LCL Filter Design for a Grid Connected Telecom Station AC-DC Converter using SiC Devices

Abstract

Power applications that require electronic switching converters are increasing, so as their requirements in terms of power density and efficiency. Passive components such as inductors and capacitors that make up the filters used in these switched power converters are of great impact on the size, cost and overall system performance. The use of wide bandgap semiconductors allows high switching frequencies at lower power losses when compared to the traditional Si ones, allowing the filter components to shrink. This work explores the use of SiC Mosfets in a 48V DC telecom storage application to reduce the required filter components to values that allows the use of the distribution grid inductance and the converter-grid connecting transformer leakage inductance as part of the LCL filter. It is shown that the system remains stable and the LCL filter plays its role for different types and values of grid loads connected in the capacitor branch of the filter.

Keywords: SiC inverter, grid-connected converter, minimize LCL filter

Authors

Alexandre Bento^1,2,*, Ricardo Luís^1,3, J.Fernando Silva^1,2,
¹INESC-id, Lisboa, Portugal
²Instituto Superior Técnico, Lisboa, Portugal
³Instituto Superior de Engenharia de Lisboa, Lisboa, Portugal
^*Author to whom correspondence should be addressed.