hello again,
first of all i think that the distsance of my equipment from the high tension wires is reasonable. the closest one is about 50 meters away in the street from my room where is located my pc. the mians line are placed over the poles are placed in away that there is not much risk of them touching with each other in even high wind storm. there may not be some problem with power generation.i checked it in other areas where the same lines provide power to houses. anyway i think its better to forward a complaint to the concerned authorities at power generation company to fix the problem because,may be there is a problem at 11kva to 220v stepdown mains transformer.so a private technician is not ligible to fix.
thanks a lot for your replies. i,ll come back with progress if there will be any.