In a metallurgical foundry, the main load is a rectifying device such as an intermediate frequency furnace, which emits a large number of harmonics. Due to the small capacity of the transformer, the grid exhibits a weak point network characteristic when the load is heavy, and the current harmonic distortion degree THDi reaches 31%, and the voltage is subjected to current. Harmonic interference makes the voltage distortion YHDv reach 21%, the power factor is as low as 0.55, the dust on site is serious, and the ventilation conditions are not good. It is both "current harmonic + voltage harmonic + reactive power + dust pollution + high temperature complex "Working conditions", ordinary equipment can not work properly under this bad situation


    Adding YDK-APF/SVG to control power quality, YDK-APF/SVG not only reflects its strong anti-interference ability, but also can correct current harmonics under this harsh condition, and it also reflects the powerful treatment of infection. Capabilities while improving voltage harmonic distortion. As shown below:

Metallurgical industry voltage and current after YDK-APF/SVG treatment


  The treatment effect is satisfactory, the voltage and current harmonics are basically disappeared, THDi is reduced to 4.3%, THDv is reduced to 4.5%, and the power factor is increased to 0.98.


Example two


         Welding industry


      In a car manufacturing plant, the main load is suspended spot welding, mechanical arm, assembly line, motor, etc. The spot welding machine is powered by single-phase 380V. The current fluctuates greatly during operation and the imbalance is serious. The phase A current (yellow) is basically 0, the phase currents of B and C are 278A, 317A, the power factor is 0.52, and the current distortion rate is 40%. Because most of the unbalanced current flows through the center line, the midline heat is severe. It is a complex and harsh working condition with both "current harmonics + serious imbalance + serious reactive power".

Welding machine voltage and current before treatment

Welding machine voltage and current after YDK-APF/SVG treatment


  After installing YDK-APF, the current harmonics and reactive power are treated. The effect is compared as follows. The three-phase current imbalance basically disappears, the neutral current is basically zero, the voltage and current harmonics basically disappear, and the THDi is reduced to 2.7%. Increased to 0.98.