Access the Coil Switching White Paper

A report on Exro's next-generation traction inverter technology. 

Coil Driver™ | EV Traction Inverter

Dynamically optimize power, torque, and efficiency through the power electronics

Minimize Total Cost of Ownership

Enhance Performance and Efficiency

Reduce Reliance on Rare Earth Metals

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Optimizing power

Traction Inverter Technology

Expanding e-motor capabilities through advanced power electronics

Coil Driver™ is an adaptive electric vehicle traction inverter that replaces the standard inverter in electric vehicles. The patented Coil Driver™ tech speeds and enhance power and efficiency at high speeds. In essence, the Coil Driver™ automatically selects between two modes in a single motor selecting between low-speed and high-speed operation.

Select mode to compare the same motor connected to a standard 3-phase drive vs Exro Coil Driver™:

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Standard 3-phase drive
Exro – Series mode
Exro – Parallel mode
Exro – System output

Higher torque at low-speed

The traction inverter’s ability to change configurations allows efficiency optimization for each operating mode, resulting in smarter energy consumption. Utilizing minimum energy with maximum results.

  • Multiple power and torque profiles in a single electric motor
  • Next-generation control algorithms
  • Compliance with international automotive standards for functional safety and reliability
  • Third-party validated technology

What is The Coil Driver™?

The Coil Driver™ is an adaptive EV traction inverter that optimizes electric motor performance and efficiency via direct control of the motor coil windings. For an in-depth explanation of the technology and its benefits watch the interview with our Chief Technology Officer, Eric Hustedt. Topics covered in the video include:

What is the Coil Driver™?
How does the Coil Driver™ charging feature function?
How does the Coil Driver™ improve efficiency?
How is the Coil Driver™ different from standard 3-phase inverters?

2022 Edison Best New Product Awards™ in manufacturing, logistics and transportation

'2022 Engine Tech Innovation of the Year' winner at AutoTech's 2022 Breakthrough Awards

Underlying technology

What is Coil Switching?

Coil switching refers to the process of controlling individual coils as the electric motor is operating. This, combined with advanced control algorithms, enables adaptive and real-time management of speed and torque. Curious to learn more about the intricacies of this groundbreaking technology? Access the Coil Switching White Paper to learn more about the benefits of this next-generation traction inverter technology and how the Coil Driver™ is poised to replace the standard 3-phase system.

Independent Assessment 

Third-Party Validation on Coil Driver™ Technology 

Independent third-party organization AVL conducted multiple tests on Exro’s Coil Driver™, demonstrating its coil switching capabilities to optimize the performance of an electric motor through the power electronics. Results also prove Exro’s Coil Driver™ has successfully combined two traditionally separate formats of power electronics for the first time, which has the potential to reduce the weight and cost of electric powertrains.

Independent third-party organization UTAC conducted a rigorous assessment of the Coil Driver™ in comparison to top 800V 3-phase inverters equipped with SiC components. The third-party results highlight the technology’s supremacy in performance and efficiency, outstripping traction inverter incumbents in the electric vehicle market. If you are interested in UTAC’s analysis, access the report now!

UTAC report
Future-proof technology

Coil Driver™ Charging Feature

Electric vehicles require an on-board charger (OBC) to convert AC power to DC in order to charge the vehicle’s battery. The Coil Driver™ technology provides bi-directional power flow capability that enables it to function both as a traction inverter and a charger for electric vehicles. This eliminates the need for an OBC, simplifies the charging process and lowers costs for charging infrastructure, while also enabling fast AC charging.

Features

Removes the need for an onboard charger

Introduces AC fast charging*

Enables V2X capabilities*

Benefits

Simplifies the powertrain, reduces weight, and improves efficiency

No need to update the charger with advances in AC charging

Reduces CAPEX and OPEX costs of building and maintaining a fleet charging infrastructure at company’s depots

Systems Engineering
Electrical engineering
Controls engineering
EVS fields of
expertise
Electrical Assembly
Mechanical engineering
Project management
Mechanical assembly

*First generation Coil Driver™ charging feature offers 19 kW (L2) input power as per J1772. V2X available on future models.

Standards and Compliance

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Component Standards

  • AEC-Q100
  • AEC-Q101
  • ROHS
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Toxic Material and Flammability

  • UL94-V0
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Functional Safety

  • ISO26262
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Automotive Quality Management System

  • IATF16949
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Automotive Electromagnetic Compatibility

  • CISPR-25
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Shock and Vibration Standard

  • ISO16750-1
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Quality Management System 

  • ISO9001:2015

Note: Some certifications and standards listed here are currently under attainment.

Light-Duty Applications

A020-100V

A020 Coil Driver™

Exro Technologies’ A020 traction inverter is an adaptive electric motor controller, that dynamically optimizes the powertrain, enhances torque, and improves performance in light-duty vehicles. This low voltage traction inverter is ideal for 2&3-wheelers, ATVs, light utility vehicles, and other light-duty applications.

A020-100V inverter specifications

Max DC voltage
120 VDC
Performance voltage
36 – 100 VDC
Max per phase current
280 Arms
Continuous per phase current
100 Arms
A020-100V Inverter Datasheet

A020-100V-55kW motor and inverter specifications

Peak power
74 HP
Continuous power
39 HP
Peak torque
138 ft-lbs
Continuous torque
71 ft-lbs
Peak power
55 kW
Continuous power
29 kW
Peak torque
187 Nm
Continuous torque
96 Nm

Benefits of the A020 low voltage inverter

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Superior low-end torque for enhanced startability and acceleration.
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Sustained power at high speeds for improved gradeability.
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Expanded efficient operating area across the speed range.
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Meet performance requirements with a simplified powertrain design.

Unique features of the A020 low voltage inverter

  • Patented technology that enables direct control of motor coil windings.
  • Innovative power electronics topology with seamless switching between series and parallel modes on the fly.
  • Adaptive optimizations to improve performance, efficiency, and reduce system cost.

Medium and Heavy-Duty Applications

L040 400V-800V
L080 400V-800V
Select product:

L040-800V Coil Driver™

L040-400V Coil Driver™

L080-400V Coil Driver™

L080-800V Coil Driver™

Exro Technologies’ high voltage portfolio is designed to enhance vehicle performance, decrease total cost of ownership, and provide integrated charging feature for medium and heavy-duty applications such as trucks, buses, commercial, municipal, and off-highway vehicles. The L040 Coil Driver™ is ideal for class 3-7 vehicles, while L080 Coil Driver™ is specifically designed for high-power applications and covers class 6-8 vehicles.

Traction Inverter

Exro Technologies' high voltage inverters - the L040 and L080 - operate within a performance voltage range of 400V to 800V. While both units can operate at the same performance voltage, the L080 system delivers double the peak and continuous current, making it ideal for high-demand applications. The Coil Driver™ automatically selects the appropriate motor configuration in real time. This expands the performance and efficiency of the motor, resulting in systems that offer maximum results with minimum energy.

L040 inverter specifications

Max DC voltage
450 VDC
Performance voltage
300 – 400 VDC
Max per phase current
350 Arms
Continuous per phase current
240 Arms
Max DC voltage
800 VDC
Performance voltage
640 - 750 VDC
Max per phase current
280 Arms
Continuous per phase current
180 Arms

L080 inverter specifications

Max DC voltage
450 VDC
Performance voltage
300 – 400 VDC
Max per phase current
700 Arms
Continuous per phase current
480 Arms
Max DC voltage
800 VDC
Performance voltage
640 - 750 VDC
Max per phase current
560 Arms
Continuous per phase current
360 Arms

Inverter and Motor System

Exro Technologies' Coil Drive System™ (CDS) utilizes our proprietary Coil Driver™ technology to enhance efficiency, increase torque, and reduce costs in medium to heavy-duty electric vehicles. CDS is an adaptive traction drive system that seamlessly integrates with existing live axle powertrains. With our patented Coil Driver™ technology, coil switching is applied to extract the most torque performance at low speeds, while extending power and high-efficiency operation at high speeds.

L040-800V-337kW system specifications

Peak power
452 HP
Continuous power
299 HP
Peak torque
2360 ft-lbs
Continuous torque
1108 ft-lbs
Peak power
337 kW
Continuous power
223 kW
Peak torque
3200 Nm
Continuous torque
1502 Nm

L080-400V-230kW system specifications

Peak power
308 HP
Continuous power
181 HP
Peak torque
1844 ft-lbs
Continuous torque
811 ft-lbs
Peak power
230 kW
Continuous power
135 kW
Peak torque
2500 Nm
Continuous torque
1100 Nm

Benefits of the high voltage inverter

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Integrated AC charging: The Coil Driver™ system provides integrated vehicle charging capability eliminating auxiliary on-board chargers.
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Next-level performance differentiator: Experience significant improvements in motor power and efficiency where it matters most, at highway speeds.
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Reduce mechanical losses: The enhanced torque at low speeds and sustained power at high speeds can eliminate multi-speed gearboxes.
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Simple vehicle integration: The Coil Driver™ traction system interfaces with a propeller shaft to existing live axles requiring little to no change to the vehicle chassis.
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Improved towing capacity: Enhanced torque enables application to carry heavier load.
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Reduce mechanical loss: Remove mechanical gearboxes, improve system efficiency, and reduce system weight.

Unique features of the high voltage inverter

  • Patented technology that enables direct control of motor coil windings.
  • Innovative power electronics topology with seamless switching between series and parallel modes on the fly.
  • Improved drive cycle efficiency and range.

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