Adjacent-cell-to-cell equalization circuit and implementation method based on lcl resonance conversion

Abstract

The invention discloses an Adjacent-Cell-to-Cell equalization circuit based on LCL resonant transformation and an implementation method. The equalization circuit comprises a microcontroller, a plurality of LCL resonant transformation modules and single cell bodies. Every two adjacent single cell bodies share one LCL resonant transformation module. Each LCL resonant transformation module and the corresponding single cell bodies are connected with the microcontroller. According to every two adjacent single cell bodies with the higher voltage and the lower voltage respectively, the microcontroller sends a pair of PWM signals with the complementary states to corresponding MOS transistors of the LCL resonant transformation module, so that the MOS transistors work in the charging state and the discharging state alternately, and energy is transmitted from the single cell body with the higher voltage to the single cell body with the lower voltage. When the PWM frequency is equal to the LCL natural resonant frequency, zero-current switching equalization is achieved. The equalization circuit is high in efficiency, large in equalization current and easy to control, and the problem that a traditional Cell-to-Cell equalization circuit is large in switching loss, and cannot achieve zero-voltage-difference equalization is solved.

Description

technical field [0001] The invention relates to an Adjacent-Cell-to-Cell equalization circuit based on LCL resonance transformation and a realization method. Background technique [0002] The world is facing an unprecedented energy and environmental crisis, which has attracted worldwide attention. However, opportunities and challenges often coexist. The Energy Internet, characterized by the combination of renewable energy and the Internet, will give birth to the third industrial revolution. As one of the five pillars of the third industrial revolution, electric vehicles are widely welcomed by people for their energy saving and environmental protection, and have become the inevitable trend of future automobile development. Lithium-ion batteries are widely used as power sources in electric vehicles and hybrid electric vehicles due to their high energy density, low self-discharge rate and no memory effect. In practical applications, in order to obtain a higher voltage level,...

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Problems solved by technology

The equalization circuit of the present invention has high efficiency, large equalization current and simple control, and overcomes the problem of large switching loss and inability to achieve zero-voltage-difference equalization in traditional Cell-to-Cell equalization circuits

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