Abstract: The present invention relates to a method for controlling the frequency of a stand-alone microgrid wherein an energy storage device of the stand-alone microgrid is operated as a main power source by controlling a battery power conditioning system (PCS) of the stand-alone microgrid in a constant voltage constant frequency (CVCF) mode. According to the present invention, it is possible to operate the frequency stably while considering the fuel cost and power generation efficiency of a stand-alone microgrid.

Abstract: The present invention relates to a power conditioning system (PCS) efficiency-considered microgrid operation device comprising: a scheduling unit for scheduling outputs of a controllable load, a battery, and an emergency internal combustion generator operated in a microgrid; and an operation control unit for controlling the operation of the battery, the emergency internal combustion generator, and the controllable load according to charging/discharging of the battery, the output or the emergency internal combustion generator, and the output of the controllable load, which have been scheduled by the scheduling unit, wherein the scheduling unit schedules charging/discharging by considering the efficiency of a PCS such that a mate of charge (SOC) of the battery is maintained within a preset range. According to the present invention, the microgrid can be efficiently operated by considering the charging/discharging efficiency of the PCS.

Abstract: The present invention provides a system and a method for switching a line short-circuit fault section in an inverter-based stand-alone microgrid, the system comprising: multiple intelligent switchgears disposed on a line in a stand-alone microgrid so as to control opening or closing of the line; a battery inverter having a built-in current limiter so as to limit a current output therefrom; and an operating system for receiving short-circuit fault information of the line from the multiple intelligent switchgears, determining a fault section, and controlling the battery inverter to limit the output current. The present invention can quickly and accurately switch a line short-circuit fault section occurring in a stand-alone microgrid which does not include separate cutoff equipment such as a recloser.

Abstract: The present invention relates to a power conditioning system (PCS) efficiency-considered microgrid operation device comprising: a scheduling unit for scheduling outputs of a controllable load, a battery, and an emergency internal combustion generator operated in a microgrid; and an operation control unit for controlling the operation of the battery, the emergency internal combustion generator, and the controllable load according to charging/discharging of the battery, the output of the emergency internal combustion generator, and the output of the controllable load, which have been scheduled, by the scheduling unit, wherein the scheduling unit schedules charging/discharging by considering the efficiency of a PCS such that a state of charge (SOC) of the battery is maintained within a preset range. According to the present invention, the microgrid can be efficiently operated by considering the charging/discharging efficiency of the PCS.

Abstract: The present invention relates to a method for controlling the frequency of a stand-alone microgrid wherein an energy storage device of the stand-alone microgrid is operated as a main power source by controlling a battery power conditioning system (PCS) of the stand-alone microgrid in a constant voltage constant frequency (CVCF) mode. According to the present invention, it is possible to operate the frequency stably while considering the fuel cost and power generation efficiency of a stand-alone microgrid.

Abstract: The present invention relates to an inverter device for a microgrid, and a method for controlling the same, the inverter device including: a waveform detector detecting a voltage waveform and a current waveform applied to a load; a control unit determining whether a sine wave appears based on the detected voltage waveform and the detected current waveform and performing voltage control or low order harmonic compensation depending on a determination result; and a switch generating a voltage waveform in a form of the sine wave by being turned on/off depending on a control signal received from the control unit and supplying the generated voltage waveform in the form of the sine wave to the load.

Abstract: The present invention relates to an inverter device for a microgrid, and a method for controlling the same, the inverter device including: a waveform detector detecting a voltage waveform and a current waveform applied to a load; a control unit determining whether a sine wave appears based on the detected voltage waveform and the detected current waveform and performing voltage control or low order harmonic compensation depending on a determination result; and a switch generating a voltage waveform in a form of the sine wave by being turned on/off depending on a control signal received from the control unit and supplying the generated voltage waveform in the form of the sine wave to the load.