An Improved Discontinuous Space Vector Modulation for Z-Source Inverter With Reduced Power Losses

This article proposes a control strategy for a three-phase Z-source inverter (ZSI) using a modified discontinuous space vector modulation. The main advantages of the proposed control strategy are the enhanced output power quality and the compromise in the reduction between the conduction and switching losses. Furthermore, the reduced switching losses are achieved by the elimination of one switching transition in each half sector with a proper selection of the shoot-through (ST) state distribution. In addition, the reduced conduction losses are achieved by dividing all sectors equally into 30°. The MATLAB/SIMULINK simulation is carried out to verify the effectiveness of the proposed control strategy and to compare it with the existing space vector modulation techniques that utilize distributions of four and six ST vectors. PLECS software is used for the calculation of the conduction and switching losses. Compared to the other modulation techniques, the key features of the proposed control strategy are the improved boosting capability of the output voltage, the low total harmonic distortion, the reduced conduction and switching losses, and the reduced inductance current ripple. An experimental test bench that comprises a three-phase ZSI feeding an R load, controlled by a dSPACE MicroLabBOX, is used to verify experimentally the effectiveness of the proposed control strategy. It is envisaged that the proposed control strategy can be very useful for electrical drive applications integrating a three-phase ZSI due to its capability to improve the output waveform and reduce the harmonic distortions, switching, and conduction losses.