Abstract: An islanding detection apparatus minimizes a reduction in power quality and detects islanding when distributed generations are operated in parallel. Also, another islanding detection apparatus for parallel distributed generations synchronizes parallel distributed generations by periodically applying a reactive current at a half cycle. Further, another islanding detection apparatus for parallel distributed generations easily synchronizes parallel distributed generations even when inverters installed in the respective distributed generations are fabricated through different makers.

Abstract: An islanding detection apparatus minimizes a reduction in power quality and detects islanding when distributed generations are operated in parallel. Also, another islanding detection apparatus for parallel distributed generations synchronizes parallel distributed generations by periodically applying a reactive current at a half cycle. Further, another islanding detection apparatus for parallel distributed generations easily synchronizes parallel distributed generations even when inverters installed in the respective distributed generations are fabricated through different makers.

Abstract: An energy generation system includes an inverter for converting a DC voltage into an AC voltage, a three-phase/two-phase transformer for transforming an output of the inverter into a three-phase/two-phase stationary coordinate system, a phase locked loop for calculating the phase and frequency of an output voltage of the inverter, a phase shifter for generating a current phase reference value, a current reference coordinate transformer for transforming the current phase reference value and the current amplitude reference value into a two-phase stationary coordinate system, a current phase calculator for outputting a current phase calculation value, a current phase calculator for outputting a current amplitude calculation value, a current adjuster for generating a current adjustment signal, an output three-phase transformer for transforming the current adjustment signal into a current adjustment signal in a three-phase stationary coordinate system, and a PWM controller for outputting a PWM control signal.

Abstract: Provided are a solar energy generation system having an adaptive maximum power point tracking function and a method thereof. The solar energy generation system includes: a minimum maintenance voltage determination unit configured to output a minimum maintenance voltage which enables the inverter to maintain an operation thereof corresponding to a grid voltage of the grid; a maximum power point tracking controller configured to determine a maximum power point tracking voltage at a maximum power point of the photovoltaic module, using the minimum maintenance voltage and an output voltage and output current of the photovoltaic module, and to output a reference voltage to track the maximum power point; a voltage calculator configured to calculate a difference between the reference voltage and the output voltage of the photovoltaic module; and a voltage adjuster configured to generate a reference current value using an output of the voltage calculator.