SINGLE-PHASE ACTIVE FILTER Russian patent published in 2018 - IPC H02J3/00 

FIELD: electric power engineering.

SUBSTANCE: invention relates to electric power and electrical engineering and can be used to improve the quality of electricity in single-phase electrical networks. In the method, the single-phase active filter provides reduction of distortion coefficient of sinusoidal current and supply network voltage and maintenance of a certain power factor at a dynamically changing non-linear load. This invention can be used to improve the quality of electrical energy of a single consumer, a group of consumers or a section of an electrical network. Further, a single-phase active filter contains an inverter, a storage capacitor, a pulsation filter, a load current measuring transducer, a filter current measuring transducer, a filter voltage measuring transducer, a storage capacitor voltage measuring transducer, and a control system controller. Said control system controller includes a storage capacitor voltage regulator, a reference current signal generator, an adder current signal calculator, an error current calculator, a current controller, and a pulse width modulator. Above reference current signal generator comprises a load current signal delay unit, a filter voltage delay unit, an instantaneous active power calculation unit, a low-pass filter, an instantaneous reactive power calculator, a phase current angle adjuster, an adder, and a reference current signal calculation unit. By switching the power keys of the inverter according to the signals of the control system, it is ensured that the storage capacitor is connected between the supply network and the load, so that the current of the supply network is as close as possible to the value generated by the reference current signal generator. To calculate the reference current signal in accordance with expression (4), the constant instantaneous active power component is used, it is generated as a result of filtering of the instantaneous active power, and the constant component of instantaneous reactive power, calculated from expression (3).

EFFECT: invention can be used to improve the quality of electricity in single-phase electrical networks.

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