Frequency division control method, distribution control device and composite power supply of composite power supply

Abstract

The invention discloses a frequency division control method of a compound power supply, a distribution control device and the compound power supply. The frequency division control method comprises the steps that a load reference total current is output according to bus voltages at the current moment and bus expected voltages; an energy state SOC of a super-capacitor is calculated, and a current distribution proportion of the super-capacitor is calculated according to the energy state SOC of the super-capacitor; then, the current distribution proportion of the super-capacitor is utilized to acquire a cut-off frequency of a filter; and finally, the filter is utilized to filter the load reference total current to obtain a low-frequency current component and a high-frequency current component, the low-frequency current component is used as a reference current of a lithium battery, the high-frequency current component is used as a reference current of the super-capacitor, and the compound power supply is subjected to frequency division control. By controlling the current distribution proportion of the super-capacitor, SOE changes of the super-capacitor are controlled, the power charged into the super-capacitor or discharged from the super-capacitor is limited, and the super-capacitor is effectively prevented from charging and discharging excessively.

Description

technical field [0001] The invention belongs to the technical field of composite power supplies, and in particular relates to a frequency division control method for a composite power supply, a distribution control device and a composite power supply. Background technique [0002] Electric vehicles have been vigorously developed in recent years due to their advantages such as low environmental pollution and good driving experience. However, lithium battery technology is still the biggest obstacle limiting the popularization of electric vehicles under the current conditions. In lithium battery technology, the lifespan problem is one of the most urgent problems to be solved. Factors that affect the life of lithium batteries include frequent charging and discharging and peak currents. In order to make up for the lack of a single power supply for electric vehicles, the latest method is to use dual power supplies, that is, lithium batteries and super capacitors to form a compos...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem of overcharging or over-discharging of the supercapacitor existing in the composite power supply for a long time in the prior art, and further propose a frequency division control method for the composite power supply, a distribution control device and a composite power supply. The distribution ratio of capacitor current K sc To control the change of SOE of the supercapacitor, limit the power charged or discharged by the supercapacitor, and effectively avoid excessive charging and discharging of the supercapacitor

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