DEVICE FOR PULSE-PHASE CONTROL OVER THREE-PHASE THYRISTOR CONVERTER Russian patent published in 1994 - IPC

FIELD: electrical engineering. SUBSTANCE: device includes controlled element - transformer-phase inverter placed only in one phase. Two other phases have phase-shifting filters instead of transformers-phase inverters ensuring with proper tuning shift of output sinusoidal voltage of transformer-phase inverter by angle +2Π/3 and -2Π/3. In this vase there is realized transfer function K_f(p)=1=R_fC_fp/1+R_fC_fp of filter. In consequence modulus of voltage across output of filter with reference to common bus of circuit remains invariable under control over phase. High accuracy of control over thyristor converter is achieved thanks to fact that form of voltage across output of transformer phase inverter based on symmetric circuit is very close to sinusoidal with proper selection of resistance of filter and fixed capacitance of filter capacitor. Spread of controlling pulses in phase does not exceed ± 1-2 el. deg within working range. EFFECT: high accuracy of control over thyristor converter. 4 dwg