Section 8 Control principle
The control response of the BR 604 can be selected in programming
mode. In principle, the controller has 3 different control modes:
1. Sequential connection
In sequential connection, the required capacitor stages are
successively connected and disconnected in stages (last in - first
out). The ranking of each step always corresponds to the power of
the smallest stage.
Advantage
: Exact definition of the next capacitor to be
connected in each case
Disadvantage
: Long settling time
In order to shorten the settling time, the BR 604 switches
several stages simultaneously for a large power-factor
requirement. This applies to all control types. The
maximum dimensions of the simultaneously switching
branches can be changed in expert mode.
2. Loop connection
In this variant, the controller operates in loop mode (first in - first
out) which minimizes the wear on the capacitor bank, i.e. where
stages are of equivalent dimensions, the stage which was
disconnected for the longest period of time is always connected
next.
Advantage
: Balanced utilization of equivalent stages and thus an
increased operating life of the capacitor bank.
Disadvantage
: This mode can only be used in control series with
groups of the same stage power.
3. Intelligent loop connection (default setting )
The intelligent control principle combines the advantages of the
network-sparing loop connection (first in - first out) with a much
faster settling time, even for large load skips, and reaches this
goal with the fewest possible switching operations of the capacitor
stages. The optimized time response is achieved by the
simultaneous switching of several or larger capacitor groups as a
function of the missing power factor in the power line. Both the
number of real switching frequencies of the capacitors as well as
the turn-on times of the branches are considered.
Advantage
: Reaches the target cos phi in a fast-optimized
settling time with a low switching frequency of the capacitors.
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Summary of Contents for BR 604
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