In order to improve the ability of harmonic suppression,and reduce the loss of switching devices,this paper proposes an active harmonic suppression method at dc side of multi-pulse rectifier(MPR) . The circulating cur...In order to improve the ability of harmonic suppression,and reduce the loss of switching devices,this paper proposes an active harmonic suppression method at dc side of multi-pulse rectifier(MPR) . The circulating current through secondary winding of active inter-phase reactor(AIPR) is derived from the current relation between the ac and dc sides of MPR when the threephase input currents are sinusoidal simultaneously,and an applicable circulating current is presented. According to the relation between voltage across secondary winding of AIPR and the applicable current,it is confirmed that harmonic energy of input line current can be consumed by the resistor in series with the secondary winding. A half-bridge PWM rectifier is designed to abstract the harmonic power and to feed the load,which can realize the recycling of harmonic energy. Experimental results show that the power factor of the proposed system is approximately equal to one when the PWM rectifier operates normally,and that the proposed system has the ability of anti-variation of load and input voltage.展开更多
To obtain the optimal operating conditions of a coupled reactor for pyridine synthesis,reactor modeling process is carried out in this paper.During the modeling process,the flow hydrodynamics,heat transfer behavior,in...To obtain the optimal operating conditions of a coupled reactor for pyridine synthesis,reactor modeling process is carried out in this paper.During the modeling process,the flow hydrodynamics,heat transfer behavior,inter-phase mass transfer behavior and reaction kinetics were taken into consideration consequently.Further,a regression program based on least square method was proposed to regress the model parameters.The prediction results agreed well with the experimental results with an average deviation of 5.9%.Finally,by setting suitable aim function,the optimal operating conditions of the coupled reactor for pyridine synthesis were determined.展开更多
12-pulse rectifier is extensively used in high power rectification, and the delta-connected autotransformer and wye-connected autotransformer are its two most popular phase-shift transformers. This paper compares the ...12-pulse rectifier is extensively used in high power rectification, and the delta-connected autotransformer and wye-connected autotransformer are its two most popular phase-shift transformers. This paper compares the 12-pulse rectifiers using the two transformers via calculating the input line current, load voltage, kVA ratings of the two autotransformer, kVA ratings of the auxiliary magnetic devices. From the viewpoint of power quality of AC mains and DC side, the two 12-pulse rectifiers are the same. The kVA rating of the IPR in the two 12-pulse rectifiers are equal, and the kVA rating of the ZSBT in the two 12-pulse rectifier are also equal to each other, under the same load power. However, the kVA of the deltaconnected autotransformer is less than that of the wyeconnected autotransformer under the same load power.Some experimental results are shown to validate the correctness of the theoretical analysis.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.50977018,51107019)the Fundamental Research Funds for the Central Universities (Grant No.HIT.NSRIF.2010101)
文摘In order to improve the ability of harmonic suppression,and reduce the loss of switching devices,this paper proposes an active harmonic suppression method at dc side of multi-pulse rectifier(MPR) . The circulating current through secondary winding of active inter-phase reactor(AIPR) is derived from the current relation between the ac and dc sides of MPR when the threephase input currents are sinusoidal simultaneously,and an applicable circulating current is presented. According to the relation between voltage across secondary winding of AIPR and the applicable current,it is confirmed that harmonic energy of input line current can be consumed by the resistor in series with the secondary winding. A half-bridge PWM rectifier is designed to abstract the harmonic power and to feed the load,which can realize the recycling of harmonic energy. Experimental results show that the power factor of the proposed system is approximately equal to one when the PWM rectifier operates normally,and that the proposed system has the ability of anti-variation of load and input voltage.
基金supports from the Natural Science Foundation of Henan(grant No.202300410063)the National Natural Science Foundation of China(grant Nos.91834303,21961132026)+1 种基金the First-class Discipline Construction Project of Henan University(grant No.2019YLZDCG01)the interdisciplinary Research for First-class Discipline Construction Project of Henan University(grant No.2019 YLXKJC04).
文摘To obtain the optimal operating conditions of a coupled reactor for pyridine synthesis,reactor modeling process is carried out in this paper.During the modeling process,the flow hydrodynamics,heat transfer behavior,inter-phase mass transfer behavior and reaction kinetics were taken into consideration consequently.Further,a regression program based on least square method was proposed to regress the model parameters.The prediction results agreed well with the experimental results with an average deviation of 5.9%.Finally,by setting suitable aim function,the optimal operating conditions of the coupled reactor for pyridine synthesis were determined.
基金supported by National Natural Science Foundation of China(No.51307034)in part by the Natural Science Foundation of Shandong Province(No.ZR2013EEQ002)
文摘12-pulse rectifier is extensively used in high power rectification, and the delta-connected autotransformer and wye-connected autotransformer are its two most popular phase-shift transformers. This paper compares the 12-pulse rectifiers using the two transformers via calculating the input line current, load voltage, kVA ratings of the two autotransformer, kVA ratings of the auxiliary magnetic devices. From the viewpoint of power quality of AC mains and DC side, the two 12-pulse rectifiers are the same. The kVA rating of the IPR in the two 12-pulse rectifiers are equal, and the kVA rating of the ZSBT in the two 12-pulse rectifier are also equal to each other, under the same load power. However, the kVA of the deltaconnected autotransformer is less than that of the wyeconnected autotransformer under the same load power.Some experimental results are shown to validate the correctness of the theoretical analysis.
