Status Analysis:
1, the main load of intermediate frequency furnace, the six phase rectifier bridge is a typical harmonic source.
2. Due to the overload operation of the transformer, the voltage distortion is caused, and the harmonics are also greatly increased.
Change control 3, six phase rectifier makes the thyristor current in the process of phase change tube rate greatly, the load waveform presents a right angle change rate, wave coefficient is poor, harmonic distortion.
4. When the power factor can not meet the requirement, it is only due to the poor wave coefficient, so the conventional reactive power compensation equipment can not be compensated.
5. When the medium frequency furnace runs at full load, the total current distortion rate is 22.5%, and the main harmonic current is 5 times, 7 times, 11 times and 13 times.
6. The effective value of the single phase current is 761 amperes.
Governance measures:
According to the actual situation in the field, an active power filter with a compensation capacity of 200A is installed in parallel to the distribution cabinet of the medium frequency furnace.
During operation, the current is stable and the single phase current effective value is 726 amperes. Compared with the compensation, the current effective value is significantly reduced, thereby reducing the electricity cost. When the intermediate frequency furnace runs at full load, the total current distortion rate is reduced to 5%.
The effect of Governance:
During operation, the current is stable, and the single phase current effective value is 726 ampere. Compared with the compensation, the current effective value is significantly reduced, thereby reducing the electricity cost. When the intermediate frequency furnace runs at full load, the total current distortion rate is reduced to 5%.