Interconnection of Power Sources having Small Frequency Difference

Small generators are connected to a grid system at different points in a disperse generation system. Difference of frequency may happen to develop between these generators and the grid due to any disturbance for a short period of time, causing deviation of power flow from the scheduled value. This deviation of power flow should be kept low. A static phase shifter (SPS), with continuously adjustable phase angle, connected between the generator and the grid may not allow the phase angle between the two systems to deviate too much to keep the power flow deviation to a minimum during the period of disturbance. A 3-phase, delta connected tapped autotransformer fitted with thyristor controlled online tap changer (OLTC) may do the function of SPS. Case studies of a sample power system verify the concept of the scheme.