Alternating-current impedance measurement method for battery in hybrid power supply power system

Abstract

The invention relates to a method for measuring the alternating current impedance of a battery in a hybrid power supply power system. The method comprises the following steps: determining the amplitude of an alternating current disturbance signal, enabling a DC / DC voltage converter to work, generating the alternating current disturbance signal, collecting output signals of a fuel battery and a lithium battery, and calculating the output power of the fuel battery and the lithium battery; calculating the required power of the load; when the required power of the load is stable, respectively calculating the impedance of the lithium battery and the impedance of the fuel battery, otherwise, only calculating the impedance of the fuel battery. Compared with the prior art, the step of detecting whether the load demand power is stable or not is added in an existing control method, when the load demand power is stable, the impedance of the fuel cell and the lithium battery is measured at the same time through the alternating-current impedance measuring device of the vehicle, and the difficulty of recognizing the internal state of the hybrid power supply power system is lowered; the cost is greatly reduced, and the internal state of the composite power supply system can be integrally identified.

Description

technical field [0001] The invention relates to the technical field of battery detection, in particular to a method for measuring AC impedance of a battery in a composite power supply power system Background technique [0002] As energy and environmental issues become more and more serious, the excessive consumption of traditional fossil energy has caused people to worry about energy depletion, and the development and utilization of new energy has attracted widespread attention, especially in the field of new energy vehicles, fuel cells and lithium batteries. Batteries have become a new trend of development. However, the dynamic response of the fuel cell is slow, and independent use will not be able to meet the frequent power changes under vehicle conditions, while the lithium battery has a high power density and a fast response rate, so a composite power system that combines fuel cells and lithium batteries is better. s solution. The internal states of fuel cells and lith...

AI Technical Summary

Problems solved by technology

Considering the cost and volume, the vehicle generally only installs an AC impedance measurement device, which is used to measure the AC impedance of the fuel cell, and other devices or complex control methods are used to identify the internal state of the lithium battery, which is difficult to identify the composite Internal state of the power system

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