China Zhenglan Cable Technology Co., Ltd Company News

Wire. A slender rod or filament of drawn metal. (This definition restricts the term wire to what would ordinarily be understood by the term solid wire. In the definition the word slender is used in the sense that the length is great in comparison with the diameter.   If a wire is covered with insulation, it is properly called an insulated wire, although the term wire refers primarily to the metal; nevertheless, when the context shows that the wire is insulated, the term wire will be understood to include the insulation.)   Conductor. A wire or combination of wires not insulated from one another, suitable for carrying a single electric current. (The term conductor does not include a combination of conductors insulated from one another, which would be suitable for carrying several different electric currents. Rolled conductors, such as busbars, are, of course, conductors but are not considered under the terminology given here.)   Stranded Conductor. A conductor composed of a group of wires or any combination of groups of wires. (The wires in a stranded conductor are usually twisted or braided together.)   Cable. A stranded conductor (single-conductor cable) or a combination of conductors insulated from one another (multiconductor cable). The component conductors of the second kind of cable may be either solid or stranded, and this kind may or may not have a common insulating covering. The first kind of cable is a single conductor, while the second kind is a group of several conductors.   Strand. One of the wires or groups of wires of any stranded conductor.   Stranded Wire. A group of small wires used as a single wire. (A wire has been defined as a slender rod or filament of drawn metal. If such a filament is subdivided into several smaller filaments or strands and is used as a single wire, it is called stranded wire.   There is no sharp dividing line of size between a stranded wire and a cable. If used as a wire, for example in winding inductance coils or magnets, it is called a stranded wire and not a cable. If it is substantially insulated, it is called a cord, defined below.)   Cord. A small cable, very flexible and substantially insulated to withstand wear. (There is no sharp dividing line in respect to size between a cord and a cable and likewise no sharp dividing line in respect to the character of insulation between a cord and a stranded wire.)   Concentric Strand. A strand composed of a central core surrounded by one or more layers of helically laid wires or groups of wires.

This year's "11" golden week (October 1-8) nationwide average daily power generation of 18.367 billion kwh, an increase of 4.79% compared with last year's holiday (October 1-7). As a key state-owned enterprise in the energy and power industry, SGCC firmly implements the new energy security strategy of "four revolutions and one cooperation", takes ensuring the safe operation and reliable power supply of the power grid as the top priority, speeds up the construction of power infrastructure, complements the weak points and forging the long ones, stabilizes the economy and benefits the people's livelihood, continuously meets the power needs of the people for a better life and gives full play to the basic guarantee Function, smooth domestic circulation, accumulate basic strength for economic development. Since then, the national power grid construction project of Hebei qianxiong hydropower station has been put into operation, and the national power grid construction project of 800 kV in Hebei Dongxiong power grid has been put into operation A large number of key power grid projects have effectively driven the upstream and downstream enterprises to resume work and production, providing safe and reliable power guarantee for social development and injecting surging momentum into economic operation. In the first three quarters of this year, 36502km and 205.44 million KVA power grid infrastructure projects of the State Grid of China were put into operation, accounting for 74% of the annual plan; 32895km and 201060000 KVA were started, accounting for 67% of the annual task, creating favorable conditions for the overall completion of the annual construction tasks. As a safeguard of the national economy, it is an important task for the State Grid Corporation of China to serve the main body of the market well. In 2020, the State Grid Corporation of China will resolutely implement the national electricity price reduction policy. It is estimated that the annual electricity tariff reduction will be about 92.6 billion yuan, and the social energy cost will be reduced. Recently, the State Grid Corporation of China (SGCC) has issued nine measures to comprehensively improve the service level of "access to electricity", which will save more than 100 billion yuan of investment for enterprises in three years. Previously, State Grid Corporation of China has issued ten service guarantee measures to further improve power supply service and support 5g development. State Grid Corporation of China firmly implements the new energy security strategy of "four revolutions and one cooperation", unswervingly follows the path of grid development with Chinese characteristics, promotes the construction of a clean, low-carbon, safe and efficient energy system, and empowers beautiful China. The State Grid Corporation of China (SGCC) has taken various measures to promote the development of clean energy and ensure that the utilization rate of hydropower, wind power and solar power is above 95% throughout the year.This year's "11" golden week (October 1-8) nationwide average daily power generation of 18.367 billion kwh, an increase of 4.79% compared with last year's holiday (October 1-7). As a key state-owned enterprise in the energy and power industry, SGCC firmly implements the new energy security strategy of "four revolutions and one cooperation", takes ensuring the safe operation and reliable power supply of the power grid as the top priority, speeds up the construction of power infrastructure, complements the weak points and forging the long ones, stabilizes the economy and benefits the people's livelihood, continuously meets the power needs of the people for a better life and gives full play to the basic guarantee Function, smooth domestic circulation, accumulate basic strength for economic development. Since then, the national power grid construction project of Hebei qianxiong hydropower station has been put into operation, and the national power grid construction project of 800 kV in Hebei Dongxiong power grid has been put into operation A large number of key power grid projects have effectively driven the upstream and downstream enterprises to resume work and production, providing safe and reliable power guarantee for social development and injecting surging momentum into economic operation. In the first three quarters of this year, 36502km and 205.44 million KVA power grid infrastructure projects of the State Grid of China were put into operation, accounting for 74% of the annual plan; 32895km and 201060000 KVA were started, accounting for 67% of the annual task, creating favorable conditions for the overall completion of the annual construction tasks. As a safeguard of the national economy, it is an important task for the State Grid Corporation of China to serve the main body of the market well. In 2020, the State Grid Corporation of China will resolutely implement the national electricity price reduction policy. It is estimated that the annual electricity tariff reduction will be about 92.6 billion yuan, and the social energy cost will be reduced. Recently, the State Grid Corporation of China (SGCC) has issued nine measures to comprehensively improve the service level of "access to electricity", which will save more than 100 billion yuan of investment for enterprises in three years. Previously, State Grid Corporation of China has issued ten service guarantee measures to further improve power supply service and support 5g development. State Grid Corporation of China firmly implements the new energy security strategy of "four revolutions and one cooperation", unswervingly follows the path of grid development with Chinese characteristics, promotes the construction of a clean, low-carbon, safe and efficient energy system, and empowers beautiful China. The State Grid Corporation of China (SGCC) has taken various measures to promote the development of clean energy and ensure that the utilization rate of hydropower, wind power and solar power is above 95% throughout the year.

NG-A is the type code of the national standard to be published, in order to standardize the naming of different models of each manufacturer; Btly is an isolated mineral insulated cable. Since there is no industry and national standard before, it usually follows the enterprise standard, so the model name of each manufacturer is different; Now the national standard will be implemented, and the unified model name is NG-A(BTLY) . The type letters of ng-a BTLY are as follows: G -- isolation N -- fire resistance A----950-1000C° B -- mineral insulated cables for wiring T --- copper conductor L --- aluminum metal sleeve Y -- PVC outer sheath BTLY cable is an improved fireproof cable based on BTTZ mineral insulated cable. The BTLY cable produced by Zhenglan Cable confirms to BS6387 standard test In fact, the performance of the two cables is the same, but the model name is different. In the future, they will be named NG-A(BTLY) cable

Power cable is used to transmit and distribute electric energy. It is often used in underground power grid, power station outgoing line, internal power supply of industrial and mining enterprises and transmission line under river and sea. In power lines, the proportion of cables is increasing gradually. Power cable is main line of power system to transmit and distribute high-power power power, including 1-500kv and above voltage levels and various insulation power cables. Construction: The basic construction of power cable consists of four parts: core (conductor), insulation, ssreec and jacket . 1.Core The core is the conductive part of the power cable, which is used to transmit the electric energy, and is the main part of the power cable. 2.Insulation Insulation layer is an indispensable part of the structure of power cable, which separates the core from the earth and the cores of different phases in electrical field to ensure the transmission of electric energy. 3.Screen The power cables with 15kV and above generally have conductor shielding layer and insulation shield layer. 4.Jacket The function of the protective layer is to protect the power cable from the invasion of external impurities and water, and to prevent the external forces directly damaging the power cable.

XLPE or Cross-linked polyethylene is a thermoset insulation material. Crosslinking polymers is a process which changes the molecular structure of the polymer chains so that they are more tightly bound together and this crosslinking is done either by chemical means or physical means. Chemical crosslinking involves the addition of chemicals or initiators such as silane or peroxide to generate free radicals which form the crosslinking. Physical crosslinking involves subjecting the polymer to a high energy source such as high-energy electron or microwave radiation. Polyethylene (PE) material itself has excellent dielectric strength, high insulation resistance, and a low dissipation factor at all frequencies making it an ideal insulator, however it is limited in its temperature range. Cross-linking the PE to become XLPE increases the temperature range of the insulation whilst maintaining the electrical properties.

Cable withstand voltage test is a way to find faults in the presence of cables. It is easily affected by various factors during the test, resulting in problems such as failure and short circuit. The main methods of several cable withstand voltage tests are described below. First, ultra low frequency withstand voltage test The ultra-low frequency (0.1Hz) withstand voltage test method first appeared in 1980, and it is mainly a non-destructive test method for observing whether there is insulation defect in cable operation, and the method has been verified by a large number of laboratory tests and field tests. The low-frequency withstand voltage test has a good application effect in the low-voltage power cable withstand voltage test. The method utilizes the principle of converting 50 Hz alternating current into direct current voltage through rectification and filtering, and then converting the direct current voltage into an alternating current voltage of 1 kHz through an inverter circuit, and then performing amplitude modulation processing by a 0.1 Hz sinusoidal oscillator, and after amplitude modulation, 1 kHz. The amplitude wave such as the AC voltage is converted into a 0.1 Hz varying beam wave. It is mainly based on the high voltage formed between the high voltage transformer and the voltage multiplying circuit, which is mainly characterized by a sine wave and is mediated by a varistor, so that the high AC voltage load output is a 0.1 Hz high voltage sinusoidal waveform. The advantages of the ultra-low frequency withstand voltage test are mainly: 1 no damage; 2 high accuracy; 3 small size, easy to carry. However, the output voltage level of this method is low, and it is mainly used in the medium and low voltage cable withstand voltage test. Second, the modulated power frequency series resonance test The method mainly utilizes the inductive reactance of the reactor and the capacitive reactance of the measured cable capacitance to generate a resonance in a 50 Hz power frequency environment, and a high voltage is generated in the process. The advantages of the modulated power frequency series resonance test are: 1 the output current waveform is basically a sine wave; 2 is high in specificity, and only after the series resonant circuit satisfies the condition for generating resonance, a high voltage is formed, and the cable to be tested is once tested. If there is a problem, it will cause a loop abnormality, which is equivalent to a short circuit of the cable. The high voltage will also appear to be uniformly dropped. Moreover, since the reactor can limit the short-circuit current, the protection device is not affected, and thus it is not necessary to install a resistor protection device. The disadvantage of this test method is that the operation is complicated, the system quality factor is not high, the automation level is low, and the noise is large, which limits its application in practice. Third, the frequency conversion series resonance test The principle of frequency conversion series resonance test is similar to the above-mentioned principle of modulated power frequency series resonance test. The difference is that the frequency conversion series resonance test realizes the resonance of the test circuit by adjusting the output voltage frequency in the variable frequency power supply; In the frequency series resonance test, the resonance of the test circuit is realized by the inductance generated by the regulating reactor at the 50 Hz power frequency. The advantage of the variable frequency series resonance test is that when the required power supply capacity of the test is lower than the power supply capacity of the cable under test, the test can be performed at a much lower power than the required power supply, which can effectively improve the efficiency of the field test and can overcome The shortcomings of the modulated power frequency withstand voltage test device make it more widely used in real life. In addition, the operating frequency of the variable frequency series resonance test is only 30 to 300 Hz, which can improve the problem that the frequency of the ultra-low frequency withstand voltage test is too low and the loss is small, which is inconsistent with the actual loss. Therefore, the results obtained by the variable frequency series resonance withstand voltage test are precise, comprehensive and reliable.