An Eight-Switch Five-Level Current Source Inverter

This paper proposes an eight-switch, three-phase, five-level current source inverter (CSI), which employs only one traditional H6 inverter and two shunt branches at the dc side to realize the five-level switching. The corresponding space-vector-modulation (SVM) strategy for the proposed CSI topology is also presented, which uses the two shunt-connected power switches to add certain special modulation-state segments to ensure the switching instants completed under lower current stresses and lower power dissipation. Compared with the state-of-the-art CSI solutions, the proposed topology has a comparable hardware cost as the three-level H6 CSI, while outputs five-level currents. The low-output total harmonic distortion (THD) may help to reduce the sizes of the passive components in the system, and the modulation scheme reduces the switching and conduction losses of the semiconductor switching devices in the H6 CSI module, which can make it possible to increase the output current rating of the system in a certain degree. Simulation and experimental results verified the performance of the proposed CSI.