| quantity obtained by subtracting from an alternating quantity its fundamental component or its reference fundamental component
NOTE 1 – The total distortion content includes harmonic components and interharmonic components if any.
NOTE 2 – The total distortion content depends on the choice of the fundamental component. If it is not clear from the context which one is subtracted an indication should be given.
NOTE 3 – The total distortion content is a time function.
NOTE 4 – An alternating quantity is a periodic quantity with zero DC component.