Predictive direct torque control of permanent magnet synchronous motors using deadbeat torque and flux control

Ao Wang,Housheng Zhang,Junjie Jiang,Duo Jin,Shengjie Zhu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.2

In consideration of the shortcomings of the large torque and flux ripples in direct torque control (DTC), and the insufficient utilization of the duty cycle module in traditional DTC based on the duty cycle modulation of PMSMs, a DTC method based on deadbeat control of the torque and flux is proposed in this paper. In the synchronous rotation, coordinate system positioned with the stator flux vector, the reference voltage vector is calculated in accordance to the deadbeat control method. Six virtual voltages are constructed in such a manner that two adjacent basic voltage vectors are evenly divided in one control cycle. The effective voltage vectors are expanded to 12. The effective voltage vector closest to the phase angle of the reference voltage vector is determined to be the optimal voltage vector. Then, the duty cycle is introduced to further reduce the error between the final output voltage vector and the voltage vector required by the system. Simulation comparisons are carried out for DTC, traditional DTC based on duty cycle modulation, and the proposed DTC. The obtained simulation results demonstrate that the proposed DTC can effectively suppress both torque ripple and flux ripple, improve the utilization rate of the duty cycle module, and reduce the stator current distortion rate.

Resolving the Landauer paradox in ferroelectric switching by high-field charge injection

Jiang, An-Quan,Lee, Hyun Ju,Hwang, Cheol Seong,Tang, Ting-Ao American Physical Society 2009 Physical review. B, Condensed matter and materials Vol.80 No.2

Structurally ordered nanofiltration membranes prepared by spatially anchoring interfacial polymerization for highly efficient separation properties

Ao Sheng,Hao Wang,Haoji Jiang,Yaxin Zhao,Hao Li,Hao Jia,Zhong Wei,Heyun Wang 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.9

The incorporation of various nanofillers into the interfacial polymerization (IP) process is widely applied to prepare higher performance NF membranes. However, few studies have reported the influence of nanofillers on nanocomposite membrane formation in the IP process. Here, an optical microscope was employed to study the change rule in the 8-NH2-POSS/PSA nanocomposite membrane formation process due to the addition of 8-NH2-POSS nanoparticles. First, the addition of 8-NH2-POSS reduced the diffusion rate of the polyacrylamide hydrochloride (PAH) water phase on the surface against the oil phase because of the interaction with the PAH molecules. Furthermore, the 8-NH2- POSS/PSA nanocomposite membrane structure was more homogeneous and exhibited uniform pinhole defects distribution due to the interaction of the 8-NH2-POSS nanoparticles to the PAH segment. A significant separation performance was observed in the 8-NH2-POSS/PSA nanocomposite membrane due to the hydrophilicity and positive charge of the 8-NH2-POSS nanoparticles. The permeation flux and MgCl2 rejection of the 8-NH2-POSS/PSA nanocomposite membrane increased up to 50.5 L/m2 h at 0.5MPa and 94.8%, respectively, which corresponded to increases of 73.5% and 8.7% as compared to the pristine PSA membrane. 8-NH2-POSS/PSA nanocomposite membranes have great application potential in the water softening and treatment of divalent metals ions under acidic conditions.

A Resistive Memory in Semiconducting BiFeO₃ Thin‐Film Capacitors

Jiang, An Quan,Wang, Can,Jin, Kui Juan,Liu, Xiao Bing,Scott, James F.,Hwang, Cheol Seong,Tang, Ting Ao,Lu, Hui Bin,Yang, Guo Zhen WILEY‐VCH Verlag 2011 ADVANCED MATERIALS Vol.23 No.10

<P><B>A ferroelectric‐resistive random access memory consisting of a conductive BiFeO<SUB>3</SUB></B> epitaxial thin film with a unipolar diode current modulated by electric polarization orientation is reported. This device has a memory that lasts for months, a sufficiently high on current and on/off ratio to permit ordinary sense amplifiers to measure “1” or “0”, and is fully compatible with complementary metal‐oxide semiconductor processing. </P>

Disturbance observer based non‑singular fast terminal sliding mode control of permanent magnet synchronous motors

Junjie Jiang,Housheng Zhang,Duo Jin,Ao Wang,Longhao Liu 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.2

The existence of load disturbance can lead to the instability of permanent magnet synchronous motor (PMSM) speed control systems. Therefore, a non-singular fast terminal sliding mode control (NFTSMC) strategy based on a disturbance observer is proposed in this paper. First, a new exponential reaching law is presented to relate the rate of convergence to the state error and switching function, which achieves an improvement of the system convergence speed while reducing system jitter. At the same time, to eliminate system jitter, a new smooth saturation function is introduced in place of the symbolic function. Second, a non-singular fast terminal (NFT) sliding surface is generated by combining a nonlinear function with a linear funtion, which makes the state error converge rapidly at different stages. Finally, a disturbance observer is built to boost the robustness of the control system by observing the outside disturbance value and feeding it back to the speed controller. The dependability and effectiveness of the proposed control strategy are confirmed by simulation experiments with MATLAB.

Rapid screening and identification of metabolites of quercitrin produced by the human intestinal bacteria using ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry

Shu Jiang,Jing Yang,Dawei Qian,Jianming Guo,Er-xin Shang,Jin-ao Duan,Jun Xu 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.2

Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF MS)technique combined with MetabolynxTM software was usedfor analysis of the metabolites of quercitrin by the isolatedhuman intestinal bacteria from the human feces. Four metabolitesof quercitrin were detected and tentatively identifiedbased on the characteristics of their protonated ions. Themetabolites were metabolized by four main metabolic pathwaysincluding hydroxylation, demethylation, deglycosylationand ring-cleavage. Quercitrin was metabolized to the hydroxyquercitrinand desmethylquercitrin by themajority of theisolated intestinal bacteria such as Bacteroides sp. 54, and wasdegraded to the deglycosylated product quercetin by rhamnosidaseand further ring-cleavage metabolite 3,4-dihydroxybenzoicacid by the minority of the isolated bacteria such asBacteroides sp. 45. The metabolic pathways and most of themetabolites of quercitrin were reported for the first time.

Experimental Investigation on Fatigue Improvement of Orthotropic Steel Bridge Deck Using Steel Fiber Reinforced Concrete

Huawen Ye,Ao Huang,Chengchuan Jiang,Wenchao Wang 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.5

The high-performance topping concrete overlay would significantly reduce the fatigue stresses at susceptible details of orthotropic steel deck (OSD) and effectively improve the fatigue performance. Full-scale fatigue tests and numerical simulations were carried out to quantify the effects of steel fiber reinforced concrete (SFRC) topping pavement in reducing the OSD fatigue stresses based on a practical bridge design. Fatigue stress of the OSD critical details was measured from tests and cracking was observed in the SFRC overlay. Both an innovative pre-pump-pulse Brillouin optical time domain analysis (PPP-BOTDA) distributed optical fiber sensor and strain gauges were also used to measure the stress at OSD fatigue-prone details, including the crossbeam cut-out, rib-to-deck weld, rib-to-crossbeam weld and splice of U-rib. The corresponding three-dimensional (3-D) finite element model was then established and verified by the test results, and used to conduct a parametric study to obtain a quantitative expression of fatigue stress reduction factor, in terms of relative elastic modulus and thickness of overlay and steel deck plate. The proposed quantitative model of the fatigue stress reduction effect can guide the cost-effective design of composite bridge deck.

Simplified model prediction current control strategy for permanent magnet synchronous motor

Zhang, Housheng,Zhu, Shengjie,Jiang, Junjie,Wang, Qingzhuang,Wang, Ao,Jin, Duo The Korean Institute of Power Electronics 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.11

A simplified model predictive current control strategy based on mathematical auxiliary line method is proposed to increase the permanent magnet synchronous motor (PMSM) predictive current control system's steady-state performance while reducing the system's computational complexity. The mathematical models of current prediction, first-order compensation, and cost function are presented by analyzing the prediction current control strategy of the conventional models. Within a control cycle, the simplified model predictive current control algorithm applies two voltage vectors and omits the error calculation of cost function. The anticipated voltage of transformer obtained from the beat-free current control standard is considered the reference voltage, and the judgment of the area, where the reference voltage vector is found and the strategy for double voltage vector is selected, is put forward. The optimal voltage vector can be directly output without the error calculation of the cost function in the method, thereby effectively reducing the computation load and complexity of the system and improving the steady-state performance. Experimental results verify the validity and accuracy of the proposed simplified model of predictive current control strategy for PMSM control.

D-RADA16-RGD-Reinforced Nano-Hydroxyapatite/Polyamide 66 Ternary Biomaterial for Bone Formation

Bo Qiao,Bin He,Ao Zhou,Yuling Li,Xiaojun Chen,Qiming Yang,Beike Chen,Bo Qiao,Dianming Jiang 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.2

BACKGROUND: Nano-hydroxyapatite/polyamide 66 (nHA/PA66) is a composite used widely in the repair of bone defects. However, this material is insufficient bioactivity. In contrast, D-RADA16-RGD self-assembling peptide (DRADA16- RGD sequence containing all D-amino acids is Ac-RADARADARADARADARGDS-CONH2) shows admirable bioactivity for both cell culture and bone regeneration. Here, we describe the fabrication of a favorable biomaterial material (nHA/PA66/D-RADA16-RGD). METHODS: Proteinase K and circular dichroism spectroscopy were employed to test the stability and secondary structural properties of peptide D-RADA16-RGD respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the surface of these materials. Confocal laser scanning (CLS), cell counting kit-8 tests (CCK-8), alizarin red S staining, cell immunofluorescence analysis and Western blotting were involved in vitro. Also biosafety and bioactivity of them have been evaluated in vivo. RESULTS: Proteinase K and circular dichroism spectroscopy demonstrated that D-RADA16-RGD in nHA/PA66 was able to form stable-sheet secondary structure. SEM and TEM showed that the D-RADA16-RGD material was 7–33 nm in width and 130–600 nm in length, and the interwoven pore size ranged from 40 to 200 nm. CLS suggests that cells in nHA/PA66/ D-RADA16-RGD group were linked to adjacent cells with more actin filaments. CCK-8 analysis showed that nHA/PA66/ D-RADA16-RGD revealed good biocompatibility. The results of Alizarin-red S staining and Western blotting as well as vivo osteogenesis suggest nHA/PA66/D-RADA16-RGD exhibits better bioactivity. CONCLUSION: This study demonstrates that our nHA/PA66/D-RADA16-RGD composite exhibits reasonable mechanical properties, biocompatibility and bioactivity with promotion of bone formation.

Experiment in Using Reinforcement Learning in Gaming: The Breakout Game Learning

Taresh Dewan,Aloukik Aditya,Manva Trivedi,Ao Chen,Danning Jiang,Sabah Mohammed 한국컴퓨터게임학회 2021 한국컴퓨터게임학회논문지 Vol.34 No.2

In this study, we investigated whether a tool such as a game toy can be used as an augmented reality tool, and a system model that can be extended to a game element using wireless communication technology such as Bluetooth and a controllable module. This is an online ship type game using augmented reality technology and wireless communication technology. In addition, the existing game element was extended by applying a smartphone app control module. The existing game method uses the method of playing the game with only limited functions in the same space. This study expands to augmented reality-based games by implementing contents in a way that matches game objects with the grafting of augmented reality technology, and uses various items that emerge as the limit of reality. Therefore, we standardized the size of game objects so that they can be used three-dimension in all spaces on the screen according to the space arrangement such as overlapping prevention, distance, and height, and augmented reality technology was used to allow the game to be played by manipulation of a smartphone. In addition, we propose a system framework-based model that can be applied to various games, and a framework that can implement various augmented reality environments. The augmented reality-based battle game proposed in this study combines a knowledge-based augmented reality system that can be extended to game elements by modularizing the function of a toy through+ a context-aware agent based on context information and an intelligent DB based on domain knowledge.