Direct current (DC)/DC converter controlled in digital mode and efficiency optimization method thereof

Abstract

The invention discloses a direct current (DC) / DC converter controlled in a digital mode and an efficiency optimization method of the DC / DC converter. The DC / DC converter comprises two parts, namely a power-level circuit and a control unit, the primary level of the power-level circuit comprises a full bridge inversion circuit composed of four groups of switching field-effect tubes Q1, Q2, Q3 and Q 4, an input end of the full bridge inversion circuit is connected with DC high voltage, an output end of the full bridge inversion circuit is connected with a primary winding of a high-frequency transformer, output of a secondary winding of the high-frequency transformer is rectified and filtered and then connected with DC low voltage output, the secondary level adopts a synchronous rectifier composed of two field-effect tubes Q5 and Q6 to lower the conduction loss of the secondary level, and high-precision pulse-width modulation (HRPWM) output of the control unit passes through a driving circuit and is connected with grid electrodes of the field-effect tubes from Q1 to Q6. The DC / DC converter controlled in a digital mode and the efficiency optimization method of the DC / DC converter achieves digital control of the DC / DC converter, meanwhile, the self-adaptive synchronous rectifier optimizes a dead time, and therefore higher conversion efficiency is achieved.

Description

technical field [0001] The invention relates to a DC / DC converter using digital control and an efficiency optimization method thereof. Background technique [0002] As one of the key energy conversion components of hybrid and pure electric vehicles, the function of the DC / DC converter is to convert the voltage of the on-board high-voltage battery pack into a 14V power supply to supply conventional low-voltage on-board equipment (unidirectional step-down mode), or at the same time 14V boost boost capability (bidirectional mode). There are many ways to realize DC / DC converters, such as the boost plus half-bridge two-stage conversion circuit adopted by Toyota Camry Hybrid in the early days, and the more common full-bridge phase-shift zero-voltage switching circuit. [0003] In terms of control methods, these DC / DC converters adopt analog control, and their core control functions, such as error amplifier, ramp generator, pulse width modulator (PWM), overvoltage and overcurrent ...

AI Technical Summary

Problems solved by technology

Driving the design using familiar traditional analog controls allows only very small improvements in conversion efficiency and power density metrics

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