Modular charging/discharging system of power battery pack of multifunctional electromobile

Abstract

The invention relates to a modular charging / discharging system of a power battery pack of a multifunctional electromobile, which aims to provide a system which can effectively meet the requirement for the bi-directional power transmission of a charging station and can exert the functions of peak clipping and valley filling as well as peak modulation and frequency modulation of a power grid. The technical scheme is as follows: the modular charging / discharging system of the power battery pack of the multifunctional electromobile comprises a charging-station monitoring system and an information management system, wherein the charging-station monitoring system is composed of a computer and a network communication system. The modular charging / discharging system is characterized by also comprising a three-phase step-down transformer, wherein the high voltage side of the three-phase step-down transformer is connected with a power grid, and the low voltage side of the three-phase step-down transformer is connected in parallel with a plurality of charging / discharging branches; each branch comprises a three-phase distribution transformer and a charging / discharging module, and the three-phase distribution transformer is connected in series with the charging / discharging module; and each charging / discharging module comprises a pulse-width modulation alternating current / direct current (PWM AC / DC) converter with the function of bi-directional power transmission, a plurality of electromagnetic isolation type DC / DC transform modules with the function of bi-directional power transmission and the information management system, and the electromagnetic isolation type DC / DC transform modules are connected in parallel.

Description

technical field [0001] The invention relates to the technical field of electric vehicle charging, in particular to a modular charging and discharging system for a power battery pack of an electric vehicle. Background technique [0002] In recent years, as people pay more and more attention to social issues such as energy crisis and environmental pollution, energy-saving and environment-friendly new energy vehicles have become an inevitable trend for the sustainable development of the automotive industry. Among them, giving priority to the development of electric vehicles is of great significance to the transformation and upgrading of my country's energy structure and the leapfrog development of the automobile industry, and will surely become the main technical route of the national new energy vehicle strategy. [0003] During the "Eleventh Five-Year Plan" period, the number of pure electric vehicles and hybrid electric vehicles put into use in Beijing has reached 1,000. Dur...

AI Technical Summary

Problems solved by technology

This puts forward the functional requirement of two-way transmission of power to the charging station, while most of the current traditional chargers use diode one-way rectification and charging, and the single function cannot meet the requirements of two-way transmission of power.

Due to the nonlinear characteristics of diode rectification, a large amount of harmonic pollution will be generated on the grid side. Harmonics will not only cause additional loss and heat generation of lines and transformers, but also cause system resonance, seriously endangering the safe operation of the power system.

Therefore, in order to meet the harmonic index, the traditional charger must add additional PFC and complex filtering device, which not only increases the cost but also reduces the reliability of the device

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