Understand the difference between variable frequency cables and ordinary power cables

Update:12-08-2020
Summary:

Product Usage Variable-frequency cables are mainly used […]

Product Usage
Variable-frequency cables are mainly used for connecting cables between variable-frequency power supplies and variable-frequency motors, as well as power transmission and distribution lines with a rated voltage of 1KV and below, for power transmission. Especially suitable for papermaking, metallurgy, metal processing, mining, railways and food Processing and other industries.
Conditions of use and advantages
1) Completely symmetrical space structure design, the cable has excellent electromagnetic compatibility.
2) Low and uniform forward (reverse) sequence and zero sequence impedance, which greatly improves the quality of power supply compared with ordinary four-core cables.
3) The high-density braided shielding and composite shielding design make the cable have good anti-electromagnetic interference and electromagnetic radiation performance, which is conducive to the application of new automatic short-circuit protection equipment.
4) The interference of higher harmonic current components to other control circuits is completely shielded.
5) The cross-sectional design of the shielding layer reaches a certain ratio to the main core, which can be used as a PE grounding wire.
6) The maximum operating temperature of the cable conductor is compatible with the insulating material.
7) Using low-smoke halogen-free flame-retardant sheath, the cable has the characteristics of less smoke and no toxic gas in case of fire, which is safe and environmentally friendly.
8) The bending radius of the cable is 12 times the cable diameter, and the flexible cable is 6 times the cable diameter.
9) The ambient temperature of PVC and XLPE insulated cables during cable laying should not be lower than 0℃.

Common product model name and model description
BPYJVP: XLPE insulated and PVC sheathed copper wire braided shielded variable frequency power cable
BPYJVP2: XLPE insulated PVC sheathed copper tape wrapped shielded variable frequency power cable
BPYJVPP2: XLPE insulated PVC sheathed copper wire braided copper tape wrapped shielded variable frequency power cable BPYJVP3: XLPE insulated PVC sheathed aluminum polyester composite film wrapped shielded variable frequency power cable
BPYJVP: XLPE insulated copper wire braided overall shield PVC sheathed inverter cable
BPYJPVP: XLPE insulated copper wire braided sub-shield and overall-shielded PVC sheathed inverter cable
BPYJPVP2: XLPE insulated copper wire braided sub-shielded copper tape wrapping and overall shielded PVC sheathed inverter cable
BPYJVP2: XLPE insulated copper tape wrapped overall shield PVC sheathed inverter cable
The difference between variable frequency cable and power cable
a) Purpose: The variable frequency cable is the connecting wire between the power supply and the variable frequency motor and the wire for transmitting electric energy. The power cable transmits electric energy. In this respect, the two cables are the same.
b) Interference: The dedicated cable for the frequency converter has good anti-interference, which enables the frequency conversion motor to transmit electric energy stably without being disturbed and without disturbing the operation of other equipment, while ordinary power cables do not have these properties. These are dependent on the internal structure of the cable,
c) Voltage: The operating voltage of the variable frequency cable is generally: 0.6/1KV, 6/10KV, 8.7/16KV The voltage of the power cable and the voltage of the variable frequency cable are roughly the same. The voltage of the power cable has extra high voltage, and the voltage of the frequency conversion cable is generally medium voltage and low voltage.
d) Structure: The core wire structure of the frequency conversion cable is arranged in parallel, the insulation adopts high-strength extrusion and each individual core wire adopts a shielding layer with different requirements. After the core wires are arranged, they must be added according to the requirements and use environment. There is another layer of shielding, and finally the cable sheath. The structure of the power cable is to use ordinary extruded core wires, single core without shielding.
e) Model: There are many types of frequency conversion cables: BP-YJVP BP-YJLV BP-YJVP1-2 BP-YJGP2 BP-YJVP3 BP-YJLVP1-2 BP-YJGRP, etc., and some cable manufacturers have different models in their own factories. Uneven. The cable cable is a universal model. It is also because there are no relevant standards for frequency conversion cables in China, so most of them are produced according to the standards of power cables, and the other is to combine foreign standards to achieve the normal use of frequency conversion motors.
f) The influence of the external environment on the frequency conversion cable and the solution: the frequency adjustment range of the frequency conversion power supply is relatively wide, but its waveform is a frequency band profile of the main frequency, including many higher harmonics, and the amplitude is also large. This kind of harmonics will inevitably spread to the cable and may cause cable breakdown. The longer the cable, the higher the high-frequency harmonic voltage. However, if the cable insulation withstand voltage level is high, the cable breakdown will not occur. The influence of the external environment on the frequency conversion cable is mainly the influence of the higher harmonics generated by the frequency converter. For AC-DC-AC inverters, due to the use of switch switching technology, its output is no longer a sine wave, but a step wave that can be decomposed into a sine fundamental wave and higher harmonics. If the structure of the cable adopts ordinary 3+1 cores, that is, three main cores and one neutral wire, this will cause the interference and harmonic voltage generated by the main core and the neutral wire to be unbalanced. For the cable to work normally, it is bound to increase The insulation level of the cable. If the main wire core and the neutral position adopt a symmetrical structure, the interference can be reduced to the lowest level due to the wire interchange effect and its symmetrical balance. The general insulation level can be used, so the cable design should adopt a symmetrical structure.

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