1. What is the inverter cable?

In layman's terms, frequency conversion cables are cables mainly used for the connection between frequency conversion power supplies and frequency conversion motors. Frequency conversion cables have a wide range of applications and are suitable for mining, metallurgy, papermaking, railway, food processing and metal processing industries.

2. So what is the biggest difference between frequency conversion cables and ordinary cables?

First of all, the variable frequency cable works in a special environment, and its working frequency adjustment range is wide, which will cause it to work regardless of the high or low operating frequency, it will have a waveform profile of the main frequency, and will contain many higher harmonics. After the generation of multiple reflection amplitudes, the voltage it bears can reach several times the working voltage. Under such working conditions, if the insulation safety factor of the frequency conversion cable is not high enough, it is very easy to cause the cable to be broken down, which will cause a series of safety accidents and cause huge losses.

Secondly, we can think that the cable will pollute the external electromagnetic waves when it is working. Especially in the industrial field, this phenomenon can occur widely, mainly because the motor power is relatively large, and the length of the cable connecting the variable frequency power supply and the variable frequency motor is also relatively long. This causes the cable to act as an effective carrier for emitting high-frequency electromagnetic waves when it is working, which is called environmental pollution of electromagnetic waves.

3. What problems do we need to overcome when designing variable frequency cables?

First of all, the problem that needs to be overcome is that ordinary cables may be broken down within a few hours under variable frequency conditions. After analysis, it can be concluded that this phenomenon is by no means caused by insulation aging, but it can be attributed to the influence of high-frequency pulse voltage on insulation. Therefore, the selection of insulation materials in cable design is very important. Analyzing common cable materials, we can know that PVC insulation often accelerates insulation breakdown due to its large dielectric loss, and cross-linked polyethylene insulation has both Heat, electricity, machinery and other excellent performance, so we choose cross-linked polyethylene as the insulating material of the frequency conversion cable. At the same time, when designing the insulation thickness of the cable, we can also increase the insulation thickness appropriately to make the frequency conversion cable safer and more reliable.

Secondly, we need to solve the problem of environmental pollution caused by high-frequency electromagnetic waves. Taking the four-core low-voltage cable as an example, we can first reduce the environmental pollution caused by high-frequency electromagnetic waves by improving the arrangement of insulated cores. If the three main cores of the cable are directly connected to the ground core, the magnetic field generated by the harmonic current will be asymmetric; the ground core is decomposed into three insulated cores with smaller cross-sections, and the three small cores are symmetrical When the cable is formed, the magnetic field can be basically symmetrical and the external interference of the magnetic field can be reduced. Secondly, the shielding structure should be strengthened. Generally, copper wire braided shielding is used. In fact, the shielding structure consumes a lot of materials, has a slow processing speed, and the shielding effect is not the best. In order to achieve a better shielding effect and facilitate production, a copper tape shielding and copper wire braided structure is adopted, which can effectively suppress the external emission of electromagnetic waves.