Patent ID: 11936310
Assignee: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 18:
19. The control device for the three-phase AC system according to claim 12, wherein when the three-phase AC system operates in an off-grid mode, a harmonic voltage in an output voltage of the inverter is controlled, and the error obtaining unit comprises:
a harmonic voltage obtaining module configured to perform coordinate transformation on the output voltage of the three-phase AC system to obtain a voltage signal, perform low-pass filtering on the voltage signal to obtain a fundamental voltage, and subtract the fundamental voltage from the voltage signal to obtain the harmonic voltage; and
a voltage reference value setting module configured to perform coordinate transformation of multiple coordinate systems on the harmonic voltage to obtain the harmonic voltages corresponding to the multiple coordinate systems, and set a reference value of the harmonic voltage in each of the coordinate systems to zero to obtain the error signal in each of the coordinate systems.