scholarly journals Cogging Torque Reduction in PMSM in Wide Temperature Range by Response Surface Methodology

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1877
Author(s):  
Xiaoshuai Duan ◽  
Xinhua Zhang ◽  
Yongbin Tang ◽  
Minghui Hao
Keyword(s):  
Response Surface ◽  
Temperature Rise ◽  
Wide Temperature Range ◽  
Response Surfaces ◽  
Large Temperature ◽  
Operating Characteristics ◽  
Cogging Torque ◽  
Temperature Range ◽  
Output Torque ◽  
Different Temperatures

In this paper, a wide temperature range permanent magnet synchronous motor (PMSM) is designed, which can be used as the servo mechanism of an electric actuator in a missile. Considering the operating characteristics of the actuator with large environmental temperature change and large temperature rise, the magnetic material characteristics at different temperatures are analyzed, and the influence of eccentric magnetic poles on the cogging torque is deduced. In order to reduce cogging torque in a wide temperature range, the poles of the motor are optimized based on the response surface method. By utilizing temperature rise calculations, the scheme that may exceed the maximum working temperature of the material is eliminated. Then, the response surfaces of the cogging torque with pole arc coefficient, thickness and asymmetry at different temperatures are established, and the optimal value ranges of the three parameters are determined. The minimum upper limits of cogging torque and meeting the specified output torque at different temperatures are used as the judging criteria, and the optimal schemes for different working environments are determined. Finally, a prototype is developed, and the output torque is more than 10 N·m, and the cogging torque is less than 0.2 N·m in a wide temperature range.

scholarly journals Water Tree Propagation in a Wide Temperature Range: Insight into the Role of Mechanical Behaviors of Crosslinked Polyethylene (XLPE) Material

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 40
Author(s):  
Siyan Lin ◽  
Kai Zhou ◽  
Yuan Li ◽  
Pengfei Meng
Keyword(s):  
Yield Strength ◽  
Electric Field ◽  
Wide Temperature Range ◽  
Mechanical Behaviors ◽  
Field Force ◽  
Temperature Range ◽  
Water Tree ◽  
Different Temperatures ◽  
Tree Length ◽  
Electric Field Force

To understand the propagation characteristics of water trees at a wide temperature range, this paper presents the effect of mechanical behaviors on the sizes of water trees. An accelerated water tree aging experiment was performed at −15 °C, 0 °C, 20 °C, 40 °C, 60 °C, and 80 °C for crosslinked polyethylene (XLPE) specimens, respectively. Depending on the micro observations of water tree slices, water tree length is not always increasing with the increase in temperature. From 0 °C to 60 °C, water tree length shows a trend from decline to rise. Above 60 °C, water tree length continues to reduce. Dynamic mechanical analysis (DMA) shows that the glass transition temperature of the new XLPE specimen is about −5 °C, and the α-relaxation is significant at about 60 °C. With the increase in temperature, the XLPE material presents different deformation. Meanwhile, according to the result of the yield strength of XLPE at different temperatures, with the increase in temperature, the yield strength decreases from 120 MPa to 75 MPa, which can promote the water tree propagation. According to the early stage in the water tree propagation, a water tree model was constructed with water tree branches like a string of pearls to calculate electric field force. According to the results of electric field force at different expansion conditions, with the increase in temperature, due to expansion of the water tree branches, the electric field force at water tree tips drops, which can suppress the water tree propagation. Regardless of high temperature or low temperature, the water tree propagation is closely related to the mechanical behaviors of the material. With the increase in temperature, the increased deformation will suppress the water tree propagation, whereas the decreased yield strength will promote water tree propagation. For this reason, at different temperatures, the promotion or suppression in water tree propagation is determined by who plays a dominant role.

scholarly journals Plausibility of Early Life in a Relatively Wide Temperature Range: Clues from Simulated Metabolic Network Expansion

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 738
Author(s):  
Xin-Yi Chu ◽  
Si-Ming Chen ◽  
Ke-Wei Zhao ◽  
Tian Tian ◽  
Jun Gao ◽  
...  
Keyword(s):  
Metabolic Network ◽  
Wide Temperature Range ◽  
Early Life ◽  
Metabolic Networks ◽  
Network Expansion ◽  
Temperature Range ◽  
Reaction Thermodynamics ◽  
The World ◽  
Different Temperatures ◽  
Metabolic Reactions

The debate on the temperature of the environment where life originated is still inconclusive. Metabolic reactions constitute the basis of life, and may be a window to the world where early life was born. Temperature is an important parameter of reaction thermodynamics, which determines whether metabolic reactions can proceed. In this study, the scale of the prebiotic metabolic network at different temperatures was examined by a thermodynamically constrained network expansion simulation. It was found that temperature has limited influence on the scale of the simulated metabolic networks, implying that early life may have occurred in a relatively wide temperature range.

Fibre-optic temperature sensor with wide temperature range characteristics

1987 ◽  
Vol 134 (5) ◽  
pp. 291 ◽  
Author(s):  
K.T.V. Grattan ◽  
J.D. Manwell ◽  
S.M.L. Sim ◽  
C.A. Willson
Keyword(s):  
Wide Temperature Range ◽  
Temperature Sensor ◽  
Fibre Optic ◽  
Temperature Range

Study on characteristics of schottky temperature detector based on metal/n-ZnO/n-Si structures

2020 ◽  
Vol 12 ◽  
Author(s):  
Fang Wang ◽  
Jingkai Wei ◽  
Caixia Guo ◽  
Tao Ma ◽  
Linqing Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Response ◽  
Large Temperature ◽  
Mems Devices ◽  
Temperature Range ◽  
Response Characteristics ◽  
High Temperature Measurement ◽  
Temperature Detector ◽  
Schottky Structure

Background: At present, the main problems of Micro-Electro-Mechanical Systems (MEMS) temperature detector focus on the narrow range of temperature detection, difficulty of the high temperature measurement. Besides, MEMS devices have different response characteristics for various surrounding temperature in the petrochemical and metallurgy application fields with high-temperature and harsh conditions. To evaluate the performance stability of the hightemperature MEMS devices, the real-time temperature measurement is necessary. Objective: A schottky temperature detector based on the metal/n-ZnO/n-Si structures is designed to measure high temperature (523~873K) for the high-temperature MEMS devices with large temperature range. Method: By using the finite element method (FEM), three different work function metals (Cu, Ni and Pt) contact with the n-ZnO are investigated to realize Schottky. At room temperature (298K) and high temperature (523~873K), the current densities with various bias voltages (J-V) are studied. Results: The simulation results show that the high temperature response power consumption of three schottky detectors of Cu, Ni and Pt decreases successively, which are 1.16 mW, 63.63 μW and 0.14 μW. The response temperature sensitivities of 6.35 μA/K, 0.78 μA/K, and 2.29 nA/K are achieved. Conclusion: The Cu/n-ZnO/n-Si schottky structure could be used as a high temperature detector (523~873K) for the hightemperature MEMS devices. It has a large temperature range (350K) and a high response sensitivity is 6.35 μA/K. Compared with traditional devices, the Cu/n-ZnO/n-Si Schottky structure based temperature detector has a low energy consumption of 1.16 mW, which has potential applications in the high-temperature measurement of the MEMS devices.

Enabling highly reversible sodium metal cycling across a wide temperature range with dual-salt electrolytes

2021 ◽  
Author(s):  
Akila C. Thenuwara ◽  
Pralav P. Shetty ◽  
Neha Kondekar ◽  
Chuanlong Wang ◽  
Weiyang Li ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
High Energy ◽  
Liquid Electrolyte ◽  
Metal Cycling ◽  
Temperature Range ◽  
Sodium Metal ◽  
Wide Range

A new dual-salt liquid electrolyte is developed that enables the reversible operation of high-energy sodium-metal-based batteries over a wide range of temperatures down to −50 °C.

Magnetic anomalies, chemical and magnetic properties at wide temperature range (15–1000 K) in LiSrxFe5-xO8 (x = 0, 0.025, 0.05)

2021 ◽  
Vol 859 ◽  
pp. 158290
Author(s):  
S. Udhayakumar ◽  
G. Jagadish Kumar ◽  
E. Senthil Kumar ◽  
M. Navaneethan ◽  
K. Kamala Bharathi
Keyword(s):  
Magnetic Properties ◽  
Wide Temperature Range ◽  
Magnetic Anomalies ◽  
Temperature Range
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