Contents I. Introduction
Precise identification of the DC-link capacitor current represents a crucial limiting factor for capacitor design. It serves as a decisive parameter governing the capacitor’s lifespan and influencing its dimensions and weight [1], [2]. As the lifespan of DC-link capacitor can be seen as a function of the surrounding ambient temperature and internal heat caused by the capacitor current flowing through the equivalent series resistance (ESR) of the capacitor, more accurate loss and lifetime predictions can be made if the dc bus capacitor current spectrum can be accurately calculated. However, Due to the action of power electronics in pulsewidth modulation (PWM), a series of current pulses is generated on the DC side, inevitably leading to complex harmonic components that are difficult to analyze accurately [3], [4].
