Abstract: An adaptive control method for a fault control-oriented economically-integrated medium-voltage grid-connected device with a silicon carbide (SiC) module, includes: calculating a three-phase bridge arm modulation wave and a fourth bridge arm modulation wave; obtaining a three-phase bridge arm neutral point clamped (NPC) circuit switching signal; obtaining a three-phase bridge arm NPC circuit output voltage; obtaining a fourth bridge arm NPC circuit switching signal; obtaining a fourth bridge arm NPC circuit output voltage; calculating a voltage-stabilizing active vector of each submodule of a cascaded H-bridge (CHB) circuit; obtaining a three-phase bridge arm CHB circuit switching signal; obtaining a fourth bridge arm CHB circuit switching signal based on the fourth bridge arm modulation wave, the fourth bridge arm NPC circuit output voltage, and the voltage-stabilizing active vector of each submodule of the CHB circuit; and performing adaptive control of a grid-connected device based on the CHB circuit switch

Abstract: An open-circuit fault diagnosis method includes: S1, injecting a switching sequence into a second driving mode of the power device; S2, collecting inverter data and calculating a first output voltage residual; determining whether the first output voltage residual enters a voltage threshold region, and obtaining a first fault flag; if yes, proceeding to step S3; else proceeding to step S4; S3, injecting the switching sequence into an all-driving mode of the power device, collecting inverter data and calculating a second output voltage residual; determining whether the second output voltage residual enters the voltage threshold region, and obtaining a second fault flag; S4, collecting inverter data and calculating a first inductor current pulsation value; and determining whether the first inductor current pulsation value pulsates within an inductor current pulsation region, and obtaining a third fault flag; and S5, performing open-circuit fault diagnosis on the power device based on the fault flags.

Abstract: An adaptive control method for a fault control-oriented economically-integrated medium-voltage grid-connected device with a silicon carbide (SiC) module, includes: calculating a three-phase bridge arm modulation wave and a fourth bridge arm modulation wave; obtaining a three-phase bridge arm neutral point clamped (NPC) circuit switching signal; obtaining a three-phase bridge arm NPC circuit output voltage; obtaining a fourth bridge arm NPC circuit switching signal; obtaining a fourth bridge arm NPC circuit output voltage; calculating a voltage-stabilizing active vector of each submodule of a cascaded H-bridge (CHB) circuit; obtaining a three-phase bridge arm CHB circuit switching signal; obtaining a fourth bridge arm CHB circuit switching signal based on the fourth bridge arm modulation wave, the fourth bridge arm NPC circuit output voltage, and the voltage-stabilizing active vector of each submodule of the CHB circuit; and performing adaptive control of a grid-connected device based on the CHB circuit switch

Abstract: An open-circuit fault diagnosis method includes: S1, injecting a switching sequence into a second driving mode of the power device; S2, collecting inverter data and calculating a first output voltage residual; determining whether the first output voltage residual enters a voltage threshold region, and obtaining a first fault flag; if yes, proceeding to step S3; else proceeding to step S4; S3, injecting the switching sequence into an all-driving mode of the power device, collecting inverter data and calculating a second output voltage residual; determining whether the second output voltage residual enters the voltage threshold region, and obtaining a second fault flag; S4, collecting inverter data and calculating a first inductor current pulsation value; and determining whether the first inductor current pulsation value pulsates within an inductor current pulsation region, and obtaining a third fault flag; and S5, performing open-circuit fault diagnosis on the power device based on the fault flags.

Abstract: The present invention provides a method, a system and a storage medium for frequency adjustment of an islanded virtual synchronous micro-grid. The method includes: performing frequency adjustment on inverters in the micro-grid in a cyclic manner until the respective inverters reach rated frequencies; where each cycle includes: determining, in a differential delay manner, an inverter with a highest active output in the micro-grid as a reference unit, and sending a local output factor of the reference unit as a maximum output factor of a current cycle to other inverters; determining, for each inverter in the micro-grid, an active power adjustment amount of the inverter according to the maximum output factor, a preset rated frequency, a local output factor and an actual angular frequency of the inverter; and performing frequency adjustment on the inverter according to the active power adjustment amount.

Abstract: The present invention provides a method, a system and a storage medium for frequency adjustment of an islanded virtual synchronous micro-grid. The method includes: performing frequency adjustment on inverters in the micro-grid in a cyclic manner until the respective inverters reach rated frequencies; where each cycle includes: determining, in a differential delay manner, an inverter with a highest active output in the micro-grid as a reference unit, and sending a local output factor of the reference unit as a maximum output factor of a current cycle to other inverters; determining, for each inverter in the micro-grid, an active power adjustment amount of the inverter according to the maximum output factor, a preset rated frequency, a local output factor and an actual angular frequency of the inverter; and performing frequency adjustment on the inverter according to the active power adjustment amount.