Electric vehicle hybrid energy management system based on adaptive wavelet transformation and control method thereof

Abstract

The invention discloses an electric vehicle hybrid energy management system based on adaptive wavelet transformation and a control method thereof. The electric vehicle hybrid energy management systembased on adaptive wavelet transformation comprises a super capacitor, a lithium battery, two DC / DC converters, a drive module, an acquisition circuit and a control module. The control method comprisesthe following steps that firstly, a total reference current required by the load is obtained through voltage loop control; then the adaptive wavelet transform algorithm is used for performing wavelettransform on the total reference current required by the load to obtain a high-frequency current component and a low-frequency current component, wherein the low-frequency current component is takenas a reference current of the lithium battery, and the high-frequency current component is taken as the reference current of the super capacitor; then, a current loop of the control module tracks thereference current of the lithium battery and the super capacitor in real time to realize the real-time distribution of the load demand power. According to the electric vehicle hybrid energy managementsystem based on adaptive wavelet transformation and the control method thereof, the super capacitor is fully utilized, and the lithium battery is effectively protected.

Description

technical field [0001] The invention relates to the technical field of electric vehicle hybrid energy management, in particular to an electric vehicle hybrid energy management system based on adaptive wavelet transformation and a control method thereof. Background technique [0002] In today's world, the situation of energy shortage and environmental deterioration is becoming more and more serious. Electric vehicles have abundant energy sources and have the advantage of no exhaust pollution, which is very beneficial to environmental protection and air cleanliness. Facing the changing output power in the actual energy supply process, the battery energy storage system needs to provide changing current, and the high-frequency and rapid charging and discharging current changes will cause great damage to the performance of the battery and reduce the service life of the battery. Therefore, considering the power density and discharge characteristics of the battery has become a key ...

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Problems solved by technology

The publication number is CN107947211A, and the publication date is April 20, 2018. It is an invention patent application titled "Optimized Configuration Method for Energy Storage in Island Microgrid Using Wavelet Packet Decomposition and Considering Frequency Response", which comprehensively considers energy storage batteries, The characteristics of the supercapacitor and the ability to absorb the frequency deviation of the system, the unbalanced power is decomposed by the Lay layer wavelet packet to obtain the wavelet packet component, and the unbalanced power is divided into low frequency component, intermediate frequency component and high frequency component by using fixed frequency division points nL and nH Three parts, which are respectively stabilized by the three, which will be able to separate the high-frequency low-amplitude fluctuation power absorbed by the system from the original unbalanced power and the corresponding breaking point as the optimal wavelet packet decomposition layer number and high frequency division points, without considering how to determine the optimal number of wavelet packet decomposition layers when the energy of the supercapacitor is insufficient

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