Overview
Electric-vehicle power electronics convert and control large amounts of power under a harsh thermal and electrical environment, and they demand devices that are automotive-qualified, efficient and reliable. The traction inverter, the on-board charger and the battery-management system each need a power stage, a current measurement and a controller, and BYD Semiconductor supplies all three with its automotive IGBT modules, isolated current sensors and AEC-Q100 Grade 1 microcontrollers. BeiLuo supplies them with genuine traceability and FAE support.
The Traction Inverter
The traction inverter turns the battery DC into the three-phase current that drives the traction motor, and it must handle a high current and a high bus voltage with a low loss. A BYD automotive IGBT module provides the phase legs with a low-inductance layout and a good thermal path, and it is built on the same IGBT technology that BYD develops and manufactures in-house. The module is chosen by the bus voltage and the phase current, and the gate drive and the thermal path are planned together with it, because at this power the thermal design is the design.
Current Sensing in the Loop
The traction inverter needs an accurate phase current for the field-oriented control and the protection. A BYD isolated current sensor measures the phase current without a shunt and with galvanic isolation, so the high-voltage power stage and the low-voltage control side stay separate and the insertion loss is low. The analog output feeds the controller's ADC directly, and the contactless measurement has no wear part, which suits a drivetrain that runs for years.
The On-Board Charger
The on-board charger converts the mains into the battery voltage, and it needs a current measurement for the charge control and the protection and a controller for the power factor correction and the communication. A BYD current sensor measures the charge current, and a BYD MCU runs the control and the vehicle communication over CAN. The automotive qualification of both devices suits the environment.
Battery Management
The battery-management system monitors the cell voltages, the temperatures and the pack current, and it balances and protects the pack. A BYD isolated current sensor measures the charge and the discharge current with the isolation that the high-voltage pack demands, and an automotive MCU runs the logic and the communication. The accuracy of the current measurement over temperature matters for the state-of-charge estimate.
The Automotive MCU
The BYD MCU line is manufactured on an automotive-qualified process and tested to AEC-Q100 Grade 1 under an IATF 16949 system, with a functional-safety capability up to ISO 26262 ASIL B and a -40 °C to +125 °C range. The 32-bit BF7006 series offers an ARM Cortex-M0 core, embedded flash, timers, an ADC and CAN and LIN interfaces, which suit the control and the communication of a charger or a battery-management unit. Confirm the qualified part number and the safety level for the specific application.
Thermal and Reliability
An under-hood or an under-floor environment swings widely in temperature, so the thermal design and the derating matter. Keep the module and the sensor within their temperature rating, provide a good thermal path and measure the worst-case temperature on the bench before you release the design.
Getting Help
Send your bus voltage, phase current, thermal environment and qualification requirements to our FAE team and we will propose an IGBT module, a current sensor and an MCU, help set the current rating and the control loop and review the thermal and isolation design. BeiLuo holds mainstream BYD automotive devices in regional warehouses and ships every order with an import declaration, a certificate of origin and a RoHS compliance file, so an EV power design can move from prototype to production without a supply gap.