Investigation of the DC-link Capacitor Current Ripple in Battery-fed PWM Inverter Systems

In battery-fed pulse-width modulated inverters, the DC-link capacitor represents a limiting factor in terms of power density. A proper design of a capacitor requires an accurate prediction of its current ripple. Therefore, this paper proposes a fast simulation model for predicting the DC-link capacitor current ripple in battery-fed pulse-width modulated inverters, which takes the influence of the battery/cable resistance and the battery/cable inductance into account. Based on this simulation model, an extensive parameter study is performed investigating the influence of different parameters on the DC-link capacitor current ripple. This study is presented in a normalized form. Thus, the presented results can be easily applied to any battery-fed pulse-width modulated inverter application.