Modular PDN design achieves high performance at 48VDC
Achieving miniaturization, lightness, and high performance through PDN utilization


The British Touring Car Championship (BTCC) has been running since 1958, with over 30 highly engineered cars competing for the title.

The BTCC can use electric motors tactically. Delta Motorsports designed a new battery pack and associated electronics for tactical boosting.

The new 48V lithium-ion battery pack features innovative intelligent power management, high-power, high-density DC-DC converters, and regulation systems.

The battery pack powers the inverter-motor combination and receives the power generated by this combination, while the high-power, high-density converter solution powers all of the vehicle's electronic circuits and devices. The power density and power management achieved with this architecture enable control of the alternator system, further improving weight, performance, and reliability.

Additionally, the system achieves miniaturization, light weight, and high performance by utilizing a modular power network (PDN).

The PDN integrates a 48VDC power source that feeds four DC-DC converters connected in parallel, which provide regulated 13.8V power at up to 92 amps (approximately 1.2 kilowatts). The four converters share the load with N+1, or aviation-grade redundancy, but three converters can also fully support the load.

The hybrid system's three-phase brushless motor is connected to the battery via a bidirectional inverter. The inverter routes battery power to the motor and regenerates the power back from the motor to the battery.

The motor initially operates the car in pure EV mode (motor only, no ICE) during the speed-limited pit lane, and then switches to mild hybrid mode (ICE in combination) when increased performance is required during the race.

◇ Innovative battery pack intelligence and management

The battery pack includes a battery management system, which controls all cell voltages and ensures the battery maintains maximum charge and discharge voltages while communicating with the motor-inverter controller. It continuously calculates and updates the amount of current the battery can supply or accept based on its state of charge (SoC). Power demand is reduced at low SoCs, while regeneration is limited at high SoCs.

The battery management system supports data logging and diagnostic functions to record the performance of the DC-DC converter. This is not only to detect faults but also to provide feedback on the exact amount of current delivered to each vehicle.

◇ Vicor DC-DC converter power module

The DC-DC converter power system uses four Vicor DCM3623 isolated regulated DC-DC converter ChiP power modules to provide a regulated 13.8V output from the battery pack at current levels up to 92A. The small profile and footprint allow for direct thermal contact mounting with micro-bore cooling plates extending between the battery cells.

The scalability and ease of paralleling of DCM modules enable a modular power architecture, allowing Delta to customize the DC-DC PDN to the small footprint required without sacrificing power.

Future electric vehicles will inevitably require smaller, lighter, and more efficient power electronics to accommodate their increasing performance demands. As manufacturers move to 48V batteries to handle this increased power, Vicor's modular approach improves power supply efficiency, reducing power loss and weight with smaller, lighter cables and connectors.