METHOD FOR GENERATION OF SYNCHRONIZING SIGNAL Russian patent published in 2005 - IPC

FIELD: electric engineering.

SUBSTANCE: for forming of synchronization signal, semi-period of feeding voltage is divided on ranges, at the beginning of each i-numbered range voltage of powering network is measured, converted to digital code U_i, which , for increase of interference resistance, is let through digital filter. Digital filter forms sine or like signal y_i at its output, after that maximum(amplitude) of signal A during semi-period is determined. For last p semi-periods of voltage of powering network ,maximum of voltage signal of feeding network for current semi-period is determined using formula:

where n - number of current semi-period; p - amount of previous semi-periods; A - maximal value of signal in semi-period. Then phase shift of inputted voltage signal is determined at current range relatively to synchronization signal using formula

which is compared to required φ_i=φ_i-1+Δφ, where φ_i-1 - phase shift at previous range; Δφ - range length. In case of coincidence of phase shifts for several times in a row, at the beginning of next range phase shift is let out before end of semi-period of powering voltage, into timer. In case of zero value of code of timer at the end of current semi-period, synchronization signal is formed, appropriate for moment of shift of powering voltage across zero.

EFFECT: higher resistance to interference.

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