Patent ID: 8493020

Claim:
An apparatus for charging and discharging a photovoltaic (PV) power conditioning system (PCS) integrated battery, the apparatus comprising: a first direct-current-to-direct-current (DC/DC) converter converting a PV voltage from a solar cell into a predetermined DC voltage according to a first DC/DC control: a direct-current-to-alternate-current (DC/AC) inverter connected to a system and performing a system voltage to DC voltage conversion or DC voltage to system voltage conversion according to a second DC/DC control: a DC link unit connected in common to an output terminal of the first DC/DC converter and an output terminal of the DC/AC inverter to stablize a DC voltage from the first DC/DC converter and a DC voltage from the DC/AC inverter; a second DC/DC converter connected between the DC link unit a battery to convert voltage bidirectionally according to the second DC/DC control; a voltage and current detector detecting PV voltage and current from the solar cell, battery voltage and current from the battery, system voltage and current from the system, and DC link voltage and current from the DC link unit; and a charging control unit determining one of a plurality of predetermined control modes based on the voltage and current detected in the voltage and current detector and controls the first DC/DC converter, the second DC/DC converter, and the DC/AC inverter according to the determined control mode.