Compensation of unbalanced three-phase voltage supply in voltage source inverter

A control method for the compensation of unbalanced voltage supply that eliminates pulsating current in the DC link of a voltage source inverter is investigated. Such a pulsating current can have detrimental effects on operating properties of the drive as well as on the quality of power supply in the electrical vicinity of the inverter. A feasible range of control parameters is determined based on the required level of immunity against unbalanced voltage supply and on the parameters of the system. The impact of the control method on the power factors and current amplitudes in individual input phases for the available range of control parameters is analyzed and discussed. Examples of numerical simulations illustrate operation of the system under investigation both with and without the compensation method used.