Bidirectional dc-dc converter and uninterruptible power supply including same

Abstract

The present invention provides a bidirectional DC-DC converter and an uninterruptible power supply including the same, which includes: a first switching transistor with a first antiparallel diode connected in sequence between positive and negative DC bus bars, a second switching transistor with a second A second switch transistor with an antiparallel diode and a third switch transistor with a third antiparallel diode, the second switch transistor is connected to the first and third switch transistors respectively to form a first node and a second node; a switch transistor assembly , which includes a plurality of switching transistors connected in series and connected in parallel with the second switching transistor; a first inductor connected between the first node and the positive pole of the rechargeable battery and / or connected between the second node and the negative pole of the rechargeable battery The second inductance between; and the control device, which is used to control the switch transistor assembly to be in the conduction state during the process of changing the switch state of the second switch transistor. The bidirectional DC-DC converter of the present invention has lower switching loss.

Description

technical field [0001] The invention relates to a DC-DC converter, in particular to a bidirectional DC-DC converter and an uninterruptible power supply including the same. Background technique [0002] A bidirectional DC-DC converter is a device that realizes the bidirectional flow of DC power, and is mainly used in uninterruptible power supplies. The bidirectional DC-DC converter usually adopts the classic buck chopper (Buck) and boost chopper (Boost) circuit topology, and has the function of buck and boost bidirectional conversion. [0003] However, when the switching transistor in the bidirectional DC-DC converter is controlled to be turned on or off, the voltage across the switching transistor is not equal to 0, that is, the turn-on and turn-off processes are not performed at zero voltage, so the The switching transistor has large turn-on loss and turn-off loss (ie, switching loss) in the working state, resulting in low switching frequency and low power conversion effic...

AI Technical Summary

Problems solved by technology

[0003] However, when the switch transistor in the bidirectional DC-DC converter is controlled to be turned on or off, the voltage across the switch transistor is not equal to 0, that is, the turn-on and turn-off process is not performed at zero voltage, so the The switching transistor has a large turn-on loss and turn-off loss (ie switching loss) in the working state, resulting in a low switching frequency and low power conversion efficiency of the bidirectional DC-DC converter

In addition, when the switching frequency of the bidirectional DC-DC converter is low, the inductor in the bidirectional DC-DC converter should use an inductor with a larger inductance value, that is, an inductor with a larger volume and a higher cost. This bidirectional DC-DC converter has low power density and high cost

Images