Unlocking Efficient EV Design with Silicon Carbide

Is the Future of Driving Electric?

The electric vehicle (EV) trend is accelerating, with over 50% of car sales expected to be EVs or hybrids by 2029. As this shift happens, the demand for advanced electrical modules that meet EV requirements is growing.

Emergence of Super EVs and Hypercars

The emergence of super EVs or hypercars, capable of outperforming even the Bugatti, is thanks to cutting-edge advancements in higher-power inverter technology. One such device that is ramping up these designs is the OnSemi NVBR26A120M1WSX silicon carbide module.

Introducing the OnSemi NVBR26A120M1WSX Silicon Carbide Module

The NVBR is a half-bridge inverter designed specifically for traction inverters in EVs. It leverages silicon carbide MOSFETs, which outperform traditional silicon MOSFETs by handling higher voltages with superior efficiency.

Key Features and Specs

• Compliance with the AQG324 automotive standard, ensuring reliability and durability in harsh environments
• SynthRDi technology, providing a robust solution for thermal management and reducing dye stress
• Automotive-grade thick MOSFETs, enabling higher efficiency and power density
• Low stray inductance, minimizing electromagnetic noise and power losses

Designing with the NVBR Module

To integrate the NVBR module into your EV design, verify that your design aligns with the AQG324 guidelines. This ensures the module will meet the demands for real-world EV applications, providing consistent performance in high-temperature environments.

Thermal Management

The NVBR module's SynthRDi technology provides a robust solution for thermal management. To utilize this feature effectively, integrate appropriate heat sinks and optimize cooling systems.

Gate Driver Signals

To connect the NVBR module to the powertrain, implement gate driver signals that supply up to 25 volts to turn the MOSFETs on and pull them down to a negative 10 volts to turn them off.

Current and Voltage-Sensing Circuits

Integrating current and voltage-sensing circuits provides real-time feedback to the microcontroller, optimizing inverter performance and enhancing overall system efficiency.

Testing and Validation

Before finalizing your design, test the module under expected operating conditions to ensure performance and reliability. Thermal testing should be conducted to verify effective heat dissipation with a chosen cooling system.

Conclusion

The OnSemi NVBR26A120M1WSX silicon carbide module is a powerful solution for EV and HEV applications. By following the steps outlined in this guide, you can integrate the NVBR module seamlessly into your EV designs and unlock its full potential.

Unlocking Efficient EV Design with Silicon Carbide

What is Silicon Carbide?

How Does Silicon Carbide Improve EV Efficiency?

• Higher Power Density: SiC enables the creation of more compact power electronics, reducing weight and increasing power density.
• Improved Thermal Management: SiC's high thermal conductivity allows for better heat dissipation, resulting in improved performance and reliability.
• Reduced Energy Losses: SiC reduces energy losses due to its low resistance and capacitance, leading to increased efficiency and range.

Benefits of Silicon Carbide in EV Design

• Increased Range and Performance: Improved efficiency translates to increased range and performance.
• Reduced Weight and Size: More compact power electronics reduce weight and size, allowing for more flexible design options.
• Enhanced Reliability and Durability: SiC's ability to withstand high temperatures and frequencies leads to improved reliability and durability.

Challenges and Limitations

• Cost and Availability: SiC is still a relatively expensive material, and its availability can be limited.
• Manufacturing Complexity: Working with SiC requires specialized manufacturing processes and equipment.
• Thermal Interface Materials: The high thermal conductivity of SiC demands advanced thermal interface materials to ensure optimal performance.

Conclusion

Silicon carbide (SiC) is a wide bandgap semiconductor material that offers superior performance compared to traditional silicon-based power electronics.

• Higher switching frequencies: SiC devices can switch at frequencies up to 100 kHz, reducing the size and weight of EV power systems.
• Lower losses: SiC devices exhibit lower conduction and switching losses, resulting in higher efficiency and reduced heat generation.
• Higher temperature operation: SiC devices can operate reliably at temperatures up to 200°C, simplifying thermal management systems.

The adoption of SiC technology in EVs enables designers to create more efficient and compact power electronics systems.

• Reduced weight: Smaller, lighter power electronics systems contribute to improved vehicle efficiency and range.
• Increased power density: Higher switching frequencies enable the design of more powerful, yet smaller, electric motors.
• Improved thermal management: Reduced heat generation and increased temperature operation simplify cooling system design.

A range of SiC device options are available for EV applications, each offering distinct benefits.

• MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors): Offer high switching frequencies and low conduction losses.
• IGBTs (Insulated-Gate Bipolar Transistors): Provide high current handling capabilities and are suitable for high-power applications.
• JFETs (Junction Field-Effect Transistors): Exhibit low noise and high input impedance, making them suitable for sensor and control applications.

When designing SiC-based power electronics systems for EVs, several factors must be considered.

• Thermal management: Proper heat sinking and cooling system design are crucial to ensure reliable operation.
• Gate driver selection: Careful selection of gate drivers is necessary to ensure compatibility with SiC devices.
• Layout and parasitics: Optimized layout and minimization of parasitic elements (e.g., inductance, capacitance) are essential for high-frequency operation.