METHOD OF DETERMINING CONTACT WELDING MACHINE POWER FACTOR Russian patent published in 2011 - IPC B23K11/24 

FIELD: process engineering.

SUBSTANCE: invention is intended for automatic control over contact welding machines. thyristor cutin state duration X at preset cutin angle is defined. Welding machine power factor cosφ is calculated for two current periods using relationship cosφ=A₀+A₁λ₂. Factors A₀ and A₁ are set discrete for every a proceeding from condition of minimisation of cosφ calculation error. During first period, thyristors are cut in with angle of α₁=90 electric degrees and preliminary value of cosφ₁ is calculated. In second period, thyristors are cutin with minimum angle α₂ satisfying the condition α₂>φ₁. Now, refined cosφ is calculated.

EFFECT: simplified determination of power factor, reduced measurement and computation errors.

5 dwg, 1 tbl