DEVICE FOR COMPENSATION OF HIGHER HARMONICS AND RECOVERY OF ENERGY INTO MAINS ADAPTED TO AC ELECTRIC DRIVE Russian patent published in 2018 - IPC H02J3/01 

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering, in particular to devices for suppressing and compensating for higher harmonics in electrical networks and for the recovery of energy into the mains, and can be used in adjustable AC electric drives with a two-link frequency converter, in which the input diode rectifier is a non-linear load. Compensation device comprises an inverter, a step-up transformer, a DC sensor of the frequency converter, a DC sensor of the compensation device, an AC sensor of the frequency converter, an AC sensor of the compensation device, a mains voltage sensor, a unit for calculating the average DC value of the compensation device, a unit for calculating the average DC value of the frequency converter, a unit for calculating the amplitude value of the alternating current of the frequency converter, a current PI controller, an adder, a unit for calculating the instantaneous phase angles of the mains voltage, a first multiplier, a subtraction unit, a block of relay regulators, a DC link voltage sensor, a signal filtering unit, a comparator, a voltage PI controller, a voltage command generating unit, and a second multiplier.

EFFECT: improving energy efficiency; device allows to regenerate the braking energy of the motor into the mains from the DC link of a two-link frequency converter with an uncontrolled rectifier.

1 cl, 2 dwg