Energization control method and system of battery cabinet

Abstract

The invention provides an energization control method of a battery cabinet for charging and discharging a lithium ion battery. The energization control method is characterized by comprising the following steps of (a) acquiring a voltage value of each battery cabinet needed to be energized; (b) grouping each battery cabinet in a mode that the battery cabinet with voltage difference smaller than a preset threshold by 20-40V is divided in a group; (c) controlling a voltage pressure value between each battery cabinet group and a busbar according to a voltage sharing mode, and sequentially connecting the battery cabinet group with minimum difference value between an average voltage and a busbar voltage in each battery cabinet group to the busbar; and (d) simultaneously charging and dischargingeach battery cabinet connected to the busbar.

Description

Technical field [0001] The present invention relates to the technical field of lithium ion batteries, in particular to a power-on control method and system of a battery cabinet for charging lithium ion batteries. Background technique [0002] Lithium batteries have high energy density, high single cell voltage, long life, no memory effect, and no pollution. Therefore, the use of lithium batteries for power supply is the development trend of battery applications. In high-power applications, firstly, lithium-ion battery cells are connected in series to form a lithium-ion battery pack to increase the power supply voltage, and then the lithium-ion battery packs are connected in parallel to increase the output power of the power supply. Both lithium-ion single cells and series-connected lithium-ion battery packs need to be monitored and managed by a battery cabinet controller including a relay. The lithium-ion battery pack and the battery cabinet controller together form the battery ...

AI Technical Summary

Problems solved by technology

[0003] Generally, when multiple parallel battery cabinets are powered on at high voltage, the voltage of the battery cabinets is inconsistent, and when they are connected in parallel, the current is too large, so the relay cannot be closed, which may cause all the battery cabinets to fail to be powered on.

When the voltage difference of multiple battery cabinets is large, if the internal resistance of the lithium-ion battery pack in the battery cabinet is small, the current will rise instantaneously if forced to connect in parallel, which will cause damage to the circuit of the battery cabinet controller and even the entire battery cabinet control system damage to

For this reason, the existing technology generally uses PCS to charge the battery cabinets with low voltage separately, and then powers on when all the battery cabinets have the same voltage. However, this requires manual control and cannot be done automatically, which brings increased labor costs and maintenance costs. increase, and the power-on time is too long, resulting in low power-on efficiency

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