Research of Evaluation Mechanism of Petrochemical Informatization Projects Based on AHPP

Feng’an Wen 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.6

To address unreasonable planning process and imbalanced budget for informatization projects of petrochemical enterprises, this paper designs an informatization projects evaluation model. Analytic Hierarchy Process (AHP) is introduced to provide theoretical support. First, this paper conducts a hierarchical analysis to the decisive project factors in the informatization construction by constructing judgment set for the ladder-type hierarchical mode. Then, it calculates the weight for each factor and makes reasonable decision, which provides guidance to the implement of the informatization projects of petrochemical enterprises.

A Double Bi-Quad Filter with Wide-Band Resonance Suppression for Servo Systems

Xin Luo,Anwen Shen,Renchao Mao 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

In this paper, an algorithm using two bi-quad filters to suppress the wide-band resonance for PMSM servo systems is proposed. This algorithm is based on the double bi-quad filters structure, so it is named, “double bi-quad filter.” The conventional single bi-quad filter method cannot suppress unexpected mechanical terms, which may lead to oscillations on the load side. A double bi-quad filter structure, which can cancel the effects of compliant coupling and suppress wide-band resonance, is realized by inserting a virtual filter after the motor speed output. In practical implementation, the proposed control structure is composed of two bi-quad filters on both the forward and feedback paths of the speed control loop. Both of them collectively complete the wide-band resonance suppression, and the filter on the feedback path can solve the oscillation on the load side. Meanwhile, with this approach, in certain cases, the servo system can be more robust than with the single bi-quad filter method. A step by step design procedure is provided for the proposed algorithm. Finally, its advantages are verified by theoretical analysis and experimental results.

A High Efficiency Two-stage Inverter for Photovoltaic Grid-connected Generation Systems

Jiang Liu,Shanmei Cheng,Anwen Shen 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

Conventional boost-full-bridge and boost-hybrid-bridge two-stage inverters are widely applied in order to adapt to the wide dc input voltage range of photovoltaic arrays. However, the efficiency of the conventional topology is not fully optimized because additional switching losses are generated in the voltage conversion so that the input voltage rises and then falls. Moreover, the electrolytic capacitors in a dc-link lead to a larger volume combined with increases in both weight and cost. This paper proposes a higher efficiency inverter with time-sharing synchronous modulation. The energy transmission paths, wheeling branches and switching losses for the high-frequency switches are optimized so that the overall efficiency is greatly improved. In this paper, a contrastive analysis of the component losses for the conventional and proposed inverter topologies is carried out in MATLAB. Finally, the high-efficiency under different switching frequencies and different input voltages is verified by a 3 kW prototype.

MTPA-based high-frequency square wave voltage signal injection strategy for IPMSM control

Zhang, Zeyu,Shen, Anwen,Li, Peihe,Luo, Xin,Tang, Qipeng The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.10

This paper proposes a high-frequency (HF) square wave voltage signal injection strategy for interior permanent magnet synchronous motor (IPMSM) maximum torque per ampere (MTPA) drives. Unlike previous methods, this strategy injects a square wave HF signal into the voltage directly regardless of the current loop bandwidth limitations. In addition, the injected frequency can surpass the cut-off frequency of the current loop. Therefore, the disturbance caused by the injected signal can be reduced. The process of MTPA operating point adjustment only needs to sample and analyze the current amplitude without additional digital filters. Thus, the dynamic response promotes, and avoids the extra hardware and calculation burden. To decrease the convergence time when the load changes rapidly, an equivalent mathematical model of an IPMSM is employed to provide prior current references. Both simulation and experimental results confirm the validity and feasibility of the proposed strategy.

The long non-coding RNA uc.4 influences cell differentiation through the TGF-beta signaling pathway

Zijie Cheng,Qijun Zhang,Anwen Yin,Mengwen Feng,Hua Li,Hailang Li,Yun Li,Lingmei Qian 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

In a previous study, we screened thousands of long non-coding RNAs (lncRNAs) to assess their potential relationship with congenital heart disease (CHD). In this study, uc.4 attracted our attention because of its high level of evolutionary conservation and its antisense orientation to the CASZ1 gene, which is vital for heart development. We explored the function of uc.4 in cells and in zebrafish, and describe a potential mechanism of action. P19 cells were used to investigate the function of uc.4. We studied the effect of uc.4 overexpression on heart development in zebrafish. The overexpression of uc.4 influenced cell differentiation by inhibiting the TGF-beta signaling pathway and suppressed heart development in zebrafish, resulting in cardiac malformation. Taken together, our findings show that uc.4 is involved in heart development, thus providing a potential therapeutic target for CHD.

A Double Bi-Quad Filter with Wide-Band Resonance Suppression for Servo Systems

Luo, Xin,Shen, Anwen,Mao, Renchao The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

In this paper, an algorithm using two bi-quad filters to suppress the wide-band resonance for PMSM servo systems is proposed. This algorithm is based on the double bi-quad filters structure, so it is named, "double bi-quad filter." The conventional single bi-quad filter method cannot suppress unexpected mechanical terms, which may lead to oscillations on the load side. A double bi-quad filter structure, which can cancel the effects of compliant coupling and suppress wide-band resonance, is realized by inserting a virtual filter after the motor speed output. In practical implementation, the proposed control structure is composed of two bi-quad filters on both the forward and feedback paths of the speed control loop. Both of them collectively complete the wide-band resonance suppression, and the filter on the feedback path can solve the oscillation on the load side. Meanwhile, with this approach, in certain cases, the servo system can be more robust than with the single bi-quad filter method. A step by step design procedure is provided for the proposed algorithm. Finally, its advantages are verified by theoretical analysis and experimental results.

A Robust Dynamic Decoupling Control Scheme for PMSM Current Loops Based on Improved Sliding Mode Observer

Shen, Hanlin,Luo, Xin,Liang, Guilin,Shen, Anwen The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.6

A complete current loop decoupling control strategy based on a sliding mode observer (SMO) is proposed to eliminate the influence of current dynamic coupling and back electromotive force (EMF) in the vector control of permanent magnet synchronous motors. With this strategy, current dynamic decoupling and back EMF compensation can be simultaneously achieved. Unlike conventional methods, the proposed strategy can avoid the disturbances caused by the parametric variations of motor systems and maintain the advantages of proportional integral (PI) controllers, which are robust and easy to operate. An improved SMO, which uses a special PI regulator other than a linear saturation function as the equivalent control law in the boundary layer of a sliding surface, is proposed to eliminate the estimated errors caused by the quasi-sliding mode and obtain a satisfactory decoupling performance. The stability and parameter robustness of the proposed strategy are also analyzed. Physical experimental results are presented to verify the validity of the method.

A Robust Dynamic Decoupling Control Scheme for PMSM Current Loops Based on Improved Sliding Mode Observer

Hanlin Shen,Xin Luo,Guilin Liang,Anwen Shen 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.6

A complete current loop decoupling control strategy based on a sliding mode observer (SMO) is proposed to eliminate the influence of current dynamic coupling and back electromotive force (EMF) in the vector control of permanent magnet synchronous motors. With this strategy, current dynamic decoupling and back EMF compensation can be simultaneously achieved. Unlike conventional methods, the proposed strategy can avoid the disturbances caused by the parametric variations of motor systems and maintain the advantages of proportional integral (PI) controllers, which are robust and easy to operate. An improved SMO, which uses a special PI regulator other than a linear saturation function as the equivalent control law in the boundary layer of a sliding surface, is proposed to eliminate the estimated errors caused by the quasi-sliding mode and obtain a satisfactory decoupling performance. The stability and parameter robustness of the proposed strategy are also analyzed. Physical experimental results are presented to verify the validity of the method.

A High Efficiency Two-stage Inverter for Photovoltaic Grid-connected Generation Systems

Liu, Jiang,Cheng, Shanmei,Shen, Anwen The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

Conventional boost-full-bridge and boost-hybrid-bridge two-stage inverters are widely applied in order to adapt to the wide dc input voltage range of photovoltaic arrays. However, the efficiency of the conventional topology is not fully optimized because additional switching losses are generated in the voltage conversion so that the input voltage rises and then falls. Moreover, the electrolytic capacitors in a dc-link lead to a larger volume combined with increases in both weight and cost. This paper proposes a higher efficiency inverter with time-sharing synchronous modulation. The energy transmission paths, wheeling branches and switching losses for the high-frequency switches are optimized so that the overall efficiency is greatly improved. In this paper, a contrastive analysis of the component losses for the conventional and proposed inverter topologies is carried out in MATLAB. Finally, the high-efficiency under different switching frequencies and different input voltages is verified by a 3 kW prototype.

Effects of different parameters on thermal and mechanical properties of aminated graphene/epoxy nanocomposites connected by covalent: A molecular dynamics study

Huiping Yu,Zhihao Tong,Pei Chen,Anwen Cai,Fei Qin 한국물리학회 2020 Current Applied Physics Vol.20 No.4

This paper is devoted to studying the thermal and mechanical properties of aminated graphene (AG)/epoxy nanocomposites connected by covalent bond using molecular dynamics (MD) simulation. The effects of crosslinking degree, mass fraction and functionalized graphene (FG) type on AG/epoxy nanocomposites are considered. The elasticity modulus (E), the glass transition temperature (Tg), the coefficient of thermal expansion (CTE) and the interfacial energy (Eint) are also investigated. The MD simulation results indicate that, when the mass fraction of AG is between 1.2% and 3.1% and crosslinking degree reaches about 70%, the E, Tg, Eint and CTE of AG/epoxy nanocomposites are significantly improved compared with those of pure epoxy and graphene/ epoxy nanocomposites. The reason is that AG not only possesses some excellent thermodynamic properties of graphene, but also has the function of curing agent to crosslink with epoxy monomer to form the carbon-nitrogen (C–N) covalent bond. A better interfacial interaction between nanoparticles and epoxy is essential in enhancing the thermal and mechanical properties of nanocomposite materials, which will provide a microscopic theoretical basis for the study of epoxy nanocomposites.