This article proposes a novel sensorless control strategy for permanent magnet synchronous motor drives using reduced order quasi resonant-based extended state observer (ROQR-ESO) and Newton–Raphson method-based phase-locked loop (NRM-PLL). Due to the low-pass filtering characteristics, the conventional linear extended state observer (LESO) is not adequately able to track the fast-varying back electromotive forces (BEMFs). On this basis, the ROQR-ESO, which plants a ROQR controller into the internal model of conventional LESO, is presented to obtain BEMFs without phase lag. Moreover, the NRM-PLL, regarded as an improved finite position set-PLL, is proposed. After the rotor position is divided into four parts by utilizing a position quartering method, the extremely accurate rotor position can be obtained only by three iterations. In this method, no parameters need to be adjusted and great dynamic response can be achieved. The capacity of the proposed scheme is verified on a 750 W permanent magnet synchronous motor drive platform.

This paper presents a 12/8-pole, three-phase, modular-stator hybrid excitation switched reluctance machine (MSHSRM) assisted with permanent magnets (PMs) as well as its design consideration and performance evaluation. The basic operating principle is illustrated through a specific form of this machine, and the magnetic equivalent circuit model is built and analyzed. Then, the main parameters of the machine are optimized by the finite-element method. The static magnetic characteristics and dynamic performance of this novel machine are simulated and compared with other two SRMs, one is segmented 12/8 SRM without PM, and the other is the conventional 12/8 SRM with unsegmented structure. Finally, two motor prototypes, including one MSHSRM and one conventional SRM of the same size are manufactured. The static magnetic characteristic and dynamic operation of two motor drives are measured to confirm the predictions. The simulation and experimental results indicate that this MSHSRM has higher power and stronger load capacities than the conventional SRM in whole speed range with higher torque/power density and higher torque per ampere.

This paper presents a novel position sensorless control for 6/4 switched reluctance motors (SRMs) using only one-phase current sensor in medium and high speed. In order to eliminate phase voltage sensors, a virtual phase voltage is established to replace the real-time phase voltage in the whole conduction cycle, so as to calculate the phase flux linkage which is called virtual flux linkage. A nonlinear model is utilized to estimate the reference flux linkage-curve of any rotor position. With only one-phase current sensor, the determination of turn off angle position and phase commutation position is achieved by the comparison of reference flux linkage and virtual flux linkage. The speed estimation is performed by two reference flux linkage-current curves at particular rotor positions. Based on the obtained turn off pulse of the present phase and the turn on pulse of next phase, the remaining trigger pulse signals of three phases are derived from a delay-time strategy. The proposed scheme requires only one-phase current sensor, without any pulse injection or complicated decoupling algorithm, achieving a simple and cost-effective drive. Simulations and experiments are carried out on a 6/4-pole prototype SRM drive system to verify the correctness and effectiveness of the proposed sensorless control scheme.

This article proposes an improved model predictive torque control (MPTC) strategy for switched reluctance motor (SRM) drives with candidate voltage vectors (CVVs) optimization, which can suppress the torque ripple effectively and enhance the system efficiency. This MPTC method is improved by three aspects. First, the flux linkage calculation is removed compared to conventional MPTC. Second, the electric cycle of SRM is divided into six sectors based on the ideal torque contribution profile and the commutation region of the motor is redefined. Finally, CVVs of each sector are adopted based on phase torque characteristics and the total number of CVVs is reduced to 2 or 3 at each control period. The cost function is designed for the torque ripple suppression and copper loss minimization by selecting the optimal voltage vector from CVVs. This improved MPTC method avoids mass useless computation compared to conventional MPTC and no longer relies on hysteresis control loops compared to direct torque control (DTC) method. In the simulation and experimental verification on a three-phase 12/8 SRM, the proposed MPTC method effectively reduces the torque ripple, improves the torque–ampere ratio and system efficiency, and improves dynamic response compared to DTC method.

With the booming of social media, sentiment analysis has developed rapidly in recent years. However, only a few studies focused on the field of transportation, which failed to meet the stringent requirements of safety, efficiency, and information exchange of intelligent transportation systems (ITSs). We propose the traffic sentiment analysis (TSA) as a new tool to tackle this problem, which provides a new prospective for modern ITSs. Methods and models in TSA are proposed in this paper, and the advantages and disadvantages of rule- and learning-based approaches are analyzed based on web data. Practically, we applied the rule-based approach to deal with real problems, presented an architectural design, constructed related bases, demonstrated the process, and discussed the online data collection. Two cases were studied to demonstrate the efficiency of our method: the “yellow light rule” and “fuel price” in China. Our work will help the development of TSA and its applications.

Hybrid-excitation switched reluctance motors (HESRMs) have attracted considerable attention for various drive applications due to their simple structure, low cost, and high-torque/power capabilities. This paper comprehensively evaluates and compares a high-torque segmented-stator HESRM drive with a conventional SRM drive in terms of static magnetic and dynamic performances. The stator of the segmented HESRM consists of six individual U-shaped segments; each one has two teeth associated with a permanent magnet (PM) installed between them. The static magnetic characteristics of a segmented HESRM and a conventional SRM, including flux distribution, phase flux linkage, electromagnetic torque, are analyzed and compared. The total fluxes created by the PM and by the excited current are strongly coupled. The details of mathematical model as well as dynamic performances of the segmented HESRM is derived and compared with the conventional SRM. Finally, a segmented HESRM and a conventional SRM of the same size are prototyped for experimental verification. From the comparative study, it is indicated that the segmented HESRM has better characteristics than the conventional SRM, such as less iron consumption, higher static and dynamic average torque production, lower torque ripple, higher power and torque densities, higher efficiency, and stronger starting capability. The measured results of static magnetic characteristic, steady-state and transient performances, and torque-speed characteristic of two SRM drives verify the finite-element analysis, modeling, and corresponding predictions.