Power Factor Controllers - KMB Systems - #1

Dr. M. Horakove 559,460 06 Liberec 7, Czech Republic tel.: +420 485 130 314, fax.: +420 482 736 896

S Y STEMS e-mail: kmb@kmb.cz, web: www.kmb.cz

Novar reactive power controllers are fully automatic instruments that allow optimum control of reactive power compensation.

The instruments feature precise voltage and current measurement circuits and their digital processing ofvalues measured provides high rendition accuracy of both true root-mean-square and powerfactorvalues thus providing accurate measurement and control even in conditions of distortion by higher harmonic components.

The high sensitive current measurement input is a general-purpose one for nominal value ofa1Aor5A metering current transformer's secondary winding. The measurement inputs can be connected to the controller in any combination, that is any phase or line voltage and any phase's current.

Instrument setup is fully automatic. The controller automatically detects both the connection configuration and the value of each compensation section connected.

Control is provided in all four quadrants and its speed depends on both control deviation value and its polarization (overcompensation / undercompensation). Connecting and disconnecting powerfactorcapacitors are carried out in such a way that achieving the optimum compensation condition is by a single control intervention at minimum number of sections connected. At the same time, the instrument chooses relay sections with regard to their even load and preferably connects those that have been disconnected for the longest time and the remanent charge ofwhich is thus minimum.

Within the control process, the instrument continually checks the relay compensation sections. If a section's outage or change in value is detected, the section is temporarily disabled for regulation under given setting. The section temporarily disabled is periodically tested and enabled for regulation again when possible.

Besides the powerfactorcapacitors, it is possible to connect powerfactorchokes (mains decompensation). Any output can be set asfixed.

An inbuilt thermal sensor provides temperature measurement inside the switchboard cabinet. The two highest outputs can be used to switch on and off cooling or heating.

All types of controllers can be ordered in a version extended with galvanic-isolated RS-232 or RS-485 communication interface. All values measured can be monitored and the controller's parameters set using a remote computer.