Distance Protection Systems Notes PDF

12/15/2024 ‫بسم هللا الرحمن الرحيم‬ Omdurman Islamic University 557 ‫حماية نظم القدرة هكا‬ Department of EEE Faculty of Engineering Sciences ‫الحماية المسافية‬ Dr....

12/15/2024 ‫بسم هللا الرحمن الرحيم‬ Omdurman Islamic University 557 ‫حماية نظم القدرة هكا‬ Department of EEE Faculty of Engineering Sciences ‫الحماية المسافية‬ Dr. Adam Abdelrahman Abdelkarim Assistant Professor E-mail: [email protected] Tel: +249918240170 ‫الحماية المسافية‬ 𝑉𝑅 = 𝑍𝑙𝑖𝑛𝑒 + 𝑍𝑙𝑜𝑎𝑑 𝐼𝑅 ‫فى الظروف الطبيعية‬ ‫وتتناسب المعاوقة تناسبا طرديا مع طول المسافة‬ 1  ‫‪12/15/2024‬‬ ‫الحماية المسافية‬ ‫عند حدوث العطل‬ ‫الحماية المسافية‬ ‫الحماية المسافية‬ ‫‪2‬‬  12/15/2024 ‫الحماية المسافية‬   E IR  I a   Z s  ( d / L) Z L 𝑉ത𝑎 ≤ 0.8 𝑍𝐿1 ҧ 𝐼𝑎ҧ ‫الجهد فى المرحل‬ 𝑉ത𝑎 ≤ 0.8 𝑍ҧ𝐿1 𝐼𝑎ҧ  Z a  0.8 Z L1 ‫الحماية المسافية‬ Impedance Relay ‫خصائص‬ 𝐕𝐚 = 𝐈𝐚 Operation zones  Z  Z r1 Z  R  jX  Z Plain Impedance relay 3  12/15/2024 ‫الحماية المسافية‬ Rarc= Resistance of arc in Ohms ‫عيوبه‬ Z= Zf+ Rarc ‫الحماية المسافية‬ This modified impedance relay (mho relay) 4  12/15/2024 Distance Relay setting ‫ضبطية مرحل المسافة‬ Z 1 = 80%xZ1 Z 2 = 120%x Z1 Z 3 = 220%x Z2 Distance Relay setting ‫ضبطية مرحل المسافة‬ 5  12/15/2024 Impedance calculation ‫حساب المعاوقة‬  Z L1  (0.24  j 0.8) *15  3.6  j12 Ohms  0.8 * (3.6  j12)  10.02 Ohms Relay will operate for R 2  X 2  10.022  100.04 Ohms ‫نحسب التيار و الجهد فى الجانب الثانوى‬ Vp Ip Vs  Is  VTR CTR VTR ‫ليكن نسبة تحويل المعاوقة‬ ZTR  CTR p V Vp Vs Ip Zp Zs   VTR   Is Ip VTR ZTR CTR CTR 6  12/15/2024 Impedance calculation ‫حساب المعاوقة‬ - ‫مثال‬ 69 kV Zline = 0.24+j0.8 Ohms/km Line L = 15 km VTR  40000/ 120 CTR  600/ 5  Z L1  (0.24  j 0.8) *15  3.6  j12 Ohms VTR ZTR   2.77 CTR Z r1  10.02 / 2.77  3.62 SecondaryOhms Example 10.8 TABLE 10.8 7  12/15/2024 345-kV transmission loop Relay connections for a three-zone directional impedance relay (only phase A is shown) FIGURE 10.27 Figure 10.31. Vp Vs Ip Zp Zs   VTR  ZTR = Is CTR SOLUTION 𝟑𝟎𝟎𝟎 𝑽𝑳𝑵/ 𝒁 = 𝟏 = 𝒁𝑷 𝟏𝟓𝟎𝟎 𝟏𝟎 𝑰𝑳/ 𝟓 We set the B12 zone 1 relay for 80% reach, that is, 80% of the line 1–2 (secondary) impedance: 0.8(8 + 𝑗50) 𝑍𝑟1 = = 0.64 + 𝑗4 = 𝟒. 𝟎𝟓 ∠𝟖𝟎. 𝟗 𝟎 𝑆𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 10 Setting the B12 zone 2 relay for 120% reach: 1.2(8+𝑗50 ) 𝑍𝑟2 = = 0.96 + 𝑗0.6 = 𝟔. 𝟎𝟖 ∠𝟖𝟎. 𝟗 0 𝑆𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 𝟏𝟎 From Table 10.8, line 2–4 has a larger impedance than line 2–3. Therefore, we set the B12 zone 3 relay for 100% reach of line 1–2 plus 120% reach of line 2–4 1. (8 + 𝑗50) 1.2(5.3 + 𝑗33) 𝑍𝑟3 = + = 1.44 + 𝑗8.96 = 𝟗. 𝟎𝟕∠𝟖𝟎. 𝟗𝟎 10 10 8  12/15/2024 ‫بسم هللا الرحمن الرحيم‬ Omdurman Islamic University 557 ‫حماية نظم القدرة هكا‬ Department of EEE Faculty of Engineering Sciences ‫الحماية المسافية‬ Dr. Adam Abdelrahman Abdelkarim Assistant Professor E-mail: [email protected] Tel: +249918240170 9