Tesla Model S Plaid battery system analysis

　　The reference information mainly comes from the disassembly information of Model S Plaid.

　　During the disassembly, the battery design of Model S Plaid has been observed to include:

　　Introduced the PCS (Charger+DCDC) design in Model 3, 11kW is a standard on-board charging system;

　　Two maintenance windows are designed at the head and tail of the battery system, respectively for the PCS and two sets of contactors (main positive and main negative fast charging contactors), and twin contactors;

　　A separate repair window is designed for PyroFuse-practice has proved that PyroFuse as a vulnerable part needs to be repaired separately;

　　The introduction of the metal shell connector on the Model Y shortens the length of the fast-charging cable. The goal is to charge 350kW with high current in the future.

　　From the overall design concept, we can see several particularly interesting aspects of Tesla's design concept:

　　Each platform has some common excellent designs, which can be transplanted similarly to modularization;

　　Although Model S and Model 3 are different platforms, the excellent design after verification can be quickly deployed simultaneously;

　　The iteration and update of a single platform is progressing towards continuous cost reduction and quality optimization.

　　Figure 1 Iteration of Tesla's battery system

　　The following is a dual-motor version. In fact, Model S plaid also has a front 1 rear 2 drive configuration.

　　Figure 2 Model S Plaid's high-pressure system

　　The electrical maintenance design of Model S Plaid is impressive. Since Tesla is developing towards CTP, its electrical design pays special attention to maintainability.

　　(1) Service Panel 1

　　Service Panel 1 is the part associated with the battery under the seat, as shown in the figure below.

　　Figure 3 Service Panel 1 of Model S Plaid battery system

　　Below this Panel, the most important components are four contactors, including fast-charging twin contactors, main positive and main negative contactors.

　　In order to reduce the heat of high current as much as possible, the input part of the connector and the contactor are designed in the most simplified way, as shown in the figure below. Remarks: According to the picture analysis, this continuous current design target is 900A current.

　　Figure 4 Busbar design of fast charging contactor

　　(2) Service Panel 2

　　The most interesting design here is that Tesla has designed a separate repair window for PyroFuse, at the bottom of the package. The advantage is that PyroFuse has a more flexible replacement strategy, which can be replaced by hoisting the vehicle. The responsive Pyro Fuse protects the entire battery and electrical system, and the fuse can be easily replaced after diagnosis.

　　Figure 5 Pyro Fuse design and maintenance window 2

　　(3) Service Panel 3

　　It is mainly divided into two layers, the bottom layer is fuse and BMS, and the upper layer is PCS. This design logic is exactly the opposite of Model 3 and Model Y. At that time, PCS was down, BMS and fuse were up. It is estimated that the actual maintenance frequency of PCS is relatively high.

　　Figure 6 Model S Plaid battery repair window 3

　　The Model S fuses have been reduced from 3 to 2, mainly because the high-voltage PTC has been removed. As long as the PCS and heat pump compressors are powered, the overall maintenance frequency is greatly reduced.

　　For the overall high-voltage output, Model S Plaid adopts the method of wiring in the package:

　　The fast-charging connector is to place the battery pack on it, and then use the cable plugging method in the compartment, and there is a hole on the floor;

　　Rear drive inverter connector: at the bottom behind the battery, as shown in the figure;

　　Front drive inverter connector: in front of the convex hull and the connector of the electric compressor.