Optimizing the drive system translates directly into improvements in system efficiency. An important challenge is to tune the drive system control logic optimally based on the three-phase AC signals. Analyzing the system in the AC domain is inherently difficult, hence a conversion from AC to DC domain makes it easier to look into the parameters, and measure them. The Tektronix MSO66B6IMDADQ0 DQ0 Feature for Inverter Motor Drive Analysis Software for MSO66B Units (Requires Option IMDA), or direct-quadrature-zero transformation is a tensor that rotates the reference frame of a three-element vector, or a three-by-three element matrix to simplify this analysis. The transform is used to rotate the reference frames of threephase AC waveforms such that they become DC signals. Simplified calculations are carried out on these DC quantities before performing an inverse transform (Inverse DQ0) to recover the actual three-phase AC results.

The most common approach to computing a MSO66B 6-IMDA-DQ0 transform involves FPGA programming and complex computations. In addition to performing the transform calculations, probing the feedback signals can be very challenging. Tektronix offers a patented on-scope measurement called MSO66B 6-IMDA-DQ0 (Direct Quadrature Zero) under the DQ0 analysis measurement category as an added option. This measurement is supported in the 3V3I configuration, takes the three-phase voltage or current signals from the motor as inputs and converts into D-Q-0 coefficients acting as a powerful debugging tool for the motor designers to tune their PWM controller circuit designs.

This offers unique advantages. First, probing needs are simplified as the same configuration is used for MSO66B 6-IMDA-DQ0 computation as Input or Output analysis, and second, the MSO66B 6-IMDA-DQ0 values are reported on the scope, both using scalar values on the measurement badge, and as vectors on the phasor diagram for easy correlation between the two plots.