Figure 2 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Diagram of a three-phase inverter with a DC breaker for the excitation winding, where '1,2,3' are numbers of the phases of the SHM armature winding.
Source publication
Brushless synchronous homopolar machines (SHM) have long been used as highly reliable motors and generators with an excitation winding on the stator. However, a significant disadvantage that limits their use in traction applications is the reduced specific torque due to the incomplete use of the rotor surface. One possible way to improve the torque...
Context in source publication
Similar publications
Electric machines with hybrid excitation have increased torque density while maintaining a wide range of speed control. This article presents the results of the optimal design of a synchronous homopolar generator (SHG) with ferrite magnets on the rotor and excitation winding on the stator for passenger cars. The use of ferrite magnets on the rotor...
Due to the high cost and the predicted shortage of rare earth elements in the near future, the task of developing energy-efficient electric machines without rare earth magnets is of great importance. This article presents a comparative analysis of optimized designs of a ferrite-assisted synchronous reluctance machine (FaSynRM) and a ferrite-assiste...
Citations
... The optimization function incorporates objectives such as weighted average electric losses evaluated over the cycle, with the weight coefficients wi determined using the trapezoid quadrature formula to calculate the portion of the area under the graph shown in Fig. 2. The weight coefficients wi calculation for operating points 1,2,3,4,5 when the coasting mode is not taken into account is given in [22]. If coasting occupies 50% of the time required for travel between stations, the weight coefficients are calculated as: ...
... The selection of the armature winding's turn number Nse is determined such that VDC rated = max(Vi/ki) [22]. In the process of electric motor development, it becomes crucial to acknowledge the discrete nature of specific parameters. ...
... In the process of electric motor development, it becomes crucial to acknowledge the discrete nature of specific parameters. This includes factors like the number of turns Nsec within the armature winding coil, as well as the standardized dimensions of rectangular wire width and height as defined in [22]. However, this particular study takes a departure from treating these values discretely and permits them to encompass positive real values, with the aim of delivering a more unbiased evaluation. ...
Nowadays rare-earth magnets available in the market are limited, while demand for them is increasing, therefore development of electrical machines without magnets of this type becomes extremely important. Simultaneously, synchronous machines without magnets have poorer torque to weight and torque to volume characteristics compared to machines equipped with magnets. The compromised solution is usage of cheap ferrite magnets as a source of auxiliary machine flux. However, the most serious disadvantage of ferrite magnets is the possibility of unrecoverable demagnetization. In order to solve the abovementioned problem this paper proposes a novel design of ferrite assisted synchronous homopolar motor (FASHM), which is equipped with magnets of special shape, resulting in higher resistivity to demagnetization. This research provides theoretical analysis of working characteristics of the motor of proposed design, developed for subway train, and compares them with the characteristics of the motor without the proposed design features. The FEM modelling demonstrates that the proposed design is superior to the existing solution. It has higher resistivity to unrecoverable demagnetization of the ferrite magnets, consumed current and power loss are decreased, the mass of motor and price of the magnets are reduced.
... The experimental motor is a pre-production prototype of an IPMSM, which was developed for automotive compressors. It was developed while prioritizing reliability and cost efficiency, with the help of recommendations provided in [46][47][48]. The motor parameters are provided in Table 1, and it should be noted that the motor inductances and rotor flux are almost stable and vary less than 5% in the whole operational range. ...
In recent decades the market share of electrical cars has increased significantly, which has paved the way for the development of automotive electronics. Some of the most important parts of modern electrical vehicles are motor drives, which are used in car training and mechanization. Electrical drives are used in powertrains for traction, in air conditioning systems to cool cars and their parts, in doors for opening/closing as well as window movements, etc. The most popular motor type in electrical vehicles is synchronous motors with permanent magnets, which are compact and provide high torque. However, these motors require the development of control systems for proper operation. This system has to have the capacity to implement several state-of-the-art techniques, which can fully utilize motor potential, increase its efficiency, and decrease battery usage. One of these techniques is field-weakening, which overcomes speed limitations due to a lack of supply voltage and increases the motor’s speed operation range. This paper discusses the most popular approaches to field-weakening, including a new method proposed by the author. It considers both the pros and cons of each approach and provides recommendations for their usage. After that, this manuscript demonstrates the experimental results of each field-weakening technique obtained in the same motor drive, compares their performance, and discusses their strengths and weaknesses. Finally, the experimental part demonstrates that the proposed field-weakening approach demonstrates similar dynamics in load transients but provides 10 times less load to the microcontroller.
... The utilization of ferrite magnets proves advantageous due to their significantly lower cost compared to rare-earth magnets and their widespread production across numerous countries worldwide [14,15]. ...
... In addition, ferrite magnets have no losses due to eddy currents and high-temperature strength [14,16]. A challenge of using ferrites in motor design is their low coercive force [14,17]. ...
... In addition, ferrite magnets have no losses due to eddy currents and high-temperature strength [14,16]. A challenge of using ferrites in motor design is their low coercive force [14,17]. For this reason, when optimizing motors with ferrite magnets, special attention must be paid to limiting irreversible demagnetization. ...
Due to the high cost and the predicted shortage of rare earth elements in the near future, the task of developing energy-efficient electric machines without rare earth magnets is of great importance. This article presents a comparative analysis of optimized designs of a ferrite-assisted synchronous reluctance machine (FaSynRM) and a ferrite-assisted synchronous homopolar machine (FaSHM) in a 370-kW subway train drive. The objectives of optimizing these traction machines are to reduce their losses, maximum armature current, and torque ripple. The optimization considers the characteristics of the machines in the subway train moving cycle. The problem of the risk of irreversible demagnetization of ferrites in the FaSynRM and FaSHM is also considered. To reduce the computational burden, the Nelder-Mead method is used for the optimization. It is shown that the FaSHM demonstrates better field weakening capability, which can reduce the maximum current, power, and cost of the inverter power modules. At the same time, the FaSynRM requires less permanent magnet mass for the same torque density and is more resistant to irreversible demagnetization, which can reduce costs and improve the reliability of the electric machine.
... The compressor motor is an IPMSM type designed with the priority to cost optimization as recommended in [30]- [32]. Parameters of the motor are demonstrated in Table I. ...
