On the compressibility of bread dough

Wang, Chunguang,Dai, Shaocong,Tanner, Roger I. The Korean Society of Rheology 2006 Korea-Australia rheology journal Vol.18 No.3

Few investigations of bread dough compressibility have been reported in the literature, despite the fact that high compression stresses are often reached in processing. Here we report some experiments on the compressibility of an Australian wheat bread dough under compressive stresses up to 5 MPa, and show that the results are consistent with a mathematical model of bread dough containing entrained air. The implications for tensile testing are also considered.

Effects of ion irradiation on microstructure and properties of zirconium alloysdA review

Chunguang Yan,Rongshan Wang,Yanli Wang,Xitao Wang,Guanghai Bai 한국원자력학회 2015 Nuclear Engineering and Technology Vol.47 No.3

Zirconium alloys are widely used in nuclear reactors as structural materials. During the operation, they are exposed to fast neutrons. Ion irradiation is used to simulate the damage introduced by neutron irradiation. In this article, we briefly review the neutron irradiation damage of zirconium alloys, then summarize the effect of ion irradiation on microstructural evolution, mechanical and corrosion properties, and their relationships. The microstructure components consist of dislocation loops, second phase precipitates, and gas bubbles. The microstructure parameters are also included such as domain size and microstrain determined by X-ray diffraction and the S-parameter determined by positron annihilation. Understanding the relationships of microstructure and properties is necessary for developing new advanced materials with higher irradiation tolerance.

Source Current Control Strategy of Active Power Filters for Unbalanced Load Compensation in Three-Phase Four-Wire Distribution Networks

Wang, Lei,Han, Xiaoqing,Meng, Runquan,Ren, Chunguang,Wang, Qi,Zhang, Baifu The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper proposes a modified control strategy to improve the performance of three-phase four-leg shunt active power filters (APFs) for the compensation of three phase unbalanced loads. Unbalanced current cannot be obtained accurately by a harmonic detector due to the lower frequency. The proposed control strategy eliminates conventional harmonic detectors by directly regulating the source current. Therefore, the computational complexity is greatly reduced and the performance of the APF is improved. A mathematic model has been developed based on the source currents. The corresponding controllers have been designed based on the sinusoidal internal model principle. The proposed control strategy can guarantee excellent compensation performance and stable operation after an extreme disturbance such as a short circuit fault. In addition, the proposed technique can selectively compensate specific harmonics. A 50kVA prototype APF is implemented in the laboratory to validate the feasibility and performance of the proposed control strategy.

An Improved One Cycle Control for Active Power Filters under Non-Ideal Voltage Conditions

Wang, Lei,Ren, Chunguang,Yang, Yu,Han, Xiaoqing,Wang, Peng The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

The one cycle control (OCC) scheme for active power filters (APFs) has shown excellent harmonic suppression and implementation simplicity. However, its real world application is limited because the non-ideal supply voltage for APFs can influence its performance so that the source currents are still distorted after compensation. This paper proposes a modified one cycle control (MOCC) scheme to improve the performance of three-phase shunt APFs under non-ideal supply voltage conditions. In this paper a detailed mathematical derivation has been presented and the key control law of the MOCC has been developed for adaption to the non-ideal supply voltages, following the control philosophy of simplicity. A relatively simple sequence filter is introduced to extract the harmonic components of supply voltages. The modified scheme can be easily implemented. The proposed control strategy has excellent performance and a 5kVA APF hardware platform has been implemented to validate the feasibility and performance of the proposed strategy.

Source Current Control Strategy of Active Power Filters for Unbalanced Load Compensation in Three-Phase Four-Wire Distribution Networks

Lei Wang,Xiaoqing Han,Runquan Meng,Chunguang Ren,Qi Wang,Baifu Zhang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper proposes a modified control strategy to improve the performance of three-phase four-leg shunt active power filters (APFs) for the compensation of three phase unbalanced loads. Unbalanced current cannot be obtained accurately by a harmonic detector due to the lower frequency. The proposed control strategy eliminates conventional harmonic detectors by directly regulating the source current. Therefore, the computational complexity is greatly reduced and the performance of the APF is improved. A mathematic model has been developed based on the source currents. The corresponding controllers have been designed based on the sinusoidal internal model principle. The proposed control strategy can guarantee excellent compensation performance and stable operation after an extreme disturbance such as a short circuit fault. In addition, the proposed technique can selectively compensate specific harmonics. A 50kVA prototype APF is implemented in the laboratory to validate the feasibility and performance of the proposed control strategy.

An Improved One Cycle Control for Active Power Filters under Non-Ideal Voltage Conditions

Lei Wang,Chunguang Ren,Yu Yang,Xiaoqing Han,Peng Wang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

The one cycle control (OCC) scheme for active power filters (APFs) has shown excellent harmonic suppression and implementation simplicity. However, its real world application is limited because the non-ideal supply voltage for APFs can influence its performance so that the source currents are still distorted after compensation. This paper proposes a modified one cycle control (MOCC) scheme to improve the performance of three-phase shunt APFs under non-ideal supply voltage conditions. In this paper a detailed mathematical derivation has been presented and the key control law of the MOCC has been developed for adaption to the non-ideal supply voltages, following the control philosophy of simplicity. A relatively simple sequence filter is introduced to extract the harmonic components of supply voltages. The modified scheme can be easily implemented. The proposed control strategy has excellent performance and a 5kVA APF hardware platform has been implemented to validate the feasibility and performance of the proposed strategy.

Design of comprehensive mechanical properties by machine learning and high-throughput optimization algorithm in RAFM steels

Wang, Chenchong,Shen, Chunguang,Huo, Xiaojie,Zhang, Chi,Xu, Wei Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.5

In order to make reasonable design for the improvement of comprehensive mechanical properties of RAFM steels, the design system with both machine learning and high-throughput optimization algorithm was established. As the basis of the design system, a dataset of RAFM steels was compiled from previous literatures. Then, feature engineering guided random forests regressors were trained by the dataset and NSGA II algorithm were used for the selection of the optimal solutions from the large-scale solution set with nine composition features and two treatment processing features. The selected optimal solutions by this design system showed prospective mechanical properties, which was also consistent with the physical metallurgy theory. This efficiency design mode could give the enlightenment for the design of other metal structural materials with the requirement of multi-properties.

Investigation of the Voltage Collapse Mechanism in Three-Phase PWM Rectifiers

Chunguang Ren,Huipeng Li,Yu Yang,Xiaoqing Han,Peng Wang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

Three-phase pulse width modulation (PWM) rectifiers are usually designed under the assumption of ideal ac power supply and input inductance. However, non-ideal circuit parameters may lead to a voltage collapse of PWM rectifiers. This paper investigates the mechanism of voltage collapse in three-phase PWM rectifiers. An analytical stability boundary expression is derived by analyzing the equilibrium point of the averaging state space model, which can not only accurately locate the voltage collapse boundary in the circuit parameter domain, but also reveal the essential characteristic of the voltage collapse. Results are obtained and compared with those of the trial-error method and the Jacobian method. Based on the analysis results, the system parameters can be divided into two categories. One of these categories affects the critical point, and other affects only the instability process. Furthermore, an effective control strategy is proposed to prevent a vulnerable system from being driven into the instability region. The analysis results are verified by the experiments.

Acid-insoluble Substances in Reduced Iron Powder from Ores

Wang Chonglin,Zhang Chunguang 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

X-ray analysis on iron ores and reduced iron powders revealed that the main acid-insoluble substances were hexagonal and tetragonal quartz, another substances were sillimanite, alumina-silicate, an unnamed zeolite, all contained Si and Al. Their particle size was in the range of . Statistics analysis showed that the AIC for high-grade magnetite powder was ) during the latest five months. The predicting value for reduced iron powder should be 0.179%. However, the testing value for reduced iron powder was . The limited difference of 0.013% might imply rare pollution coming from the reduction and milling processes. The most important step for control AIC should be the separation process of iron ore powders.

Investigation of the Voltage Collapse Mechanism in Three-Phase PWM Rectifiers

Ren, Chunguang,Li, Huipeng,Yang, Yu,Han, Xiaoqing,Wang, Peng The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

Three-phase pulse width modulation (PWM) rectifiers are usually designed under the assumption of ideal ac power supply and input inductance. However, non-ideal circuit parameters may lead to a voltage collapse of PWM rectifiers. This paper investigates the mechanism of voltage collapse in three-phase PWM rectifiers. An analytical stability boundary expression is derived by analyzing the equilibrium point of the averaging state space model, which can not only accurately locate the voltage collapse boundary in the circuit parameter domain, but also reveal the essential characteristic of the voltage collapse. Results are obtained and compared with those of the trial-error method and the Jacobian method. Based on the analysis results, the system parameters can be divided into two categories. One of these categories affects the critical point, and other affects only the instability process. Furthermore, an effective control strategy is proposed to prevent a vulnerable system from being driven into the instability region. The analysis results are verified by the experiments.