The main part of central and group power factor correction in systems with a variable load is the power factor controller. A proper power factor controller and the correct design of PFC are key to the reduction of reactive energy costs. Nowadays, when four¬ quadrant energy meters are used, the right power factor controller is essential to achieve the highest efficiency of PFC system. Reliable, smart and advanced BMR controllers assure effective reduction of reactive energy and long working life of PFC systems.

Regulation method description
Device digitalizes measured phase voltage and phase current in one or three phases. From those values device calculates power factor, effective values of voltage and current, apparent power, reactive power. On the basis of allowed reactive power, which is setas a requested power factor value in the controller, device counts requested compensation power. In accordance with its size and sign, controller connects or disconnects appro priate capacitor stages. Within the particular power levels controller uses advanced method of circular switching. Capacitor stage which has been disconnected for the the longest period of time is the next one to be switched on by the controller. The procedure of switching on is the same for every following step as well. Optimal regulation process is achieved due to one regulation loop with minimum number of switched stages. Controller is equipped with an alarm output. Alarm can be activated by different parameters such as under voltage, overvoltage, undercurrent, over current, power factor level, harmonics level, temperature and by number of contactor operations.

Cascade operation
The two controllers in variant C can be connected together to expand the number of controlled steps or substitute for each other in a system with two main power supplies. Any one of the controllers can behave as a master or slave.