What is the key impact of the busbar specification inside the fixed switch cabinet on power transmission?
Publish Time: 2025-03-04
In the power system, the fixed switch cabinet is an important device for distributing and controlling electric energy, and its internal busbar specification plays a vital role in power transmission. As the main transmission channel of current, the selection of busbar specifications is directly related to the safety, stability and efficiency of power transmission.
Current carrying capacity: the basic consideration of busbar specifications
The current carrying capacity of the busbar is its most basic performance indicator, which determines the maximum current value that the busbar can safely transmit. The current carrying capacity of the busbar is closely related to the material, cross-sectional area and heat dissipation conditions of the conductor. Generally speaking, under the same material and heat dissipation conditions, the larger the cross-sectional area of the busbar, the higher its current carrying capacity. For example, copper busbars can carry more current than aluminum busbars under the same specifications due to their good conductivity. When the fixed switch cabinet needs to transmit a large current, if the selected busbar specification is too small, the busbar will heat up due to overload, and in severe cases, it may even cause a fire, endangering the safe operation of the power system.
Resistance: Affecting power transmission loss
The resistance of the busbar will cause the loss of electric energy during transmission, which will be dissipated in the form of heat energy. According to Joule's law, the heat generated by the current passing through the conductor is proportional to the square of the current, the resistance of the conductor and the power-on time. The busbar resistance is related to the conductor material, length and cross-sectional area. The lower the resistivity of the material, the smaller the busbar resistance; when the length is constant, the larger the cross-sectional area, the smaller the resistance. If the busbar specification is not properly selected and the resistance is too large, a large amount of power loss will be caused. This not only reduces the efficiency of power transmission and increases the cost of electricity, but may also cause the busbar temperature to rise, affecting the normal operation of surrounding electrical components.
Reactance: Related to power transmission stability
In addition to resistance, the reactance of the busbar will also affect power transmission. Reactance is mainly caused by the inductance of the busbar, which affects the voltage stability and reactive power distribution of the power system. In an AC power system, when current passes through a busbar with inductance, an alternating magnetic field is generated around the busbar, thereby generating reactance. The reactance size of the busbar is related to the geometry, spacing and current frequency of the busbar. Reasonable busbar specification design can reduce reactance, reduce voltage drop, and ensure voltage stability during power transmission. Otherwise, the voltage at the receiving end may be too low, affecting the normal operation of power equipment and even causing instability in the power system.
Short-circuit tolerance: ensuring system safety
When a short-circuit fault occurs in the power system, a huge short-circuit current will be generated instantly. The busbar must have sufficient short-circuit tolerance to withstand the electric force and heat shock generated by the short-circuit current to ensure the safety of the fixed switch cabinet and the entire power system. The short-circuit tolerance of the busbar is related to factors such as the material, specification and fixing method of the busbar. Larger busbars usually have stronger short-circuit tolerance, which can effectively avoid damage such as deformation and fusing of the busbar when a short-circuit fault occurs, provide sufficient time for the protection device of the power system to operate, and ensure the safe and reliable operation of the power system.
In summary, the busbar specifications inside the fixed switch cabinet play a vital role in power transmission. From current carrying capacity to resistance, reactance and short-circuit tolerance, each aspect directly affects the quality and safety of power transmission. Therefore, when designing and selecting the internal bus specifications of the fixed switch cabinet, the actual needs of power transmission must be fully considered, and various factors must be comprehensively considered to ensure the rationality of the bus specifications, thereby providing a solid guarantee for the stable operation of the power system.
