Harmonic Mitigating Transformers

Ultra-Efficient Transformers

Medium Voltage Transformers

Cast Coil Transformers

Specialty / Custom Transformers

General Purpose Transformers

Surge Protection Devices

Harmonic Mitigating Transformers

PQI has been on the leading edge of harmonic mitigation solutions longer than any other manufacturer in the industry. Our products are manufactured to the highest quality standards (ISO 9001), and our product designs have been proven highly effective in real-world scenarios. For these reasons, many engineers insist upon PQI for the most effective harmonic mitigation solutions.

All PQI Distribution TransFilters™ result in:

  • Reduced power costs
  • Reduced penalty losses due to harmonic currents
  • Reduced transformer heating and A/C loading
  • Reduced THDv to less than 5% at nonlinear loads or motor drives
  • Reduced losses in the loads, thereby reducing A/C requirements
  • Improved switch-mode power supply’s “ride-through” capability
  • Balanced primary phase currents
  • Assured system compatibility with sensitive electronic loads

Our Type DV Distribution TransFilters™ provide flexibility to engineer almost any solution; however, we also offer specialty harmonic mitigation transformers and filters designed to offer distinct advantages in certain applications.


 PQI Product

 Typical Application

 Typical Industry

 Additional Benefits Within Specialty Application

DV High K-Factor loads All – Capable of developing 12-, 18-, 24- and 36-pulse primary systems
DD Motor drive loads All – Provides isolation from upstream transients
– Eliminates phase-to-ground voltage excursions at the motor drive  
SY 240V server loads Data Centers – Maintains voltage bandwidth required by rack-mounted servers
– Reduces servers’ load current by 15% and l2losses by 33%  
GY 240V gaming machine loads Casinos – Maintains voltage bandwidth required by gaming machines
– Reduces servers’ load current by 15% and l2R losses by 25%
Z Filter
(l0 Filter & Mini-Z)
High K-Factor loads (l0Filter)
Load-end of branch circuits (Mini-Z)
Casinos, Call Centers, 
Commercial Buildings
– Reduces neutral-to-ground voltages to <4V at nonlinear loads (<1V for Mini-Z)
– Increases general purpose (K 1) transformer capacity by up to 54%
– Protects upstream neutral conductor
– Increases feeder and bus capacity
– Balances feeder and bus phase currents (and branch circuit for Mini-Z)
PV High K-Factor loads All – Capable of developing 12-, 18-, 24- and 36-pulse primary systems
PY Medium K-Factor loads All

– Capable of developing 12-, 18-, 24- and 36- pulse primary systems