Power system stability may be defined as that property of the system which enables the synchronous machines of the system to respond or a disturbance from a normal operating condition so as to return to a condition where their operation is again normal. Stability studies are usually classified into three types depending upon the nature and order of magnitude of the disturbance. These are transient, dynamic, and steady-state stability studies. The neutral of is grounded through a reactance of 0.04 The neutral of is not grounded. Neutrals of all transformers are grounded. Work on a base of 1000 MVA, 500 KV in the transmission line. Neglect prefault current