DEVICE FOR DETERMINATION OF POWER COMPONENTS WITHIN THREE-PHASE THREE-WIRE AC CIRCUITS Russian patent published in 2012 - IPC G01R21/00 

FIELD: electricity.

SUBSTANCE: device for determination of power components within three-phase three-wire AC circuits contains two normal and two reverse Park-Clark transducers, seven LF filters, a phase-lock-loop frequency control unit, a unit for determination of the angle between voltage and current of fundamental harmonic direct sequence, a multiplier, four units for calculation of the signal mean-square value, a null detector, three switches and a unit for calculation of power components. The device enables frequency variation monitoring with the help of the phase-lock-loop frequency control system that simultaneously enables detection of the current and voltage fundamental harmonic direct sequence and the current-voltage shift angle with the help of the normal and reverse Park-Clark transducers and LF filters. Additionally, with the help of the LF filters, the fundamental harmonic is detected while the units for calculation of the signal mean-square value help to determine the effective values of input signals and fundamental harmonics. Signals parameters calculation is done by the unit for calculation of power components. The null-detector determines the mode of synchronisation of frequencies of phase-lock-loop frequency control and the input signal and sanctions power components calculation solely in this mode. The fundamental harmonic detection is performed with the help of the LF filters.

EFFECT: higher accuracy of power components determination.

5 dwg