EV-E900U充电桩电缆

The operation quality, safety and reliability of power supply system are not only related to the quality of wire and cable, but also related to the construction quality of cable accessories and lines.

1.电缆的敷设方式

1 cable laying method

电缆的敷设方式有以下几种:直埋敷设、穿管敷设、浅槽敷设、电缆沟敷设、电缆隧道敷设、架空敷设几种方式都有优缺点,一般要考虑城市发展规划,现有建筑物的密度电缆线路长度敷设条数及其周围环境的影响等。从技术上比较,电缆隧道方式和电缆沟敷设方式便于电缆的施工、维护和检修。在一些发达国家城市中,城市规划建设时,已考虑公用隧道。实践证明公用隧道运行效果良好,大大降低了重复投资次数和反复开挖路面的现象,但初期投资巨大,建筑材料耗资金,在国内,由于各种因素的限制,这种敷设方式是极少的。相比而言,直埋敷设和浅槽敷设则是属于经济型的敷设方式,直埋电缆是最经济而广泛系用电敷设方式,它运用于郊区和车辆通行不太频繁的地方。但不利于电缆的维护和检修,一旦遇到电缆故障,即使使用测试仪测出故障点,也要重新挖开电缆沟,极不方便。因此电缆敷设方式的选择,要结合实际情况,根据工程条件、环境特点、电缆型号和数量等因素,用发展的眼光,按照满足运行可靠性、便于维护的要求和技术经济合理的原则确定。EV-E900U充电桩电缆

Cable laying methods are the following: laying, laying, shallow trench laying, cable trench laying, cable laying, tunnel overhead laying methods have advantages and disadvantages, generally consider the city development plan, the density of existing buildings laying cable line length number and its surrounding environment etc.. From the technical comparison, the cable tunnel and cable trench laying way is convenient for the construction, maintenance and repair of the cable. In some cities in developed countries, public utilities have been considered in urban planning and construction. Practice has proved that the running effect of the public good tunnel can greatly reduce the duplication of investment, and the number of the phenomenon of repeated excavation of the road, but the huge initial investment, building materials consumption funds, in China, due to a variety of factors, this kind of way of laying is rare. In contrast, buried and shallow trench laying is laying mode belongs to the economy, is the most economical and widely buried cable system electricity laying mode, it is applied to the suburbs and the traffic is not too frequent. But it is not conducive to the maintenance and repair of the cable, once encountered cable fault, even if the use of test to measure the fault point to reopen cable channel, very convenient. So the cable laying methods, combined with the actual situation, according to the engineering conditions and environmental characteristics, the number and type of cable and other factors, the vision of development, to meet the operation reliability and convenient maintenance requirements and reasonable technical and economic principles.

2.电缆的选型

2 cable selection

常用的电力电缆有油浸电缆、聚氯乙烯绝缘电缆、交联聚乙烯电缆等,根据使用场合的不同,又延伸为不同种类的特种电缆。目前,随着生产技术和生产工艺的不断提高,交联聚乙烯电缆已成为使用最广的电缆产品,在电缆选型时,应根据使用的不同环境和条件,结合具体情况进行选择,尽量减少穿越各种管边铁路,公路和通讯电缆;如采用直埋和浅槽敷设方式时,应考虑使用加钢铠的电缆。EV-E900U充电桩电缆

Power cables are commonly used in oil filled cable, PVC insulated cables, XLPE cables, according to the use of different occasions, and extended to different types of special cable. At present, with the production technology and the continuous improvement process, XLPE cable cable products has become the most widely used in cable selection, should be used according to the different environment and conditions, combined with the specific circumstances of the choice, try to reduce the pipe edge through the various railway, highway and communication cable; such as the use of buried and shallow trench laying the way, should consider the use of cable with steel armor.

3.电缆截面积的选择

3 cable cross-sectional area selection

电缆截面积的选择,关系到投资多少、线路的损耗和电压质量、电缆的使用寿命等。如选用截面积偏小,会导致电压质量下降、线路损耗过大,则会使初期投资太高。因此应根据负荷预测结果,发展规划,选择合适的截面积,使电力电缆满足最大工作电流下的缆芯温度要求和电压降要求,最大短路电流作用下的热稳定要求。由于负荷预测工作难度性高、准确性较低,因此,选择电缆截面积时,还要满足《城市中低压配电网改造技术导则》和《城市电力网规划导则》要求。EV-E900U充电桩电缆

The choice of cable cross-sectional area is related to the number of investment, line loss and voltage quality, the service life of the cable. Such as the use of cross-sectional area is too small, will lead to a decline in the quality of the voltage, line loss is too large, will make the initial investment is too high. It should be development plan according to the forecast results, select the appropriate load, the cross-sectional area of the cable core power cable, meet the temperature requirements under the maximum working current and voltage drop, thermal stabilization requirements under the maximum short-circuit current. Because of the high accuracy and low accuracy of load forecasting, the selection of the cross section of the cable can meet the requirements of the technical guidelines for the transformation of urban low voltage distribution networks and the guidelines for urban power network planning.

在三相四线制低压电网选用电力电缆时,还要考虑零线截面积的选择,在公用低压网络中,由于受用户因素影响较大,三相负荷平衡难以控制,为改善电压质量,降低线损,零线截面积应与相线截面积相同。

In three-phase four wire power cable selection of low-voltage power grid, but also consider the zero line cross-sectional area of choice in public low-voltage network, because the user is affected by the factors, it is difficult to control the three-phase load balance, to improve the quality of voltage, reduce the loss, the zero line cross-sectional area should be the same as the phase area.

4.关于电缆网络及电缆网络自动化

4 cable network and cable network automation

随着电力电缆在配电网中的不断推广与使用,配电网可分为电缆网络和架空网络(含架空、电缆混合网络)。《关于〈城市中低压配电网改造技术导则〉的实施情况及补充意见》也对电缆配电网络自动化提出了具体要求。因此,在配电网区域网络采用电缆网络时,应按照配电自动化的要求,采用新技术、中国电线电缆网 新设备,有条件的要考虑自动化试点工作,条件不成熟的也要在配套设备选型时,考虑有充分余地,为实现自动化方案打下基础。

With the popularization and application of power cable in distribution network, distribution network can be divided into cable network and overhead network (including overhead and cable hybrid network). "On the implementation of the technical guidelines for the transformation of urban low voltage distribution network," and also put forward specific requirements for the cable distribution network automation. Therefore, the cable network in the distribution network of regional network, should be in accordance with the requirement of distribution automation, using new technology and equipment Chinese cable network , has the condition to consider the pilot work automation, the conditions are ripe, but also in the equipment selection, consider the full room, lay the foundation for the realization of automation solutions.

5.电力电缆施工中应注意的问题

5 should pay attention to the construction of power cable

1)、是大电流电力电缆引发的涡流问题

1) is the eddy current problem caused by high current power cable

电力电缆在施工中,有采用钢支架的,有采用钢质保护管的,有采用电缆卡与架空敷设的,凡是在电力电缆周围形成钢(铁)性闭合回路的,均有可能形成涡流,特别是在大电流电力电缆系统中,涡流更大。在电力电缆施工时,必须采取措施,使电缆周围不能形成钢(铁)性闭合回路,防止电缆引起涡流现象发生。

Power cable in construction, with steel support, a steel protection tube, using cable card and overhead, usually in the form of power cable around the steel (iron) closed loop, are likely to form a vortex, especially in the high current power cable system, higher eddy current. In the construction of power cable, measures must be taken to avoid the formation of steel (iron) closed loop around the cable, so as to prevent the eddy current caused by the cable.

2)、是电力电缆的转弯引起的机械性损伤问题

2) is the mechanical damage caused by the turn of power cable

由于电力电缆外径较大,运输、敷设较为困难,电力电缆对转弯半径的要求也比较严格。电力电缆在施工中,如果转弯角度过大,可能使导体内部受到机械损伤,而机械损伤因被电缆绝缘强度下降,直到出现故障,施工中发现一次电缆头故障,在电缆头制作时,三根电缆头长度一致,与设备连接时由于受地形限制,中相电缆头偏长而成为拱形,电缆头根部受损放电。后采取措施,在设备的连接,适当缩短中相电缆头连接长度,使三相电缆头均不受外力,实践证明运行效果良好。由此可见,电缆施工过程中,要尽可能减少电缆受到的扭力,在电缆转弯和裕留电缆时,让电缆处于自然弯曲,杜绝内部机械损伤现象。

Due to the large diameter of the power cable, transportation, laying more difficult, the power cable to turn radius requirements are more stringent. Power cable in the construction, if the turning angle is too large, may cause the internal conductor by mechanical damage, and mechanical damage caused by cable insulation strength decreased, until the failure, found that the construction of a cable fault in making cable head, three cable head same length, and equipment connected by terrain that is head of the cable is too long and become an arch, cable head damaged discharge. After the measures taken in the connection of the equipment, appropriate to shorten the length of the cable connector in the middle phase, so that the three phase cable head are not subject to external forces, practice has proved good results. Thus, the cable construction process, as far as possible to reduce the torque of the cable, in the cable turn and stay cable, let the cable in the natural bent, put an end to the phenomenon of internal mechanical damage.

3)、是电力缆防潮问题

3) is the power cable moistureproof problem

运行经验表明,中、低压电力电缆故障大部分为电缆中间

Operating experience shows that most of the faults of medium and low voltage power cables are cables