Abstract: An energy storage system includes an energy storage device that stores energy generated from a new and renewable energy power plant, a power management device that monitors a total amount of power produced by at least one new and renewable energy power plant in a plurality of regions, determines an operation mode of the energy storage device based on a result of monitoring a reference capacity of an integrated line through which power of the plurality of regions is transmitted and a result of monitoring the total power amount, and controls a power capacity flowing through the integrated line according to the operation mode, and a power conversion device that receives a command corresponding to the operation mode from the power management device and controls an operation of the energy storage device according to the command.

Abstract: An energy storage system includes an energy storage device that stores energy generated from a new and renewable energy power plant, a power management device that monitors an amount of power of the new and renewable energy power plant, determines an operation mode of the energy storage device based on a result of monitoring a reference capacity of a line connected to the new and renewable energy plant and the amount of power, and controls a power capacity flowing through the line according to the operation mode, and a power conversion device that receives a command corresponding to the operation mode from the power management device and controls an operation of the energy storage device according to the command.

Abstract: A universal serial bus (USB) hub having a plurality of input power sources receives power through an upstream cable or from a local power source unit, and uses it for internal power consumption in the USB hub and for distribution to other USB functions through at least one downstream port. The hub includes a power source interface for inputting both bus power provided through the upstream cable and self-power generated by the local power source unit. Whether or not self-power is to be supplied is determined based on whether or not a user connects an additional power source cable to the USB hub. Thus, it is not necessary for the user to purchase a bus power USB hub or a self-power USB hub separately. The user can easily select a power source supply method which would fit his needs by simply adding a power source cable for self-power.