Electronic trip device comprising, in series, a finite and infinite impulse response filter

摘要

The circuit comprises a sampler (6), a circuit (8) which raises the applied signal to its squared value and an FIR filter (9) for each phase of the network. A maximum circuit (14) is connected to the output of the FIR filters (9) and to the input of an IIR filter (5). A comparison circuit (7) with comparison thresholds is connected to the output of the IIR filter. The sampler introduces a displacement between two successive samples after a predetermined number of samples.