A Novel Multifunctional Distributed Compensation Scheme for Stiff Source connected Induction motors

Abstract

This paper presents a control scheme for Static Compensators applied in distribution systems (DSTATCOM),that are used for regulation of voltage magnitude at point of common coupling (PCC) and it also has the function of eliminating harmonics of voltage through PCC-voltage-detection method. Voltage-magnitude regulation is accomplished throughquadrature-current injection at PCC and harmonic mitigation is released reading the voltage at PCC and producing harmonic currents capable of voltage-distortion compensation at PCC. Using this method there is not necessity of source or loadcurrentmeasurement. The voltage regulator was implemented using a four-wire three-phase shunt-connected VSI.If it operates in a voltage control mode, it can make the voltage of the bus to which it is connected a balanced sinusoid, irrespective of the unbalance and distortion in voltage in the supply side or line current.  Similarly when operated in a current control mode, it can force the source side currents to become balanced sinusoids. Loads connected to a stiff source cannot be protected from voltage disturbances using a distribution static compensator (DSTATCOM). In this paper, a new control algorithm based multifunctional DSTATCOM is proposed to operate in voltage control mode under stiff source. This scheme provides fast voltage regulation at the load terminal during voltage disturbances and protects induction machine drive system. The simulation results are obtained using MATLAB/SIMULINK software.