Patent ID: 11909303
Assignee: HYOSUNG HEAVY INDUSTRIES CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 6:
7. A method of bypassing a sub-module in a high voltage direct current (HVDC) system, the method comprising:
a system controller command receiving operation of receiving, by a sub-module controller, a control command from a system controller;
an energy storage operation of, when the control command indicates energy storage, controlling, by the sub-module controller, an insulated gate bipolar transistor1 (IGBT1) and an insulated gate bipolar transistor2 (IGBT2) of the sub-module to construct a path through which energy is storable in a capacitor in the sub-module;
an energy release operation of, when the control command indicates energy release, controlling, by the sub-module controller, the IGBT1 and the IGBT2 of the sub-module to construct a path through which the energy of the capacitor in the sub-module is releasable;
a bypass operation of, when the control command indicates bypass, controlling, by the sub-module controller, the IGBT1 and the IGBT2 of the sub-module to block a path with the capacitor in the sub-module and construct a bypass path;
a capacitor voltage transmitting operation of, when it is checked whether a voltage of the capacitor in the sub-module is greater than a bypass switch-on voltage by the sub-module controller and the voltage of the capacitor is less than the bypass switch-on voltage by the sub-module controller, transmitting the voltage of the capacitor to the system controller;
a bypass switch driving unit turning-on operation of, when the voltage of the capacitor in the sub-module is greater than the bypass switch-on voltage by the sub-module controller, comparing the voltage of the capacitor in the sub-module with a bypass switch-on voltage by a voltage monitoring unit and, when the voltage of the capacitor is greater than the bypass switch-on voltage by the voltage monitoring unit, turning a bypass switch driving unit on; and
a bypass switch turning-on operation of turning, by the bypass switch driving unit, a bypass switch on,
wherein the bypass switch-on voltage by the voltage monitoring unit is positioned between the bypass switch-on voltage by the sub-module controller and a capacitor limit voltage.