Closed-Form Analytical Investigation of an Induction Motor Drive Fed from Four-Switch Inverter in Six-step Operation Mode

The technique of decomposition of space vectors in the four-switch voltage source inverter fed three-phase induction motor is presented in this paper. The analytical results of the machine are accomplished in alphabeta complex plane by space vector decomposition and by using mixed p-z approach. Two possible modes of six step operation, utilizing in different ways only four voltage vectors are investigated. For both modes of operation an analytical closed-form solution of the steady-state currents and electromagnetic torque is derived. Theoretical waveforms are verified by experiment