Seven-Phase Induction Motor Drive Based on Stator Flux Vector Control

In this paper, a rotor-flux-oriented control scheme for seven-phase induction motor drive, having the stator flux components instead of the stator current components as main control variables, is presented. As a consequence, a simple stator flux regulator can replace the conventional current regulators implemented in the synchronous reference frame. The proposed Stator Flux Vector Control (SFVC) scheme uses a flexible modulation strategy for seven-phase Voltage Source Inverters (VSIs) that allows the simultaneous modulation of voltage space vectors in different d-q planes. This problem is completely solved using the Duty-Cycle Space Vector (DCSV) representation, which describes the state of the switches by means of complex variables. Using the DCSV representation it is possible to combine the multiple space vector representation, useful in modeling multi-phase machines, with traditional carrier-based PWM principle, suitable for the modulation of multi-phase VSIs. The validity of the proposed control scheme is confirmed by experimental tests.