A method for characterizing power quality events in an electrical system, comprising: processing electrical measurement data from or derived from energy-related signals captured by at least one first intelligent electronic device, IED, in the electrical system, wherein the at least one first IED is installed at a first metering point in the electrical system; processing electrical measurement data from or derived from energy-related signals captured by at least one second IED in the electrical system, wherein the at least one second IED is installed at a second metering point in the electrical system; and deriving electrical measurement data for at least one first virtual meter in the electrical system from a) the electrical measurement data from or derived from the energy-related signals captured by the at least one first IED, and b) the electrical measurement data from or derived from the energy-related signals captured by the at least one second IED, wherein the at least one first virtual meter is installed or located at a third metering point in the electrical system, wherein the third metering point is different from both the first metering point and the second metering point, and wherein the first metering point and the second metering point are in particular physical metering points in the electrical system, characterized in that: the electrical measurement data from or derived from energy-related signals captured by the at least one first IED is processed to generate or update a first dynamic tolerance curve associated with the first metering point; the electrical measurement data from or derived from energy-related signals captured by the at least one second IED is processed to generate or update a second dynamic tolerance curve associated with the second metering point; and the method further comprises using the derived electrical measurement data to generate or update a third dynamic tolerance curve associated with the third metering point. processing electrical measurement data from or derived from energy-related signals captured by at least one first intelligent electronic device, IED, in the electrical system, wherein the at least one first IED is installed at a first metering point in the electrical system; processing electrical measurement data from or derived from energy-related signals captured by at least one second IED in the electrical system, wherein the at least one second IED is installed at a second metering point in the electrical system; and deriving electrical measurement data for at least one first virtual meter in the electrical system from a) the electrical measurement data from or derived from the energy-related signals captured by the at least one first IED, and b) the electrical measurement data from or derived from the energy-related signals captured by the at least one second IED, wherein the at least one first virtual meter is installed or located at a third metering point in the electrical system, wherein the third metering point is different from both the first metering point and the second metering point, and wherein the first metering point and the second metering point are in particular physical metering points in the electrical system, characterized in that: the electrical measurement data from or derived from energy-related signals captured by the at least one first IED is processed to generate or update a first dynamic tolerance curve associated with the first metering point; the electrical measurement data from or derived from energy-related signals captured by the at least one second IED is processed to generate or update a second dynamic tolerance curve associated with the second metering point; and the method further comprises using the derived electrical measurement data to generate or update a third dynamic tolerance curve associated with the third metering point. the electrical measurement data from or derived from energy-related signals captured by the at least one first IED is processed to generate or update a first dynamic tolerance curve associated with the first metering point; the electrical measurement data from or derived from energy-related signals captured by the at least one second IED is processed to generate or update a second dynamic tolerance curve associated with the second metering point; and the method further comprises using the derived electrical measurement data to generate or update a third dynamic tolerance curve associated with the third metering point.