Digital measurement of transient disturbances in electric power network with additional lowpass analog circuit

The paper presents a DSP-based system for measurement of the short-term transient distortions in electric power networks. These distortions typically possess short duration times and high amplitude values and thus they are very di.cult to acquire by standard digital data acquisition systems. We propose to apply an additional analog lowpass RC circuit before digital data acquisition. A properly chosen analog RC filter extends the duration time of transient distortion and simultaneously reduces its amplitude making it significantly simpler to acquire digitally. Next, digital signal processing is used for cancelling the analog convolution of the acquired signal with a RC filter. The paper discuses results obtained for di.erent con.gurations of the proposed measurement system including RC filter selection and digital deconvolution filter design. The algorithm was implemented in a Texas Instruments C617 DSK toolkit. Laboratory experiments with voltage signals are presented in the paper.