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Liu J.,Harbin University of Science and Technology | Li X.,Harbin University of Science and Technology | Gao H.,Shanghai Electrical Cable Research Institute | Guo H.,China National Offshore Oil Corporation
Gaodianya Jishu/High Voltage Engineering | Year: 2014

The umbilical cables used for subsea oil production have complex units, so the traditional analytical method is unable to determine their insulation thickness and ampacity. To solve this problem, we used a finite element method to calculate and analyze the electric filed and temperature field in umbilical cables. We also compared umbilical models with different insulating materials, different insulation thicknesses and different structure forms, and then proposed a method of optimization design based on ANSYS, for determining the ampacity of umbilical cable. It is shown that the relative positions of units in umbilical cable hardly affect the distribution of electric field, while the electric field mainly focuses on the phase-phase line of inner conductor in the units. According to analysis of electric field, the critical thickness of crosslinked polyethylene(XLPE) is 0.25 mm. As for the umlicical cables with different structures, the one with central steel tube has ampacity up to about 60 A, which is superior to the type with central cable. However, there are slight differences in peak electric field and amplicity between XLPE cable and ethylene-propylene rubber (EPR) cable. Conclusively, the finite element method is applicable for determining the insulation thickness and ampacity of umbilical cables.


Pan G.,Shanghai University | Guo Q.,Shanghai University | Ding J.,Shanghai University | Zhang W.,Shanghai University | Wang X.,Shanghai Electrical Cable Research Institute
Tribology International | Year: 2010

To obtain a composite coating possessing both good conductivity and high wear resistance, a series of coatings with conductive graphite and epoxy resin were designed. The seepage critical value (SCV) of conductive coatings was used to identify the transformation between continuous phase and dispersed phase for graphite/epoxy composite coatings. Before SCV, the coatings were insulated with epoxy resin as continuous phase and the wear behavior was primarily characterized of adhesive wear with local adhesive spalling of epoxy resin. After SCV, the coatings appeared conductivity and the surface resistance decreased monotonically with the increase of graphite content. Both the curves of friction coefficient vs. graphite content and wear rate vs. graphite content showed the same model with two valleys at graphite content of 30% and 50%, respectively. At graphite content of 50%, an optimal solid lubricant film was obtained which leaded to the lowest friction coefficient and wear rate, due to a possible dynamic equilibrium between the transfer and spalling of debris. The tribological behaviors of these coatings were evaluated using a ring-on-block tribo-tester under dry sliding friction. Crown Copyright © 2009.


Chen J.,Shanghai University | Chen J.,Chizhou University | Guo Q.,Shanghai University | Zhao Z.,Shanghai University | And 3 more authors.
Journal of Applied Polymer Science | Year: 2013

PEEK/PEI/PES plastics alloys in weight ratios of 70/30/0, 70/25/5, 65/30/5, 60/30/10, 60/35/5, and the three kinds of single high performance engineering plastics 100/0/0, 0/100/0, 0/0/100 were prepared by twin-screw extrusion molding. A single glass-transition temperature (T g) of each alloy in the former five kinds of the plastics alloys could be measured by DSC and always rose to higher one than that of the pure PEEK by about 20°C. The crystalline degrees of these alloys could also ascended to more than 35.81% higher than that of the pure PEEK, especially for the alloy of the ratio 60/30/10 reached the maximum crystalline degree 37.76%. Adding PEI or PEI and PES, the crystalline temperatures of the PEEK alloys were decreased. The wear resistances of the alloys under dry sliding condition were considerably improved compared with pure PEI or PES, and the specific wear rate of the pure PEI or PES were four to six times as large as that of the alloys. However, the specific wear rates of the alloys were six to eight times larger than that of the pure PEEK, and the friction coefficients of the alloys were higher than that of the pure PEEK for 0.2-0.3. The polymeric transferred film on the steel ring surface against the alloys could be found, but no film on that against pure PES or PEI was found. © 2012 Wiley Periodicals, Inc.


Chen J.,Shanghai University | Chen J.,Chizhou College | Guo Q.,Shanghai University | Zhao Z.,Shanghai University | And 2 more authors.
Procedia Engineering | Year: 2012

The PEEK/PEI/PES plastic alloys were processed by twin-screw extruder at 370°C with five mass ratios of 70/30/0, 70/25/5, 65/30/5, 60/30/10, and 60/35/5, respectively. Their thermal properties and crystallization behavior were investigated by the differential scanning calorimetry. The measured results showed that all the plastic alloys had a single glass-transition temperature (Tg), which revealed good compatibility among the three members of PEEK, PEI and PES. For the alloy with the mass ratio of 70/30/0, the minimum Tg of 160.6 °C was obtained, but the alloy of 60/35/5 had the maximum Tg of 164.5 °C, which indicate that PEI, PES and the amorphous plastics could increase Tg of the PEEK alloys and was 20°C higher than that of pure PEEK. The melting points (Tm) of these alloys were from 334.4°C to 336.3°C and their crystallinity degrees were from 35.8% to 37.8%, whereas both were slightly higher than that of pure PEEK. However, the cold crystallization temperatures of the alloys were lower than that of pure PEEK, which could be attributed to the reason that the rheological properties of the alloys were improved by PEI. Tensile strength of the plastic alloy with the ratio of 60/30/10 presented the maximum value of 108MPa and was higher than that of pure PEEK. After thermal ageing at 158°C (below T g) or 178°C (above Tg) respectively for 168h, their tensile strengths decreased only slightly, but elongation rates at break reduced significantly, of which thermal ageing above Tg would recede the elongation at break more severely. The plastic alloy of 60/30/10 could be used as the cable insulating jacketing for nuclear power station. © 2012 Published by Elsevier Ltd.


Chen J.,Shanghai University | Chen J.,Chizhou College | Guo Q.,Shanghai University | Zhang S.,Shanghai University | And 2 more authors.
Procedia Engineering | Year: 2012

The plastic alloys of PEEK/PEI/PES were prepared with extrusion molding at 370°C in ratios of 70/30/0, 70/25/5, 65/30/5, 60/30/10, 60/35/5 (w/w). Friction and wear behaviors of the alloys were investigated under dry sliding contact condition. And wear resistances of PEEK/PEI/PES alloys were considerably improved than pure PEI and PES. The friction coefficients of the alloys were higher than the pure PEEK for 0.2-0.3. The specific wear rates of the pure PEI or PES were 4-6 times as large as the specific wear rate for the alloys of PEEK/PEI/PES, and the specific wear rate for the alloys of PEEK/PEI/PES is 7~9 times as large as the specific wear rate of the pure PEEK. The plastics alloys would produce the transferred film containing PEEK on the steel counterface. However, the transferred film of pure PES or PEI was not found on the steel ring surface. A thin symmetrical and tough transferred film in the worn steel surface against the alloy specimens could reduce friction and wear. © 2012 Published by Elsevier Ltd.


Tang T.,Shanghai Electrical Cable Research Institute | Zong X.H.,Shanghai Electrical Cable Research Institute | Yu Z.G.,Shanghai Electrical Cable Research Institute | Lu X.H.,Shanghai Electrical Cable Research Institute | Han Y.W.,Shanghai Electrical Cable Research Institute
2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2015 - Proceedings | Year: 2015

As an important part of the High Temperature Superconducting (HTS) cable system, the stability and reliability of cryogenic system are the key to successful commercial application for HTS cables. A cryogenic refrigeration system combined of open and closed refrigeration for 35 kV/2000 A HTS cables has been developed. The system passed its trial run after site installation, and was put into operation on December 9, 2013 in Baosteel. The closed subcooled liquid nitrogen circulation is applied as the type of cooling for this system. It will provide a nominal refrigeration capacity of 4000 W at 70 K, and has operation temperature of 70∼76 K and operation pressure of 0.55∼0.65 Mpa respectively. © 2015 IEEE.


Zhang X.Z.,Shanghai Electrical Cable Research Institute | Zong X.H.,Shanghai Electrical Cable Research Institute | Han Y.W.,Shanghai Electrical Cable Research Institute | Tian X.,Shanghai Electrical Cable Research Institute | And 2 more authors.
2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2015 - Proceedings | Year: 2015

Stainless steel is usually non-magnetic or low magnetic austenitic stainless steel, which may convert to martensite when mechanical deformed. The stainless steel corrugated pipe becomes magnetic when marttensite exist, which cause hysteresis loss happens when AC current pass through the cable inside the corrugated pipe. In this paper, the hysteresis loss of the corrugated pipe was tested, and the metallographic and hysteresis loop of the steel was learned. © 2015 IEEE.


Zhang D.Y.,Shanghai Electrical Cable Research Institute | Zong X.H.,Shanghai Electrical Cable Research Institute | Tian X.,Shanghai Electrical Cable Research Institute | Tang T.,Shanghai Electrical Cable Research Institute | And 2 more authors.
2015 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2015 - Proceedings | Year: 2015

This paper introduces a development of CD HTS cable control system and the practical situation of project, in which the redundancy architecture and multiple security mechanism are taken, all those measures can effectively improve the reliability of the whole system. © 2015 IEEE.


Zhu Y.,Shanghai Electrical Cable Research Institute | Jia X.,Shanghai Electrical Cable Research Institute | Yang J.,Shanghai Electrical Cable Research Institute | Wu C.,Shanghai Electrical Cable Research Institute | Yuan C.,Shanghai Electrical Cable Research Institute
Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials | Year: 2015

Crosslinking polyethylene (XLPE) insulated medium voltage (MV) power cable is widely used in power transmission and distribution areas and its reliability is very important to the power utilities. In order to assess the cable status effected by production process, material used and installation conditions, 6 types of 10 kV XLPE cable samples were manufactured and experimentally aged with full loader for one year in water and in the air, respectively. After that step-rise breakdown test was carried out to characterize the aging degree of those cables. It is shown that the insulation material is the key factor determining the original cable status, and manufacture process also influences the original status to some extent. It is verified by the breakdown strength that cables laying in the water aged more greatly than those laying in the air. In order to analyze the aging results theoretically, the isothermal relaxation current (IRC) method were carried out on cable samples with different aging stages. It is shown that the aging factor deduced from the IRC currents has a strong relation with the insulation used. At the same time, it could be seen that the aging factor increment differs from each other. It was strongly verified that insulation must be the key factor to determine the cable's quality and life time, and the manufacturing process influences the life time to some extent. Finally, it could be concluded that IRC, which is a non-destructive assessing technology, can be used to evaluate not only aging degree, but also the original quality of cables. © 2015 IEEE.


Zhu Y.,Shanghai Electrical Cable Research Institute | Gao X.,Shanghai Electric Power Company | Yang J.,Shanghai Electrical Cable Research Institute | Jia X.,Shanghai Electrical Cable Research Institute
Gaodianya Jishu/High Voltage Engineering | Year: 2016

Two types of 110 kV high voltage alternating current (HVAC) cable samples, i.e. unaged and 13-year-field-aged cable samples, were selected to investigate the feasibility of isothermal relaxation current (IRC) method on insulation condition evaluation for XLEP insulated HVAC cable. At the same time, the space charge of sheet samples sliced from cable insulation was also carried out to analyze trap distribution and relaxation mechanism associated with the insulation aging condition. It is found that the aging factor of unaged sample acquired by IRC is higher than 1.89, and a lot of heterocharge accumulates near the surface of the sliced samples. Meanwhile, the crosslinking byproducts residing in the insulation act as deep traps. These deep traps are associated with the third type of relaxation deduced from the isothermal relaxation current, which leads to a high aging factor. Aging factor of aged cable is significantly higher than that of unaged cable. Furthermore, the heterocharge accumulation and the maximum distortion electric field evaluated by space charge distribution distinctly increase in the aged cable, which are the same variation trends as the aging factor acquired by the isothermal relaxation current. Therefore,the IRC method can be applied to condition assessment for XLPE insulated HVAC cable. © 2016, High Voltage Engineering Editorial Department of CEPRI. All right reserved.

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