Apparatus and method for pcs management in optimal efficiency range

A power conversion unit efficiency control system comprising:

• an energy storage system (ESS) comprising a vanadium ion battery (VIB);
• a power conversion unit connected to a power grid and the ESS;
• and
• a power conversion unit operatively connected to the power conversion system (PCS),
• wherein the power conversion unit performs a control to achieve power conversion according to a specific charging/discharging range of the ESS so as to satisfy an optimal efficiency range of the PCS by considering power efficiency.

A control method of a power conversion unit, the contort method comprising:

• using the power conversion unit to provide:
• a control of transferring at least one of a power of a power grid and a power of an energy storage system (ESS) to an electric vehicle charging system, and
• a management control to correspond to an optimal efficiency range with respect to power conversion by controlling charging/discharging of the ESS according to an electric vehicle charging speed,
• wherein the power conversion unit performs a control to achieve the power conversion according to a specific charging/discharging range of the ESS so as to satisfy the optimal efficiency range of a power conversion system (PCS) connected to the ESS by considering power efficiency.