Vector Control of Active Front-End Rectifier for Electric Motors under Unbalanced Condition

The situation when the voltage source inverter is supplied with unbalanced system of voltages is investigated. This can cause problem in the operation of an electric drive as the voltage pulsations can arise in the DC bus. As a solution to such a problem, Active Front-End rectifier is employed for the motor application before the inverter stage. With the vector control of front-end rectifier the effect of unbalance voltage supply can be mitigated and a constant power is drawn from the power network at the input of the voltage source inverter. With this the drive performance is improved while solving the power quality issue. Vector control method is discussed in the paper. Space Vector Pulse Width Modulation (SVPWM) technique is used to generate switching sequence for the front-end rectifier. While various types of unbalance is simulated using MATLAB/SIMULINK, the results obtained proved the control system to be effective