Enhancing power quality of high‐speed railway traction converters by fully integrated T‐LCL filter

Abstract

Modulating the traction converters produces current harmonics at the switching frequencies and their multiples. These harmonics should be minimized to meet the network specifications. The LC‐trapped filters, tuned to these frequencies, can easily meet this requirement, but the existing applicable trap filters have not been studied with the traditional traction system topologies. Thus, this paper presents a trapped LCL filter with an LC resonator on the converter side, called a fully integrated T‐LCL filter, for the traction power supply system. The model and analysis reported in this research demonstrate that the presented filter has several advantages, which can be summarized by: reducing the size by winding many coils through magnetic integration, attenuating the switching frequency and its multiple harmonics that reduce the current total harmonic distortion, assuring durability against the filter parameters differences, and preserving system stability under transient conditions. The proposed filter can become a promising trap filter based on these advantages. Simulation models of an ac/dc single‐phase traction rectifier with the proposed filter were created and tested in MATLAB/Simulink, verifying its superiority. Finally, the filter is validated by performing hardware‐in‐the‐loop experiments.

Magnetic Integrated Double-Trap Filter Utilizing the Mutual Inductance for Reducing Current Harmonics in High-Speed Railway Traction Inverters

“…To address the problems of difficulties, complexities, and expense, HIL has been used to assess power inverters [71], [73], [75]- [78]. The evaluation by HIL validation of the network-tied converter with passive filters is made more desirable, according to the results in [8], [32], [36], [43], [70], [75], [76].…”

“…After completing the design processes, all of the integrated DTLCL, discrete SPRLCL, LCL, and L filters parameters are provided in Table 1. In addition, the same controller implemented in [36], [43], [45], [48], [53], [69], [70] may be used for the traction inverter with the integrated DTLCL filter, which is not discussed here. Section 4 will present the verification results for the proposed filter's design feasibility.…”

Research on harmonic generation principle of series‐connected multi‐pulse rectifiers and optimization design method for main transformers

“…In [7][8][9] the magnetic structures have several inductor windings and transformer windings integrated into a core, the volume of the magnetic devices reduces significantly. In [10,11] the fully integrated T-LCL filters are proposed, the filters are the trapped LCL filter with the LC resonator on the converter side. In [12] the design technique of magnetically inte-grated LLCL filters for grid-tied is proposed.…”

“…In [12] the design technique of magnetically inte-grated LLCL filters for grid-tied is proposed. In [10][11][12] the converters reduce the size by winding many coils through magnetic integration, which is the existing most extensive methods for power density increasing. However, these methods only fit for the high-frequency PWM converters.…”

Harmonics suppression in high-speed railway via single-phase traction converter with an LCL filter using fuzzy logic control strategy

“…Therefore, developing controllers suitable for LCL type single-phase converters faces huge challenges. Traditional PI linear controllers are usually used for gridside converters of high-speed railways [12,13]. However, the process of adjusting the PI parameters in the voltage or current control loop can be a problem, as incorrect settings may result in undesired low-frequency oscillations in traction networks.…”