Design of special cable for inverter motor


In the production process of special-purpose cables for […]

In the production process of special-purpose cables for variable frequency motors, the process of extruding the insulated cores and forming the cables is the most critical process. Insulation core extrusion process The quality of the insulation core will directly affect the electrical performance of the cable. In order to improve the quality of the cable, we choose high-performance insulation materials for production, such as special cables for 1.8 / 3kv inverter motors, using 10kV cross-linked insulation materials, special cables for 6 / 10kv inverter motors use 35kv cross-linked insulation materials, conductor shielding, insulation shielding And insulation materials are imported materials. In the production process, special attention is paid to the purification of raw materials, the shielding is tightly packed with the insulating material, and the insulation eccentricity and the uniform outer diameter of the insulation are controlled, which can reduce the interface effect and improve the electrical performance of the cable.

The energy saving effect of the frequency conversion device is very obvious. The frequency conversion speed regulation motor is used in the high-power motor, and the entire generator set can save electricity by 30%. And after the use of variable frequency speed regulation, the soft start of the motor is achieved, the motor works smoothly, the motor bearing wear is reduced, and the motor life and maintenance cycle are extended. Therefore, the frequency conversion speed regulation technology has been widely used in petroleum, metallurgy, power generation, railway, mining and other industries.

Cable symmetry design

For 1.8 / 3KW and below dedicated motors for variable frequency motors, and symmetrical 3 + 1 core and 4 core cables can only be used as the input cables of the main power supply, but it is best to use symmetrical structure cables. Inverter and inverter motor cables must use symmetrical cable structure. There are two types of symmetrical cable structure: 3 cores and 3 + 3 cores. The 3 + 3 core cable structure is the fourth core of the three large, small and four core insulated wires. Neutral core) is broken down into three smaller insulated cores, and the three cores and three smaller cores are symmetrically formed into cables. For 6 / 10kV variable frequency motor special cables, the cable structure is different from 6 / 10kV ordinary power cables. For ordinary power cables, the three insulated cores are shielded with copper tape to form a cable, while the special-purpose variable-frequency motor cables are shielded with copper wire and copper tape and extruded with a phase-separated sheath, and then symmetrically formed into cables. The symmetrical cable structure is It has better electromagnetic compatibility and plays a role in suppressing electromagnetic interference. It can offset the odd-order frequencies in high-order harmonics, improve the anti-interference performance of the special-purpose cable for variable frequency motors, and reduce the Electromagnetic radiation.