A differential operation principle of the automatic bus transfer system pickup unit as a way of decreasing the emergency clearing time.a

A proper choice of the design and operation algorithm of emergency control devices like high-speed bus transfer (HSBT) is only possible proceeding from a study and analysis of steady-state and transient processes in emergency modes of operation (short-circuit faults, power supply disconnection, or phase open-circuit fault). The numerical experiments for studying such modes that were carried out, using the Matlab Simulink software package, on the mathematical models of an industrial power supply system involving synchronous motors connected to it made it possible to synthesize a new differential HSBT pickup unit featuring a high-speed response to emergency events. In doing so, special attention was paid to an analysis of transient operation modes with the aim of minimizing the probability of false actuations. The obtained study results have found practical application in the HSBT devices installed at the facilities of PJSC MOSENERGO. The experience gained from the operation of a new device jointly with high-speed circuit breakers produced by the Tavrida-Elektrik state-owned corporation has demonstrated essential advantages in comparison with the conventional HSBT designs.

Characteristic Analysis and Experimental Verification of Electromagnetic and Vibration/Noise Aspects of Fractional-Slot Concentrated Winding IPMSMs of e-Bike

In this study, we performed the electromagnetic and mechanical characteristic analyses of an 8-pole 12-slot interior permanent magnet synchronous motor (IPMSM). Permanent magnet synchronous motors are classified into surface permanent magnet synchronous motor and interior permanent magnet synchronous motors according to the type of rotor. The IPM type is advantageous for high-speed operation because of the structure where the permanent magnet is embedded inside the rotor, and it has the advantage of having a high output density by generating not only the magnetic torque of the permanent magnet, but also the reluctance torque. However, such a motor has more vibration/noise sources than other types, owing to changes in reluctance. The sources of motor noise/vibration can be broadly classified into electromagnetic, mechanical, and aerodynamic sources. Electromagnetic noise sources are classified into electromagnetic excitation sources, torque pulsations, and unbalanced magnetic forces (UMFs). Vibration and noise cause machine malfunctions and affect the entire system. Therefore, it is important to analyze the electromagnetic vibration source. In this study, the electromagnetic characteristics of an IPMSM were analyzed through the finite element method to derive the UMF. Vibration and noise analyses were performed by electromagnetic–mechanical coupling analysis, and vibration and noise characteristics based on electromagnetic noise sources were analyzed.

Control algorithm to improve the vibronoise characteristics of synchronous multi-phase magnetoelectric electric drive

Vibrations and noises occur during the operation of synchronous motors. To reduce them, more advanced engine designs and special control algorithms are used. The application of a multiphase (m > 3) synchronous motor design allows you to influence the configuration of the magnetic field in a wider range. Thus, the task to develop a control algorithm that improves the vibration-noise characteristics of a multiphase motor is relevant. The finite element method is used to calculate the magnetic field in a 2D formulation, implemented in the Elcut software package. Also, the simulation methods with the MatLab Simulink package are applied. The authors suggest the algorithm to control multiphase synchronous motors with permanent magnets that reduces the level of vibrations. Improvement of vibration-noise characteristics is achieved when the motor is supplied with currents of the certain form, and they compensate the pulsation of electromagnetic forces that occur between various parts of the electric machine. This algorithm is based on the measurement of the electromagnetic forces and the torque directly in the process of control. The results of modeling the operation of the engine with the developed control algorithm are presented. The authors have compared the characteristics obtained using the developed control algorithm and the characteristics that correspond to the sinusoidal source supply. The vibration-noise characteristics of a permanent magnet synchronous motor can be improved by using the control system. This control system generates currents in an appropriately synthesized form. In this case, the power consumption will increase slightly.

SIMULATION OF STARTING MODES OF SYNCHRONOUS ELECTRIC DRIVE OF A PUMP STATION

The article studies the starting modes of a synchronous electric drive of a pumping station, in direct and soft start of high-voltage synchronous motors of an irrigation pumping station of the first stage. The analysis of negative starting factors of synchronous machines is made on the basis of computer modeling of the research object. The simulation results are clearly shown for the main parameters of a synchronous electric drive, such as its rotation speed, stator currents, electromagnetic torque on the shaft, etc.

Teeth Arrangement and Pole–Slot Combination Design for PMLSM Detent Force Reduction

This paper introduces and investigates a new design method that employs both teeth arrangement and pole–slot combination to reduce the detent force of permanent magnet linear synchronous motors (PMLSMs) for precision position control. The proposed topology is a 10-pole, 12-slot-based PMLSM comprising two sections that significantly reduce the detent force without implementing a skewing design. It was analytically and experimentally confirmed that the proposed design effectively reduces detent force with a negligible sacrifice of mover length. The general characteristics and servo performance of the proposed PMLSM were experimentally examined and then discussed.

Review of air-cooling strategies, combinations and thermal analysis (experimental and analytical) of a permanent magnet synchronous motor

This paper gives a brief review of advanced cooling methods and applications to the permanent magnet synchronous motors (PMSMs), as well as investigates the cooling systems design problem for PMSM systems. Heat sources and losses together with analytical and practical analyses are described. Next, the temperature distribution and its influence on the PMSM is investigated using simulation results. The main part of the paper includes a review of the proposed cooling methods that will release the requirement of heat transfer of the PMSM. The finite element methods (FEM) are applied using the AnSys CFD software to obtain high accuracy thermal model of the PMSM system. The new developed forced air-cooling methods are given in details, which enable to effectively redistribute the temperature and heat transfer increasing the efficiency of the PMSM machine. Examples of CFD simulation are outlined to illustrate the effectiveness and benefits of the strategies developed.

Disturbance-Observer-Based U-Control (DOBUC) for Nonlinear Dynamic Systems

U-model, which is a control-oriented model set with the property of generally facilitate nonlinearity dynamic inversion/cancellation, has been introduced to the Disturbance Observer-Based control (DOBC) methods to improve the performance of the nonlinear systems in this paper. A general DOB based U-Control (DOBUC) framework is proposed to improve the disturbance attenuation capability of U-controller for both linear and nonlinear systems combined with (based on) the U-model-based dynamic inversion which expands the classical linear disturbance observer control to general nonlinear systems. The proposed two-step DOBUC design procedures in which the design of DOB and U-controller are totally independent and separated, enables the establishment of global exponential stability without being subject to disturbances and uncertainties. Comparative simulation experiments with Nonlinear DOBC in controlling Wind Energy Conversion Systems (WECS) and Permanent Magnet Synchronous Motors (PMSM) demonstrated the proposed method.