Load analysis

A large number of non-linear loads such as electric welding machines, laser welding machines and large-capacity inductive loads (mainly electric motors) are used in the car body workshop, resulting in serious harmonic currents in the load currents of all transformers in this workshop. , 5, 7, 9 and 11 times, the total voltage distortion rate of the 400V low-voltage bus bar reaches more than 5%, and the total current distortion rate (THD) reaches about 40%, resulting in total harmonic distortion of the 400V low-voltage power supply and distribution system voltage The rate seriously exceeded the standard, and caused serious harmonic power loss in electrical equipment and transformers. At the same time, all transformer load currents in this workshop have serious reactive power requirements, and the average power factor of some transformers is only about 0.6, there is a serious power loss problem, and the transformer output active power capacity is seriously insufficient. Due to a large amount of harmonic current and a large amount of reactive power demand, the main transformer generates serious heat, and the power distribution system has the following power quality problems: large reactive power shortage, serious harmonic current, and large power loss.

Recommended solution: fast anti-harmonic low-voltage intelligent power capacitor + active filter (APF) / static reactive power generator (SVG).

Choose fast anti-harmonic low-voltage intelligent power capacitors, which can quickly and accurately compensate for the rapid change of reactive power and improve the power factor; part of the active filter capacity is divided into phases to dynamically compensate the reactive power, and part of the active filter capacity is used to filter out harmonic.

Note: The scheme design of reactive power compensation can be flexibly configured according to the capacity allocation of the active part and the passive part. If the reactive power of the active part of the two-way compensation is sufficient to adjust the dynamically changing reactive power, parallel reactive power compensation can be considered.

The power factor is effectively improved to avoid fines;

Reduce energy consumption and reduce production costs;

Filter out system harmonics, reduce the harm caused by harmonics to the system, and extend the service life of equipment;

Improved power quality, safety, stability and reliability of automobile production equipment;

Eliminate the hidden danger of system resonance and ensure the safety and reliability of the power supply system;

Avoid the impact of harmonics and reactive power on the power grid.