirectional direct current-direct current converter capable of suppressing switching loss and simplifying a control system. Background technique [0002] Some vehicles and the like are provided with two power supply systems including batteries having different voltage values. When the two DC power systems having different voltage values ​​are connected to each other, generally, a DC step-up circuit and a DC step-down circuit are provided in parallel between the DC power systems, and these circuits are appropriately used. [0003] In addition, it has been proposed to use a bidirectional DC-DC converter in order to obtain a sufficient high-voltage DC voltage with a small-scale circuit when the power is mutually integrated in a DC power supply system. [0004] For example, in JP-A-2002-165448, a bidirectional DC-DC converter is described. The bidirectio...

AI Technical Summary

Problems solved by technology

[0005] However, in a configuration in which a DC step-up circuit and a DC step-down circuit are installed in parallel between two DC power supply systems, there are problems in that the circuit scale increases, and if they are operated simultaneously, the voltage loss inside the circuit waiting for full performance

[0006] In addition, in the bidirectional DC-DC converter described in the above-mentioned publication, the switching element of the DC-AC conversion part is a switching element for turning on and off a large current. , it has to pass through the unsaturated region of the switching element, so it actually becomes an analog action, so a large switching loss occurs

[0007] Also, in the case of fully synchronously driving the primary-side DC-AC converter and the secondary-side DC-AC converter, when the current of one DC-AC converter flows, if the other DC-AC converter is turned on, a large current flows in Danger of switching elements

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