Electric means of transportation have seen a rapid expansion partly due to flexibility to commuters and carbon emission reduction. However, transportation electrification is creating severe power quality problems in the utility grid. A single-phase voltage-source traction converter (VSTC) plays a vital role in high-speed train operation. However, it is partly blamed for injecting instability into the vehicle-grid coupling systems (VGCSs). Therefore, understanding the function of VSTC and complying with various grid codes and technical standards for VGCSs is essential. Furthermore, grid-connected VSTC must comply with strict safety standards, such as IEEE Std. 519 and IEEE Std. 16. However, with hundreds or thousands of literature available, it is difficult to choose an effective control method that meets all the requirements. Consequently, to illustrate a clear picture of the development of effective control strategies, this work review recent control techniques, mainly for harmonics rejection and low-frequency oscillation suppression. Factors affecting grid stability and control performance are first identified and discussed in detail. Then, effective control methods to alleviate the disturbance are elaborated. Moreover, future trends on control strategies for VSTCs considering the recent advancements of artificial intelligence are extensively discussed.

The process of electric multiple units (EMUs) passing long downhill sections is inevitable in the construction of mountain railways. Moreover, huge regenerative braking energy (RBE) will be sent back to the traction network, threatening voltage safety. Due to the lack of accurate vehicle-grid integrated models considering slope parameters in studying the RBE, this article proposes a modeling scheme, taking China railway high-speed 3 (CRH3) EMUs as an example. First, based on the extended dual pulsewidth modulation (PWM) mathematical model, the quantitative formula for calculating the motor braking power of the CRH3 EMUs is established. Moreover, the slope parameters are introduced into the vehicle-grid model via force analysis and regenerative braking power calculation. Then, by substituting the calculated results into the extended dual PWM mathematical model, the target instruction parameters are solved. Next, the accurate electrical characteristics, including catenary voltage, electromagnetic torque, and converter voltage, are simulated to evaluate the voltage safety. Finally, by comparing the simulation and semi-physical experiment results with the experimental data from the Chengdu to Chongqing railway line, the feasibility, validity, and accuracy of the model are verified.

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.

In this paper, for insulated gate bipolar transistor (IGBT) open-switch faults in voltage-source inverter-based field-oriented control induction machine drives, both the diagnosis method and the fault-tolerant strategy are presented. In the fault diagnosis method, phase voltages are reconstructed from the variables of the control system. Thus, additional sensors can be avoided. Then, the voltages of healthy and faulty conditions are analyzed. Next, the residual behaviors for faulty conditions are derived based on a comprehensive switching function model that considers the health state of the power switch. On this basis, fault detection and localization criteria can be obtained. In the fault-tolerant strategy, the three-phase six-switch (TPSS) topology and three-phase four-switch (TPFS) topology are combined. TPSS topology can provide the zero state, which eliminates the torque ripple caused by the zero state synthesis. An analytical comparison of torque ripples of TPSS and TPFS is given. It shows that TPFS topology has lower torque ripple at higher speed and lighter load while TPSS topology has lower torque ripple at lower speed and heavier load. By combining them, the lower torque ripple can be achieved at both high and low speed and heavy and light load. Finally, hardware-in-the-loop tests are carried out to show the effectiveness of the proposed methods.

This article presents a cost-effective prognostic method for the bond wires in the insulated-gate bipolar transistor (IGBT). Consider that the crack propagation in the wire bond leads to the bond wire liftoff, the corresponding state equation is established from the fracture mechanics theory, with the consideration of the uneven distribution of the temperature swings. Hence, the proposed model can work under different loading conditions. With the fact that the ON-state voltage (V _ce,on ) of the IGBT shifts with the crack propagation, the history V _ce,on is used to predict the remaining useful lifetime (RUL), through which numerous power cycling tests are avoided, and low economical cost for doing prognosis is fulfilled. In this article, the functional relationship between the increase of Vce,on and the crack length of each bond wire is obtained through finite-element simulation, while the effects of the temperature variation and metallization degradation to the V _ce,on are compensated. Thus, the output equation can be obtained. Then, the unknown parameters of the aforementioned equations and the current crack length can be estimated by the particle-based marginalized resample-move algorithm. Finally, the RUL can be predicted effectively by evolving the particles obtained in the algorithm. The proposed method has been validated by the power cycling test.

The direct-quadrature (DQ) model, mirror-frequency impedance (MFI) model, and harmonic state-space (HSS) model are three main modeling methods for single-phase power electronic converter systems. These models are established under three different frameworks: the dq-frame, the mirror-frequency frame, and the extended harmonic domain frame. The purpose of this article is to demonstrate how to create a unified modeling framework and to provide an unambiguous relationship between the impedances in these three domains. The unified model framework facilitates flexible and scalable modeling by making different models to be easily interconnected with other systems. In addition, to simplify the stability analysis and impedance measurement process, the three modeling methods are reduced to first-order single-input and single-output (SISO) equivalent models, respectively, based on the model reduction technique. Finally, the impedance measurement and stability analysis results of electric multiple units (EMUs) accessed vehicle-grid system demonstrate the accuracy of the conversion and SISO equivalence technique.