PIER B | PIER Journals

2024-11-21

PIER B

Vol. 109, 57-67, 2024

download: 7

Analysis of Eddy Current Losses and Stresses in High-Speed Permanent Magnet Synchronous Motors with Frameless Torque

Xiping Liu , Haiao Sun , Zhangqi Liu and Canwei Zhang

In this paper, a high-speed frameless torque permanent magnet synchronous motor is designed to determine the optimal structure of the rotor by comparing the air gap magnetism, cogging torque and output torque of the motor through finite element analysis. The effects of different material rotor sheaths on eddy current loss are compared and analyzed, and the copper shield is used to optimize the rotor eddy current loss of the high-speed frameless torque motor. Through the analytical method, based on the theory of thick-walled cylinder, the stress calculation is carried out on the multilayer rotor structure of the high-speed permanent magnet synchronous motor with copper shielding layer, and a comparative analysis is carried out with the simulation results to verify the validity of the analytical calculations and the reasonableness of the optimization of the rotor eddy current loss.

Analysis of Eddy Current Losses and Stresses in High-speed Permanent Magnet Synchronous Motors with Frameless Torque

2024-11-19

PIER B

Vol. 109, 41-56, 2024

doi:10.2528/PIERB24070604

download: 31

Design of F-Shaped Parasitic MIMO Antenna with DGS for Vehicle-to-Everything Communication

Maruti R. Jadhav and Uttam L. Bombale

Multiple-Input Multiple-Output (MIMO) antennas are essential for transmitting and receiving information in Vehicle to Everything (V2X) communication. However, the MIMO antenna designs at V2X are complex because of the mutual coupling problem. Several approaches have been designed to improve antenna isolation. However, these approaches have drawbacks like gain, bandwidth, and radiation efficiency reductions. This work introduces a compact four-port MIMO antenna that operates at a 5.85 GHz to 5.9 GHz frequency range for V2X communication. Here, the slotted circular microstrip patch MIMO antenna is considered. The antenna's length, width, and patch are optimized by metaheuristic optimization called Aquila Optimization (AO). A substrate Rogers RT5880, which has a defected ground structure (DGS) and a parasitic patch, is used to design the antenna. F-shaped parasitic elements are placed near each antenna element to improve isolation. The DGS with a U-shaped parasitic element minimizes the mutual coupling among the adjacent antenna elements. The considered overall dimension has a compact size, and it achieves better envelope correlation coefficient (ECC < 0.5), total active reflection coefficient (TARC < -10 dB), diversity gain (DG > 9.9 dB), channel capacity loss (CCL < 0.4), and mean effective gain (MEG < 3 dB) at 5.88 GHz. Hence, it is proposed that the developed design is useful for applying V2X communications.

Design of F-shaped Parasitic MIMO Antenna with DGS for Vehicle-to-everything Communication

2024-11-16

PIER B

Vol. 109, 29-40, 2024

doi:10.2528/PIERB24092103

download: 42

Design and Optimization of Series-Connected Hybrid Excitation Permanent Magnet Synchronous Motor

Jianwei Liang , Tian Song , Peiyao Guo , Xiubin Zhu , Zhangsheng Liu and Yuqian Zhao

To address the problems that the traditional permanent magnet synchronous motor air-gap flux is difficult to adjust and that the weak magnetic speed expansion ability is poor, a new series-connected hybrid excitation permanent magnet synchronous motor is proposed. A DC excitation winding is added to the rotor, allowing the excitation field generated by this winding to form a series connection with the magnetic field of the permanent magnets. The structure of this paper includes an overview of the novel rotor structure and principle of operation. For the complex rotor structure, a multi-objective genetic algorithm is used for optimisation, followed by finite element analysis to compare the performance of the initial motor, the optimised motor and the conventional motor in terms of no-load air-gap magnetism, reverse electromotive force as well as output torque and efficiency. The magnetic load of the motor in the demagnetized state is increased from 0.2 to 0.266 compared to the unexcited state, and the magnetization capacity is improved by 33%. The output torque of the optimized motor is 252 N.m at low speed; the output torque of the conventional motor is 220 N.m; and the starting torque of the motor is improved by 14.5%. The maximum speed is increased from 10,000 rpm to 11,500 rpm, and the speed expansion capacity is improved by 15%. The effectiveness and feasibility of the series-connected hybrid excitation permanent magnet synchronous motor are verified.

Design and Optimization of Series-connected Hybrid Excitation Permanent Magnet Synchronous Motor

2024-11-11

PIER B

Vol. 109, 17-28, 2024

doi:10.2528/PIERB24091803

download: 110

A Low-Profile Single-Layered Wideband Combinational Reconfigurable Antenna for 4G and 5G Applications

Sweta Agarwal , Akanksha Singh and Manoj Kumar Meshram

A single-layered monopole wideband combinational reconfigurable antenna for 4G and 5G applications is presented in this paper. Coplanar waveguide (CPW) feeding method is utilized to get single-layered structure. The three characteristics of this antenna are reconfigurable: frequency, polalization, and radiation pattern. This antenna consists of a parasitic element attached to a rectangular ring antenna. An RF-PIN diode is used to connect this parasitic element to the loop antenna. Additionally, two parasitic elements are connected to the ground plane of the proposed antenna via a pair of RF-PIN diodes. The suggested antenna functions in seven distinct states with the use of these three RF-PIN diodes. The suggested antenna operates at frequencies of 3.24-3.52 GHz, 2.78-2.94 GHz, and 2.54-2.9 GHz with an omnidirectional radiation pattern in states 1, 2, and 5. In states 3 and 4, it has an end-fire radiation pattern in the left and right directions of the proposed antenna, covering a wide frequency band of 2.47-3.57 GHz. Lastly, the suggested antenna operates in dual bands at frequencies of 2.49–2.9 GHz and 3.6-3.76 GHz in states 6 and 7. It offers reconfigurability of polarization at the higher band. The suggested antenna is made of glass epoxy FR-4. For verification of the suggested antenna, the prototype is designed and tested. The simulated and experimental results agree quite well.

2024-10-26

PIER B

Vol. 109, 1-16, 2024

doi:10.2528/PIERB24090305

download: 71

Ultrawideband High-Gain Stacked Microstrip Antenna with Modified E-Shaped Active Exciter and Four Single-Sided Bowtie Passive Elements

Mikhail S. Shishkin

The article presents a method that allows for the high gain of a stacked microstrip antenna on an air substrate in an ultrawide frequency range. The method uses an active exciter in the form of a modified E-shaped patch, as well as four single-sided bowtie passive elements placed in the corners above the active one. The active element can match an antenna in an ultra-wide frequency range (up to 100%) with an impedance bandwidth matching of 10 dB or better, whereas passive elements are able to produce unidirectional radiation in the range of approximately 70-80% with a gain of more than 10 dBi. Based on the method under study, an ultrawideband antenna design was made which operates in a frequency band of 3,915 to 11,046 MHz (95.3%) with an impedance bandwidth matching of 10 dB and a bandwidth about 83% with |S₁₁| ≤ -15 dB; the usable bandwidth with a gain of more than 10 dBi in the normal direction to the antenna plane with a cross-polar discrimination more than 55 dB is 77% (3,925-8,837 MHz). At frequencies below 4 GHz and above 9 GHz, the phase center shifts, and accordingly, the main lobe of the radiation pattern (radiation maximum) deflects. All antenna elements (one active and four passives) are made of sheet metal (e.g., stainless steel) and are connected to the conductive screen by steel or dielectric racks. The antenna dimensions are 1.05λ_max × 1.2λ_max × 0.1λ_max (1.7λ₀ × 1.9λ₀ × 0.2λ₀). Owing to its high performance, the antenna may be used as a measuring device in radio monitoring systems or in laboratories.