Power Factor Correction





Wind turbines have become significant contributors to power generation throughout the world.

As a result, utility regulations for wind turbines have become more constrained, and now require stable voltage, reactive energy supply to the network and voltage control to support network failures.

Wind Cluster and its partners provide a wide range of dynamic reactive power compensation, power factor correction systems, voltage control and equipment designed to support grid fault ride through.

We offer single components like capacitors, capacitor duty contactors, power factor controllers measuring e.g. cosᵩ of a supply system and automatically controlling the connection and disconnection of compensation capacitors according to desired cosᵩ.

Alternatively we can supply complete custom made power factor correction systems as may be preferred.

Basic explanations about power factor correction

All inductive devices, such as motors, transformers etc. require magnetizing current to create the magnetic field necessary for the device to operate. Such devices use actual power in kW and reactive power in kvar. Actual and reactive power shall be compensated and in balance.

It is the nature of inductive loads, that current is falling behind the voltage. For capacitors it is opposite and current overtake the voltage trough phase.

If Inductive resistance and capacitive resistance of capacitors is equal then both current values are compensated.

If both values are equal this mean that power factor cos φ which is result between actual power P and apparent power S is 1.

cos φ = P / S

It is a question of money, but also with capacitors and their equipment - POWER FACTOR CORRECTION SYSTEMS - we discharge distribution system (cables, switchgear LV, MV, HV...).

Capacitots offer us reactive energy "for free" and prolong life time of all system parts.


Capacitor duty contactors, switches and circuit breakers

LV capacitor duty contactors, nominal power KC 12-60kvar up to 690V 50/60Hz - EN 60947-4-1

For MV and HV capacitor banks - back to back systems - vacuum contactors, disconectors, circuit breakers -IEC 60470 Standard (05-2000)






Power Factor Control relays, protection relays

• Power factor controllers for automatic LV systems
  - 6 or 12 relay outputs



• Power factor controllers for automatic LV and MV&HV systems
  - up to 14 outputs
  - RS485



• Protection relay for MV&HV systems 
  - differential protection YY
  - line current and voltage control
  - RS485


LV Filter and MV inrush & filter reactors

• LV filter reactors type FKD - RB
  - 400, 440, 525V 50Hz
  - 5-120kvar
  - detuning factors p=5,67%, 7%, 14%
  - 3-6W/kvar power loss
  - iron core , Al or Cu winding

• MV damping inrush current reactors
  - indoor, outdoor
  - air core
  - single/three phase

• MV filter reactors
  - indoor, outdoor
  - air / iron core
  - single/three phase

Load break switches:

Fuses, bus bars,...

Instrumentation, current and voltage transformers

Cabinets: custom made - indoor,


Fixed power factor systems with or without filter harmonic reactors


  • Local transformer compensation 
  • Capacitors in delta connection 
  • Indoor, outdoor, wall mounting


  • Need lees space 
  • Flexibility if we plan some expansion 
  • Wall or floor fixed option

Automatic power factor systems


  • Compensation when low cos φ 
  • Used where higher harmonics aren´t present 
  • Indoor and outdoor version


  • Corrected cos φ 
  • Adaptation to distribution and technological


  • Low losses 
  • Modular system



Basics about system measurement to design PFC bank

PQ and harmonic measurements are made in industrial power systems in order to:
  - get needed system data to design of capacitor banks
  - verify the design and installation of capacitor banks,
  - verify compliance with utility THD (I,U) requirements,
  - investigate suspected resonances, harmonics and other problems.

The results of these measurements are used to make calculations, verifications, comparison with standards and system designing. The selection of the measured quantities, measurement points in the system, and the types of instruments and transducers should be based upon the measurement objective. The measurement results must always be a good basis for further engineering and design work (studies, making a system preposition..). First measurements must be realized, after all calculations must be made to put the results into a useful form. In case of very sophisticated solutions some simulations must be done.


Wind Cluster - Aahavevej 69 DK-8600 Silkeborg - info@windcluster.com - Phone: 70 20 22 56 - Mobile: 40 35 10 33 - CVR #

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