04-06-2012, 12:35 PM
Harmonic Current Reduction in Railway Systems
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Abstract
This paper deals with the problem of harmonic mitigation solutions in a Romanian traction substation which supplies a railway electric transportation line. The power line measurements were made using an ABB Power recorder and analyzer during a whole day. The quantities recorded have been the frequency, the total rms values of the voltage and current, the current and voltage harmonic distortion factors and the first fifteen current and voltage harmonics. The analysis of data shows that the harmonic distortion factor of the voltage is always less than IEEE 519 recommended limit thanks of high power of the transformer comparatively with the power of the load. In order to keep the current distortion within allowed limits, the proposed filter installation must lead to a significant diminution of 3rd and 5th harmonics and a less significant diminution of the superior order harmonics.
In this concrete application, the proposed solution for harmonics mitigation is based on passive power filtering. The simulations carried out under Matlab Simulink environment show that the installation of two single tuned filters for third and fifth harmonics plus a high-pass filter for higher order harmonics would reduce harmonics levels and harmonic distortion factor to within acceptable limits even in the most unfavourable situations. Proliferation of power electronics loads, such as diode-based rectifier groups supplying DC electric traction motors, produces harmonics distortion as well as many other troubles in the electrical power system. Therefore, the analysis of power quality on a rail system is essential to assess the effects on the adjacent distribution network.
The current harmonics and power quality aspects are very complicated because of the frequent and strong transient regimes. Consequently, some standards and recommendations have been established in order to avoid the potential problems caused by railway harmonics. The most used standard for harmonic pollution limits is IEEE 519-1992. In addition to its recommendations, there are specific railway standards, such as EN 50238/2003, some general EMC standards that may be applied to railway systems, such as EN 50121 or EN 62236 which are compatible with general EMC standards EN 61000, and in addition, each railway company has developed its own standards.Even proper estimating methods for traction load harmonic have been proposed.Many papers look at improving techniques to assess the power quality of a railway system. Modelling techniques used to simulate electrified railways are adapted to simulate power quality aspects with improved computational efficiency. have focused their analysis on the design criteria used in the power filters.
[attachment=24117]
Abstract
This paper deals with the problem of harmonic mitigation solutions in a Romanian traction substation which supplies a railway electric transportation line. The power line measurements were made using an ABB Power recorder and analyzer during a whole day. The quantities recorded have been the frequency, the total rms values of the voltage and current, the current and voltage harmonic distortion factors and the first fifteen current and voltage harmonics. The analysis of data shows that the harmonic distortion factor of the voltage is always less than IEEE 519 recommended limit thanks of high power of the transformer comparatively with the power of the load. In order to keep the current distortion within allowed limits, the proposed filter installation must lead to a significant diminution of 3rd and 5th harmonics and a less significant diminution of the superior order harmonics.
In this concrete application, the proposed solution for harmonics mitigation is based on passive power filtering. The simulations carried out under Matlab Simulink environment show that the installation of two single tuned filters for third and fifth harmonics plus a high-pass filter for higher order harmonics would reduce harmonics levels and harmonic distortion factor to within acceptable limits even in the most unfavourable situations. Proliferation of power electronics loads, such as diode-based rectifier groups supplying DC electric traction motors, produces harmonics distortion as well as many other troubles in the electrical power system. Therefore, the analysis of power quality on a rail system is essential to assess the effects on the adjacent distribution network.
The current harmonics and power quality aspects are very complicated because of the frequent and strong transient regimes. Consequently, some standards and recommendations have been established in order to avoid the potential problems caused by railway harmonics. The most used standard for harmonic pollution limits is IEEE 519-1992. In addition to its recommendations, there are specific railway standards, such as EN 50238/2003, some general EMC standards that may be applied to railway systems, such as EN 50121 or EN 62236 which are compatible with general EMC standards EN 61000, and in addition, each railway company has developed its own standards.Even proper estimating methods for traction load harmonic have been proposed.Many papers look at improving techniques to assess the power quality of a railway system. Modelling techniques used to simulate electrified railways are adapted to simulate power quality aspects with improved computational efficiency. have focused their analysis on the design criteria used in the power filters.