Electrified Powertrain Integration:
Two Paths in Focus
Reducing EV costs and complexity is increasingly achieved through system-
level integration. Two leading approaches are shaping the discussion:
X-in-1 electric drive units (EDUs) and direct AC battery systems. Both offer
efficiency and cost benefits, but with distinct trade-offs.
Vs face constant pressure to cut costs, reduce weight,
and improve range. Multi-system integration helps meet
these goals by combining components into compact
units, improving packaging and performance. OEMs known
for rapid tech adoption have already implemented integrated
architectures, prompting others to accelerate their strategies.
This raises a key question: should integration focus on the
EDU or shift to the battery?
X-in-1 EDU – Mainstream Integration
X-in-1 EDUs combine the inverter, e-motor, gearbox, and often
DC/DC converters, on-board chargers, and battery manage-
ment systems into one housing. This reduces interfaces and
improves packaging. AVL benchmarking shows up to 10 %
cost savings, 8 % weight reduction, and 12 % volume reduction
compared to distributed systems. AVL’s 6-in-1 dual-motor EDU
demonstrator achieves ~95 % peak efficiency.
The X-in-1 approach benefits from established industrializa-
tion paths and supplier ecosystems. However, challenges
include modularity and validation complexity, requiring careful
engineering for EMC, NVH, and serviceability.
Direct AC Battery – Integration at Pack Level
The direct AC battery concept eliminates the traction invert-
er by segmenting the battery into three sections (U, V, W) to
generate 3-phase AC voltage directly. Integrated semiconduc-
tor switching enables sinusoidal power output, removing the
need for a separate inverter, DC/DC converter, and on-board
charger.
AVL simulations show ~1 % inverter efficiency gain and up
to 6 % motor loss reduction. This architecture also supports
flexible AC/DC charging via pack-level switching. Key challeng-
es include managing the three-voltage segment architecture,
advanced balancing algorithms, and thermal design.
Safety is enhanced by eliminating high voltage in idle states,
simplifying manufacturing and service.
One Target, Different Trade-Offs
Both integration paths aim to improve cost, efficiency, weight,
and packaging but shift complexity to different parts of the
powertrain. Centralizing components reduces vehicle-level
integration but concentrates EMC and NVH challenges.
AVL’s engineering methodologies support both approaches,
offering technology-agnostic, data-driven recommendations
tailored to customer platforms. Virtual development and prov-
en design practices enable “first time right” decisions, acceler-
ating time to market.
Key Advantages and
Disadvantages
X-in-1 EDU
Proven integration path with clear cost, efficiency,
and packaging benefits
Higher validation complexity and limited
serviceability
Direct AC Battery
Efficiency gains through decreased motor losses.
Overall efficiency and cost advantage by replacing
inverter and on-board charger
Higher complexity in battery development and vali-
dation including switching technology and thermal
management
2025