Impact of Harmonic Power Terms on the Energy Measurement in AC Railways

In electric ac railways, a nonnegligible amount of active power and reactive power can be associated with harmonics. Electric railways are characterized by a mix of moving loads in variable operating conditions with a substantial superposition of different distortion patterns. The EN 50463-2 standard for the measurement of energy and of active power and reactive power does not include harmonic power terms, leading to possible inaccuracy. This article reports the estimate of the harmonic power for ac railways in real scenarios and its variability due to the operating conditions and moving loads, together with the uncertainty in the energy consumption estimate.