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Interesting problems – convincing solutions

Problems due to high reactive currents

SYSTEM ELECTRIC: Reducing harmonics, improving voltage quality
SYSTEM ELECTRIC: Application Silicon Carbide production
SYSTEM ELECTRIC: Application Silicon Carbide production
Silicon Carbide-crystals

The company ESD-Sic b.v. in the Netherlands is one of the leading manufacturers of silicon carbide. During the production process, a mixture of pure quartz sand and petroleum coke is heated under a plastic tarpaulin (Picture 1) to a temperature of approximately 2300° C by supplying electric energy with a rated voltage of 500 - 600 V, 50 Hz. Both source materials react to silicon carbide. The reactive power load of the process is 7000 - 8000 kVAr.
Picture 2 shows the exposed silicon carbide roller which has grown after some days around the U-shaped graphite core.
Picture 3 + 4 shows the silicon carbide crystals extracted from the solidified melt.


700 kVAr oven capacitor bank from SYSTEM ELECTRIC
SYSTEM ELECTRIC: Reducing harmonics, improving voltage quality
SYSTEM ELECTRIC: Inductive correction system

Capacitive electrical network load
- specific cos φ reduction


The problem

In Wilmersdorf, Germany, a solar park of Sun Concept GmbH is planned to go on line with a power of P = 1,000 kW peak. The system’s cos φ is ideal – close to 1. Based on the electrical network conditions (mainly cable systems and other solar supply systems), the local power supply company requests a cos φ (at the transfer point) of ≤ 0.95 inductive. The aim was a range of 0.93 – 0.95 for the cos φ.


An automatically controlled inductive power factor correction system of 325 kVAr, 400 V / 50 Hz. The integrated 9 inductances (reactors) are arranged in a control series of 1:1:2:2:4:4:4:4:4 in 26 steps of 12.5 kVAr each, as required, so that the cos φ is reliably kept in the range 0.93 – 0.95.