High-frequency harmonic resonance has been a frequently encountered issue in railway traction power supply system (TPSS) since high-speed trains that are equipped with ac-dc-ac traction drive system were serviced in China High-Speed Railway (HSR) lines. This high-frequency harmonic resonance is excited when the frequency of harmonic components introduced by the grid-side traction ac-dc converter in trains matches the inherent resonance frequency of TPSS. Traditional solutions for this HSR high-frequency resonance focus on providing damping to the TPSS. In this work, with a focus on avoiding the resonance excitation, a solution from the trains' perspective through adoption of single-phase grid-side pulse-width-modulated (PWM) converter with LCL filter in high-speed trains is proposed. Compared with the traditional traction system topology with L-type filter, the total inductance value of LCL filter is designed to be the same with that of L-type filter and there is only an additional small capacitor adopted in the proposed solution. Therefore the design in this work meets the space and weight requirements of the traction converter system. In this work, an all-parallel 27.5-kV 50-Hz autotransformer (AT)-fed power-supply system and the proposed grid-side LCL filter based converters are modeled and simulated in real-time hardware in loop (HIL) experimental platform. The results show that the proposed solution can effectively suppress the high-frequency resonance of TPSS.

A city‐scale time–history analysis‐driven framework is proposed for the quantitative evaluation of building seismic resilience and repair scheduling with repair resource constraints. First, a calculation method for the post‐earthquake residual functionality of buildings based on engineering demand parameters is proposed. Second, the repair‐scheduling unit (RSU) concept is proposed for city‐scale repair scheduling. Moreover, two repair priority indices are introduced to evaluate the repair priority of each RSU. Next, the concept of job block is proposed to compute the repair time of an RSU with insufficient repair resources. Subsequently, the workflow of repair simulation is presented to calculate the community recovery curve and resilience index quantitatively. Finally, 68,930 residential buildings of Beijing City's 16 administrative districts are simulated to demonstrate the proposed method. The outcomes of this work are expected to be a useful reference for building seismic resilience evaluation and repair scheduling of communities. Consequently, it could be an aid to pre‐earthquake disaster risk reduction planning and post‐earthquake rapid recovery of building functionalities.

This paper develops an online inter-turn fault diagnosis method for permanent magnet synchronous machine (PMSM). The mathematical model of the PMSM with inter-turn fault is established. The zero sequence voltage component and zero sequence current component are analyzed in the PMSM, respectively. Then the new fault indicators are defined to remove the influence of the variation of the rotor speed and an effective frequency tracking algorithm is presented to extract fault indicators. In this proposed method, not only the inter-turn fault can be effectively detected, but also the phase in which this fault occurs can be accurately identified. The experiments are carried out and the experiment results verify the effectiveness of the proposed method.Index Terms-Fault diagnosis, frequency tracking, permanent magnet machine, zero sequence component.

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