Harmonic Mitigation Using Three Level Bidirectional Neutral Point Clamped (BNPC) Based Three Phase Shunt Active Power Filter

A new three-phase three level inverter topology is proposed in this work. The presented structure is characterized by the use of a Bidirectional Neutral Point Clamped (BNPC) in order to compensate harmonics and to eliminate the reactive power and load varying under sever source voltages conditions. The control technique is based on Lyapunov candidate. An energy-based Lyapunov control strategy is developed and tested for a three-phase Multilevel Shunt Active Power Filter (MSAPF) based on a three-level three-phase bidirectional neutral point clamped. This method determines the control law that makes the derivative of the Lyapunov function always negative for all values of the states. To keep the DC bus voltage of MSAPF constant and reduce inverter losses, a Proportional-Integral (PI) regulator is used. The simulation is done in Matlab/Simulink software and the results show the effectiveness of the proposed control technique to reduce the total harmonic distortion of source current produced by the nonlinear load.