Design, modeling and identification of the Mains Side Converter in an 11.7 kW wind/photovoltaic hybrid renewable generation system

This study focuses on the grid connection of a 11.7kW hybrid generation system using photovoltaic panels and a wind turbine. The conversion is accomplished by a multicell converter divided in two stages: the Generation Side Converter (GSC) and the Mains Side Converter (MSC). This paper will present in detail the design of MSC highlighting the key components (LCL filter, the InterCell Transformer, switching cells), their models and parameters' identification.

I. Introduction

Interleaved power conversion is the interconnection between multiple commutation cells with the same switching frequency and duty-cycle, but different phases [1]. The objective is to reduce or cancel the ripple by phase shifting the pulses by 360°/N, where N is the number of switching cells. In this case, the apparent switching frequency in the output is increased N times compared to each cell's frequency. Consequently, the energy stored in the filter impedance will be reduced by a factor of N² for the same output ripple, due to the higher output frequency [2]. With smaller filter's passive components, the system overall dynamics is also enhanced and a better performance is achieved.