How big a cable is used to connect the high voltage motor excitation cabinet to the motor

1. introduction

High-voltage motors are widely used in industrial production, power systems, petrochemicals and other fields. The reliability and safety of their operation are crucial to the stable operation of the entire system. As an important part of high-voltage motors, the excitation cabinet is responsible for providing stable excitation current for the motor to ensure the normal operation of the motor. Therefore, the selection of the connecting cable between the excitation cabinet and the motor is of great significance to the safe operation of the motor.

1. Cable Type Selection

2.1 Cable materials

Cable materials mainly include copper and aluminum. Copper cables have higher conductivity and tensile strength, but their prices are relatively high; aluminum cables are cheaper, but their conductivity and tensile strength are relatively poor. When selecting cable materials, it is necessary to comprehensively consider factors such as the power, current, and cost of the motor.

2.2 Cable structure

The cable structure mainly includes single-core and multi-core. Single-core cable has high mechanical strength and tensile strength, but is prone to electromagnetic interference; multi-core cable has good anti-interference performance, but relatively poor mechanical strength and tensile strength. When selecting the cable structure, it is necessary to comprehensively consider factors such as the working environment of the motor and electromagnetic interference requirements.

1. Cable specification selection

3.1 Cable cross-sectional area

The cross-sectional area of ​​the cable is an important factor affecting the current carrying capacity of the cable. When selecting the cross-sectional area of ​​the cable, it is necessary to calculate it based on factors such as the rated current of the motor, the length of the cable, and the laying method to ensure that the current carrying capacity of the cable meets the operating requirements of the motor.

3.2 Cable length

The length of the cable will affect the resistance and voltage drop of the cable. When selecting the cable length, it is necessary to calculate it based on the distance between the motor and the excitation cabinet and try to shorten the cable length to reduce the impact of resistance and voltage drop on the operation of the motor.

1. Cable performance requirements

4.1 Electrical conductivity

The electrical conductivity of the cable directly affects the operating efficiency of the motor. When selecting the cable, you need to choose a material with higher electrical conductivity, such as copper or high conductivity aluminum.

4.2 Tensile properties

The tensile strength of the cable is the key factor to ensure that the cable does not break during laying and operation. When selecting cables, it is necessary to select materials and structures with higher tensile strength.

4.3 Anti-interference performance

The cable may be affected by external electromagnetic interference during operation, which may affect the normal operation of the motor. When selecting cables, you need to choose a structure with good anti-interference performance, such as multi-core cables or shielded cables.

1. Safety factor considerations

When selecting cables, a certain safety factor needs to be considered to cope with abnormal situations such as overload and short circuit that may occur during the operation of the motor. The selection of the safety factor needs to be comprehensively considered based on the operating characteristics of the motor, the working environment and other factors.

1. Cable laying method

The cable laying method will affect the heat dissipation and anti-interference performance of the cable. When choosing the cable laying method, it is necessary to select according to factors such as the distance between the motor and the excitation cabinet, the working environment, etc., such as direct burial, bridge laying, pipe laying, etc.

1. Cable connection method

The connection method between the cable and the motor and excitation cabinet will affect the connection reliability and operation stability of the cable. When selecting the cable connection method, it is necessary to select a connection method with higher connection reliability, such as crimping, welding, etc.

1. Cable protection measures

During operation, the cable may be affected by the external environment, such as moisture, corrosion, etc. When selecting the cable, it is necessary to consider the cable protection measures, such as waterproofing and anti-corrosion.

1. in conclusion

The selection of the connecting cable between the high-voltage motor excitation cabinet and the motor is crucial to the safe operation of the motor. When selecting the cable, it is necessary to comprehensively consider factors such as the cable type, specification, performance, safety factor, etc. to ensure that the cable can meet the operating requirements of the motor. At the same time, it is also necessary to consider the cable laying method, connection method and protection measures to improve the reliability and stability of the cable.