Title:
CHANGEEOVER METHOD OF SQUARE VOLTAGE WAVEFORM PULSE ROW
Document Type and Number:
Japanese Patent JPS55100076
Kind Code:
A
Abstract:
PURPOSE:To prevent a thyristor from commutation failure by a method wherein change-over is performed in the intermediate position of the wide pulse length of the pulse row, when the square voltage waveform pulse row sent to the gate circuit of the pulse length modulation system inverter is changed-over. CONSTITUTION:Each of the signal generation circuits 6, 7, 8 is arranged corresponding to each of the pulse row memory circuits 3, 4, 5 and therewith, the square voltage waveform pulse rows 17, 18, 19 of the U phase, the V phase and the W phase are made to be changed over at one of 90 deg. or 270 deg., 30 deg. or 210 deg., 150 deg. or 330 deg., which is nearer in a half cycle. And further, the pulse row of each phase is made to be changed over at the intermediate position of the widest pulse length among the square voltage waveform pulses corresponding to the voltage signals. Therefore, the commutation time of thyristor is secured in case of change-over, thus, permitting to prevent the commutation failure.
Inventors:
GATSUSHIYOU IKUHEI
Application Number:
JP754779A
Publication Date:
July 30, 1980
Filing Date:
January 24, 1979
Export Citation:
Assignee:
TOYO ELECTRIC MFG CO LTD
International Classes:
H02M7/48; (IPC1-7): H02M7/48; H02P13/18