FILTER OF SYMMETRICAL COMPONENTS OF ELECTRIC SIGNAL Russian patent published in 2003 - IPC

FIELD: measurement technology. SUBSTANCE: invention is related to devices designed to isolate components of reverse sequence of voltage. It can be used in mix of facilities meant for measurement , protection and signaling in three-phase A C systems. In filter of symmetrical components of electric signal terminal of phase A of controlled signal is connected to first input of first adder, terminal of phase B is coupled through inverting input of first differentiation unit to second input of first adder and through inverting input of first proportionality unit to third input of first adder. Terminal of phase C is coupled through noninverting input of second differentiation unit to fourth input of first adder and through inverting input of second proportionality unit to fifth input of first adder which output is coupled through noninverting input of third proportionality unit to first output of filter. It also has third and fourth differentiation units, second and third adders and fourth and fifth proportionality units. Terminal of phase A is additionally connected to first input of second adder and to first input of third adder. Terminal of phase B is additionally connected to second input of second adder, noninverting input of third differentiation unit is connected to second input of third adder and to third input of third adder through inverting input of first proportionality unit. Output of second adder is coupled through noninverting input of fourth proportionality unit to second output of filter. Terminal of phase C is additionally connected to third input of second adder, to fourth input of third adder through inverting input of fourth differentiation unit and to fifth input of third adder through inverting input of second proportionality unit. Output of third adder is coupled through noninverting input of fifth proportionality unit to third output of filter. While filter operates under unsteady condition component of electric signal of reverse zero sequence is formed across first output, component of zero sequence is formed across second output and component of forward zero sequence is formed across third output. EFFECT: generation of full spectrum of symmetrical components of electric signal at high speed and increased accuracy of measurement of signal under unsteady condition of operation. 1 dwg