New Process and Materials Offer Better Efficiency for Power Conversion

The process of converting AC to DC to run electronic devices involves inefficiency that is multiplied by the millions of devices that require them. What if this process could be made much more efficient? That's the promise that new materials used in power conversion may offer.

Commonly used electronic devices such as laptops, computers, cellphones, hybrid cars, and industrial motors make use of DC power that is converted from the AC power coming from your wall sockets. In the process of converting AC power into DC power, a lot of electricity is wasted. In fact, a significant percentage- about 10 percent- of the total power generated in the United States is wasted during conversion from alternating current to direct current.
To tackle the problem of reducing the waste of energy during power conversion, Transphorm, a startup backed by Google Ventures, Kleiner Perkins Caufield & Byers, and other investors, has introduced a power conversion module that makes use of the mechanical properties of gallium nitride, a compound used in LEDs, instead of traditionally used silicon.
Inefficient power conversion not only results in monetary loss, but also harms the planet. These new power conversion modules include devices such as circuits, transistors, and modules, including all the components required for power conversion.

• Where is Gallium Found in Nature?

  Gallium is not found naturally, but occurs in trace amounts in zinc and bauxite ores and is obtained by the process of smelting. Classified as a poor metal, it has a silver hue. This is known as a poor metal because it becomes brittle at lower temperature and liquefies at even slightly high temperatures. Though it is stable in air and water, it reacts with acids and alkalis. Gallium is never used in its pure forms; instead, its compounds are used for various applications. For making these new, more efficient power conversion modules, gallium nitride is used.

• Mechanical Properties of Gallium Nitride

  Owing to its unique material and electronic properties, gallium nitride is set to replace silicon in these power devices. Any power device having gallium nitride shows five main characteristics including high operating temperature, high dielectric strength, high current density, high-speed switching, and low on-resistance. When compared to silicon, GaN show ten times higher electrical breakdown, exceptional carrier mobility, and three times the bandgap.
  Gallium nitride has a property of inherent negligible charge storage, and it allows the designing of power switch circuits of extraordinarily high efficiency in compact sizes that permit very low heat losses.
  

• Advantages of Using Gallium Nitride in New Power Conversion Modules

  Gallium nitride has the potential to replace silicon in all future electronic devices due its wide bandgap characteristic. The advantages of use of GaN include lower voltage drop in unipolar devices, increased power output, reduced heat sink requirements, increase transient characteristics and switching speeds, low electrical noise due to 10x lower recovery charge, high voltage capability and up to 100x the power density of Si devices.
  The basic claim by the company is gallium nitride can help systems become 90 percent or more efficient. This technology is at its nascent stage and is not fully implemented. Once it is implemented, the company claims, it will reduce hundreds of terawatts of energy loss.
  
  By Vandana Singhal