(Solved):   6. a. Draw the transformer winding connection and phasor diagram, if the vector group on t ...

 

6. a. Draw the transformer winding connection and phasor diagram, if the vector group on the nameplate of a three phase transformer is as follows: ii. Dd1 [4] i. Yd7 [4] b. A generator with no load frequency of 61.0Hz and slope sp of 1MW/Hz is connected to Load 1 consuming 1MW of real power at 0.8 PF lagging. Load 2 (that to be connected to the generator) consumes a real power of 0.8 MW at 0.707 PF lagging. i. Find the operating frequency of the system when Load 1 is connected to the generator [2] ii. Find the operating frequency of the system when both Load 1 and Load 2 are connected to the generator. [3] iii. What action could a system operator take to restore the system frequency to 60Hz after both loads are connected to the generator? [4] c. With the aid of phasor diagrams briefly explains the effect of load increase on a synchronous generator operating alone at: (NB. Please state any assumptions taken) i. Lagging power factor [4] ii. Leading power factor [4]