Power electronics is a key technology for advanced use of electricity. Today already 40% of the worlds’ energy use is provided by electric power. It is expected that this share is going to rise to about 60% until 2040. Total sales of power semiconductors is growing 10% per year. This is driven by need for efficient use of electricity, increasing use of renewable energy and change to electric vehicles.
Electricity has to be converted in many steps, from power generation to use, by adjusting voltage and frequency. Using conventional silicon based power electronics 5-10% of the energy is lost in each step and up to 20% with simple passive 50Hz transformers. With Silicon Carbide (SiC) these losses can be radically reduced, theoretically up to 90%! This will have large impact on high power electrical systems.
Main applications for SiC, next 5 years:
- Electric vehicles motor drives, chargers and charge stations
- Power supplies with battery back-up (UPS) for data centers
- Solar power inverters for DC to AC conversion
- Industry motor drives for speed controlled pumps, fans and machines
- Train motor drives and auxiliary power
In longer term, SiC will also be important for real high voltage applications:
- Offshore wind AC to DC conversion
- Solid state power transformer for grid
- Speed control of MW motors in process industry
When fully implemented SiC will reduce total electric energy consumption with 10%, thus contribute with 10% “negawatts”.
The main benefits with SiC power electronics are:
1. Energy efficiency
- For an electric car where current goes several times between battery and motor, SiC extends driving range 10%.
- For a commuter train, efficient re-use of braking energy save 30% electricity.
- For an industrial application with 24h operation ROI for replacing an old transformer with SiC is less than 3 years.
2. System efficiency
- Smaller size
Switching frequency can be increased 10x, and correspondingly reduce size of capacitors, coils and magnetics. Makes power transformer 80% smaller. Lower weight also makes the installation easier and improves functionality.
- Less cooling.
Lower losses generate less heat and thus require less cooling of power transformer. This simplifies the whole system design by e.g. replacing water cooling with passive air-cooling.
- Lower cost
Less use of material and simplified cooling reduce total cost for power transformer significantly.