Simulated annealing in the analysis of resonant DC link inverters

A technique is proposed for calculating preprogrammed modulation patterns for convertors having outputs comprising discrete pulses, such as the resonant DC link inverter. The problem is one of large-scale combinatorial optimisation. An algorithm based on simulated annealing is introduced which proceeds by minimising a cost function that describes the system parameters which are to be optimised. Results are presented using an example cost function appropriate for implementing an approximation to harmonic elimination. Harmonic spectra are included which allow comparisons to be made between simulated annealing, `conventional´ optimisation techniques, and sigma-delta modulation. Simulated annealing is found to allow improved control of the spectra generated by discrete pulse convertors