To calculate the instantaneous power to the maximum monitor work pulses, work values instantaneous power values are made available. In the work values and the Work pulses is a recalculation of instantaneous pulses needed, which is explained in the following two Sections.
Work pulses
The work pulses can be provided by a power counter of the utility. It is energy proportional pulses. The instantaneous power can be calculated from the interval of the pulse of Work pulses. Decreases in the interval of the working pulses, then increases the power. To calculate the instantaneous power
from the pulse interval. one still needs the Pulse value of the power meter. The pulse value is information about the number of Pulses per kilowatt hour. Either one can see the power meter directly or calculate from the data of the meter.
Example of the instantaneous power can be calculated work in 1 hour
Measured pulse interval ti = 0.5 s.
From the pulse interval ti = 0.5 s, the number of the pulses is calculated in an hour.
(1) 3600 s / 0.5 s = 7200 pulses / h
With a pulse value of the power meter of 0.1 kWh / Imp.
(2) Pmom = 7200 pulses / h x 0.1 kWh / pulse
Pmom = 720 kW
Pmom: instantaneous
Imp: Impulse
Example for calculating the pulse value of the power meter
Counter reading
- Provide the counter revolution of 1 kWh (800 U / kWh)
- 6 pulses per revolution
- Current Transformer 2000 / 5A
- Voltage transformer factor = 1
(1) Current transformer factor = 2000 / 5A = 400
Work values
Modern power meters will often output work values. The work values can be easily converted to the instantaneous power. This must be the difference between the currently received, and the last received work value and from it you get the instantaneous work. This must then only be divided by the the elapsed time interval input between the two work values.
Example of the calculation instantaneous power calculation work in 1 hour:
Measured input distance of the input work values ti = 5 s.
Wi = 100 kWh.
Wi-1 = 95 kWh.
Wmom = Wi - Wi-1 = 100 kWh - 95 kWh = 5 kWh
Pmom = 5 kWh / 0.5 kW * 3600 s = 5 s / 5 s = 3600 kW
Pmom = 3600 kW
Pmom: instantaneous power
Wmom: instantaneous work
Wi: current received work value
Wi-1: last received work value