A general switching method suitable to control three-phase AC chopper circuit is presented. Such a method can be used with different circuit configurations of the AC chopper. Detailed harmonic analysis of the AC chopper when controlled by the time ratio control (TRC) strategy is given. TRC has the advantages of linear control of the fundamental component of the output voltage and elimination of all harmonics of order less than the frequency ratio by two. Also, the control signal can be generated easily. Experimental results verifying the analysis are presented.