Unlocking the Potential: SiC Power Switches Revolutionizing Renewable Energy Systems

There is a global energy revolution underway. According to the International Energy Agency’s report, renewable energy is projected to account for approximately 95% of global energy growth by 2026. Solar energy is expected to contribute more than half of this 95%.

Today, driven by ambitious clean energy goals and government policies, the adoption of renewable energy in solar power, electric vehicle (EV) infrastructure, and energy storage is rapidly accelerating. The increasing prevalence of renewable energy also presents more opportunities for deploying power conversion systems in industrial, commercial, and residential applications. By utilizing wide-bandgap devices such as silicon carbide (SiC), design engineers can achieve a balance between four key performance metrics: efficiency, density, cost, and reliability.

SiC has several advantages over traditional IGBT-based power applications in renewable energy systems:

1. Higher Efficiency: SiC devices have lower switching losses and reduced conduction losses compared to IGBTs. This results in higher overall system efficiency, allowing for more efficient conversion of renewable energy sources such as solar or wind into usable electricity.

2. Higher Power Density: SiC devices can operate at higher temperatures and voltages, enabling higher power densities in the same physical footprint. This leads to more compact and lightweight power systems, which are particularly beneficial for applications with space constraints or mobility requirements, such as electric vehicles or portable renewable energy systems.

3. Improved Thermal Performance: SiC devices have better thermal conductivity and can handle higher junction temperatures, allowing for improved heat dissipation and thermal management. This results in more reliable and robust power systems, especially in demanding operating conditions typically found in renewable energy applications.

4. Faster Switching Speeds: SiC devices have faster switching capabilities, enabling higher switching frequencies and reducing the size of passive components such as inductors and capacitors. This leads to smaller and more cost-effective power systems with improved dynamic response, which is essential for efficient energy conversion and grid integration in renewable energy systems.

Driving SiC Power Switches with Gate Drivers

Due to the characteristics of SiC power switches, special considerations are required when driving them with gate drivers. The choice of gate driver can have a reasonable impact on the performance of SiC in its application.

SiC power switches require gate drivers capable of handling high voltage and rated current. The gate driver must provide sufficient gate charge to switch the SiC power switch and prevent voltage spikes.

Compared to IGBTs, SiC power switches are more susceptible to short circuits, which can lead to severe damage to power electronic systems. Typically, the short-circuit withstand time for IGBTs is around 10µs, while for SiC, it is approximately 2µs. Therefore, when designing with SiC power switches, it is essential to consider adding protection components that provide features such as desaturation or overcurrent protection. Some gate drivers, such as the UCC21710 gate driver, have built-in short-circuit protection features that can detect and respond to short-circuit events. For more information on short-circuit protection methods for SiC FETs, refer to the application note “Understanding Short-Circuit Protection Methods for SiC MOSFETs.”

While SiC power switches can operate in high-temperature environments, monitoring the thermal performance of SiC power switches and preventing overheating is still crucial. In addition to the built-in short-circuit protection features, the UCC21710 also has integrated sensors for temperature monitoring, eliminating the need for separate temperature sensors.

Conclusion

To fully harness the power output of renewable energy systems, it is crucial to maximize efficiency while achieving a balance between cost, size, and reliability. SiC power switches offer numerous advantages in high-power applications and are an ideal choice for solar energy and electric vehicle charging. To maximize the impact of SiC in these applications, TI provides gate driver products optimized for SiC power switches. These gate driver products come in multiple power levels and various degrees of integrated protection, helping to simplify SiC power designs.