Reduction of current chopping noise with DSP controller in switched reluctance motor drive system

摘要

A novel current chopping mode was used in a switched reluctance motor drive system to make full use of the characteristics of digital signal processor ( DSP) TMS320F240. The necessity of this 180° phase-shift current control (PSCC) mode is introduced first and then the principle of PSCC covering both hardware requirement and software programming is described in detail. The analysis made indicated that with this mode, the chopping frequency in winding can reach 20 kHz with 10 kHz power switches and the control frequency can reach 40 kHz at the same time. Subsequently, based on the linear and nonlinear mathematical models of the switched reluctance motor (SRM) , some simulation work has been done. The simulation results show that when this mode is applied to SRM drive ( SRD ) system, the current waveform becomes better. So the ripple the torque is reduced simultaneously and the vibration and acoustic noise are reduced involuntarily. Stationary tests show that the acoustic noise is greatly diminished. Finally, some experiments were made using a 50 kW SRD system for electric vehicle ( EV) . Experimental results indicate that this mode can be implemented feasibly and it has a good action on the SRD system.