This project we worked on, explores the integration of a 48V 6-phase Permanent Magnet Synchronous Motor (PMSM) system in a two-wheeler or three-wheeler electric vehicle (EV), with a focus on its design, implementation, challenges, and the benefits it offers.
Motor controllers being critical components in electric vehicles, works wonders when integrated with advanced systems like the 48V 6-Phase Permanent Magnet Synchronous Motors.
Let us take you inside our innovation lab at Embitel for a quick tour!
System Overview
The control system for a 48V 6-phase PMSM is composed of several critical components, including a Motor Control Unit (MCU), sensors, and an inverter. These elements work together to efficiently manage motor speed, torque, and overall performance. The 48V PMSM is designed for integration into the wheel hub or as a mid-drive motor, offering a balance between lower voltage safety and enhanced efficiency.
We have developed a prototype system integrating the 48V 6-phase PMSM, MCU, sensors, throttle, and other necessary components into a test vehicle, enabling real-world testing and validation of the system’s performance.
Check out our 3 phase 48V mid drive platform solution for Electric 2 wheelers and 3 wheelers.
Key Components and Functions of Our 6 Phase Mid Drive Platform
- Motor Control Unit (MCU): The MCU processes inputs from various sensors and controls the PMSM to achieve desired performance metrics. It manages motor speed, torque, and smooth operation under varying conditions.
- Sensors: The system employs a range of sensors, including encoders, current sensors, and voltage sensors. Additional sensors such as torque sensors and throttle position sensors provide crucial input for different operational modes. These sensors deliver real-time data on motor position, speed, and current, essential for precise and efficient motor control.
- 6-Phase Inverter: In a 48V 6-phase system, the inverter converts the DC power from the battery into the AC power required by the PMSM. The inverter ensures smooth motor operation through precise control of phase currents and voltages. Field Oriented Control (FOC) algorithms optimize motor performance, ensuring efficient operation under various conditions.
- Mid-Drive Motor – PMSM Motor: The mid-drive PMSM motor offers several advantages, such as improved efficiency, high torque density, and smooth operation (detailed below).
Design and Implementation
Simulation and Modelling
The design process begins with simulations using tools like MATLAB/Simulink. These simulations model the 48V 6-phase PMSM and its control system, helping optimize control algorithms and validate system performance before physical implementation.
Integration
Integrating the 48V 6-phase PMSM into either a hub or mid-drive system requires careful consideration of the motor’s placement and the overall vehicle design. For hub motors, integration is straightforward as the motor is built into the wheel hub. For mid-drive systems, the motor is centrally mounted and connected to the drivetrain, offering improved weight distribution and efficiency.
Field-Oriented Control (FOC) Algorithm for 6-Phase Systems
The FOC algorithm is pivotal to our 6-phase PMSM systems, offering enhanced motor performance and efficiency through:
- Park and Clarke Transformations: These transformations simplify control by converting six-phase currents to a two-axis system (d-q frame), facilitating more efficient motor control.
- Decoupling of Torque and Flux: Allows for independent control of torque and magnetic flux, optimizing motor performance and efficiency.
- SVPWM Modulation: Space Vector Pulse Width Modulation (SVPWM) ensures high-efficiency motor driving, crucial for smooth operation in 6-phase systems.
High Dynamic Response and Smooth Operation: Our FOC technology ensures quick adaptation to varying load conditions, providing a smoother and more comfortable ride with reduced torque ripple.
Operational Modes for 6 Phase PMSM Systems
The system supports multiple operational modes, including:
- Throttle Mode: Allows the rider to control speed directly via the throttle.
- Field Weakening Mode: Extends the vehicle’s maximum speed by adjusting the magnetic field strength in the motor, allowing for efficient operation beyond the motor’s base speed.
- Regenerative Braking: Recovers energy during deceleration, converting kinetic energy back into electrical energy, thus extending the vehicle’s range and improving efficiency.
- Cruise Control Mode: Maintains a constant speed as set by the rider, offering a comfortable riding experience on longer trips.
Challenges and Advantages
Challenges
- Complexity in Control: Managing a 6-phase PMSM involves more complex control algorithms compared to 3-phase systems, requiring advanced control strategies like 6-phase Space Vector Pulse Width Modulation (SVPWM).
- Thermal Management: Proper thermal management is crucial due to the increased power density and heat generated by the 6-phase PMSM, necessitating effective cooling solutions.
- System Integration: Integrating the 48V 6-phase PMSM into different vehicle architectures (hub or mid-drive) requires careful design and calibration to ensure optimal performance.
Advantages
- Enhanced Efficiency: The 6-phase configuration improves efficiency and performance by reducing ripple currents and enhancing torque density.
- Improved Safety: Operating at 48V offers increased safety compared to higher voltage systems, reducing the risk of electrical hazards.
- Smooth Operation: The use of FOC with a 6-phase PMSM results in smoother operation and better performance
- Functional Safety: Adherence to MAC and ISO 26262 guidelines, with rigorous coverage studies and simulations for full compliance.
Business and Industrial Use Cases
Urban Delivery Services
- Challenge: Efficient, reliable vehicles for navigating congested streets.
- Solution: Our 6-phase PMSM systems offer precise control and regenerative braking, improving efficiency and reducing downtime.
- Impact: Lower operational costs and improved service quality.
Last-Mile Transportation
- Challenge: Compact, lightweight, and efficient vehicles for short distances.
- Solution: Our systems provide a compact design and advanced control, enhancing performance and reliability.
- Impact: Reduced operational costs and increased vehicle uptime.
Public Transportation Fleets
- Challenge: Robust, reliable vehicles for continuous operation.
- Solution: Our systems offer high dynamic response and effective thermal management.
- Impact: Reliable service with reduced maintenance and operational costs.
Industrial Logistics and Warehousing
- Challenge: Efficient vehicles for handling heavy loads with frequent stops.
- Solution: Precise torque control and regenerative braking improve efficiency.
- Impact: Higher operational efficiency and lower energy costs.
Agriculture and Farming Equipment
- Challenge: Robust equipment for varied and harsh conditions.
- Solution: Our systems offer high efficiency, torque density, and effective cooling.
- Impact: Increased reliability and reduced operational costs.
Recreational Vehicles
- Challenge: Efficient and reliable motors for e-bikes and e-scooters.
- Solution: Our systems provide smooth operation and enhanced energy efficiency.
- Impact: Increased customer satisfaction and brand loyalty.
Conclusion
The integration of 48V 6-Phase PMSM systems with advanced control algorithms is crucial for the future of electric two and three-wheelers. At Embitel, our expertise and innovative solutions ensure superior performance, efficiency, and reliability, driving the evolution of sustainable transportation. For more information on our 6-phase PMSM systems and how they can benefit your EV projects, contact us at sales@embitel.com.
Frequently Asked Questions
- What are the key advantages of 6-phase motor controllers over 3-phase systems?
- Can 6-phase motor controllers be used in both two-wheelers and three-wheelers?
- How does vector control improve the performance of 6-phase motor controllers?
- What role does AI play in the future of 6-phase motor controllers?
- Can 6-phase motor controllers be customized for specific applications?
6-phase motor controllers offer enhanced power delivery, smoother operation with reduced torque ripple, improved thermal management, and built-in redundancy for increased reliability, making them ideal for demanding applications.
Yes, 6-phase motor controllers are versatile and can be used in both two-wheelers and three-wheelers, providing the necessary power and control for a wide range of electric vehicle platforms.
Vector control, or field-oriented control, allows for precise control of torque and speed by managing magnetic flux and torque independently, ensuring optimal performance across various operating conditions.
AI can enhance 6-phase motor controllers by enabling predictive maintenance, optimizing performance in real-time, and improving overall reliability through smarter control algorithms.
Yes, 6-phase motor controllers can be tailored to meet the specific requirements of different electric vehicle platforms, ensuring seamless integration and optimal performance across various use cases.
