A modeling method of a bi-directional DC-DC converter

Abstract

The invention discloses a modeling method of a bi-directional DC-DC converter which comprises the following steps of respectively establishing a Lagrange mechanics-based model of a bi-directional DC / DC converter of a hybrid electric vehicle hybrid power supply system according to the modal 1, the modal 2 and the modal 3 of a Buck mode and a Boost mode thereof; the models are discretized separately. Based on the discretized Lagrangian model and hybrid automata theory, the discretized Lagrangian model is extended, and the differential equation corresponding to the discretized Lagrangian model isembedded in the discrete event state automata model, so the hybrid automata model is obtained, and certain technical effect is realized.

Description

technical field [0001] The present invention relates to the field of modeling of bidirectional DC / DC converters, in particular to a modeling method of bidirectional DC-DC converters. Background technique [0002] The bidirectional DC / DC converter is an important component of the hybrid power system of the hybrid electric vehicle. It can adjust the energy bidirectional transmission according to the requirement while keeping the polarity of the DC voltage at both ends of the converter unchanged. In the composite power system, the bidirectional DC / DC converter is matched with different energy storage units. According to the location of the energy storage unit, the converter can work in Buck mode or Boost mode. When the energy storage unit is located on the low-voltage side, the converter can The effect of raising its output voltage is to work in Boost mode; when the energy storage unit is on the high-voltage side, the converter lowers its output voltage and works in Buck mode. ...

AI Technical Summary

Problems solved by technology

[0003] The present invention provides a modeling method for bidirectional DC-DC converters, which solves the problem of adopting a simple average model ignoring its high-frequency dynamic characteristics, or using accurate The discrete model makes the amount of calculation too large, the continuous time model is not suitable for digital control, and ignores the problem that its hybrid characteristics do not fully describe the various operating modes of the entire system, and realizes considering the hybrid of bidirectional DC-DC converters Features, complete description of each working mode of the bidirectional DC-DC converter, the calculation amount of the built model is moderate, and the simulation results show that its technical effect of high tracking accuracy

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