**4. Brief steel plant system description**

The steel plant system consists of 49 buses and 38 two winding transformers. The plant is fed from two utility substations at 230 KV and through four 230/34.5 KV transformers. From 34.5 KV many 34.5/13.8 KV transformers are installed to feed difference load including three electric Arc Furnaces (EAF1, EAF2, EAF3) and two Ladle Furnaces (LF1, LF2). Part of The single line diagram of the arc furnaces of this system is shown in figure 2.

Fig. 2. Partial single line diagram of steel plant system.

This system was simulated by using a software package and the results of load flow, total harmonic distortion, and power factor at some buses are shown in table 1.


Table 1. Load flow, THD, and power factor results


Table 2. Filtre Data

The steel plant system consists of 49 buses and 38 two winding transformers. The plant is fed from two utility substations at 230 KV and through four 230/34.5 KV transformers. From 34.5 KV many 34.5/13.8 KV transformers are installed to feed difference load including three electric Arc Furnaces (EAF1, EAF2, EAF3) and two Ladle Furnaces (LF1, LF2). Part of The single line diagram of the arc furnaces of this system is shown in figure 2.

This system was simulated by using a software package and the results of load flow, total

**110 110 MVA 110 MVA** 

**EAF 2 LF 1 EAF 3 LF 2 EAF 1** 

**25 MVA 25 MVA** 

1 230.00 1.00 0.00 6.47 56 2 34.50 0.95 -1.90 10.31 59 3 34.50 0.95 -1.90 10.31 59 5 34.50 0.95 -1.90 10.30 59 45 0.48 0.91 -3.80 10.11 58 46 0.48 0.91 -3.80 10.11 58

Filter Location Order Rated KV Kvar XL Q Bus # 1 2nd 230.00 35035.00 377.47 75.00 Bus # 5 5th 34.50 30572.00 79.00 39.50 Bus # 5 7th 34.50 24745.00 120.20 84.10

LF Angle (deg)

**SVC 2 TCR=160 MVAR FC=110 MVAR** 

> THD (%)

**Flat Products**

Power Factor

LF Voltage (p.u)

harmonic distortion, and power factor at some buses are shown in table 1.

**SVC 1 TCR=140 MVAR FC=120 MVAR** 

**ELECTRICITY (SEC)**

 **3x133 MVA**

**34.5 kV** 

**230 kV** 

**MVA** 

**4. Brief steel plant system description** 

Fig. 2. Partial single line diagram of steel plant system.

Voltage (KV)

Bus# Nominal

Table 1. Load flow, THD, and power factor results

Table 2. Filtre Data


Table 3. Load Flow, THD, and Power Factor Results

Single-tuned filters were designed for the metal plant system according to the next paragraph theories and its input data are provided in table 2. The results of load flow, total harmonic distortion, and power factor of buses 1, 2, 3, 5, 45, and 46 after installing filter are shown in table 3. Also the spectrum and waveform of bus 34.5 kV is provided in figure 3.

Fig. 3. Spectrum of voltage at bus 34.5 kV
