FREQUENCY CONVERTER (ALTERNATIVES) Russian patent published in 2005 - IPC

FIELD: power converter engineering; induction motor supply frequency and voltage regulation.

SUBSTANCE: proposed frequency converter has control unit and groups of parallel-connected pairs of series-interconnected switches, as well as phasing unit and filter unit both connected to frequency converter inputs, and transformers whose quantity depends on input voltage phase number; some outputs of control unit are connected through phasing unit to control inputs of respective switches and other outputs of control unit are series-connected through filter unit and phasing unit to control inputs of other switches. Transformer primary windings are connected to some respective groups of switches connected to inputs of frequency converter and secondary windings of different transformers are connected in series; extreme leads of these groups of windings are connected to other respective groups of switches connected to frequency converter outputs. In addition, invention is concerned with frequency converters for three phases of input voltage and for three phases of output voltage incorporating switches built around transistors and diodes, and with transformers having different number of primary and secondary windings. Proposed frequency converter incorporates provision for electrical isolation, extension of regulation range, and elimination of higher harmonics in output voltage.

EFFECT: simplified circuit arrangement, reduced mass and size, enhanced reliability of frequency converter, and reduced energy loss.

4 cl, 4 dwg