A PWM strategy dedicated to RMS current reduction in DC link capacitor of an embedded three phase inverter

This article presents an extension of the Double Carrier Pulse Width Modulation strategy (DCPWM) presented in called Extended DCPWM (Ext-DCPWM) strategy aiming at reducing the RMS current flowing through DC link filtering capacitors on embedded systems. Instead of utilizing two adjacent active vectors as classic PWM strategies, this new strategy utilizes two non-adjacent active vectors in the case of low modulation index or three consecutive active vectors in the case of high modulation index. Analytical calculations show that this new strategy is particularly effective in terms of filtering capacitor RMS current for high power factor compared to space vector PWM (SVPWM) which is used as the strategy of reference. It is also shown that induced switching losses of this new strategy can be 50% lower than that of SVPWM. The implementation on DSP boards can be done easily with help of current sensors.