Which of the following statments in NOT correct?
A.
The purpose of a power system is to deliver the power the customers require in real time, on demand, within acceptable voltage and frequency limits, and in a reliable and economic manner.
B.
In normal operation of a power system, the total power generation is balanced by the total load and transmission losses.
C.
The system frequency and voltages on all the buses are within the required limits
D.
According to optimal economic operation of power systems, economy is the only possible consideration.