Analysis of fault current limiting and reactive power compensating operations of new transformer type topology with current controlled inverter

The new transformer type topology with the current controlled inverter, which could be operated as both the fault current limiter and the reactive power compensator, was suggested in this paper. The suggested topology consisted of the flux-lock reactor with a power switch and the full bridge inverter. The operation of this topology could be divided into the normal state and the short circuit state. In the normal state, the current controlled inverter based on the algorithm of the polarized ramp time (PRT) current control could be operated to compensate the reactive power of grid due to nonlinear load or variation of load. In the short circuit state, the fault current could be limited by opening the power switch and the impedance of the system could be changed by adjusting the resistance connected with a power switch. The operational characteristics of the proposed new transformer type topology combined with the current controlled inverter for both the normal state and the short circuit state were analyzed from the simulation results.