China Zhenglan Cable Technology Co., Ltd Company News

Precautions 1、 Observe the appearance of the wire. The insulation (sheath) layer of qualified products is soft, tough and flexible, and the surface layer is tight, smooth and free of roughness. If the plastic wrapping the wire is easy to peel off, there is a problem of insufficient plastic strength. 2、 It depends on the cross-section of the wire. The surface of copper core or aluminum core of qualified products should have metallic luster. Copper with black surface or aluminum with white surface indicates that it has been oxidized. 3、 Pay attention to check the quality certificate when purchasing wires. If the quality of the wire is qualified, the wire quality should also be tested, and there will be no big problem.

4. Wire and cable with unqualified conductor resistance Conductor resistance is an important indicator for evaluating the compatibility of wire and cable conductor materials and cross-sections. When the conductor resistance exceeds the standard, the loss of the current passing through the line is increased, and the heating of the wire and cable is aggravated. The main reason for the unqualified conductor resistance is that some companies shrink the copper material, which accounts for 80% of the raw material cost, in order to reduce the cost, reduce the cross-sectional area of the conductor or use recycled copper with too high impurities, which causes the conductor resistance of the wire and cable to seriously exceed the standard. , In the process of use, in addition to easily causing fire, it will also accelerate the aging of the insulating layer covering the wire.

The metal shielding methods of medium-voltage XLPE insulated power cables are mainly composed of copper tape overlap wrapping shielding and sparse copper wire shielding. According to the GB/T12706-2008 standard for cables with rated voltage from 6kV to 35kV, the average overlap ratio of copper tape in the copper tape shielding method is not less than 15% of the width of the copper tape (nominal value), and the minimum value is not less than 5%. The thickness of copper tape for single-core cables is ≥ 0. 12mm, the average thickness of multi-core cables is ≥ 0. 10mm, and the minimum thickness of copper tape is not less than 90% of the nominal value. The copper wire shield consists of loosely wound soft copper wires, the surface of which should be fastened by reversely wound copper wires or copper tapes, and the average gap between adjacent copper wires should not be greater than 4mm. The shielding on the cable structure is a measure to improve the distribution of the electric field. The role of the metal shielding mainly has the following aspects: 1. When the cable is normally energized, the metal shielding layer passes the capacitive current, and when the short-circuit fault occurs, the short-circuit current passes. 2. The electromagnetic field caused when the cable is energized is shielded in the insulated core to reduce electromagnetic interference to the outside world, and the metal shielding layer also limits the impact of the external electromagnetic field on the interior. 3. The power station protection system requires the outer metal shield to have better lightning protection properties. 4. Homogenize the electric field to prevent axial discharge. Since the semi-conductive layer has a certain resistance, when the metal shielding layer is poorly grounded, the cable will discharge along the surface due to uneven potential distribution in the cable axis.

3. Wire and cable with aging insulation layer   The unqualified tensile strength and elongation of the insulating sheath before aging directly greatly shortens the working life of the wire and cable, and the insulator is easily broken during construction or in a long-term energized and high-temperature environment, resulting in live conductors. If exposed, there is a risk of short circuit that can cause electric shock. The main reasons for its failure are: first, the use of recycled materials for production to reduce product costs; second, small enterprises that do not have production qualifications cut corners for profit.

2. Wires and cables with unqualified structural dimensions The main problem of the structure size is the thickness of the sheath and the thickness of the insulation. When the sheath and insulation thickness of the cable do not meet the standard, the electrical strength of the wire and cable will be seriously reduced, resulting in a shortened service life of the wire and cable. and cables may break, insulation may not work properly, resulting in electrical shorts and fires.

On May 30, the country's first tidal-light complementary smart photovoltaic power station - National Energy Group Longyuan Zhejiang Wenling Chao-light complementary smart photovoltaic power station achieved full-capacity grid-connected power generation, creating a new energy comprehensive application of photovoltaic and tidal power generation in perfect harmony. This indicates that my country has made new achievements in the comprehensive utilization of marine energy and the three-dimensional development and construction of new energy.   The power station is the first and currently the only Chaoguang complementary smart photovoltaic power station in China. It is located in Wugen Town, Wenling City, Zhejiang Province. Silicon bifacial modules. The power station complements China's largest tidal power station, comprehensively utilizes solar energy and tidal energy, forming a scene of "the sun and the moon work together, and the water and the water generate power together".   It is understood that the level of intelligence and automation of the power station has reached the domestic first-class level, realizing few people and no one on duty. The power station uses UAV inspection technology and AI intelligent diagnosis system, relying on the big data analysis of the digital platform, to carry out remote diagnosis of photovoltaic power generation equipment health monitoring, to detect potential equipment problems in advance, and the early warning accuracy rate is over 85%, reaching the industry's leading position, achieving from The transformation from "people looking for information" to "information looking for people", equipment operation and maintenance has changed from passive to active, which effectively guarantees the economic benefits of the power station.