An Active Line Conditioner to Balance Voltages in a Distributed Generation System

An active line conditioner is proposed to correct dynamically voltage unbalances in a three phase AC system. In this system it is shown that the injection of a correction voltage Vinj in one phase is sufficient to nullify the negative sequence voltage component in the incoming three phase supply. The resulting three phase voltages at the load terminals are essentially positive sequence voltages and hence are balanced. The dynamic cancellation of the negative sequence voltage component by the proposed scheme drastically improves the performance of induction motor loads connected to a weak ac system. A thorough analysis of the scheme along with the suitable design guides is presented. Simulation results for different operating conditions are also presented to illustrate the merit of the proposed technique. The presented, simulation results demonstrate the effectiveness of the control technique. The performance of proposed system is analyzed using simulations with MATLAB/SIMULINK 7.4.0 (R2007a)