THREE-PHASE FREQUENCY TRANSFORMER WITH NATURAL COMMUTATION

摘要

FIELD: electricity.;SUBSTANCE: invention relates to electrical engineering and may be used in stand-alone power supply systems for frequency and voltage stabilisation in source with high frequency of the generated voltage. The three-phase frequency converter with natural commutation includes three-phase-single-phase frequency converter (1) containing three pairs of thyristors (2-7) with inverse-parallel connection. The above thyristors are coupled with single-phase-three-phase transformer with rotary magnetic field (9) through the filter (8). The magnetic field includes primary winding 1 and 2 (10) and (11), phase-shifting capacitor (12), secondary windings (13-15), control system (16) with the first input being coupled with terminals to connect high frequency source and it's neutral conductor. The second input is coupled with the secondary transformer windings with the rotary magnetic field (9). The control system consists of a synchronisation unit (17), sawtooth-voltage generator (18-20), comparators (21-23), logic elements AND (24-29), master frequency generator (30), transformer and rectifier unit (31). The first control system outputs (16) are the inputs of synchronization unit (17) having outputs 1, 2 and 3 being connected to the sawtooth-voltage generator 1, 2 and 3 (18,19, 20) inputs. At the same time generators outputs are connected with the first inputs of comparators 1, 2 and 3 (21, 22, 23). The second inputs of comparators are coupled with transformer-rectifier unit output (31) and it's input is the second input of the control system (16). The output of comparator 1 (21) is linked with the first inputs of logic elements AND 1 and 2 inputs (24, 25). The second comparator output (22) is coupled with the first inputs of logic elements AND 3 and 4 inputs (26, 27). The output of comparator 3 (23) is coupled with the first inputs of logic elements AND 5 and 6 (28, 29) inputs. The second inputs of logic elements 1, 3 and 5 (24, 26, 28) are linked with the first master frequency generator output, while the second inputs of the logic elements AND 2, 4 and 6 (25, 27, 29) are coupled with the second output of the master frequency generator (30). The outputs of logic elements AND (24-29) are the outputs of control system (16) and connected to the corresponding control electrodes of thyristors.;EFFECT: increase of efficiency factor, reliable operation of three-phase frequency converter and reduced level of electromagnetic interferences.;2 dwg