Power distribution network control system and method based on UPQC circuit hybrid regulation

The invention belongs to the technical field of electric energy quality, and particularly discloses a power distribution network control system and method based on UPQC circuit hybrid regulation, and the system is characterized in that at least two transformers are connected in series between an AC power grid and a load, and the primary sides of the two transformers are connected in series between the AC power grid and the load; the UPQC circuit comprises a series converter and a parallel converter which are provided with a common direct current bus, and the series converter and the parallel converter are coupled together through a direct current capacitor in the middle; the series converter is connected in series between the alternating-current power grid and the load through the second transformer and is used for compensating voltage harmonic waves from the alternating-current power grid and suppressing voltage fluctuation together with the voltage-stabilized power supply; and the parallel converter is conn