Efficiency Optimization of Variable Iron Loss Resistance Asynchronous Motor Based on Grey Wolf Optimization Algorithm

Guo Zhen,Tong Di,Zhao Yan-cheng,Chen Shuang,Nai Ji-qiu,Ye Ming-hao 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1

Asynchronous motor is widely used in various industrial fields. When asynchronous motor works in case close to the rated load, it will run at maximum efficiency. However, most of the load is 50–100% of rated load and it will lead to the serious waste of energy. This paper proposes an efficiency optimization control strategy based on the grey wolf optimization algorithm to improve the operating efficiency of asynchronous motors at light loads. The motor loss model considering the change of iron loss is established and it makes the asynchronous motor model more accurate. The grey wolf optimization algorithm is used to find the optimized flux value. When the asynchronous motor operates at the optimal flux, the loss power of the motor is decreased and the operation efficiency improves effectively. The proposed method reduces the flux search time and improves the stability of the system. The simulation model is established and the simulation results are provided to verify the feasibility of the proposed control strategy achieving the global efficiency optimum of asynchronous motor.

The relationship between bacterial diversity and organic carbon mineralization in soft rock and sand compound soil

Guo Zhen,Li Juan,Ge Lei,Yang Chenxi,Han Jichang 한국미생물학회 2020 The journal of microbiology Vol.58 No.9

The soil organic carbon (SOC) mineralization rate in sandy soil plays an important role in improving soil quality, and a research is needed to determine management practices that optimize the mineralization rate. When sandy soil is improved by adding soft rock, the specific promotion process of bacterium to SOC mineralization remain unclear. To investigate these mechanisms, we selected four treatments with soft rock to sand volume ratios of 0:1 (CK), 1:5 (C1), 1:2 (C2) and 1:1 (C3) to study. The mineralization rate of organic carbon was measured using the lye absorption method. Highthroughput sequencing and scanning electron microscopy were used to determine the bacterial community structure and soil microstructure, respectively. The results showed that the organic carbon content of the sandy soil increased significantly (182.22–276.43%) after using the soft rock treatments. The SOC mineralization rate could be divided into two stages: a rapid decline during days 1–8 and a slow decline during days 8–60. With increased incubation time, the intensity of the cumulative release of organic carbon gradually weakened. Compared with the CK treatment, the SOC mineralization accumulation (Ct) and the potential mineralizable organic carbon content (C0) in the C1, C2, and C3 treatments increased significantly, by 106.98–225.94% and 112.22– 254.08%, respectively. The cumulative mineralization rate (Cr) was 18.11% and 21.38% smaller with treatments C2 and C3, respectively. The SOC mineralization rate constant (k) decreased significantly after the addition of soft rock, while the half-turnover period (Th) changed inversely with k. Compared with the CK treatment, the number of gene copies of the soil bacteria increased by 15.38–272.53% after adding soft rock, with the most significant increase in treatment C3. The bacterial diversity index also increased significantly under treatment C3. The three dominant bacteria were Proteobacteria, Actinobacteria, and Chloroflexi. The correlation between Cr and one of the non-dominant bacteria, Firmicutes, was large, and the bacteria had a significant positive correlation with k. At the same time, the abundance of Firmicutes under treatments C2 and C3 was small. As the proportion of soft rock increased, the soil particles changed from point contact to surface contact, and the adhesion on the surface of the particles gradually increased. Results from this study show that the retention time of SOC can be increased and the carbon sequestration effect is better when the ratio of soft rock to sand is set to 1:2.

Fatigue Life Estimation of Cold Drawn Contact Wire

Guo, Zhen,Kim, Yong-Seok,Hong, Suk-Woo,Li, Hao-Chuang,Koo, Jae-Mean,Seok, Chang-Sung,Lee, Ki-Won,Kwon, Sam-Young Korean Society for Precision Engineering 2014 International Journal of Precision Engineering and Vol.15 No.11

To evaluate the bending fatigue characteristics of contact wire, a stroke-based bending fatigue tester on contact wire has been developed by Kang et al. But this tester is too cumbersome and complicated. This paper is investigated with a new fatigue life estimation method based on Juvinall's method for estimation of S-N curve, which is widely used in steel structure, in order to estimate the bending S-N curve of cold drawn contact wire. First, the ultimate tensile strength and the axial tension fatigue test was performed with standard specimens, and the bending fatigue life for the cold drawn contact wire structure was predicted by using an improved S-N curve prediction method. Finally, the tested bending fatigue life of the structure was compared with the fatigue life estimated by the new method. As the result, the predicted bending S-N curve of the contact wire agreed fairly well with the experimental bending fatigue lives using the S-N curve and ultimate tensile strength of cold drawn material.

Bending Fatigue Life Evaluation of Cu-Mg Alloy Contact Wire

Guo Zhen,석창성,김용석,Li Haochuang,구재민,이기원,권삼영 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.7

Contact wire is one of the most important components used to supply electricity to railway vehicles which equipped with apantograph. When the speed of electric vehicle is not as high as now, the failure of contact wire caused by friction and wear behaviorsof carbon strip/contact wire were considered more important. But the fatigue fracture become more and more important for the failureof contact wires on account of several fatigue fractures happened while the speed of electric vehicle increase continuously. A bendingfatigue tester simulating the working conditions of contact wires developed by Kang and etc has been used to evaluate the fatiguecharacteristic of pure copper and Cu-Sn alloy contact wires. In this study, this bending fatigue tester also is used to evaluate thefatigue characteristics of Cu-Mg alloy contact wire which developed for 400km/h high speed rail in Korea. Test result is alsocompared with the result of Kang's research on pure copper contact wire. Finally, in order to evaluate the fatigue life of contact wiresfor any mean stress, the relationships between plastic strain and fatigue life were abstained for two kinds of contact wires combinedthe FE analysis.

Power Sharing Strategy of A Series-parallel-connected EV Charger

Guozhen Hu,Huang Lei,Xuejun Ma,Guorong Zhu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In order to meet different requirements of rechargeable batteries in Electric vehicles, a charger with hybrid structure, which designed as module and combined in series and parallel, was proposed in this paper. Each individual module uses ZCS phase-shifted full-bridge converters. And in order to ensure power sharing of each module, the outer loop power control strategy based on average current sharing method has been adopted. A combination prototype was built following the proposed strategy. Experimental results verify the correctness of the proposed scheme and the performance of power sharing system can meet the charging application.

Extraction of parishin B and parishin C from Gastrodiae Rhizoma by subcritical water technology

Guozhen Wu,Hongjing Dong,Jia Li,Lanping Guo,Yan Cheng,Yanling Geng,Xiao Wang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

Subcritical water extraction (SWE) was used to extract bioactive parishin B (PB) and parishin C (PC) fromGastrodiae Rhizoma. Extraction conditions were optimized by Box-Behnken design (BBD) of responsesurface methodology (RSM). The highest yield of PB was 7.46 ± 0.18 mg/g when the solid/liquid ratio(SLR) was 4.5 mg/mL at an extraction temperature of 118 C and extraction time of 50 min, and the highestyield of PC was 5.27 ± 0.07 mg/g when the SLR was 22 mg/mL at an extraction temperature of 145 Cand extraction time of 23 min. Compared with heating reflux extraction the yield of PB was about 1.3times higher, and that of PC about 2.6 times higher; Compared with ultrasound assisted extraction theyield of PB was about 3 times higher, and that of PC about 6 times higher. Degradation of parishin Aby SWE showed that the increasing mechanism of PB and PC mainly attributed to the conversion of PAinto PB and PC. This study suggests that SWE was an efficient and green way to extract natural productswith greater values.

New Active Damping Strategy for LCL-Filter-Based Grid-Connected Inverters with Harmonics Compensation

Guozhen Hu,Changsong Chen,Duan Shanxu 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.2

The use of LCL filters in pulse width modulation voltage source converters is a standard solution for providing proper attenuation of high-order grid-current harmonics. However, these filters can cause the undesired effect of resonance. This paper proposes an active damping strategy with harmonics compensation. It can alleviate the harmonics around the resonance frequency caused by the LCL filters. The proposed strategy is attractive since it is simple, does not depend on grid parameters and does not increase the number of sensors. Simulation and experimental results verify the effectiveness of the proposed active damping strategy.

樟樹葯業信仰初探

Guozhen Qiu 국제아세아민속학회 1997 아세아민속연구 Vol.1 No.-

SPH simulation of solitary wave interaction with coastal structures

Cai, Guozhen,Luo, Min,Wei, Zhaoheng,Khayyer, Abbas Techno-Press 2022 Ocean systems engineering Vol.12 No.3

This paper adopts the Smoothed Particle Hydrodynamics (SPH) open-source code SPHinXsys to study the solitary wave interaction with coastal structures. The convergence properties of the model in terms of particle size and smoothing length are tested based on the example of solitary wave propagation in a flat-bottom wave flume. After that, the solitary wave interactions with a suspended submerged flat plate and deck with girders are studied. The wave profile and velocity field near the surface of the structures, as well as the wave forces exerted onto the structures are analyzed.

The Effect of Garden Path Technique of Grammar Instruction on Learning Relative Clauses

Yin Guozhen,Sun Wei,Shin Yousun 21세기영어영문학회 2023 21세기영어영문학회 학술대회 Vol.2023 No.4