THREE-PHASE STATIC FREQUENCY CONVERTER WITH DIRECT COUPLING Russian patent published in 2019 - IPC H02M5/297 G05F1/14 H02P13/06 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, in particular, to three-phase static converters of AC voltage at the input of alternating voltage at the output for frequency change without intermediate conversion and can be used to convert low-frequency alternating voltage into high-frequency alternating voltage. Three-phase static frequency converter with direct coupling comprises control unit, three-phase voltage transformer with primary and secondary windings. Primary winding of each phase A, B, C is made with three additional leads, dividing it into four sections with identical number of turns. Beginning of the primary winding of each phase is connected to the end of the primary winding of the same phase. Semiconductor switches are connected to a three-phase power supply. Each phase of power supply source E_A, E_B, E_C is connected to four semiconductor switches: two switches connected to phase E_A power source are connected to first and third leads of transformer phase A primary winding, and two switches connected to phase E_B power source are connected to the second and fourth leads of the transformer phase A primary winding, two switches connected to the E_B phase power supply are connected to the first and third outputs of the transformer phase B primary winding, and two switches connected to phase E_C power source are connected to the second and fourth terminals of the transformer phase B primary winding, two switches connected to the E_C phase power source are connected to first and third leads of transformer phase C primary winding, and two switches connected to phase E_A power source are connected to the second and fourth leads of the transformer phase C primary winding. Switching frequency of each of switches connected to first leads of primary windings of transformer phases, and the switching frequency of each of the switches connected to the transformer primary windings third terminals is twice as different from the switching frequency of each of the switches connected to the transformer primary windings second terminals, and switching frequency of each of switches connected to fourth outputs of primary windings of transformer phases. Shift angle between the start-up of switches switching at the same frequency makes one third switching period of one switch switching with that frequency.

EFFECT: possibility of converting a three-phase alternating voltage system of low frequency to a three-phase alternating voltage system of high frequency without intermediate conversion.

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