Allen-Bradley Powermonitor 3000 User Manual page 37

Table 3.5 Energy and Demand Results
Parameter
Kilo-Watt Hours Forward
Kilo-Watt Hours Reverse
Kilo-Watt Hours Net
Kilo-VAR Hours Forward
Kilo-VAR Hours Reverse
Kilo-VAR Hours Net
Kilo-VA Hours Net
Amp Hours Net
Demand Current
Max Demand Current
Demand Kilo-Watts
Max Demand Kilo-Watts
Allen-Bradley HMIs
(t2 - t1) = Elapsed interval duration and is less than T
First Order Projection
The first order demand projection utilizes the instantaneous demand
as a starting point, computes the trend of the instantaneous demand,
computes the time remaining in the interval, and performs a first order
projection of what the final demand will be at the end of the interval.
This method may be useful where your system has a significant base
load with additional loads that are switched in and out during the
interval.
Second Order Projection
The second order demand projection begins with the first order
projection. It computes the rate of change of the first order trend,
computes the time remaining in the interval, and performs a second
order projection of what the final demand will be at the end of the
interval. This method may be useful where your power system has
little or no base load and a load profile that increases over the
duration of the interval. A second order projection is more sensitive to
rapid load changes than the other methods.
Description
The total real power consumed
The total real power produced
The sum of forward and reverse power
The total reactive power consumed
The total reactive power produced
The sum of forward and reverse reactive power
The total apparent power consumed
Accumulated amp-hours consumed.
The calculated demand for average current.
The maximum (peak) demand for current.
(included in Min/Max Log)
The calculated demand for real power.
The maximum (peak) demand for real power
(included in Min/Max Log)
1
∫
•
--------------- -
Demand =
t2 t1 –
Range
0 to 1.0x10
0 to 1.0x10
0 to 1.0x10
0 to 1.0x10
0 to 999.9x10
0 to 999.9x10
Publication 1404-UM001D-EN-E - October 2004
Powermonitor 3000 Operations
t2
P t ( ) t d
t1
Units
12 kWh
12 kVARh
kVAh
12
12 Ah
Amps
21
kW
21
3-11