Elements of the Theory of Multiphase Valve Electromechanical Systems

Multiphase valve electromechanical systems with an odd number of phases (three, five, seven, nine, etc.) have been investigated. It has been established that, with an increase in the number of phases, the copper consumption and losses in copper do not increase as compared to a three-phase machine. The increase in the number of phases of the multiphase motor winding, while maintaining unchanged power, makes it necessary to reduce the supply voltage of the converter; i.e., the phase voltages of the motor are reduced (the motor becomes “low-voltage motor”). However, this increases the input current of the converter. The increase in the number of phases of the motor at a constant power leads either to a decrease in the phase inductance, or to a decrease in the phase current compared to a three-phase winding. This can help improve switching the keys of the converter. As the number of phases increases, the loading current of the converter keys decreases. The results of experiments confirming the theoretical studies are presented.