充电系统用电缆EV-VVPV

EV-VVPV

聚氯乙烯绝缘铜丝编织屏蔽取氯乙烯护套电动汽车传导充电系统用电缆

Many researches have been done on the measurement of DC resistance of aluminum stranded conductors. In GB3048, the distance between the voltage and current terminals and the measuring current are measured. For qualified single stranded wire core of normal process, in the actual measurement there are still problems to be discussed, such as the potential end shape on the measurement results, the four electrode method to measure the resistance of the key points, how to realize the measurement of the current uniform etc.. I put forward the following views on the above problems.EV-VVPV充电系统用电缆

一、用合格单线和正常绞合工艺绞出的线芯电阻有一定的余量EV-VVPV充电系统用电缆

A qualified single line and normal line core stranding process out of resistance of some margin

绞合线芯中各单线间的绝缘，电流都是沿单线成螺旋状流动，且线芯的全部单线都可靠地与电流引入端相接。计算1m长绞线中各层展开的长度，按并联电阻计算公式，计算绞线的直流电阻公式如：

The insulation of each single wire in the twisted wire core is in a spiral flow along a single line, and all the single wires of the wire core are reliably connected with the current leading end. The length of each layer in the 1m long wire is calculated, and the DC resistance formula is calculated according to the formula of the parallel resistance:EV-VVPV充电系统用电缆

实际绞合线芯的单线间还存在一定电导，电导的大小与单丝表面情况有关。电导存在使线芯中有直流不完全沿单线螺旋状流动，有一部分电流是沿单丝成轴向流动。此时线芯直流电阻比电流完全沿单丝成螺旋状流动时还要小些。由于绞合后铝单线的电阻无明显变化，在单线合格下，即使考虑到线芯成缆后长度增加1％，绞合线芯电阻还是有一定余量。

There is a certain conductance between the single strand of the actual wire core. The existence of the conductance makes the core of the wire is not completely along the single wire spiral flow, a part of the current is flowing along the axial direction of the filament. At this time, the DC resistance of the wire core is smaller than that of the current. Because of the resistance of the twisted aluminum wire, there is no obvious change in the single wire, even if the length of the cable core is increased by 1%, the resistance of the twisted wire core has a certain margin.

二．产生测量值不合格的原因

Two. The cause of the unqualified measurement value

出现绞线电阻不合格现象，原因都在于电阻测量中测量电流未能均匀地流经试样。

The reason for the failure of the twisted wire resistance is that the measured current in the resistance measurement can not flow uniformly through the sample.

线芯的全部单丝可靠地与电流引入端相接，且线芯中的单丝间绝缘电流沿单丝成螺旋状流动。那么在单丝直径相同、质地均匀的情况下，试样上垂直于线芯的截面应该是等位面，处于该截面上的单丝间电位差为零。在等位情况下，电压端间电位差不会因电压夹具的形状，与试样接触的方式及其对试样的压紧力的改变面变化 。

All the single wires of the wire core are reliably connected with the current leading end, and the insulation current between the filaments in the wire core flows along a single filament. In the case of the same diameter and uniform texture, the cross section perpendicular to the core should be the equipotential plane, and the potential difference between the filaments on the section is zero. Under the condition of the equal position, the voltage difference between the voltage terminals will not be changed due to the shape of the voltage clamp, the contact mode with the sample and the change of the clamping force on the sample.

目前测量绞线电阻的夹具形状多为刀状与围状，通过拧紧螺栓对试样产生压力。由于铝单丝表面氧化膜的存在，当测量电流通过这种形式夹具引入试样时，其电流分布往往是不均匀的，绞线外层单丝的电流密度。该现象随绞线截面增加而严重。V型电流夹具虽比刀状，圆环状电流夹具有了较大的改进，但还不能使电流达到理想的均匀状态。分布不均匀的测量电流使相距1m的两电压端的电压差，大于均匀测量电流下两电压端间的电压差。在这种情形下，对电压端夹具形状，压力作近一步改进也往往不能奏效。因此，解决电阻测量问题的关键是如何测量电流均匀及电压端夹具的要求，可使测量电流均匀而降底。

At present, the shape of the clamp for measuring the resistance of the wire is mostly a knife shape and a surrounding shape. Because of the existence of oxide film on the surface of aluminum wire, the current distribution is uneven when the measuring current is introduced into the sample by this kind of fixture. This phenomenon is serious with the increase of the cross section of the twisted wire. Although the current clamp of V type is more than the cutter shape, the circular current clamp has a great improvement, but it can not make the current reach the ideal uniform state. The voltage difference between the two voltage terminals of the 1m is not equal to that of the measured current, which is greater than the voltage difference between the two voltage terminals under uniform current. In this case, it is often not possible to make a near - improvement in the shape of the voltage - end fixture. Therefore, the key to solve the problem of resistance measurement is how to measure the current uniformity and the requirements of the voltage clamp.

三．解决方法

Three. Solutions

为了使线芯内部电流均匀，试样端可采取处理。处理方法是采用端部焊接法，并尽量使电流端同线芯焊接处靠近。采用此法目前还存在着一些问题。

In order to make the internal current of the wire core uniform, the sample end can be treated. The method is to use the end welding method, and try to make the current end with the wire core welding near. There are still some problems in this method.

除了焊接法，还有端部冷压接铝鼻子法，此方法能达到测量电流均匀简单有效的好方法。要使电流均匀，必须减小引入端与试样的接触电阻。采用压缩型的的螺栓拧紧的方法要小。压缩型的接触电阻为几微欧至十几微欧，而夹紧型电流端与试样的接触电阻为几十至一、二百微欧。采用冷压接方法，测量电流直接从铝鼻子引入，可以较好地克服因单丝间氧化膜存在电流分布不均匀现象。

In addition to the welding method, as well as the end of the cold pressed aluminum nose method, this method can achieve a simple and effective method to measure current uniformity. In order to make the current uniform, the contact resistance between the sample and the sample must be reduced. The use of compression bolt tightening method to small. Contact resistance compression type for a few European Ten micro ohm contact resistance, and the clamping end and the current sample is ten to one of two hundred microhm. The method of cold pressing is adopted to measure the current directly from the nose of aluminum, which can overcome the phenomenon that the current distribution is uneven.

铝绞合导体电阻测量方法的解决,对电力电缆产品可作出公正的评定,电阻的准确测量为企业减小单丝直径,节约原材料,进行工艺改进提供重要依据,从这方面来讲，更具有实际意义.

The measurement method of aluminum stranded conductor resistance, the power cable products can make a fair assessment, accurate measurement of resistance for the enterprise to reduce the filament diameter, saving raw materials, the process provides important basis to improve, in this regard, has more practical