The integrity of transmission-line voltage measurements in a digital-electricity power system in the presence of line-voltage disturbances during a sample period is ensured via detection or prevention by (a) acquiring at least three measurements of transmission-line voltage, performing numerical analysis on the measurements to produce a polynomial function, and estimating accuracy of the polynomial function based on magnitude of variance of the individual measurements; (b) applying a negative or positive bias to the transmission line during the sample period and acquiring voltage measurements to determine a rate of voltage change with the bias applied; (c) shifting a start time of a first sample period on a first transmission line in reference to a second sample period on a second transmission line to reduce overlap of sample periods across both transmission lines; and/or (d) synchronizing start times of respective sample periods on first and second transmission lines.