JAGUAR LAND ROVER XJ_e &
RANGE ROVER E
PHEV CASE STUDY
ELECTRIFICATION DEVELOPMENT AHEAD OF ITS TIME
Zytek were engaged by JLR to investigate the feasibility of providing custom power electronics in order to boost the performance of a nominated electric machine.
Phase 1 – Feasibility Study
The first phase of the project, a feasibility study, highlighted that with an increased current capability, coupled with a boost in DC voltage, it was possible to achieve the power and torque requirements needed to maintain vehicle performance with the chosen downsized engine.
Phase 2 – Build, Test and Integration
The second phase included the build, test and integration phases, resulting in a driveable vehicle for appraisal by management teams.
Electric Machine & Power Electronics
The electric machine chosen for the project was an available unit, but when driven by the supplied off-the-shelf electronics, did not offer the performance needed to supplement the loss of performance when fitted with a downsized engine.
Various options for power electronics were simulated, including simply supplying more current, using more advanced commutation schemes, and boosting the DC link voltage from the battery using a new design of high power DCDC converter.
A combination of all of the above was agreed to be implemented to maximise performance available.
Inverter & Converter
The integrated inverter and high power DCDC converter was designed to fit in an identified location in the rear of the vehicle, with 3 phase cables running to the electric machine integrated into the transmission.
The DCDC converter was designed as a 3 phase device, using 3 water cooled inductors at its heart. Control was via a high speed interleaved switching methodology, offering strategies for full and partial operation to maximise efficiency.
The inverter was designed around switching media and proprietary DC capacitor technology to meet the peak and continuous current demands. The resulting housing was machined from solid due to low unit volumes required for the project.
Assembly & Testing
The integrated units were assembled at Zytek’s facility and tested using both static HV benches and onwards onto the dynamic test benches to complete motor characterisation and calibration activities.
Finally, integration support was given during the vehicle build phase to ensure the project was driven to a successful conclusion.