Integrated Powertrain System - MotorTransformer

Comparison of Andromeda's vehicle-to-building solution compared to what is available commercially.

Andromeda Power, LLC

Recipient

Long Beach, CA

Recipient Location

33rd

Senate District

69th

Assembly District

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$482,130

Amount Spent

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Active

Project Status

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Project Update

The project team selected a Nissan Leaf as the demonstration platform for the Integrated Powertrain System, which enables high-power bidirectional alternating current (AC) charging using onboard components, with the MotorTransformer at its core. The MotorTransformer uses the electric vehicle’s traction motor as an isolation transformer and converts DC power from the battery into AC power that can be supplied to a building. High-voltage laboratory testing validated MotorTransformer operation up to 50 kilowatts, including evaluations of thermal stability, efficiency, harmonic behavior, insulation integrity, and electrical safety under sustained operating conditions. The MotorTransformer was developed without disassembling motor coils or adding components to the windings, preserving structural integrity while supporting a scalable and cost-effective conversion approach. Dual active bridge modulation was implemented to control frequency, phase, and duty cycle for efficient bidirectional power transfer.

During 2025, the project advanced beyond component-level validation through the development and testing of multiple subsystems required for vehicle integration, while continuing sustained bidirectional AC operation of the MotorTransformer. These subsystems included a CHAdeMO-based vehicle-to-everything battery interface, SAE J3068-compliant EV and building interfaces, a three-phase grid energy meter, configurable MotorTransformer switching hardware, and a centralized vehicle-to-building controller and gateway supervising all subsystems. Together, these elements formed a complete pre-integration powertrain system architecture.

In 2026, the project will focus on integrating the powertrain system into the electric vehicle platform and conducting vehicle-to-building functional demonstrations based on the validated subsystems and control architecture.

The Issue

Today, high-power electric vehicle interconnection with buildings or the grid is available only through direct current (DC) charging and bidirectional systems. These offboard DC systems are costly, bulky, and infrastructure-intensive, which limits deployment and accessibility. As a result, most vehicles cannot directly discharge high-power alternating current (AC) to the grid or support site loads.

Enabling vehicles to supply high-power AC using onboard components could significantly reduce infrastructure cost and complexity. However, this requires safe bidirectional power conversion, grid compliance, and robust electrical isolation.

Project Innovation

The Integrated Powertrain System enables high-power bidirectional AC operation using onboard electric vehicle components, reducing reliance on costly offboard DC interconnection equipment.

The system repurposes existing traction motor and power electronics so that the motor functions as an isolation transformer while onboard inverters support controlled bidirectional power flow.

This architecture allows an electric vehicle to supply grid-compatible AC without adding dedicated external conversion hardware. Advanced control software coordinates power conversion, protection, and operating modes between the electric vehicle and external building or grid interfaces during vehicle-to-building operation. By minimizing additional hardware and infrastructure, the Integrated Powertrain System provides a scalable pathway toward more accessible vehicle-to-building and vehicle-to-grid applications.

Project Goals

Modify an electric vehicle traction motor to function as a high-power isolation transformer for bidirectional AC operation

Adapt the EV power electronics and control architecture to enable bidirectional AC charging and discharging.

Validate operation of the modified powertrain in both vehicle driving mode and vehicle-to-building power delivery mode.

Identify and assess technical and commercialization pathways for deploying a low-cost AC vehicle-to-building solution.

Project Benefits

The Integrated Powertrain System enables electric vehicles to provide vehicle-to-building backup power and energy management services without relying on dedicated stationary storage or offboard bidirectional charging infrastructure. By leveraging onboard vehicle components, the system reduces total system cost while avoiding emissions associated with fossil-fuel backup generators. Vehicle-to-building capability improves resilience by supplying power during outages caused by extreme heat events, wildfires, and public safety power shutoffs. Compatibility with standard building electrical interfaces increases deployment potential across residential, commercial, and fleet applications. Overall, the technology advances a lower-cost, scalable pathway for improving grid resilience and energy reliability.

Affordability

The Integrated Powertrain System can provide backup power services comparable to behind-the-meter stationary storage at a lower overall cost, without the need for dedicated batteries or offboard bidirectional DC charging equipment.

Reliability

Vehicle-to-building operation enhances resilience by enabling electric vehicles to supply power during grid outages, helping mitigate impacts from extreme weather events and public safety power shutoffs.