METHOD FOR SYNCHRONISING TWO THREE-PHASE ELECTRIC ENERGY SYSTEMS Russian patent published in 2015 - IPC H02J3/38 

FIELD: electricity.

SUBSTANCE: method for accurate synchronising two three-phase electric energy systems is performed digitally using output digital signals of analogue-to-digital converter for all three phases of industrial three-phase voltage of the first Ua1(ti), Ub1(ti), Uc1(ti) and second Ua2(ti), Ub2(ti), Uc2(ti) electric energy systems measured at time instants ti, where i is an integer number, and digitised with sampling time dt = t(i+1)-ti, at that value dt is significantly less than period T of industrial three-phase voltage, dt≤≤T. Usage of all three voltage phases (Ua, Ub, Uc) of two electric energy systems (instead of one voltage phase) leads to significant improvement of synchronisation parameters for two electric energy systems. Large number of signals (voltage of three phases) leads to increase in accuracy for determined moment of the switch connection. Usage of rotary fields U1(ti), U2(ti) generated by three phases Ua1(ti), Ub1(ti), Uc1(ti) and Ua2(ti), Ub2(ti), Uc2(ti) of industrial three-phase voltage allows considering phase difference between all three pairs of phase voltage (Ua1 and Ua2, Ub1 and Ub2, Uc1 and Uc2), and in result connection of the switch takes place with the least current rush for all three phases.

EFFECT: increased accuracy for determined moment of the switch connection and automatic control for identity of phase sequencing for two electric energy systems.

3 dwg