Q5. Consider there are 2 generators feeding a load of 375 MW. The fuel-cost function ($/h) of each unit is given below, where the active power P is expressed in MW. C₁ = 40P₁ +2P₁² C₂ = 12P₂ +3P₂² The inequality constraint equations for the generators are given as; P₁ ≤ 250MW P₂ ≤ 350MW Find, a) The optimum generations of generator 1 and 2. b) The minimized total generation cost of the system.

By comparing the principle of operation of a "three" phase generation system with a single-phase system, state what are the bendfits of three phase systems? In your own words, define the "skin effect" in transmission lines and discuss how can it be minimised? Name three advantages of AC transmission in comparison to DC transmission. What are the units of active, reactive and apparent power? The current in a single-phase motor lags 50° behind the voltage. What is the power factor of the motor?

Reactive power.

Q2) The bus-bar (A) and (B) are linked by a bus-bar reactor of 1000 KVA with 10% reactance on bus-bar (A). The system has 2 generators each one of 5000 KVA with 5 % reactance, and on bus-bar (B) two motors each one of 5000 KVA with 12% reactance. Find the steady state apparent power (MVA) given to the symmetrical short circuit occurred on bus-bar (B) in the circuit shown below. Ма Mi B Gi A G₂ Xr m