AC drive with particular reference to traction drives

New developments in the design of high speed electric trains are discussed, with reference to the AC drive system. The three level converter-inverter system applying advanced IGBTs, which is implemented in the latest Shinkansen train sets operating in eastern Japan between Tokyo and Nagano, is described. Advanced control techniques lead to a unity power factor seen by the AC supply as well as minimising the line harmonics, power loss, motor torque ripple, and audible noise. Therefore by using advanced AC drive systems the high speed train offers high level performance, efficiency, and passenger comfort