Power Conversion System (PCS) is a device for bidirectional conversion of electrical energy connected between the battery system and the grid and/or load. This device should have charge and discharge functions, active and reactive power control functions and off-line switching functions.

As the increasing demand for minimizing carbon emissions worldwide, the shift to renewable energy resulting in the growing demand for energy storage system. A critical component of any energy storage system is the power conversion system (PCS). The PCS is the intermediary device between the storage element, typically large banks of (DC) batteries, and the (AC) power grid.