PHEP CH 22 Flashcards
(10 cards)
Which of the following would not cause a low lagging power factor?
Transmission Lines
In order to maintain losses as low as possible, what would be the best location for sources of VARS?
Adjacent to the customers’ equipment.
Which of the following changes in system operating conditions would tend to change a lagging power factor from .85 to .90?
An increase in the field excitation of a synchronous condenser
A synchronous condenser which is in operation at the time of a system disturbance:
Will have a stabilizing effect on the system
During off peak periods on a power system it may sometimes be necessary to operate synchronous condenser under excited because:
Long term transmission lines cause static capacitive effect which may over balance the inductive effect of the load during that time
When a synchronous condenser is producing VARS:
An increase in DC field current will cause an increase in reactive power
Which one of the following statements concerning capacitors is not correct
Capacitors increase the amount of current being carried in a circuit
In a system using capacitors for power factor correction:
All 3 (installed in parallel, installed is sufficient # to supply desired amount of reactive power, not economically practical to correct power factor unity)
Capacitors are sometimes:
installed in series with the distribution circuit
From the power triangle diagram below, what would be the power factor of the circuit if a 40 kva capacitor were installed?
97%
