A Practical Method for Assessment of Harmonic Emission of Electrified Railway

The electrified railway is one of main harmonic sources in utility. Compared with normal load, the most characteristics of traction are random time varying and non-symmetry. So the harmonic of traction load is very different from normal load of utility. So the evaluating method right for normal load may be not suitable for traction load. So finding a proper estimating method for traction load harmonic is main purpose of this paper. A practical method of evaluating harmonic emission level of electrified railway is brought out based on IEC61000-3-6 in this paper, including confirmation of emission limits, distribution method of emission limits of user and detailed evaluating harmonic emission of traction loads. An example is used to illustrate the rationality of proposed idea