METHOD FOR CONTROLLING FOUR-QUADRANT CONVERTER Russian patent published in 2005 - IPC

FIELD: electrical engineering; input converters for forced-switching rectifier installations of ac electrified trains.

SUBSTANCE: proposed method includes alternate closure of input voltage supply through inductance coil and its opening throughout entire positive half-cycle of supply voltage until current attains sum of desired value and permissible deviation, as well as difference in desired value and permissible deviation, respectively, during each switching operation; closure of input voltage supply during entire negative half-cycle of supply voltage until current equals difference in desired value and permissible deviation, as well as opening of input voltage supply until current is brought to sum of mentioned values. Permissible current deviation is found from formula ΔI = U_m/8π²mfL, where U_m is peak value of supply voltage; L is inductance of converter input circuit; m is number of switching operations within half-cycle; f is supply voltage frequency. Proposed method provides for complete use of capacity of power semiconductor devices, maximal possible rate of switching operations, improved waveform of input current, and its maximal approach to quasi-sinusoidal waveform resulting in enhanced power factor and reduced load on supply mains.

EFFECT: enhanced power characteristics of converter due to organizing current passage with maximal number of switching operations.

1 cl, 9 dwg