Power analyzer for converter testing based on cRIO hardware platform

The output circuits of modern frequency converter are made up of switching elements that shape output voltage using pulse width modulation. For this reason the output voltage contains many harmonic components and thus the sampling frequency has to be sufficiently high. For accurate evaluation of efficiency of frequency converter both input and output power have to be measured from the same time window. The same time window has to be consisted of the integer multiply of signal cycles. At the same time mechanical power from analog or frequency signals from torque and revolution sensors can be measured. This paper describes concept and implementation of such a power analyzer using a flexible CompactRIO platform.