Automotive powertrain

There are three key elements to an EV’s powertrain. These are:

• The on-board charger (OBC) - This takes the current from the AC mains (coming from a residential block, office or street-based charging point) and converts it into DC. This DC current is then used to charge the battery. When fast charging (from a charging roadside station) is being carried out, the OBC does not need to be involved. Here the current can be supplied straight to the battery.
   
• The battery management system (BMS) - This is responsible for looking after the Li-ion battery. It must ensure that the battery operates in a way that ensures the longest possible working lifespan and the conditions that it is running at are maintained within optimal margins, the cell loads being balanced accordingly. Via sensors situated on individual battery cells, it can monitor the temperature levels and other parameters. This will safeguard against the prospect of thermal runaway or other problems occurring.
   
• The inverter - This has the job of using the charged energy in the battery to propel the EV’s traction motor, as well as controlling its rotational speed. Though the energy stored in the battery is in a DC form, it needs to be converted back into AC before it reaches the motor.

In order to utilise the available charging current as effectively as possible, the OBCs placed in EVs need to support high efficiency operation. This will also mean that there is less wasted energy turned into heat, so the cost involved and space taken up by thermal management will both be lowered. At the same time, there is increasing pressure to increase the power densities of OBCs. That will allow their contribution to the overall weight of the vehicle to be reduced, enabling greater distances to be travelled on the stored charge. The higher temperature-withstand levels, elevated voltage capabilities, and faster switching speeds that WBG technology is able to support are going to be pivotal in future OBC designs - enabling more efficient, robust and compact solutions. The need to downsize EVs’ inverters and boost their operational efficiency (through mitigating switching losses) are very similarly apparent. Once again, it will be the use of WBG that will be the foundation for this.

The BMS technology being incorporated into the new breed of EVs will call for more advanced sensors. These will have higher resolutions, so that temperature and current fluctuations can be more accurately determined, as well as increased responsiveness, in order that arising situations can be addressed at the earliest stage, before damage is done to the vehicle or the occupants put in any danger. The speed of the supporting communication infrastructure will need to be increased too.

With regard to ICE powertrains, the attention is now firmly placed on making the vehicles they are incorporated into as clean as possible. Advanced technology is helping to reduce exhaust gas emissions, so that increasingly stringent environmental regulations can be complied with. Improvements in systems efficiency are translating into heightened levels of fuel economy. Direct injection techniques mean that fuel is utilised better, as it is introduced right into the combustion chamber. Alongside this, better thermodynamic arrangements and exhaust gas manipulation mean that heat energy is not lost, but can be made use of elsewhere. More sophisticated engine management system (EMS) implementations will require high-performance microcontrollers, power discretes and power management ICs.

The devices that EBV stocks enable continued powertrain innovation, covering WBG and Si power components, digital ICs, and current sensors. Among them are the following: