Topological structure of two-way DC/DC converter and converter

Abstract

The invention relates to a topological structure of a two-way DC / DC converter and a converter. The topological structure comprises an input end, an output end, inductors L1 and L2, coupling inductors LP, LO and LS, diodes D1, D2, D3 and D3X, field effect transistors S1, S2, S3 and S4 and capacitors C1 and C2, wherein one end of the L2 and the homonymous end of the LP are connected with the anode of the input end, the other end of the L2 is connected with the cathode of the D2 and the source electrode of the S2, the heteronymous end of the LP is connected with the homonymous end of the LO, the anode of the D1 and the drain electrode of the S1, the heteronymous end of the LO is connected with the homonymous end of the LS and the drain electrode of the S4, the heteronymous end of the LS is connected with one end of the C2, the other end of the C2 is connected with the drain electrode of the S2, the cathode of the D3 and the source electrode of the S3, the cathode of the D1 is connected with one end of the C1 and one end of the L1, the other end of the L1 is connected with the anode of the D3 and the cathode of the D3X, the anode of the D3X, the other end of the C1, the source electrode of the S1, the source electrode of the S4 and the anode of the D2 are connected with the cathode of the input end, the drain electrode of the S3 is connected with the anode of the output end, and the cathode of the output end is connected with the anode of the D3X. At a BOOST state, the invention has higher gain, the capacitor has higher energy storage density, and the system has strong reliability.

Description

technical field [0001] The invention relates to the technical field of DC / DC converters, in particular to a topology structure of a bidirectional DC / DC converter and a bidirectional DC / DC converter. Background technique [0002] Bidirectional DC / DC converters are widely used in hybrid vehicles and braking / generating energy feedback systems of high-power electromechanical equipment. At present, in large-scale motor equipment (such as tire cranes), supercapacitors are mostly used as energy storage devices, and the braking / power generation energy of the motor is controlled and stored and fed back through a bidirectional DC / DC converter to achieve energy saving. [0003] At present, bidirectional DC / DC converters mostly adopt a non-isolated BUCK / BOOST topology. Due to the limitation of the topology, there are mainly two problems in the prior art in bidirectional DC / DC converters. First, the gain of the BOOST converter is generally low. The gain of the BOOST converter is usuall...

AI Technical Summary

Problems solved by technology

First, the gain of the BOOST converter is generally low

The gain of the BOOST converter is usually less than 5. When the circuit works in continuous mode, the number of supercapacitors (each with a withstand voltage value of 2.7V) that needs to be connected in series is large, and it is often necessary to add a complicated voltage equalizing circuit. greatly reduces the reliability of

Especially in tire cranes where the input voltage is relatively high (such as V O =640V), the minimum voltage V at the capacitor terminal Omin >128V (the final value of discharge), the number of supercapacitors that need to be connected in series will be more, and a complicated voltage equalizing circuit must be added, and the reliability of the entire device will be greatly reduced

Second, the step-up and step-down gains cannot take into account the energy storage density of the capacitor

[0004] Since the energy storage density of a capacitor is related to the voltage difference between charging and discharging of the capacitor, in order to increase the energy density of an equal-capacity capacitor, when the minimum discharge voltage is determined, the charging voltage value needs to be increased, which further reduces the reliability of the system

At present, no effective way to solve this problem has been proposed in the products or literature at home and abroad.

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