QPT has used its RF expertise to create patented solutions that enable GaN to operate a PWM switching speed of up to 2 MHz in a VFD design to provide ultrafast switching in 1-2 ns without EMC issues.  Now, for the first time, all the benefits of GaN’s high-frequency operation delivers up to 80% less energy wastage in chopping compared to existing VFDs designs.

Our next generation products will drive GaN even faster but our first generation VFDs are designed to support existing, legacy, motor control chips that cannot go faster than 2 MHz so that customers can simply replace their Si or SiC power stage with our GaN-based qGaN integrated drive power transistor module as a fast and simple upgrade to a more power efficient VFD.

Comparing the power usage of current VFD designs and a VFD with QPT technology over a typical operational cycle shows that QPT design consistently deliver significant savings in energy wastage in these real-world conditions, depending on the application. Note how the 97% efficiency of existing VFDs drops of rapidly as the speed drops while the QPT VFD design starts at around 99% and then hardly declines as the speed decreases. Thus, at half speed, traditional VFDs are at 95% efficiency, at quarter speed 93% efficiency and falling off rapidly thereafter to 88% efficiency at 12.5 while the QPT efficiency is virtually unchanged!

Another benefit of running the GaN at 2 MHz is that the whole QPT VFD design can be reduced in size by a factor of twenty compared to current silicon implementations running at 100 KHz.  This is because the size of the inductors and capacitors all reduce as the switching speed increases. 

We are creating a range of components and reference designs so that companies can build next-generation VFDs based on QPT technologies that will be drop-in replacements for existing, industry-standard VFDs. These will not only deliver energy savings but are also smaller, lighter and require fewer components as, for example, big, expensive, power wasting filters are no longer required.