Wide bandgap semiconductors, like Gallium Nitride (GaN) and Silicon Carbide (SiC) are shaping the future of power electronics by boosting power efficiency and reducing physical footprint. Server farms, alternative energy sources, and electrical grids will all be affected! Mike Hoffman and Daniel Bogdanoff sit down with Kenny Johnson to discuss in today’s electrical engineering podcast.
Tech Assessment (Good timeline information)
Agenda – Wide Bandgap Semiconductors
Use in Power Electronics
3:00 What is a wide bandgap semiconductor? GaN (Gallium Nitride) devices and SiC (Silicon Carbide) can switch on and off much faster than typical silicon power devices. Wide bandgap semiconductors also have better thermal conductivity. And, wide bandgap semiconductors have a significantly lower drain-source resistance (R-on).
For switch mode power supplies, the transistor switch time is the key source of inefficiency. So, switching faster makes things more efficient.
4:00 They will also reduce the size of power electronics.
6:30 Wide bandgap semiconductors have a very fast rise time, which can cause EMI and RFI problems. The high switching speed also means they can’t handle much parasitic inductance. So, today’s IC packaging technology isn’t ideal.
8:30 Wide bandgap semiconductors are enabling the smart grid. The smart grid essentially means that you only turning on things being used, and turning off power completely when they aren’t being used.
9:35 Wide bandgap semiconductors will probably be integrated into server farms before they are used in power grid distribution or in homes.
10:20 Google uses a lot of power. 2.3 TWh (terawatt hour)
NYT article: http://www.nytimes.com/2011/09/09/technology/google-details-and-defends-its-use-of-electricity.html
It’s estimated Google has 900,000 servers, and that accounts for maybe 1% of the world’s servers.
So, they are willing to put in the investment to work out the details of this technology.
11:50 The US Department of Energy wants people to get an advanced degree in power electronics. Countries want to have technology leadership in this area.
13:00 Wide bandgap semiconductors are also very important for wind farms and other alternative forms of energy.
Having a solid switch mode power supply means that you don’t have to have extra capacity.
USA Dept of Energy: If industrial motor systems were wide bandgap semiconductors took over, it would save a ton of energy.
14:45 A huge percentage of the world’s power is consumed by electrical pumps.
16:20 Kenny’s oldest son works for a company that goes around and shows companies how to recover energy costs.
There aren’t many tools available for measuring wide bandgap semiconductor power electronics.
19:30 Utilities and servers are the two main industries that will initially adopt wide band gap semiconductors
20:35 When will this technology get implemented in the real world? There are parts available today, but it probably won’t be viable for roughly 2-5 years.
21:00 Devices with fast switching are beneficial, but have their own set of problems. The faster a devices switches, the more EMI and RFI you have to deal with.
Spread spectrum clocking is a technique used to pass EMI compliance.
24:00 Band gaps of different materials: Diamond 5.5 eV Gallium Nitride (GaN) 3.4 eV Silicon Carbide (SiC) 3.3 eV