Reference Manual
BLR-CM/BLR-CM3phase
Rev. 08
2018-09
19
Sensitivity is used for two checks:
1.
The controller is using sensitivity to check, if a switching operation is necessary or if it’s possible. If the demand
for compensation is bigger as 60% of the smallest for regulation available step, BLR-CM is selecting from step
database, if there are suitable steps to switch.
2.
To avoid hunting, the controller is only using steps, which will not overshoot more than 40% (100%-60%) of its
size.
Step exchange: Step exchange is supporting automatic control and combined filter control algorithm to reach an opti-
mum result. If the controller detects that target-pf is not reached it starts searching for a step which gives better results.
If step exchange is active, the controller can replace a switched-in step against a step which matches better, to reach
the target.
Switch cycle balancing: Switch cycle balancing is taking care that steps with similar sizes (tolerance can be programmed
in percent) are used in a way, that they have the same number of switch cycles. At selection of suitable step for next
switching operation, the values of switch cycles, which are saved in step database, are compared. A balanced attrition
of contactors and capacitors is assured by this.
2.5.5.1
CONTROL ON / FREEZE / OFF
ON:
Automatic control is running
FREEZE:
Automatic control is stopped; status of exit relays is frozen
OFF:
Automatic control is stopped; all exit relays are off
2.5.5.2
COS PHI 1
This is the setting for target cosφ1. It will be valid during normal operation.
2.5.5.3
COS PHI 2
This is the setting for target cosφ2. It will be valid when a switch over is caused by the digital input or another program-
mable action.
2.5.5.4
SWITCH INTERVAL
The switch interval is the time delay between switching steps in regulation.
The switch interval has two different functions:
Protecting the contactors by reducing the number of switching cycles.
Building of the average of the reactive power in the time of the switch interval.
Step recognition is automatically set OFF, when switch interval is off. In regulation mode LIFO, minimum
switching interval is 1 sec longer, as the longest discharging time. In HV-version, the minimum switching time
delay is 8.7 sec.
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