Energy metering – SATEC PM180 Operation Manual User Manual
Page 23
Chapter 2 Device Description
Metering
PM180 Substation Automation Unit
21
The accumulated demand represents the relative energy accumulated from the
beginning of the present demand interval and expressed in power units. It grows from
zero at the beginning and up to the final block demand at the end of the demand
interval. If the accumulated demand exceeds the allowed demand at any point, the
final block interval demand is more than the present accumulated demand (or equal if
the load is disconnected).
The predicted demand shows the expected sliding window demand value at the end
of the present demand interval, assuming that the load does not change. The
predicted demand reflects load changes immediately as they happen.
Power demands are calculated for all device energy accumulators, including the
Summary and TOU energy registers (see
The following table shows demand quantities provided by the device.
Parameter
Block
Demand
Sliding
Demand
Accumulated
Demand
Predicted
Demand
Volt demands
×
Ampere demands
×
Voltage THD demand
×
Current THD demand
×
Current TDD demand
×
kW demand (import and export)
Ч
Ч
Ч
Ч
kvar demand (import and export)
Ч
Ч
Ч
Ч
kVA demand
Ч
Ч
Ч
Ч
Summary energy demand (16
configurable registers)
Ч
Ч
Ч
Maximum Demands
Every demand parameter is provided with the maximum demand register, which
contains a time-stamped peak demand value recorded since the last reset. Maximum
power demand registers are linked to the corresponding sliding demand source
registers. If you wish to use block interval demands instead of sliding window
demands as a source, set the number of the block intervals in the sliding window to
1.
For the TOU demand registers, the device allows automatic recording (profiling) of
the daily and monthly maximum demands to the data log together with the TOU
energy readings.
Energy Metering
The PM180 provides true four-quadrant energy measurements for kWh imported and
exported, kvarh imported and exported, and kVAh, with Class 0.2 ANSI C12-20:2002
or Class 0.2S IEC 62053-22:2003 accuracy. Net and total energy measurements for
kWh and kvarh, and volt-hours and ampere-hours calculations are provided.
The device provides nine-digit energy counters by default. You can set the counters
to have fewer digits by changing the default energy roll value in your device (see
General Setup Device Option
in Chapter 7).
Energy Pulses
The PM180 outputs energy pulses through relay contacts with a user-selectable
pulse rate (see
Chapter 7). The pulse type (complete pulse or KYZ pulse), pulse width and polarity
are freely programmable.
Energy Pulse LEDs
The PM180 has two pulse LEDs on the front that provide energy pulsing for imported
kWh and kvarh.
The LED pulse rate (pulse constant) is user-selectable (see
General Setup Device
Option
in Chapter 7) and is programmed in secondary units. It does not depend on
the ratings of the external transformers. The LED pulse rate is set at the factory to
0.1 Wh/pulse corresponding to one equivalent disk revolution.