Current reference

  • Menu: 4.6.1-3

Description

Reference signal of the relative apparent current.

The following parameters define when a reference signal is set or revoked:

  • Reference value – Reference value with which the actual current is compared.
  • Hysteresis – To prevent the continuous setting and resetting of the reference signal due to noisy actual current values, a hysteresis window can be set around the reference value according to the formula reference value ± hysteresis value. When the upper or lower limit of the hysteresis window is reached, a reference signal is set or revoked.
  • Delay time – The condition for setting the reference signal must be fulfilled for at least the duration of the delay time.
  • Signal – Setting at which the reference signal is set.

I0

Reference value of the relative apparent current

I1

Lower limit of the hysteresis window (reference value - hysteresis value)

I2

Upper limit of the hysteresis window (reference value + hysteresis value)

Δt

Delay time

F1

Polarity: Value > reference value

F2

Polarity: Value < reference value

Following is an explanation of how to set/reset the reference signal for the polarity Value > reference value (F1):

If the actual current exceeds the limits of the hysteresis window, the delay time starts to elapse.

  • If the actual current is above the limit for the duration of the delay time, the reference signal is set after the delay time has elapsed (time t1).
  • If the actual current exceeds the lower limit before the delay time has elapsed, the reference signal is not changed (time t2).
  • If the actual current is below the limit for the duration of the delay time, the reference signal is revoked after the delay time has elapsed (time t3).
  • If the actual current falls below the upper limit before the delay time has elapsed, the reference signal is not changed (time t4).