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Power Quality Filters PQFI-PQFM-PQFS

The best solution to tough power quality problems caused by harmonics, load unbalance and reactive power demand

Hitachi Energy's PQF active filters offer the following system benefits:

  • Compliance with the strictest power quality regulations thanks to their unique control concept, thereby avoiding penalties and/or refusal by utilities to connect installations to the electrical grid.
  • Reduced production downtime and/or commercial installation downtime.
  • Increased system efficiency and reduction of CO2 emissions.
  • No detailed network analysis required and rapid and easy implementation of the solution.
  • Thanks to its active concept, well adapted to low-voltage installations that are typically upgraded frequently.


Hitachi Energy's PQF active filters can be applied to small, medium or large applications and are suitable for both industrial and commercial installations in low-voltage networks. They can also be employed in medium-voltage networks through the use of a coupling transformer.

Why Hitachi Energy?

PQF active filters are the standard in the active filtering field for product performance.  Hitachi Energy’s PQF come with:

  • Unprecedented filtering efficiency with unique closed loop control system and individual harmonic selection capability 
  • Stepless reactive power compensation of both inductive and capacitive loads
  • Load balancing in both 3- and 4-wire systems
  • Increasing of system reliability to unprecedented levels with full redundancy functionality
  • Advanced communication features with Modbus RTU and Modbus TCP

Brief performance data

Connection method 3-wire 3-wire 3-wire/4-wire
Network voltage V1: 208-480V
V2- 480-690V
V1: 208-480V
V2: 480-690V (limited to 600V for cULus versions)
Line current rating V1: 300 - 450 A
V2: 180 - 320 A
V1: 70 - 100 - 130 - 150 A
V2: 100 A
30 - 45 - 60 - 70 - 80 - 90 - 100 - 120 A
Modularity Maximum 8 units can be combined (4 units for PQFS)
Redundancy Master/master or master/slave arrangement
Harmonic range 2nd to 50th order
Harmonics freely selectable 20 orders 3-wire: 20 orders
4-wire: 15 orders
Filtering degree Programmable per harmonic in absolute Ampere value
Harmonic attenuation factor Better than 97% at rated load
Compensation method Closed loop
Reaction time < 0.5 ms instantaneous response
Response time (filtering) 2 networks cycles typically (10-90% filtering)
Target cos ϕ Programmable from 0.6 (inductive) to 0.6 (capacitive)
Load balancing modes Between phases: ON/OFF Between phases: ON/OFF
Between phase and neutral: ON/OFF
Digital I/O 2 digital inputs/6 digital outputs (potential free)
Alarm contact 1 NO/NC alarm contact (potential free)
Programming Using PQF-Manager GUI
Certification CE, cUL & CTick CE & CTick

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