Harmonic cancellation transformers account for nearly half of the total industry sales of harmonic mitigation equipment, according to Allied Industrial Marketing, a Milwaukee-based marketing firm. In its study titled “Industry Benchmark Report for North America,” the company discusses the direct correlation between the increase in the popularity of active filters and the resulting negative effect on harmonic mitigation transformer sales. Both techniques offer similar harmonic mitigation performance, which is less than 5% THID. The expected growth of active filters will lessen the market share of passive filters and harmonic cancellation transformers. The Chart illustrates the present market share for the three different mitigation technologies — 42% for all passive-type harmonic filters, 11% for all harmonic cancellation techniques that use active components, and 47% for all harmonic cancellation transformers.