Design and Analysis of a New Topology for Bidirectional Converter in Flywheel Energy Storage System

A bidirectional converter (BDC) is required in areas where generated energy is stored. Some of the application areas are uninterruptible power system, transportation,, flywheel energy storage systems, etc. Bidirectional flow of power using buck mode and boost mode along with efficiency and high power density is important need of such systems. This report proposes a new topology of BDC with the help of Silicon Controlled Rectifier (SCR) and insulated-gate bipolar transistor (IGBT) with a new control logic to get zero switching losses by using zero voltage transition (ZVT) and zero current transition (ZCT) methods. The proposed method make sure zero switching power loss (ZSPL) for buck mode as well as boost mode for BDC. The method is easy to implement and it can achieve ZSPL for both switch-on and switch-off of the main devices leading to improved efficiency. The principle of operation, design procedure and analysis, are explained for buck mode and boost mode of the proposed topology.