Alstom MiCOM P546 - Page 449

Application Notes P54x/EN AP/La4
MiCOM P543, P544, P545 & P546
(AP) 6-5
AP
4.1.3.6 Example minimum dead time calculation 74
4.1.3.7 Reclaim timer setting 74
4.2 Current transformer supervision 75
4.2.1 Standard CTS 75
4.2.2 Differential CTS 75
4.3 Circuit breaker condition monitoring 76
4.3.1 Setting the  ^ thresholds 76
4.3.2 Setting the number of operations thresholds 76
4.3.3 Setting the operating time thresholds 76
4.3.4 Setting the excessive fault frequency thresholds 76
5. TWO CIRCUIT BREAKER CONTOL (P446) WORKED EXAMPLE 77
5.1 Introduction 77
5.2 Circuit breaker status 78
5.3 Voltage inputs 78
5.4 Application settings 78
5.4.1 CB CONTROL menu: 78
5.4.2 CONFIGURATION menu: 79
5.4.3 CT & VT RATIOS menu: 79
5.4.4 GROUP 1 LINE PARAMETERS menu: 79
5.4.5 GROUP 1 DISTANCE menu: 79
5.4.6 GROUP 1 PHASE DIFF menu: 79
5.4.7 GROUP 1 SYSTEM CHECKS menu: 80
5.4.8 GROUP 1 AUTORECLOSE menu: 81
5.5 PSL (Programmable Scheme Logic) MAPPING 82
6. CURRE
NT TRANSFORMER REQUIREMENTS 83
6.1 Recommended CT classes (British and IEC) 83
6.2 Current differential requirements 83
6.3 Zone 1 reach point accuracy (RPA) 84
6.4 Zone 1 close-up fault operation 84
6.5 Time delayed distance zones 84
6.6 Determining Vk for an IEEE “C" class CT 84
6.7 Worked example for CT requirements 85
6.7.1 Important notes to be considered 85
6.7.2 System data 85
6.7.3 Calculation of Primary X/R 85
6.7.4 Calculation of Source Impedance Zs 85
6.7.5 Calculation of full line impedance (full 100 kms) 86
6.7.6 Calculation of total impedance till remote bus bar 86
6.7.7 Calculation of through fault X/R 86
6.7.8 Calculation of through fault If 86
6.7.9 Calculation of line impedance till Zone1 reach point (80kms) 86