Talk:Diversity factor

please give me some more clariffication regarding this. if the MDB diversity factor is considered as .9,then can we take the DBs(which are feeding from MDB) diversity factor as 1? The diversity factor should be always greater than 1.0. Only the Demand Factor is always less than 1.0. You cannot consider the MDB diversity factor as 0.9.

Maximum Demand

As a graduate electrical engineer, I am still struggling to calculate maximum demand of circuits / distribution boards. Could somebody please clarify this confusing topic ?

Example problems would be good, such as a simple 3 phase 50kW motor for example. —Preceding unsigned comment added by 116.212.192.158 (talk) 23:00, 3 March 2010 (UTC) You cannot calculate the maximum demand, which is, by definition, the actual maximum real power demand (kilowatts) measured over a defined time interval (often every 30 minutes within each month)for any given variable load, or combination of variable loads. This measure is, for example, used by power supply utilities to enable them to assess the maximum demand on their grid, for which they must always have spinning generation capacity available. If a maximum demand occurs over and above the spinning capacity then the grid will be overloaded and load will need to be shed so as to avoid frequency droops. Consumers are usually penalised by power utility suppliers based upon their maximum demand and therefore consumers will seek to limit this by ensuring, for example, that their multiple large loads cannot be started simultaneously. — Preceding unsigned comment added by Gianfielding (talk • contribs) 04:05, 25 April 2017 (UTC)

Issues with IEEE definition

It is worth noting that the IEEE definition is quoted (it looks like verbatim) but is somewhat flawed. First, the term is described as a "probability", but the definition then states that the value is always greater than 1.0, which is clearly not possible for a probability. Second, the contrast with diversity is inapt because diversity is described here as the fractional run-time of a single device (i.e., the duty cycle) rather than the fractional load of an aggregation of devices, which includes other phenomena, such as load coincidence and load state synchronization. Rewriting this will be challenging because the term diversity factor is defined by IEEE in at least two standards and used accordingly by utility engineers, in spite of these problems.

One approach to improving this page is to quote and critique the IEEE definitions and then list the relevant related terms separately with suitable discussion.

--Chassin (talk) 19:14, 24 December 2010 (UTC)

It looks like this comment was addressed by removing the introductory paragraph in its entirety rather than addressing the problems with it. It now appears that this page discusses only related topics but never actually defines diversity factor as it is conventionally used in electric power engineering. Nor does it address the problems and challenges with the existing definition. It seems to me that these would be the primary purpose of this page.

The definition of diversity factor is conventionally given as:

Diversity factor is the ratio of the sum of the individual maximum demands of the various subdivisions of a system (or part of a system) to the maximum demand of the whole system (or part of the system) under consideration. Diversity is usually more than one.

An example of computing diversity factor (quoting from an article in EC Magazine) is:

Consider two facilities with the same maximum demand but that occur at different intervals of time. When supplied by the same feeder, the demand on such is less the sum of the two demands. In electrical design, this condition is known as diversity.

Diversity factors have been developed for main feeders supplying a number of feeders, and typically, they are 1.10 to 1.50 for lighting loads and 1.50 to 2.00 for power and lighting loads.

Diversity factor and load factor are closely related. For example, consider that a feeder supplies five users with the following load conditions: On Monday, user one reaches a maximum demand of 100 amps; on Tuesday, two reaches 95 amps; on Wednesday, three reaches 85 amps; on Thursday, four reaches 75 amps; on Friday, five reaches 65 amps. The feeder’s maximum demand is 250 amps.

The diversity factor can be determined as follows:

Diversity factor = Sum of total demands ÷ Maximum demand on feeder = 420 ÷ 250 = 1.68 × 100 = 168%

(See http://www.ecmag.com/section/codes-standards/diversity-vs-demand#sthash.eqbQ28h8.dpuf)

I'm not convinced this is the best example to use, but it does illustrate the meaning of diversity factor.

--Chassin (talk) 17:36, 7 December 2013 (UTC)

Definition Formula

I am trying to understand the formula. But what is AggregatedLoad_i supposed to mean? The Sum seems to be redundant here. 130.83.100.237 (talk) 14:08, 16 November 2022 (UTC)