In oder to effectively control the output power in three-phase wireless power transfer system, taking the voltage-fed three-phase series resonance inverter as an example, based on traditional 180° control mode, a new control mode named switch on-off mixed symmetric control mode was proposed by adding a short cutoff pulse in the 180° conduction process of the switch, and adding a short setup pulse in the 180° block process symmetrically. The equivalent output line voltage and phase voltage of the resonance compensating network would be varied, which can effectively control the output power of the inverter system. By mathematical modeling, the functional relationship between the power transmission capacity and the pulse electrical angle was derived, which provids a theoretical basis for system design and analysis. From the simulation and the experimental results, it could be concluded that the output power of system could be controlled by this new control scheme, meanwhile, the theoretical analysis was verified.
