Steel Melting & Rolling Industry
TYPE OF INDUSTRY – Steel Melting & Rolling Industry Yemen. Middle East Asia.
YEAR OF IMPLEMENTATION – 2010
Plant was operating on Captive Generation of 58 Mw. The Plant are having Medium Frequency Induction Furnaces, LRF and Rolling Mills with Oxygen plants. Plant was having following issues.
- Low power factor
- Not able to operate Furnaces & Rolling Mill together.
- Poor Plant Loading Factor.
- Frequent Electrical breakdown
- Heating of transformer and cables.
After conducting Power Quality Audit in the plant, following observations are made:
Total Harmonic Distortion (THD) Voltage is high > 10 % . The higher order Harmonics like 11th , 13 th & 23 rd etc are predominant which generate high voltage distortion.
Power factor in Rolling Mill is low < 0.70 due to DC drives and 5th & 7th Harmonics are Predominant due to use of 6 Pulse Converter.
Due to High Harmonics distortion, the Generators are not able to operate at full load.
Tuned Harmonic Filter Banks at 11 KV Main Bus to control THD <5 % as per IEEE 519-1992 .
Automatic Harmonic Filter Banks on Rolling Mill Transformers.
IGBTs Based Static Var Generators to control Leading PF on 11 KV bus.
Design, Manufacturing & Installation of Passive Tuned Harmonic Filters at 11 KV Main Bus.
- 5th Tuned Harmonic Filter Banks -2600 kvar , 15.20 KV , 3phase , 50Hz
- 7th Tuned Harmonic Filter Banks -1300 kvar , 15.20 KV , 3phase , 50Hz
- 11th Tuned Harmonic Filter Banks -6064 (3032 k x 2no) kvar , 15.20 KV , 3phase , 50Hz
Design, Manufacturing & Installation of Automatic Harmonic Filter Banks on Rolling Mill & Oxygen plant Transformers – 1500 kvar /525 V – 2nos.
Design, Manufacturing & Installation of IGBTS Based Static Var Generator +/- 750 kvar , 440 V to inject Inductive & Capacitive Kvar to avoid over compensation on Generators.
THDI & THDV reduced to < 3% at main 11 KV Bus
PF improvement to 0.99 lag .
Avoid Leading PF on 11 KV Bus .
Increase Loading Capacity of Generators. Hence Furnaces & Rolling Mills both can operate Simultaneously .
Increase Plant Productivity.