A practical harmonic guideline for adjustable speed drive applications

A general and simple technique is presented for the preliminary harmonic assessment of various ASD (adjustable speed drive) applications. With limited information available, the technique can tell if any ASD installation may cause the violation of the IEEE recommended harmonic limits. If the results indicate limit violations, a detailed harmonic investigation can then be considered. Otherwise, expensive harmonic studies can be eliminated. The results presented are applicable to the six-pulse DC link converter type ASDs with a specified voltage range. However, similar charts are readily available for other ASD types and voltage ranges. The methodology proposed can be implemented in a simple spreadsheet and applied to a wide variety of nonlinear loads