Protection and Switchgear

Bhavesh Bhalja is currently Professor and Head, Department of Electrical Engineering, A D Patel Institute of Technology, New Vidyanagar, Gujarat. A Ph D from IIT Roorkee, he has close to a decade of teaching experience. R. P. Maheshwari is currently Professor, Department of Electrical Engineering, IIT Roorkee. A Ph D from Roorkee University (now IIT Roorkee), he have over 15 years of teaching experience. Nilesh Chothani is currently Assistant Professor, Department of Electrical Engineering, A D Patel Institute of Technology, New Vidyanagar, Gujarat. His areas of interest are digital protection, system modelling and simulation, and artificial intelligence techniques.

CHAPTER 1: PROTECTIVE RELAYING FUNDAMENTALS; 1.1 GENERAL BACKGROUND; 1.2 ZONES OF PROTECTION; 1.3 REQUIREMENTS OF PROTECTION SYSTEM; 1.4 UNIT AND NON-UNIT PROTECTION; 1.5 PRIMARY AND BACK-UP PROTECTION; 1.6 HISTORICAL DEVELOPMENTOTECTION; 1.7 CLASSIFICATION OF PROTECTIVE RELAYS; 1.7 ELECTROMECHNICAL (ELECTROMAGNETIC) RELAYS; 1.7.1 THERMAL RELAYL (ELECTROMAGNETIC) RELAYS; 1.7.2 ATTRACTED ARMATURE RELAY; 1.7. 3INDUCTION RELAYS; 1.7.3.1 INDUCTION DISC RELAY; 1.7.3.2 INDUCTION CUP RELAY; 1.7.4 BALANCE BEAM RELAY; 1.7.5 UNIVERSAL TORQUE EQUATION; 1.8 SOLID STATE RELAYS; 1.8.1 INTRODUCTION; 1.8.2 COMPARISON BETWEEN STATIC AND ELECTROMECHANICAL RELAYS; 1.8.3 CLASSIFICATION OF STATIC RELAYS; 1.8.4 GENERALIZED STATIC TIME-OVERCURRENT RELAYS; 1.9 DIGITAL RELAYING; 1.9.1 MERITS AND DEMERITS OF DIGITAL RELAY; 1.9.2 GENERALIZED BLOCK DIAGRAM OF DIGITAL RELAY; 1.9.3 SAMPLING AND DATA WINDOW; 1.10 ADAPTIVE RELAYING; 1.11 TRIPPING MECHANISM OF RELAY; 1.12 DIFFERENT RELAY ALGORITHMS; 1.12.1 ALGORITHMS ASSUMING PURE SINUSOIDAL RELAYING SIGNAL; 1.12.2 ALGORITHMS BASED ON SOLUTION OF SYSTEM DIFFERENTIAL EQUATIONS; 1.12.3 ALGORITHMS APPLICABLE TO DISTORTED RELAYING SIGNALS; 1.12.3.1 FOURIER ANALYSIS BASED ALGORITHM; 1.12.3.2 WALSH FUNCTION TECHNIQUE; 1.12.3.3 LEAST ERROR SQUARE TECHNIQUE; 1.13 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 2: CURRENT BASED RELAYING SCHEME FOR TRANSMISSION LINE; 2.1 INTRODUCTION; 2.2 VARIOUS TYPES OF TRANSMISSION LINE FAULTS; 2.3 OVERCURRENT PROTECTION OF TRANSMISSION LINE; 2.3.1 INSTANTANEOUS OVERCURRENT RELAY; 2.3.2 DEFINITE TIME OVERCURRENT RELAY; 2.3.3 INVERSE TIME OVERCURRENT RELAY; 2.3.4 INVERSE DEFINITE MINIMUM TIME OVERCURRENT RELAY; 2.4 APPLICATION OF OVERCURRENT RELAY USING DIFFERENT RELAY CHARACTERISTICS; 2.4.1 INSTANTANEOUS RELAYS; 2.4.2 DEFINITE TIME RELAYS; 2.4.3 INVERSE TIME OVERCURRENT RELAYS; 2.5 PHASE AND GROUND RELAYS; 2.5.1 SETTING RULES FOR PHASE AND GROUND RELAYS; 2.5.2 SCHEME USED IN PRACTICE; 2.6 DIRECTIONAL PROTECTIONONAL PROTECTION; 2.6.1 NECESSITY OF DIRECTIONAL PROTECTION RELAYS; 2.6.2 DIRECTIONAL RELAY CHARACTERISTICS; 2.6.3 POLARIZING QUANTITY; 2.6.4 DIRECTIONAL GROUND-FAULT RELAYS; 2.6.5 DIRECTIONAL OVER CURRENT PROTECTION SCHEME FOR A TRANSMISSION LINE (67); 2.7 MODERN DIGITAL/NUMERICAL OVERCURRENT & EARTH FAULT RELAY; 2.8 OVER CURRENT RELAY COORDINATION IN AN INTERCONNECTED POWER SYSTEM; 2.8.1 INTRODUCTION; 2.8.2 LINKNET STRUCTURE; 2.8.3 DETERMINATION OF PRIMARY/BACK-UP RELAY PAIRS; 2.9 EXAMPLES; 2.10 SUMMERY; EXERCISE; MULTIPLE CHOICE QUESTIONS; UNSOLVED EXAMPLE; REFERENCES; CHAPTER 3: PILOT INDEPENDENT DISTANCE RELAYING SCHEME; 3.1 INTRODUCTION; 3.2 TRANSMISSION LINE PROTECTION; 3.3 DISTANCE PROTECTION; 3.3.1 FAULT DISTANCE MEASUREMENT; 3.3.2 STEPPED DISTANCE CHARACTERISTICS; 3.4 REACH OF DISTANCE RELAY; 3.5 SELECTION OF MEASURING UNIT; 3.6 CURRENT AND VOLTAGE CONNECTIONS; 3.6.1 CONNECTION FOR PHASE-FAULT RELAYS; 3.6.2 CONNECTION FOR EARTH-FAULT RELAYS; 3.7 DISTANCE PROTECTION USING STATIC COMPARATORS; 3.7.1 COMPARATOR FOR IMPEDANCE RELAY; 3.8 PROBLEMS & REMEDIES IN DISTANCE PROTECTION; 3.8.1 CLOSE-IN FAULT; 3.8.2 FAULT RESISTANCE; 3.8.3 REMOTE INFEED; 3.8.4 MUTUAL COUPLING; 3.8.5 SERIES COMPENSATED TRANSMISSION LINES; 3.8.6 POWER SWING; 3.8.7 OVERLOAD; 3.8.8 TRANSIENT CONDITION; 3.9 EXAMPLES ON SETTING OF DISTANCE PROTECTION; 3.10 SYMMETRICAL COMPONENT BASED DISTANCE RELAY; 3.11 DIGITAL DISTANCE RELAYING SCHEME; 3.12 SUMMERY; EXERCISE; MULTIPLE CHOICE QUESTIONS; EXAMPLES; REFERENCES; CHAPTER 4: PILOT RELAYING SCHEME FOR TRANSMISSION LINE; 4.1 INTRODUCTION; 4.2 PILOT PROTECTION SYSTEM; 4.3 TYPES OF PILOT COMMUNICATIONS; 4.3.1 PILOT COMMUNICATION BASED ON SIGNAL; 4.3.2 PILOT COMMUNICATION BASED ON FREQUENCY; 4.4 WIRE PILOT RELAYING SCHEME; 4.4.1 CIRCULATING CURRENT BASED WIRE PLOT RELAYING SCHEME; 4.4.2 VOLTAGE BALANCE TYPE WIRE PILOT RELAYING SCHEME; 4.5 CARRIER CURRENT PROTECTION SCHEME; 4.5.1 PHASE COMPARISON SCHEME; 4.5.2 DIRECTIONAL COMPARISON SCHEME; 4.6 BLOCKING AND UNBLOCKING CARRIER AIDED DISTANCE SCHEME; 4.6.1 CARRIER BLOCKING SCHEME; 4.6.2 CARRIER UNBLOCKING SCHEME; 4.7 TRANSFER TRIPPING CARRIER AIDED DISTANCE SCHEME; 4.7.1 UNDER REACH TRANSFER TRIPPING SCHEME; 4.7.2 OVER REACH TRANSFER TRIPPING SCHEME; 4.8 SUMMERY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 5: GENERATOR PROTECTION; 5.1 INTRODUCTION; 5.2 DIFFERENTIAL PROTECTION; 5.2.1 MERTZ-PRICE DIFFERENTIAL PROTECTION; 5.2.2 HIGH IMPEDANCE DIFFERENTIAL PROTECTION; 5.2.3 BIASED PERCENTAGE DIFFERENTIAL PROTECTION; 5.2.4 RELAY SETTING; 5.3 STATOR EARTH FAULT PROTECTION; 5.3.1 STATOR EARTH FAULT PROTECTION FOR LOW IMPEDANCE GROUNDING; 5.3.2 STATOR EARTH FAULT PROTECTION FOR HIGH IMPEDANCE GROUNDING; 5.4 STATOR WINDING TURN TO TURN FAULT PROTECTION; 5.5 ROTOR GROUND FAULT PROTECTIONAULT PROTECTION; 5.6 LOSS OF EXCITATION (FIELD FAILURE) PROTECTION; 5.7 NEGATIVE PHASE SEQUENCE (UNBALANCE LOADING) PROTECTION; 5.8 OUT OF STEP PROTECTION; 5.9 REVERSE POWER PROTECTION; 5.10 ABNORMAL FREQUENCY AND VOLTAGE PROTECTION; 5.10.1 OVER FREQUENCY PROTECTION; 5.10.2 UNDER FREQUENCY PROTECTION; 5.10.3 OVER VOLTAGE PROTECTION; 5.10.4 UNDER VOLTAGE PROTECTION; 5.10.5 VOLTAGE DEPENDANT OVERCURRENT PROTECTION; 5.10.6 NEUTRAL VOLTAGE DISPLACEMENT PROTECTION; 5.10.7 PROTECTION AGAINST UNINTENTIONAL ENERGIZATION AT STANDSTILL; 5.10.8 THERMAL PROTECTION USING RTD; 5.11 NUMERICAL PROTECTION OF GENERATOR; 5.11.1 FUNCTIONS OF MODERN NUMERICAL/DIGITAL GENERATOR PROTECTION RELAY; 5.11.2 NUMERICAL DIFFERENTIAL PROTECTION OF GENERATOR; 5.12 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; EXAMPLES; REFERENCES; CHAPTER 6: TRANSFORMER PROTECTION; 6.1 INTRODUCTION; 6.2 ABNORMAL CONDITION IN TRANSFORMER; 6.2.1 MAGNETIZING INRUSH; 6.2.2 OVER FLUXING; 6.2.3 LOW OIL LEVEL IN TRANSFORMER TANK; 6.3 NON ELECTRICAL PROTECTION; 6.3.1 BUCHHOLZ RELAY; 6.3.2 SUDDEN PRESSURE RELAY (SPR); 6.3.3 OIL AND WINDING TEMPERATURE RELAY; 6.4 OVERCURRENT PROTECTION; 6.4.1 OVERCURRENT RELAY WITH HRU SUPPLEMENT; 6.5 EARTH FAULT PROTECTION; 6.6 INTER-TURN FAULT; 6.7 DIFFERENTIAL PROTECTION; 6.7.1 BASIC CONSIDERATIONS FOR TRANSFORMER DIFFERENTIAL PROTECTION; 6.7.2 STABILIZING OF DIFFERENTIAL PROTECTION DURING MAGNETIZING INRUSH CONDITIONS; 6.7.2.1 TIME DELAY; 6.7.2.2 HARMONICS RESTRAINT; 6.8 DIGITAL/NUMERICAL PROTECTION OF TRANSFORMER; 6.8.1 NUMERICAL RELAY; 6.8.2 FEATURE OF DIGITAL/ NUMERICAL RELAYS; 6.9 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; UNSOLVED EXAMPLE; REFERENCE OF BOOKS; CHAPTER 7: INDUCTION MOTOR PROTECTION; 7.1 INTRODUCTION; 7.2 FAULTS/ABNORMAL CONDITIONS IN INDUCTION MOTOR; 7.3 PROTECTION SCHEMES OF INDUCTION MOTOR; 7.3.1 THERMAL OVERLOAD PROTECTION (49); 7.3.2 PROTECTION AGAINST UNBALANCE CURRENTS (46); 7.3.3 PROTECTION AGAINST PHASE REVERSAL; 7.3.4 PHASE FAULT PROTECTION (87); 7.3.5 EARTH FAULT PROTECTION (50N); 7.3.6 STALLING PROTECTION (LOCKED ROTOR) (51); 7.3.7 LOSS OF LOAD PROTECTION; 7.3.8 UNDER VOLTAGE (27); 7.4 NUMERICAL PROTECTION OF INDUCTION MOTOR; 7.5 EXAMPLES; 7.6 SUMMERY; EXERCISE; MULTIPLE CHOICE QUESTIONS; UNSOLVED EXAMPLE; REFERENCES; CHAPTER 8: PROTECTION OF BUSBAR; 8.1 INTRODUCTION; 8.2 BUSBAR ARRANGEMENTS; 8.2.1 SINGLE BUSBAR ARRANGEMENT; 8.2.2 SINGLE BUSBAR ARRANGEMENT WITH SECTIONALIZE; 8.2.3 MAIN AND TRANSFER BUS-BAR ARRANGEMENT; 8.2.4 DOUBLE BUS-BAR ARRANGEMENT; 8.2.5 ONE AND HALF BREAKER ARRANGEMENT; 8.3 BUSBAR FAULTS AND PROTECTION REQUIREMENT; 8.4 IMPACT OF CT SATURATION ON BUSBAR PROTECTION; 8.4.1 ISSUE; 8.4.2 CT SATURATION; 8.4.3 RATIO MISMATCH; 8.4.4 REMEDIES; 8.5 CLASSIFICATION OF BUSBAR PROTECTION SCHEMES; 8.5.1 DIRECTIONAL COMPARISON PROTECTION SCHEME; 8.5.2 DIFFERENTIAL PROTECTION SCHEME; 8.5.2.1 CIRCULATING CURRENT DIFFERENTIAL PROTECTION; 8.5.2.2 BIASED PERCENTAGE DIFFERENTIAL PROTECTION; 8.5.3 HIGH IMPEDANCE VOLTAGE DIFFERENTIAL PROTECTION; 8.5.4 PROTECTION USING LINEAR COUPLERS; 8.6 DIGITAL/NUMERICAL PROTECTION OF BUSBAR; 8.6.1 DECENTRALIZED BUSBAR PROTECTION; 8.6.2 CENTRALIZED BUSBAR PROTECTION; 8.7 RECENT TRENDS IN BUSBAR PROTECTION; 8.8 COMMERCIALLY USED TECHNIQUE; 8.9 EXERCISE; SUMMARY; MULTIPLE CHOICE QUESTIONS; REFERENCE; CHAPTER 9: CURRENT AND POTENTIAL TRANSFORMER FOR RELAYING SCHEMES; 9.1 INTRODUCTION; 9.2 OPERATING PRINCIPLE OF CT AND PT; 9.3 CONSTRUCTION AND PERFORMANCE OF CT; 9.3.1 EQUIVALENT CIRCUIT AND VECTOR DIAGRAM OF CT; 9.3.2 MAGNETIZATION (EXCITATION) CURVES; 9.3.3 CT SATURATION CHARACTERISTIC; 9.3.4 CT BURDEN; 9.3.5 CT ACCURACY; 9.3.6 OPEN CIRCUIT CT SECONDARY VOLTAGE; 9.4 PERFORMANCE OF POTENTIAL TRANSFORMER (PT); 9.4.1 EQUIVALENT CIRCUIT OF ELECTROMAGNETIC TYPE PT; 9.4.2 CAPACITOR VOLTAGE TRANSFORMER (CVT); 9.4.2.1 EQUIVALENT CIRCUIT OF A CVT; 9.4.2.2 CVT TRANSIENT RESPONSE AND FERRO RESONANCE; 9.5 SPECIFICATION OF CT & PT; 9.5.1 SPECIFICATION OF CT; 9.5.2 SPECIFICATION OF PT; 9.6 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 10: PROTECTION AGAINST TRANSIENTS AND SURGES; 10.1 INTRODUCTION; 10.2 SOURCES OF TRANSIENTS OR SURGES IN EHV LINE; 10.2.1 SWITCHING OF TRANSMISSION LINE; 10.2.2 SWITCHING OF CAPACITOR BANK; 10.2.3 SWITCHING OF COUPLING CAPACITOR VOLTAGE TRANSFORMER (CCVT); 10.2.4 SWITCHING OF REACTOR; 10.2.5 ARCING GROUND; 10.2.6 LIGHTNING STROKES; 10.3 OVERVOLTAGE PHENOMENON DUE TO LIGHTNING AND SWITCHING; 10.3.1 SURGES AND TRAVELLING WAVES; 10.3.2 WAVE PROPAGATION ON TRANSMISSION LINE; 10.3.3 REFLECTION AND ATTENUATION; 10.3.3.1 REFLECTION; 10.3.3.2 ATTENUATION OF TRANSIENTS; 10.3.3.2.1 ATTENUATION OF TRANSIENTS USING FILTER; 10.3.3.2.2 ATTENUATION OF TRANSIENTS USING ISOLATION TRANSFORMER; 10.4 NEUTRAL GROUNDING; 10.4.1 EFFECTS OF UNGROUNDED NEUTRAL ON SYSTEM PERFORMANCE; 10.4.2 METHODS OF NEUTRAL GROUNDING; 10.4.2.1 SOLID GROUNDING; 10.4.2.2 RESISTANCE GROUNDING; 10.4.2.3 REACTANCE GROUNDING; 10.4.2.4 RESONANT GROUNDING; 10.4.3 GROUNDING PRACTICES; 10.5 PROTECTION AGAINST TRANSIENTS AND SURGES; 10.5.1 PROTECTION AGAINST LIGHTNING; 10.5.1.1 EARTHING SCREEN (OVERHEAD SHIELDING); 10.5.1.2 OVERHEAD GROUND WIRES; 10.5.1.3 SURGE MODIFIER OR ABSORBER; 10.5.1.4 LIGHTNING ARRESTER (SURGE DIVERTER); 10.6 TYPES OF LIGHTNING ARRESTERS; 10.6.1 ROD GAP ARRESTER; 10.6.2 HORN GAP ARRESTER; 10.6.3 MULTI GAP ARRESTER; 10.6.4 EXPULSION TYPE ARRESTER; 10.6.5 VALVE TYPE ARRESTER; 10.6.5.1 SILICON CARBIDE (SIC) LIGHTNING ARRESTER; 10.6.5.2 METAL OXIDE (MO) LIGHTNING ARRESTER; 10.6.6 SELECTION PROCEDURE FOR LIGHTNING/SURGE ARRESTERS; 10.6.7 COMMON RATINGS OF LIGHTNING/SURGE ARRESTERS; 10.7 CONCEPTS OF BASIC INSULATION LEVEL; 10.7.1 SELECTION OF BASIC INSULATION LEVEL (BIL); 10.7.2 IMPULSE RATIO; 10.7.3 STANDARD IMPULSE TEST VOLTAGE; 10.7.4 VOLT-TIME CHARACTERISTIC; 10.8 INSULATION COORDINATION; 10.9 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 11: AUTORECLOSING AND SYNCHRONIZING; 11.1 INTRODUCTION; 11.2 HISTORY OF AUTORECLOSING; 11.3 ADVANTAGES OF AUTORECLOSING; 11.4 CLASSIFICATION OF AUTORECLOSING RELAY; 11.4.1 AUTORECLOSING BASED ON NUMBER OF PHASES; 11.4.2 AUTORECLOSING BASED ON NUMBER OF ATTEMPTS; 11.4.3 AUTORECLOSING BASED ON SPEED; 11.5 SEQUENCE OF EVENTS OF A TYPICAL SINGLE-SHOT AUTORECLOSING SCHEME; 11.6 FACTORS TO BE CONSIDERED DURING RECLOSING; 11.6.1 CHOICE OF ZONE IN CASE OF DISTANCE RELAY; 11.6.2 DEAD TIME/ DEIONIZING TIME; 11.6.3 RECLAIM TIME; 11.6.4 INSTANTANEOUS LOCK OUT; 11.6.5 INTERMEDIATE LOCK OUT; 11.6.6 BREAKER SUPERVISION FUNCTION; 11.7 SYNCHRONISM CHECK; 11.7.1 PHASING VOLTAGE METHOD; 11.7.2 ANGULAR METHOD; 11.8 AUTOMATIC SYNCHRONIZING; 11.9 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 12: SYSTEM RESPONSE TO SEVERE UPSETS; 12.1 INTRODUCTION; 12.2 NATURE OF SYSTEM RESPONSE TO SEVERE UPSETS; 12.2.1 SYSTEM RESPONSE TO ISLANDING CONDITIONS; 12.2.2 UNDERGENERATED ISLANDS; 12.2.3 OVERGENERATED ISLANDS; 12.2.4 REACTIVE POWER BALANCE; 12.2.5 POWER PLANT AUXILIARIES; 12.2.6 POWER SYSTEM RESTORATION; 12.3 LOAD SHEDDING; 12.4 FACTORS TO BE CONSIDERED FOR LOAD SHEDDING SCHEME; 12.4.1 MAXIMUM ANTICIPATED OVERLOAD; 12.4.2 NUMBER OF LOAD SHEDDING STEPS; 12.4.3 SIZE OF LOAD SHED AT EACH STEP; 12.4.4 FREQUENCY SETTING; 12.4.5 TIME DELAY; 12.5 RATE OF FREQUENCY DECLINE; 12.6 FREQUENCY RELAYS (81); 12.7 ISLANDING; 12.7.1 ISSUES WITH ISLANDING; 12.7.2 METHODS OF ISLANDING DETECTION; 12.8 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 13: THEORY OF ARC INTERRUPTION; 13.1 INTRODUCTION; 13.2 FUNDAMENTAL OF CIRCUIT BREAKING; 13.3 ARC PHENOMENON; 13.4 CHARACTERISTIC OF ARC; 13.5 THEORY OF ARC QUENCHING IN AC CIRCUIT; 13.5.1 RESTRIKING VOLTAGE; 13.5.2 ARC VOLTAGE; 13.5.3 TRANSIENT RESTRIKING VOLTAGE (TRV); 13.5.4 RATE OF RISE OF RESTRIKING VOLTAGE (RRRV); 13.5.5 RECOVERY VOLTAGE; 13.6 ARC INTERRUPTION THEORIES; 13.6.1 HIGH RESISTANCE INTERRUPTION; 13.6.2 LOW RESISTANCE INTERRUPTION; 13.6.2.1 SLEPIAN'S THEORY (RACE THEORY); 13.6.2.2 CASSIE'S THEORY (ENERGY BALANCE THEORY); 13.7 FACTORS AFFECTING RRRV, RECOVERY VOLTAGE AND TRV; 13.7.1 POWER FACTOR OF THE CIRCUIT; 13.7.2 CIRCUIT CONDITION AND TYPES OF FAULT; 13.7.3 ASYMMETRY OF SHORT CIRCUIT CURRENT; 13.7.4 SHORT LINE FAULT; 13.8 CURRENT CHOPPING (INTERRUPTION OF SMALL INDUCTIVE CURRENT); 13.9 INTERRUPTION OF CAPACITIVE CURRENT; 13.10 RESISTANCE SWITCHING; 13.11 THEORY OF ARC INTERRUPTION IN DC CIRCUIT; 13.11.1 CIRCUIT DESCRIPTION; 13.11.2 EFFECT OF CIRCUIT INDUCTANCE; 13.12 EXAMPLES; 13.13 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; UNSOLVED EXAMPLES; REFERENCES; CHAPTER 14: TYPES OF CIRCUIT BREAKERS; 14.1 INTRODUCTION; 14.2 RATINGS OF CIRCUIT BREAKERS; 14.2.1 RATED CURRENT AND RATED VOLTAGE; 14.2.2 RATED BREAKING CAPACITY; 14.2.3 RATED MAKING CAPACITYTY; 14.2.4 SHORT TIME RATINGCITY; 14.2.5 RATED STANDARD DUTY CYCLE; 14.3 FUNCTION OF HIGH RATING CIRCUIT BREAKERS; 14.4 LOW VOLTAGE CIRCUIT BREAKER; 14.4.1 SWITCHESE CIRCUIT BREAKERS; 14.4.1.1 LOAD BREAK SWITCH; 14.4.1.2 ISOLATING SWITCHH; 14.4.2 FUSES; 14.4.2.1 ADVANTAGES AND DISADVANTAGES OF FUSES; 14.4.2.2 MATERIALS OF FUSE ELEMENT; 14.4.2.3 PROPERTIES OF FUSE ELEMENT; 14.4.2.4 CHARACTERISTICS OF FUSE; 14.4.2.5 KIT-KAT FUSE; 14.4.2.6 HIGH RUPTURING CAPACITY (HRC) FUSE; 14.4.2.7 EXPULSION TYPE FUSE; 14.4.2.8 LIQUID QUENCHED FUSE (LQF); 14.4.3 MINIATURE CIRCUIT BREAKERS (MCB); 14.4.4 EARTH LEAKAGE CIRCUIT BREAKERS (ELCB); 14.5 HIGH VOLTAGE CIRCUIT BREAKERS; 14.5.1 AIR BREAK CIRCUIT BREAKER; 14.5.2 OIL CIRCUIT BREAKER; 14.5.2.1 BULK OIL CIRCUIT BREAKERS (BOCB); 14.5.2.2 MINIMUM OIL CIRCUIT BREAKERS (MOCB); 14.5.3 AIR-BLAST CIRCUIT BREAKER; 14.5.4 SULPHUR HEXAFLUORIDE (SF6) CIRCUIT BREAKER; 14.5.4.1 NON-PUFFER TYPE SF6 CIRCUIT BREAKER; 14.5.4.2 PUFFER TYPE SF6 CIRCUIT BREAKER; 14.5.4.3 SELF BLAST TYPE SF6 CIRCUIT BREAKER; 14.5.5 VACUUM CIRCUIT BREAKER; 14.5.6 HIGH VOLTAGE DIRECT CURRENT (HVDC) CIRCUIT BREAKERS; 14.6 MAINTENANCE OF CIRCUIT BREAKERS; 14.6.1 MAINTENANCE OF MEDIUM VOLTAGE CIRCUIT BREAKER; 14.6.2 MAINTENANCE OF HIGH VOLTAGE CIRCUIT BREAKER; 14.7 TESTING OF CIRCUIT BREAKER; 14.8 EXAMPLES; 14.9 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 15: TESTING, COMMISSIONING AND MAINTENANCE OF RELAYS; 15.1 INTRODUCTION; 15.2 TYPE TESTS; 15.2.1 OPERATING VALUE TEST; 15.2.2 OPERATING TIME TEST; 15.2.3 RESET VALUE TEST; 15.2.4 RESET TIME TEST; 15.2.5 TEMPERATURE RISE TEST; 15.2.6 CONTACT CAPACITY TEST; 15.2.7 OVERLOAD TEST; 15.2.8 MECHANICAL TEST; 15.3 COMMISSIONING AND ACCEPTANCE TESTS; 15.3.1 INSULATION RESISTANCE TEST; 15.3.2 SECONDARY INJECTION TEST; 15.3.3 PRIMARY INJECTION TEST; 15.3.4 TRIPPING TEST; 15.3.5 IMPULSE VOLTAGE TEST; 15.4 MAINTENANCE TESTS; 15.4.1 REQUIREMENT OF ROUTINE MAINTENANCE TEST; 15.4.2 FREQUENCY OF ROUTINE MAINTENANCE; 15.4.3 RECORDS OF COMMISSIONING AND MAINTENANCE; 15.5 TEST SETUP OF DIFFERENT TYPES OF RELAYS; 15.5.1 OVERCURRENT RELAY TEST BENCH; 15.5.2 OVERVOLTAGE RELAY TEST BENCH; 15.5.3 BIASED DIFFERENTIAL RELAY TEST BENCH; 15.5.4 DISTANCE RELAY TEST BENCH; 15.6 DIFFERENT TESTING METHODS; 15.6.1 STEADY STATE TESTING; 15.6.2 DYNAMIC TESTING; 15.6.3 SYSTEM MODEL TESTING; 15.7 COMPUTER BASED RELAY TESTING; 15.8 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 16: RECENT DEVELOPMENTS IN PROTECTIVE RELAYS; 16.1 INTRODUCTION; 16.2 FAULT DETECTION, CLASSIFICATION AND LOCATION SCHEME; 16.3 CONCEPT OF SYNCHRONIZED PHASOR MEASUREMENT; 16.4 CONCEPT OF WIDE AREA PROTECTION AND MEASUREMENT; 16.5 WAVELET TRANSFORM BASED ALGORITHM; 16.6 TRAVELLING WAVE BASED SCHEME; 16.7 APPLICATION OF ARTIFICIAL INTELLIGENCE (AI) TECHNIQUES IN PROTECTIVE RELAYS; 16.7.1 NEURAL NETWORK BASED SCHEME; 16.7.2 FUZZY LOGIC BASED SCHEME; 16.7.3 EXPERT SYSTEM BASED SCHEME; 16.7.4 GENETIC ALGORITHM BASED SCHEME; 16.8 SUMMARY; EXERCISE; MULTIPLE CHOICE QUESTIONS; REFERENCES; CHAPTER 17: INTRODUCTION TO PSCAD; 17.1 INTRODUCTION; 17.2 DIFFERENT LIBRARY MODELS; 17.2.1 VOLTAGE SOURCE MODEL; 17.2.1.1 DATA FORMAT FOR INTERNAL CONTROL; 17.2.1.2 SOURCE CONTROL MODES; 17.2.2 TRANSMISSION LINES; 17.2.3 MACHINES AND TRANSFORMERS; 17.2.4 ON-LINE FREQUENCY SCANNER (FFT); 17.2.5 SEQUENCE FILTER; 17.2.6 PROTECTION COMPONENTS; 17.2.7 LINE TO GROUND IMPEDANCE; 17.2.8 LINE TO LINE IMPEDANCE; 17.2.9 CSMF (CONTINUOUS SYSTEM MODEL FUNCTIONS); 17.2.10 BREAKERS; 17.2.11 CONTROL PANELS; 17.3 MAKING A SIMPLE CIRCUIT IN PSCAD; 17.4 CASE STUDY OF OVERCURRENT RELAY COORDINATION; 17.5 CASE STUDY OF IMPLEMENTATION OF DISTANCE RELAYING SCHEME; 17.5.1 EMTP/PSCAD MODELS; 17.5.2 STUDY OF SIMULATION CASE; 17.5.3 PSCAD VIEW OF DISTANCE RELAY; 17.5.3.1 SIGNAL PROCESSING BLOCK; 17.5.3.2 PROTECTION SCHEME BLOCK; 17.5.4 PHASE 'A' TO GROUND FAULT; 17.5.5 THREE PHASE FAULT; TUTORIAL-17.1; TUTORIAL-17.2; TUTORIAL-17.3; ANNEXURE -A; ANNEXURE -B; REFERENCES; APPENDICES