The paper treats of correcting calculation errors of the BLDC motor speed, based on the time elapsed between successive changes in the shaft position sensor signal. The developed method enables correction of errors of the deployment of sensors as well as rotating elements of the observation system of the motor shaft position. The correction algorithm performance was analysed with the aid of a model implemented in Matlab-Simulink environment. After confirming usefulness of the developed method through simulation, its usefulness was verified in real closed-loop feedback systems with a BLDC motor. The results of measurements carried out at the developed laboratory station are presented.
Permanent magnet motors are more and more frequently used in various applications. In this group motors with a trapezoidal EMF deserve a special attention. They are characterized by a simple construction, high efficiency and high torque overload. A certain drawback of BLDC motors are difficulties with an operation at a speed above the nominal value. The article presents the results of investigations into the variablestructure electronic commutator designed for the drive of a small electric vehicle equipped with BLDC motors. Such a solution allows extending the standard range of the drive's speed. The considerations contained in the article focus on the possibilities and effects of regeneration mode in the proposed topology of converter. A theoretical analysis has been presented as well as computer simulations carried out by means of Matlab- Simulink, which were then verified at a laboratory. The tests were finished with trias conducted using a small electric vehicle Elipsa.
This research presents the novel control strategy of the brushless DC motor. The optimal current driver is designed using Linear Quadratic Regulator and feedback linearization. Additionally, the current reshaping strategy is applied to control the motor torque. Thus, the torque controller is built based on the optimal current driver. The motor is simulated using the FEM analysis.
This paper considers a Brushless Direct Current (BLDC) machine prototype with six poles and 36 stator slots including a three phase double-layered distributed winding. Presented modifications of rotor construction are identified in order to achieve the best possible compromise of eddy-current losses and cogging torque characteristics. The permanent magnet (PM) eddy-current loss is relatively low compared with the iron loss; it may cause significant heating of the PMs due to the relatively poor heat dissipation from the rotor and it results in partial irreversible demagnetization. A reduction in both losses is achieved by magnet segmentation mounted on the rotor. Various numbers of magnet segmentation is analysed. The presented work concerns the computation of the no-load iron loss in the stator, rotor yoke and eddy-current loss in the magnets. It is shown that the construction of the rotor with segmented magnets can significantly reduce the PM loss (eddy-current loss). The eddy-current loss in PMs is caused by several machine features; the winding structure and large stator slot openings cause flux den sity variations that induce eddy-currents in the PMs. The effect of these changes on the BLDC motor design is examined in order to improve the machine performance. 3-D finite-element analysis (FEA) is used to investigate the electromagnetic behaviour of the BLDC motor.
This paper presents a simplified modeling, simulation and Experimental analysis of permanent magnet brushless dc motors (PMBLDC) for sensorless operation. This model provides a mechanism for monitoring and controlling of voltage, current, Speer and torque. The sensorless scheme employs direct back emf based zero crossing detection for controlling the dynamic characteristics.
The distortion of air gap magnetic field caused by the rotor eccentricity contributes to the electromechanical coupling vibration of the brushless DC (BLDC) permanent magnet in-wheel motor (PMIWM) in electric vehicles (EV). The comfort of the BLDC in-wheel motor drive (IWMD) EV is seriously affected. To deeply investigate the electromechanical coupling vibration of the PMIWM under air gap eccentricity, the PMIWM, tyre and road excitation are analyzed first. The influence of air gap eccentricity on air gap magnetic density is investigated. The coupling law of the air gap and the unbalanced magnetic force (UMF) is studied. The coupling characteristics of eccentricity rate, air gap magnetic density, UMF, phase current and vibration acceleration are verified on the test bench in the laboratory. The mechanism of the electromechanical coupling vibration of the BLDC PMIWM under air gap static eccentricity (SE), dynamic eccentricity (DE) and hybrid eccentricity (HE) is revealed. DE and HE deteriorate the vibration acceleration amplitude, which contributes the electromechanical coupling vibration of the PMIWM. The research results provide a solid foundation for the vibration and noise suppression of the PMIWM in distributed drive EV.
In order to develop a PM BLDC motor control system, which will be tolerant of selected faults, simulation work was first performed and then verified on a universal test stand. The results were published in earlier works. The next stage of works was the implementation of previously developed algorithms on the target research test stand – in this case, the prototype vehicle. This last stage of the laboratory work has been presented in this article, i.e. it has been presented the results of experimental research related to the reproduction of rotor angle position, used after the detection of a rotor position sensor fault. A new test stand with the laboratory prototype of a vehicle with two PM BLDC motors is presented. A zeroth-order algorithm (ZOA) was used as a fault compensation method. The effectiveness and usefulness of the previously proposed methods have been confirmed.