DROP FREQUENCY CONTROLLER FOR MAINTAINING DIFFERENT FREQUENCY QUALITIES IN INDEPENDENT TYPE MULTI-MICROGRID SYSTEM, AND INDEPENDENT TYPE MULTI-MICROGRID SYSTEM USING SAME

摘要

The present invention relates to a drop frequency controller for maintaining different frequency qualities in an independent type multi-microgrid system, and an independent type multi-microgrid system using the same. The present invention provides: a drop frequency controller for maintaining different frequency qualities in an independent type multi-microgrid system, and an independent type multi-microgrid system using the same, the controller comprising: a drop frequency control unit, which receives a system frequency from a corresponding microgrid so as to calculate a normalized frequency deviation, thereby outputting a DC link voltage deviation; a power control unit for generating a reference current so as to allow a DC link voltage to follow a voltage obtained by adding a DC link voltage command to the DC link voltage deviation output from the drop frequency control unit; and a current control unit for outputting a modulation signal to a corresponding connected converter so as to allow a terminal current to follow the reference current output from the power control unit.