Train Impedance Reshaping Method for Suppressing Harmonic Resonance Caused by Various Harmonic Sources in Trains-Network Systems With Auxiliary Converter of Electrical Locomotive

Abstract

With the development of electrified railway, harmonic resonance accidents occur from time to time. Based on the mechanism of resonance, a harmonic resonance suppression radical method by impedance reshaping is proposed. Thus, the equivalent impedance of the train position is significantly reduced. Compared with the traditional method of improving harmonic current, this method of impedance reshaping can not only suppress the resonance caused by its own harmonic, but also suppress the resonance caused by other trains or other unknown harmonic sources. Harmonic impedance of the train in the resonant frequency is reshaped by detecting the resonance voltage and controlling the auxiliary converter harmonic current. The resonance identification and parameter settings of the impedance reshaping control are also discussed. The proposed harmonic resonance suppression strategy is fully tested with an auxiliary converter control in a simulation trains-network system model. The performance of the proposed strategy is further evaluated on the experimental platform. Both the results verify the effectiveness and feasibility of the proposed strategy. The application of SiC devices makes it effective to suppress the resonance of thousands of hertz. The experiment was validated in two cases. One is the resonance caused by the harmonic current of the train itself. The second is the resonance caused by the harmonic current of trains in other locations. In both cases, the train using impedance reshaping method can ensure that the resonance of its position is effectively suppressed.

A Harmonic Impedance Identification Method of Traction Network Based on Data Evolution Mechanism

“…where y i is the measured data, andŷ i and y respectively denote the estimate value and average value of the measured data y i . In (7), SST reflects the uncertainty of the dependent variable y and SSR reflects the uncertainty of the estimate value depended on the independent variable x. In other words, SCD γ 2 determines the fluctuation in the dependent variable caused by the variation of the independent variable.…”

“…Thus, the harmonic problem, a huge impact on the normal operation of trains, is a hidden danger to the security of RESs. Based on the above, proper harmonic suppression [7,8] and good matching characteristics of the harmonic impedance [9] are the key to improving harmonic problems and power quality [10,11], while the harmonic impedance of the traction network is an important parameter.…”

Analysis of harmonic influence of improved PFC circuit on SS4G electric locomotive

“…With the continuous improvement of power technology, China's electric locomotives have been upgraded from Shaoshan 1 to Shaoshan 9 [1][2][3][4][5]. As an early electric locomotive, SS4G locomotive played an important role in heavy haul railway freight transportation [6][7][8][9]. In the process of line operation, as a special traction load system, AC-DC electric locomotive widely uses power electronic switches, which is one of the important factors for harmonic generation of locomotive [10][11][12].…”

Field Tests for Evaluating the Inherent High-Order Harmonic Resonance of Traction Power Supply Systems Up to 5000 Hz

“…It has been reported that the high-order harmonic resonant accidents of electrical railways occurred in many countries, such as New Zealand [1], Korea [2], Britain [3], Italy [4], [5], Spain [6], Thailand [7], China [8]- [10] and so on. This kind of accidents has become serious threat to the safe and stable operation of railways [11], [12].…”