Control options for a bi-directional multilevel traction chopper

A high power bi-directional multilevel chopper is developed as a design prototype for an inverting DC traction substation with active power filtering incorporated. The "imbricated cells multilevel chopper" topology is put into practise, where capacitors are used as floating voltage sources. Control options for this chopper are discussed and simulation results are compared. Differences between analog and digital control are also highlighted as a DSP-implemented control strategy is considered for duty-cycle control in the final system.