METHOD OF FREQUENCY CONVERTER CONTROL Russian patent published in 2008 - IPC H02M5/297 

FIELD: electrical engineering.

SUBSTANCE: invention is related to electrotechnics and may be used in design of control systems with valve frequency converters for induction heaters. Method of frequency converter control with implicitly expressed link of direct current, which contains at least one three-phase bridge on controlled valves and works for the load as oscillating circuit, consists in generation and alternate supply of control pulses to controlled valves that form direct and reverse voltage half-waves in the load, cyclical change of working controlled valves groups, synchronised with change of instantaneous values of phased or linear supply voltages. After another controlled valve that forms direct or reverse voltage half-wave in the load is disconnected, its neighboring controlled valve is connected, and connection of another controlled valve that forms direct or reverse half-waves of voltage in load is performed after disconnection of specified neighboring controlled valve.

EFFECT: higher reliability of frequency converter operation with implicitly expressed DC link.

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