Add harmonic order table

On November 13, 2015, Teledyne LeCroy announced the Harmonics Calculation option for the MDA800 series motor drive analyzer. This optional software package enriches the basic specifications of the motor drive analyzer software by adding new harmonic order tables that include advanced harmonic filtering for AC input and drive output numerical table measurements, Total Harmonic Distortion (THD) measurement parameters for voltage, current, and power, and spectral waveform displays.

The basic motor drive analyzer software provides only Full Spectrum (without harmonic filter) or Fundamental harmonic filters. The newly released options add Fundamental+N and Range filters. The Fundamental+N filter allows users to specify the (N) harmonic quantity. While very similar to the Range filter, it differs in that users can set a starting point other than the Fundamental one. These filters provide flexibility and the ability to identify measurements affecting specific frequency bands to motor drive engineers who need to analyze heat generated by harmonic distortion during motor rotation or analyze whether specific harmonics significantly affect the drive's operating characteristics.

This approach is superior to a simple low-pass filter where the filter cannot be selected. In particular, for variable frequency drive outputs that undergo significant changes depending on the operating state, this advanced harmonic filtering function can be more effective because it cannot be filtered by a simple low-pass filter.

The harmonic calculation option added THD measurement parameters to the numeric table display. Along with other numeric table parameters, users can simply touch the numeric table parameter to observe the characteristics of these parameters for each cycle.

This waveform is time-correlated with other waveforms captured by the MDA and can be used to interact with other control or power system waveforms, as well as to analyze complex drive characteristics or debug drive system issues. Statistical details of the measurement set are also displayed. This additional information is highly helpful for debugging during dynamic operation and goes beyond what is typically provided by a power analyzer.



Measurement and spectrum display for up to 9 waveforms

The newly added table displays a detailed list of harmonic contributions of voltage, current, and power according to harmonic order. The table shows harmonic measurements and spectrum displays for up to nine waveforms (voltage, current, and power corresponding to each phase of a three-phase system). Users can perform this in both steady state (fixed frequency) and dynamic operating state (variable frequency).

The fixed frequency method provides specifications similar to those found in typical power analyzers (up to the 100th harmonic order). The symmetrical specification enhances the flexibility of variable frequency drive outputs up to 50 harmonic orders. The dynamic, variable frequency mode overcomes the limitations of individual frequency degree transformation (DFT) per cycle and the large PLL width of typical power analyzers, enabling software algorithms for harmonic analysis in high-dynamic drive output conditions where the drive frequency changes rapidly.