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Control Method for Fault-Tolerant Active Power Filters
Chenyu Zhang,Jianyong Zheng,Jun Mei,Kai Deng,Fuju Zhou 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.3
New direct and indirect current control methods for a fault-tolerant active power filter topology are presented in this paper. Since a three-phase four-switch topology has a phase bridge current which cannot be directly controlled, a hysteresis control method in the α-β plane which controls the three-phase current in the two-phase stationary coordinate system is proposed. The improved SVPWM algorithm is able to eliminate the operation of the trigonometric functions in the traditional algorithm by rotating the α-β coordinates and alternating the sequence of the output vectors, which in turn simplifies the algorithm and reduces the switching frequency. The selection of the DC-side reference voltage and DC-side capacitor equalization strategy are also discussed. Simulation and experiments demonstrate that the proposed control method is correct and feasible.
Control Method for Fault-Tolerant Active Power Filters
Zhang, Chenyu,Zheng, Jianyong,Mei, Jun,Deng, Kai,Zhou, Fuju The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.3
New direct and indirect current control methods for a fault-tolerant active power filter topology are presented in this paper. Since a three-phase four-switch topology has a phase bridge current which cannot be directly controlled, a hysteresis control method in the α-β plane which controls the three-phase current in the two-phase stationary coordinate system is proposed. The improved SVPWM algorithm is able to eliminate the operation of the trigonometric functions in the traditional algorithm by rotating the α-β coordinates and alternating the sequence of the output vectors, which in turn simplifies the algorithm and reduces the switching frequency. The selection of the DC-side reference voltage and DC-side capacitor equalization strategy are also discussed. Simulation and experiments demonstrate that the proposed control method is correct and feasible.
Synthesis and Characterization of a Novel Preceramic Polymer for SiBNC Ceramic Fibers
Chenyu Zhang,Yong Liu,Yongjie Cui,Minqiang Jiang,Keqing Han,Hui Zhang,Muhuo Yu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5
A new approach for the synthesis of polymer precursor for quaternary SiBNC fibers is presented. The inexpensive, commercially available reactants n-propylamine (C3H7NH2), trichlorosilane (SiHCl3) and boron trichloride (BCl3) were used in a simple one-step reaction. The reaction mainly involved the co-polymerization between Si-Cl, B-Cl and N-CH2CH2CH3 with C3H7NH2 evaporation. Characterization of synthesized polymer was performed by FT-IR and NMR. The polymer has a relatively linear-chain chemical structure, and could be easily converted into flexible green fibers by melt-spun with diameter of 24 μm. After pyrolysis process at 1000 oC under nitrogen atmosphere, SiBNC ceramic fibers were obtained with a diameter of about 19 μm. Those fibers showed average tensile strength of 1.05 GPa and it remained in the amorphous state up to 1600 oC, which made them as the promising candidates for reinforcements in ceramic matrix composites for hightemperature application.
Soft switching high step-down series-capacitor based converter with coupled-inductor technique
Chen, Zhangyong,Chen, Yong,Zhang, Chenyu,Wu, Yunfeng The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.4
High voltage step-down converters are very popular in distributed power systems, voltage regular modules, automatic vehicles, etc. To avoid extreme duty cycles, a series capacitor-based buck converter with a coupled inductor is proposed in this paper. In this converter, the voltage stresses of the power switches are clamped to half of the input voltage. Thus, low voltage rating MOSFETs with a low R<sub>ds,on</sub> could be utilized to improve the performance of the proposed converter. Moreover, synchronous MOSFETs are also used to reduce the conduction losses of the switches. Zero voltage switching (ZVS) for the main power switches is achieved using the coupled-inductor technique. In addition, through adding a bypass flowing path, a negative current is established to guarantee the ZVS condition of the power switches. The operating principle of the proposed converter is described in this paper, and the DC voltage gain ratio, automatic current sharing, soft switching condition and design guideline of the critical parameters are also given. Finally, experimental results obtained from a 60 V/200 W prototype are presented to verify the analysis of the proposed converter.