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5BMETERING FUNCTIONS
PROTECTION, CONTROL AND METERING FUNCTIONS
In the thermal demand the average is logarithmic and continuous, which means that
the values of the load are weighted, being their weights smaller as the time
increases, having less and less influence in the final result.
In the thermal demand the average is logarithmic and continuous, which means that
the values of the load are weighted, being their weights smaller as the time
increases, having less and less influence in the final result.
The thermal demand calculation algorithm is configured by defining the time within
which the thermal demand reaches 90% of the value for a fixed load. The time unit
for that configuration is the minute and a typically used interval is 15 minutes.
The algorithm is executed every second, so the thermal request value always exists
unlike the block calculation method which obtains a new result at the end of the
interval. Figure 2-12 shows the behavior of the thermal demand, with a 15 minutes
time constant and a constant load of 100, which is eliminated within 60 minutes.
For the thermal demand calculation, the following expression is evaluated every
second:
k
D
D
D
D
c
)
'
(
'
−
+
=
Where: D is the new value of the demand, D’ represents the previous demand value
and Dc is the real value of the variable whose demand is being calculated, “k” is a
constant selected so that the continuous evaluation of D reaches the 90% of Dc
within the time window specified (Considering Dc constant during the evaluation
time).
The algorithm presents a response similar to the one shown in Figure 2-65
Summary of Contents for smART P500
Page 1: ...Instruction Manual Multifunction Protection Relay smART P500...
Page 23: ...2BTABLES INDEX THIS PAGE HAS BEEN LEFT BLANK INTENTIONALLY...
Page 39: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 9 Wye Wye Connection measured neutral...
Page 40: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 10 Wye Wye Connection sensitive neutral...
Page 41: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 11 Open Delta Connection measured neutral...
Page 42: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 12 Open Delta Connection sensitive neutral...
Page 511: ...2BANSI CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 6 Moderately ANSI curve...
Page 513: ...2BANSI CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 7 Very inverse ANSI curve...
Page 515: ...2BANSI CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 8 Extremely inverse ANSI curve...
Page 532: ...4BRECLOSER CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 14 Recloser Curves 101 119...
Page 535: ...4BRECLOSER CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 15 Recloser Curves 120 142...
Page 538: ...4BRECLOSER CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 16 Recloser Curves 151 202...