Control Method of Resonant AC Heating System Powered by Battery Dual Circuits

Abstract

The invention provides a battery double-circuit power supply resonant AC heating system, a control method and a battery system. The battery double-path power supply resonant AC heating system comprises a first bridge arm, a second bridge arm and two groups of resonant branches, where the first bridge arm comprises a first power switch tube group consisting of a plurality of power switch tubes, a drain electrode of the first power switch tube group is connected with a positive electrode of a battery, and a source electrode is connected with a negative electrode of the battery; the second bridgearm comprises a second power switch tube group consisting of a plurality of power switch tubes, wherein the drain electrode of the second power switch tube group is connected with the positive electrode of the battery, and the source electrode is connected with the negative electrode of the battery; one ends of two groups of resonant branches are connected with the neutral points of the bridge arms, and the other ends of the two groups of resonant branches are connected with the neutral point of the battery; and the two bridge arms are driven by two sets of complementary PWM signals. The problems that the heating speed is slow, the effect is poor, the efficiency is low and the like in the existing battery heating method in the low-temperature environment are solved, an external charging pile or a battery can be flexibly applied to provide heating energy, and the application range and the scene are wide.

Description

technical field [0001] The invention relates to the field of thermal management of vehicle-mounted batteries, in particular to a resonant AC heating system with dual-circuit power supply for batteries, a control method and a battery system. Background technique [0002] The charging and discharging performance of lithium-ion power batteries will be greatly deteriorated by the low temperature environment, which will seriously affect the driving range of electric vehicles in winter, and will also cause permanent damage to the battery life. Therefore, in a low-temperature working environment, the power battery should be preheated before the normal driving of the electric vehicle, so that the battery cells can reach the normal working temperature range and improve their working performance. [0003] Low-temperature heating of the battery is a powerful means to ensure the high-efficiency, long-lasting and safe operation of the power battery in a low-temperature environment. Acco...

AI Technical Summary

Problems solved by technology

However, its disadvantage is that it can only use the energy of the power battery itself for heating, and it cannot work normally when the battery power is low.

In addition, when an external charging pile is connected, charging cannot be performed when the power battery self-powered solution is used for heating. After heating, additional charging time is required to replenish the power consumed by heating, which seriously affects the user experience of electric vehicles.

In addition, the existing AC heating device generally adopts a hard switching scheme, and a higher AC heating frequency will generate a large semiconductor power switch tube loss, which will affect the overall efficiency of the heating device

At the same time, the large switching stress and loss also bring challenges to the reliability of the heating device, which greatly limits the application possibilities of internal heating methods.

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