Electrical Power Systems

Structure of Power Systems and ew Other Aspects 5
The demand factor is usually less than 1.0. Demand factor gives an indication of the simultaneous
operation of the total connected load. Demand factor can also be found for a part of the system,
for example, an industrial or commercial or domestic consumer, instead or the whole system.
Utilization actor: It is the ratio of the maximum demand of a system to the rated
capacity of the system. Thus, the utilization factor (U) is
U =
Maximum demand of the system
Rated system capacity
...(1.2)
The rated capacity of the system may be selected to be the smaller of thermal-or voltage drop
capacity. The utilization factor can also be obtained for a part of the system.
Plant actor: Also known as capacity factor or use factor. It is the ratio of the total actual
energy produced over a specified period of time to the energy that would have been produced
if the plant (or generating units) had operated continuously at maximum rating. Therefore, the
plant factor is,
Plant actor =
Actual energy produced
Maximum plant rating ´T
Plant factor is mostly used in generation studies. It is also given as,
Annual Plant actor =
or Annual Plant actor =
Actual energy generation
Maximum plant rating
Actual annual energy generation
Maximum plant rating ´ 8760
...(1.3)
...(1.4)
...(1.5)
Diversity actor: It is the ratio of the sum of the individual maximum demands of the
various subdivisions or groups or consumers to the maximum demand of the whole system.
Therefore, the diversity factor (D) is given as
Sum of individual maximum demand
D = ...(1.6)
Coincident maximum demand
or D =
n
å
i=1
P
P
c
i
...(1.7)
where
Pi = maximum demand of load i
Pc = coincident maximum demand of group of n loads.
The diversity factor can be equal or greater than unity. rom eqn. (1.1), the demand
factor is
D =
Maximum demand
Total connected load
\ Maximum demand = Total connected load × D ...(1.8)