FILTER FOR VOLTAGE OF REVERSE SEQUENCE Russian patent published in 2000 - IPC

FIELD: measuring, protection and signaling devices of three-phase A C systems. SUBSTANCE: filter for voltage of reverse sequence has adder, three proportional units, first and second differentiation units. Terminal of voltage signal of phase A is connected to first input of adder, terminal of voltage signal of phase B is coupled via inverting input of first differentiation unit to second input of adder, terminal of voltage signal of phase C is linked via noninverting input of second differentiation unit to fourth input of adder and via inverting input of second proportional unit to fifth input of adder whose output is coupled to input of third proportional unit so that output of third proportional unit is output of filter. All components of proposed filter can be realized on inertia-free elements which guarantees its high speed of response under all possible conditions of operation. Isolation of signal of voltage of reverse sequence without conversion of phase of primary signal substantially rises accuracy of operation of filter. EFFECT: enhanced speed of response and accuracy of measurement of voltage signal of reverse sequence under unstationary operational conditions. 1 dwg