Analytic research on harmonic torque of the speed regulating control system with cycloconverter-fed synchronous motor

Starting with the analysis on output harmonic voltage of 3-phase 6-pulse cycloconverter, the analytic calculating equation on harmonic torque of the speed regulating control system with cycloconverter-fed no damping windings synchronous motor is obtained. The main harmonic spectrum of an actual example is achieved by this equation. The theoretic results are validated by simulation calculation and the difference is within the error range. This analysis can be used as a certain reference for harmonic torque calculation of similar system.