So back when we (that's an inclusive "we") worked on the elecmeter tagging standard, we decided not to include a special tag for demand, vs. power. However, since then, I've realized that most power quality meters include both:
Power: "instantaneous" reading of active power (actually, an average over a few cycles)
Demand: average reading of active power over the utility billing demand interval (typically 15 minutes)
I've now realized that it would be best to have both power and demand tags defined, where demand is specifically defined as active power averaged over the billing demand interval. This is what we're doing now with our own meters.
I would post this in the electric meter working group, but I think when we had that working group it pre-dated the WG section of the forum and I can't find it. (Well, I'm sure I could but it would take me a while digging through forum history.)
Keith BishoρTue 14 Jan 2020
Completely agree with adding demand.
The only change I would recommend is removing "utility" and "billing" from the definition. With submeters, these reading may have no association with with those 2 concepts but simply serve as a rolling average of power over a period of time.
Chad RuchTue 28 Jan 2020
I would keep in mind that demand can be used to describe heating, cooling, airflow, etc. demand from an airHandlingEquip and/or airTerminalUnit when discussing this.
JCI has points called PI Cooling Demand, PI Heating Demand, Cooling Required, and Heating Required.
Distech, Honeywell, and Trane have points called Terminal Load.
Also, demand control ventilation (DCV) should be considered as well.
Hans LangelsSun 2 Feb 2020
If power is understood as "electrical power" then the definitions of power, input power ("demand" or "consumption") and output power ("generation") per IEV (International Electrotechnical Vocabulary) are given as:
IEC DD 113-03-52 power power
derivative with respect to time t of energy E being transferred or transformed, thus P=dEdt
NOTE 1 For power in electric circuits, see IEC 60050-131.
NOTE 2 The coherent SI unit of power is watt, W.
IEC DD 113-03-53 input power input power
for a given system, power transferred to that system from an external system
IEC DD 113-03-54 output power output power
for a given system, power transferred from that system to an external system
It would be beneficial to use these standard terms and definitions.
Stephen Frank Mon 13 Jan 2020
So back when we (that's an inclusive "we") worked on the
elec
meter
tagging standard, we decided not to include a special tag for demand, vs. power. However, since then, I've realized that most power quality meters include both:I've now realized that it would be best to have both
power
anddemand
tags defined, wheredemand
is specifically defined as active power averaged over the billing demand interval. This is what we're doing now with our own meters.I would post this in the electric meter working group, but I think when we had that working group it pre-dated the WG section of the forum and I can't find it. (Well, I'm sure I could but it would take me a while digging through forum history.)
Keith Bishoρ Tue 14 Jan 2020
Completely agree with adding
demand
.The only change I would recommend is removing "utility" and "billing" from the definition. With submeters, these reading may have no association with with those 2 concepts but simply serve as a rolling average of
power
over a period of time.Chad Ruch Tue 28 Jan 2020
I would keep in mind that
demand
can be used to describe heating, cooling, airflow, etc. demand from anairHandlingEquip
and/orairTerminalUnit
when discussing this.Also, demand control ventilation (DCV) should be considered as well.
Hans Langels Sun 2 Feb 2020
If power is understood as "electrical power" then the definitions of power, input power ("demand" or "consumption") and output power ("generation") per IEV (International Electrotechnical Vocabulary) are given as:
IEC DD 113-03-52 power power
NOTE 1 For power in electric circuits, see IEC 60050-131.
NOTE 2 The coherent SI unit of power is watt, W.
IEC DD 113-03-53 input power input power
IEC DD 113-03-54 output power output power
It would be beneficial to use these standard terms and definitions.
Brian Frank Tue 24 Mar 2020
We have added elec-demand to Haystack 4 preview 3.9.8.
I made it a subtype of
active-power
I added the following as a child point of
ac-elec-meter
Feedback on the points listed under elec meter?
Also as part of this change I added
ac
to all theac-elec-meter
points