A study on the effect of DC-link decoupling capacitors

DC-link capacitors are usually utilized in voltage source converters to stabilize the DC-link voltage and suppress the transmission of current harmonics into the power grid. To guarantee the reliability of voltage source converters, in addition to select the DC-link capacitors with optimum capacitance, appropriate rated voltage and enough ripple current capacity, thermal design is also of great importance. In this paper, the DC-link capacitors heating in voltage source inverters is evaluated. A novel cooling structure of DC-link capacitor is designed. The heating dissipation capability of the novel structure capacitor increases more than 60% compared to the traditional one, which is a key step to increase the power density of voltage source inverter.