Fire-Retarding Asphalt Pavement for Urban Road Tunnels: A State-of-the-Art Review and Beyond

With the rapid urbanization and development of metropolises, urban road tunnels have been constructed at an increasing rate, significantly alleviating urban traffic pressure, and improving urban resilience. Fire hazards have become a major threat to modern road tunnels due to the growing popularity of electric vehicles and high-density...

Design knowledge graph-aided conceptual product design approach based on joint entity and relation extraction

Design knowledge is critical to creating ideas in the conceptual design stage of product development for innovation. Fragmentary design data, massive multidisciplinary knowledge call for the development of a novel knowledge acquisition approach for conceptual product design. This study proposes a Design Knowledge Graph-aided (DKG-aided)...

Improved PER-DDPG based nonparametric modeling of ship dynamics with uncertainty

This study contributes to addressing the challenge of quickly obtaining an effective and accurate nonparametric model for describing ship maneuvering motion in three degrees of freedom (3-DOF). To achieve this, an intelligent ship dynamics nonparametric modeling method named improved PER-DDPG is proposed. This method leverages the deep...

A state-of-art review on development and progress of backfill grouting materials for shield tunneling

Backfill grouting plays a vital role in shield tunneling. This paper aims to present a comprehensive review of the development and progress of backfill grouting materials specifically designed for shield tunneling. Initially, the various components of grouts, such as pozzolanic materials, filling fine aggregates, and chemical additives, are...

An efficient multi-objective optimization strategy for Halbach array permanent magnet synchronous machines based on nonlinear semi-analytical model

In this article, an efficient multi-objective optimization strategy for the Halbach array permanent magnet synchronous machine (PMSM) is developed by taking into consideration the nonlinear B-H behavior of soft magnetic materials. Based on the harmonic modeling (HM) technology, the electromagnetic performances (EPs) of the Halbach array PMSM...

Compensation Method of Position Estimation Error for High-Speed Surface-Mounted PMSM Drives Based on Robust Inductance Estimation

This article proposes a compensation method of position estimation error for high-speed surface-mounted permanent magnet synchronous motors based on robust inductance estimation. The proposed method relies on the variation of the estimated δ-axis back back-electromotive force when a small current is injected into the γ axis. The inductance...

Discrete-Time Dynamic-Decoupled Current Control for LCL-Equipped High-Speed Permanent Magnet Synchronous Machines

This article proposes a discrete-time dynamic-decoupled current controller for an LCL-equipped high-speed permanent magnet synchronous machine with only the motor currents measured. The controller is designed in the synchronous coordinate based on a complex z-domain transfer function. The main contribution of the proposed current controller...

Dynamic-Decoupled Active Damping Control Method for Improving Current Transient Behavior of LCL-Equipped High-Speed PMSMs

In this article, a novel dynamic-decoupled active damping current controller is proposed for an LCL-equipped high-speed permanent magnet synchronous machine. Compared with the conventional stationary current-control method for the LCL-type system, the proposed method is established in the synchronous rotating frame for improving the current...

Variation Regularity and Measurement of Zero-Sequence Inductance of Fractional Slot Concentrated Winding PMSMs

The zero-sequence inductance is a vital parameter for the performance analysis of permanent magnet machines, especially under faulty conditions or in open-winding machines. This paper focuses on the zero-sequence inductance calculation of fractional slot concentrated winding permanent magnet synchronous machines (FSCW-PMSMs), and reveals the...

A General Single-Sensor Damping Framework for LCL-Equipped High-Speed PMSM Drives

This letter proposes a general single-sensor active damping framework for LCL-equipped high-speed permanent magnet synchronous machines. By the proposed method, arbitrary damping assignment and stability for the LCL resonance within the Nyquist frequency are achieved with only the inverter-current feedback or motor-current feedback. Moreover,...

Surface functionalized N-C-TiO₂/C nanocomposites derived from metal-organic framework in water vapour for enhanced photocatalytic H₂ generation

Surface-functionalized nitrogen/carbon co-doped polymorphic TiO₂ phase junction nanoparticles uniformly distributed in porous carbon matrix were synthesized by a simple one-step pyrolysis of titanium based metal–organic framework (MOF), NH₂-MIL-125(Ti) at 700 °C under water vapour atmosphere. Introducing water vapour...

Rotor Eddy Current Loss Reduction with Permeable Retaining Sleeve for Permanent Magnet Synchronous Machine

This article presents a new rotor design to reduce rotor eddy current loss of a high-speed permanent magnet synchronous machine for flywheel energy storage system. Instead of using common nonmagnetic sleeves, the new rotor incorporates permeable retaining sleeves (PRSs) to fix permanent magnets on the rotor hub. The PRSs are made of permalloy...

A New Rotor Structure for High Speed Flywheel Permanent Magnet Synchronous Machine

This paper presents a new rotor design with assembled permeable retaining sleeve (APRS) to improve performances of a high speed permanent magnet synchronous machine (PMSM). The APRS consists of equal number of permeable and nonmagnetic parts, which are alternately arranged and assembled together circumferentially via keyways. Electromagnetic and...

Investigation Study of the Influence of Pole Numbers on Torque Density and Flux-Weakening Ability of Fractional Slot Concentrated Winding Wheel-Hub Machines

Fractional slot concentrated winding machines (FSCWMs) with the low operation speed and large diameter usually have a large number of poles and slots; thus, numerous pole/slot combinations are feasible. The common practice to choose pole/slot combinations by multiplying the basic combinations may neglect some competitive candidates. Taking 36...

Multi-dimensional indoor location information model

Aiming at the increasing requirements of seamless indoor and outdoor navigation and location service, a Chinese standard of Multidimensional Indoor Location Information Model is being developed, which defines ontology of indoor location. The model is complementary to 3D concepts like CityGML and IndoorGML. The goal of the model is to provide an...