The effects of alternating magnetic field on the corrosion morphologies, corrosion rate, and corrosion products of copper in 3.5% NaCl solution, sea water, and magnetized sea water were investigated using electrochemi...The effects of alternating magnetic field on the corrosion morphologies, corrosion rate, and corrosion products of copper in 3.5% NaCl solution, sea water, and magnetized sea water were investigated using electrochemical test, scanning electron microscopy/energy dispersive analysis system of X-ray （SEM/EDAX）, and X-ray diffraction （XRD）. The results show that the corrosion rate of copper in magnetized sea water is minimal. Moreover, the surface of the specimen in magnetized sea water is uniform and compact as compared with those in 3.5% NaCl solution and sea water. The corrosion products of copper in magnetized sea water are mainly Cu2O and CuCl2. However, the corrosion products in sea water are CuCl, Cu2Cl（OH）3, and FeCl3-6H2O. The electrochemical corrosion mechanisms of copper in the three media were also discussed.展开更多
This paper deals with the experimental study on the correlation between partial discharge （PD） characteristic parameters and corresponding aging degree of insulation in the course of the aging within eros,s-linked p...This paper deals with the experimental study on the correlation between partial discharge （PD） characteristic parameters and corresponding aging degree of insulation in the course of the aging within eros,s-linked polyethylene （XLPE） insulation. The aging tests were performed on a section of 10 kV transmission cable by means of water needle method. The PD macroscopic characteristic parameters were found to be significantly dependent on the corresponding aging degree of insulation in the course of aging of XLPE, and different kind of aging stage has different characteristics. Beside, there are similar regularity but different PD amplitude in the course of aging of XI.PE insulation in different electrolyte, and their insulation life is different. Therefore, according to the chan ging regularity of the PD macroscopic characteristic parame ters within XLPE insulation judging the aging degree of XLPE insulation will be an effective method.展开更多
The general configuration of CEV1 electric vehicle’s electrical system and the design scheme of its control sequence are presented, which are modularized by using VMU as master control unit, PMU as power management u...The general configuration of CEV1 electric vehicle’s electrical system and the design scheme of its control sequence are presented, which are modularized by using VMU as master control unit, PMU as power management unit, BMU as battery management unit. It is a rather advanced and practical general design scheme of electric vehicle, because the division of its module function is definite, which is advantage for research, manufacture and maintenance.展开更多
High-speed permanent magnetic generators (HSPMG) are common and important power generation equipments used in distributed generation systems. A 100 kW level HSPMG is investigated in this paper, and it is fluid-thermal...High-speed permanent magnetic generators (HSPMG) are common and important power generation equipments used in distributed generation systems. A 100 kW level HSPMG is investigated in this paper, and it is fluid-thermal coupling analyzed. The transient 2D electromagnetic field while machine is under rated operating is analyzed by using the time-stepping FEM, from which the electromagnetic performances and the loss distributions are obtained. Then, an analysis model for fluid-solid temperature field analysis is established. Taking losses as the distributed heat sources, the 3D thermal field is coupling calculated. The variations of heat transfer coefficient and temperature of fluid in stator grooves along the axial direction, as well as the whole region 3D temperature distribution in HSPMG are obtained. Then, considering the variations of heat sources distributions and heat transfer conditions, 3D temperature fields of HSPMG operating under different speeds are calculated, and the influences of machine operating speed on the HSPMG thermal performance are studied, based on which, the functions of machine temperature with operating speed and stator windings resistance are proposed. The obtained conclusions may provide a useful reference for the design and research of HSPMG.展开更多
文摘The effects of alternating magnetic field on the corrosion morphologies, corrosion rate, and corrosion products of copper in 3.5% NaCl solution, sea water, and magnetized sea water were investigated using electrochemical test, scanning electron microscopy/energy dispersive analysis system of X-ray （SEM/EDAX）, and X-ray diffraction （XRD）. The results show that the corrosion rate of copper in magnetized sea water is minimal. Moreover, the surface of the specimen in magnetized sea water is uniform and compact as compared with those in 3.5% NaCl solution and sea water. The corrosion products of copper in magnetized sea water are mainly Cu2O and CuCl2. However, the corrosion products in sea water are CuCl, Cu2Cl（OH）3, and FeCl3-6H2O. The electrochemical corrosion mechanisms of copper in the three media were also discussed.
文摘This paper deals with the experimental study on the correlation between partial discharge （PD） characteristic parameters and corresponding aging degree of insulation in the course of the aging within eros,s-linked polyethylene （XLPE） insulation. The aging tests were performed on a section of 10 kV transmission cable by means of water needle method. The PD macroscopic characteristic parameters were found to be significantly dependent on the corresponding aging degree of insulation in the course of aging of XLPE, and different kind of aging stage has different characteristics. Beside, there are similar regularity but different PD amplitude in the course of aging of XI.PE insulation in different electrolyte, and their insulation life is different. Therefore, according to the chan ging regularity of the PD macroscopic characteristic parame ters within XLPE insulation judging the aging degree of XLPE insulation will be an effective method.
文摘The general configuration of CEV1 electric vehicle’s electrical system and the design scheme of its control sequence are presented, which are modularized by using VMU as master control unit, PMU as power management unit, BMU as battery management unit. It is a rather advanced and practical general design scheme of electric vehicle, because the division of its module function is definite, which is advantage for research, manufacture and maintenance.
基金supported by the National High Technology Research and Development Program of China ("863" Program) (Grant No. 2007AA050501)the Heilongjiang Critical Priority Research (Grant No. GB08A302)
文摘High-speed permanent magnetic generators (HSPMG) are common and important power generation equipments used in distributed generation systems. A 100 kW level HSPMG is investigated in this paper, and it is fluid-thermal coupling analyzed. The transient 2D electromagnetic field while machine is under rated operating is analyzed by using the time-stepping FEM, from which the electromagnetic performances and the loss distributions are obtained. Then, an analysis model for fluid-solid temperature field analysis is established. Taking losses as the distributed heat sources, the 3D thermal field is coupling calculated. The variations of heat transfer coefficient and temperature of fluid in stator grooves along the axial direction, as well as the whole region 3D temperature distribution in HSPMG are obtained. Then, considering the variations of heat sources distributions and heat transfer conditions, 3D temperature fields of HSPMG operating under different speeds are calculated, and the influences of machine operating speed on the HSPMG thermal performance are studied, based on which, the functions of machine temperature with operating speed and stator windings resistance are proposed. The obtained conclusions may provide a useful reference for the design and research of HSPMG.
