Today, Eastec will share with you the "Busbar", an important component in the power distribution system.
Busbar is a multi-layer composite structure connecting bar, which can be regarded as the highway of the power distribution system. compared to traditional wiring methods. Busbar has the characteristics of easy design, low impedance, anti-interference, good reliability, space saving, simple and fast assembly and so on.
The busbar is mainly used for the electrical connection between the cells and the cells, thus forming the series and parallel relationship of the circuit. On the other hand, the Busbar itself can be used as a sampling point for the voltage and temperature of the cell because it is directly connected to the cell.At present, the following are typical representative modules of the three battery Busbar connections, from left to right, BMW i3, Chevy Volt, Tesla Model 3.
Eastec will discuss and share with you the following square modules.
As can be seen from the figure, Busbar is arranged on the wire harness isolation plate. Voltage and temperature collection points are located at the two protruding feet of the Busbar, which are connected by laser welding. The Busbar in this mold is aluminum material, which is welded with the core by laser. It belongs to the same material welding, and the welding is more reliable and the connection resistance is small.
As you can see from the figure, the soft Busbar is used here. Soft busbar connection has several considerations, one is the expansion force of the three element cell, in the process of continuous charging and discharging of the cell, due to the chemical reaction inside the cell, the thickness of the cell will become larger, shown as expansion to both sides, at this time the cell pole will change with the expansion, if busbar does not have a certain ductibility, Then the cell pole column may be pulled cracking, resulting in leakage and other safety problems;
In addition, Busbar is generally connected by laser welding. Using soft Busbar, the high consistency of the cell can be guaranteed by using its ductility and excellent performance of welding.
Therefore, making the Busbar have a certain ductility, which can not only deal with the risk of pulling the pole due to the expansion of the cell, but also deal with the high consistency of the cell.
Eastec has always been adhering to the service tenet of "quality, lead time,cost, reputation", with smart supply chain, excellent production and processing technology and advanced testing methods, it can provide users with different standards of busbar components. We sincerely hope to cooperate with you in a friendly way and work together to overcome connection challenges together.