Method for the evaluation of partial discharge signals which, in the vicinity of an insulation of the electrical line conductor of a multiphase alternating current, of which the alternating currents flowing in one line conductor in each case have fixed phase shifts in relation to one another, are detected at only one location or are detected at multiple locations and overlaid on one another, wherein - at least one characteristic variable (K) is defined, on the basis of which partial discharge signals can be compared with one another, - each partial discharge signal is assigned a phase position of the alternating currents at the point in time of the detection of the partial discharge signal, - a characteristic variable value of each characteristic variable (K) is ascertained for each partial discharge signal, - each partial discharge signal is assigned a numerical tuple that is formed of each characteristic variable value of the partial discharge signal and the phase position assigned to the partial discharge signal, - clusters (C) of the partial discharge signals are ascertained in a multidimensional space (S) with points (V) formed by the numerical tuples, characterised in that - a partial discharge activity is ascertained from the ascertained clusters (C) for each line conductor, wherein a pulse duration, pulse height, electric charge, energy and/or repetition rate of a partial discharge signal is defined as characteristic variable (K), wherein a cluster centroid (P) is determined for each cluster (C) and the cluster (C) is assigned to a line conductor that is determined from the phase position of the cluster centroid (P), wherein trends of the partial discharge activities on any line conductor are identified through evaluations of the temporal distributions of activity values of the individual line conductors. - at least one characteristic variable (K) is defined, on the basis of which partial discharge signals can be compared with one another, - each partial discharge signal is assigned a phase position of the alternating currents at the point in time of the detection of the partial discharge signal, - a characteristic variable value of each characteristic variable (K) is ascertained for each partial discharge signal, - each partial discharge signal is assigned a numerical tuple that is formed of each characteristic variable value of the partial discharge signal and the phase position assigned to the partial discharge signal, - clusters (C) of the partial discharge signals are ascertained in a multidimensional space (S) with points (V) formed by the numerical tuples, characterised in that - a partial discharge activity is ascertained from the ascertained clusters (C) for each line conductor, wherein a pulse duration, pulse height, electric charge, energy and/or repetition rate of a partial discharge signal is defined as characteristic variable (K), wherein a cluster centroid (P) is determined for each cluster (C) and the cluster (C) is assigned to a line conductor that is determined from the phase position of the cluster centroid (P), wherein trends of the partial discharge activities on any line conductor are identified through evaluations of the temporal distributions of activity values of the individual line conductors. <EOS>