Long Lifetime DC-link Voltage Stabilization Module for Smart Grid Application

Power converters enable efficient and flexible control and conversion of electric energy among different smart grid players (i.e. producers, energy storage systems, and loads). One of the expected features of smart grid is that it will be more reliable compared to conventional grid. However, power converters are one kind of the lifetime limiting components applied in smart grid. One of the major causes is the malfunction of electrolytic capacitors (E-Caps) which are widely used for stabilizing the dc-link voltage in various types of power converters applied in smart grid. A dc-link module is therefore proposed in this paper with a reduced value of dc-link capacitor and a series voltage compensator. It allows the replacement of the popularly used E-Caps with alternatives of longer lifetime, like power film capacitors. The basic concept, implementation and operation principle of the dc-link module are given. The theoretical analysis is verified by simulation and experimental results.