Temperature controlling system and method used during lithium ion power battery pack charging or discharging procedure

Abstract

The invention relates to a temperature controlling system and a temperature controlling method used during a lithium ion power battery pack charging or discharging procedure. The system comprises a battery pack module, a temperature detecting unit, a temperature regulating unit, a controlling circuit, and a current detecting module used for detecting the current direction of the battery pack. The controlling circuit comprises a central controlling unit and a relay which are connected to each other. The battery pack module, the temperature detecting unit, and the central controlling unit are orderly connected. The current detecting module is arranged between the central controlling unit and the battery pack module. The temperature of the battery pack is regulated by the temperature regulating unit. Through the relay, the central controlling unit turns on or shuts off the temperature regulating unit according to the battery pack current direction detected by the current detecting module and the battery temperature detected by the temperature detecting unit. According to the invention, the output current can be regulated according to the temperature of the battery pack. An additional circuit or the battery pack is selected for providing currents for the temperature regulating unit according to charging or discharging conditions. With the system and the method provided by the invention, purposes of security ensuring, energy saving, and battery energy utilization rate improving are achieved.

Description

technical field [0001] The invention belongs to the technical field of power management, and in particular relates to a temperature control system and method during the discharge process of a lithium-ion power battery pack. Background technique [0002] The number of lithium-ion power batteries required for the normal operation of pure electric vehicles is about 100-130. In order to facilitate management and later maintenance, a modular design is generally adopted. Each battery module is composed of 10-13 batteries in series; The space of the battery is limited, so the batteries are closely packed. When the battery pack is charging, or when the vehicle is discharging at different rates under different driving conditions such as high speed, low speed, acceleration, deceleration, etc., heat will be generated at different rates, and the space is narrow, so as time accumulates A large amount of heat will be accumulated, resulting in a large change in the temperature of the batt...

AI Technical Summary

Problems solved by technology

[0004] The heat dissipation of lithium-ion battery packs mainly includes air-cooling, liquid-cooling and phase-change materials and other modes: liquid is used as the heat transfer medium, the heat transfer coefficient between the pool walls is high, and the cooling and heating speeds are fast; the disadvantage is: sealing requirements High; relatively heavy weight; complex repair and maintenance; components such as water jackets and heat exchangers are required, and the structure is relatively complicated

Fluid heating means that the air or liquid is heated and introduced into the battery module, and then the heat is transferred to the battery. However, due to the limitation of the flow rate and space in the battery module, the efficiency of gaseous air to conduct heat to the solid-state battery is low, and each Uneven flow rate, it is difficult to ensure uniform heat transfer

At present, the heating plate heating, heating wire winding heating, electric heating film coating heating and other methods are used, which may easily cause the battery pack to heat up too quickly, and the heating wire is close to the battery, which may easily cause accidents such as short circuit

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