Practical Power System Protection

INTRODUCTION TO POWER SYSTEM PROTECTION

• Importance of the Protection System
• References
• HV equipment
• Protection Panel
• Protection Single Line Diagram
• What do we want to protect?
• Function of protection systems
• Protection system elements

Protection Classification, Types & ANSI Codes

• Common Acronyms
• ANSI Standard Device Numbers
• 21 Distance Relay
• 21G Ground Distance
• 21P Phase Distance
• 24 Volts-per-Hertz Relay / Overfluxing
• 25 Synchronizing or Synchronism-Check Device
• 27 Undervoltage Relay
• 27P Phase Undervoltage
• 32R Reverse Power
• 46 Reverse-Phase or Phase Balance Current Relay or Stator Current Unbalance
• 49 Machine or Transformer Thermal Relay / Thermal Overload
• 50 Instantaneous Overcurrent Relay
• 50BF Breaker Failure
• 50N Neutral Instantaneous Overcurrent
• 51 Time Overcurrent Relay
• 51N Neutral Time Overcurrent
• 51V Voltage-Relained Time Overcurrent
• 59 Overvoltage Relay
• 67 Directional Overcurrent Relay
• 67N Neutral Directional Overcurrent
• 79 Ac Reclosing Relay / Auto Reclose
• 81 Frequency Relay
• 81O Over Frequency
• 81U Under Frequency
• 86 Locking-Out Relay
• 87 Differential Protective Relay
• 87B Bus Differential
• 87G Generator Differential
• 87GT Generator/Transformer Differential
• 87L Line Current Differential
• 87M Motor Differential
• 87RGF Restricted Ground Fault
• 87T Transformer Differential

Protection Single Line Diagram

• PSLD
• Line Protection
• Feeder Protection
• Generator Protection
• Transformer Bay

Numerical Protection Relays

• Protection Technology from Siemens
• SIPROTEC RELAY FAMILIES
• Hardware structure of the SIEMENS numerical multi-functional device
• SIPROTEC 4 relay block diagram
• SIPROTEC 5
• Properties of SIPROTEC 5
• SIPROTEC 5 expansion modules
• Modular device concept, freely configurable
• Devices without Jumpers- no more opening of the device
• Sampling rate up to 16 kHz
• Draw out of the terminal blocks
• On-Site operation panel
• ABB Relion Protection Relays
• ABB Relay hardware
• MiCOM Relays

START WITH DIGSI 5

• DIGSI 5 installation
• SIPROTEC drivers
• Manage device drivers
• Upgrade DIGSI 5 Version
• DIGSI 5 User interface
• Start with DIGSI 5
• DIGSI 5 function library
• Function Point
• Embedding of Functions in the Device

Working Online with the SIPROTEC 5 (Practical Section)

• Relay Offline Vs. Online Mode
• Device Information
• Config Information
• Process Mode
• Commissioning Mode
• Simulation Mode
• Function Points
• Edit device time
• Copy the online device to the project
• Assign an online device to the project
• Change the assigned device
• Create a backup from a device
• Load the Configuration to the device
• Retrieve Device Data

SIPROTEC 5 Web UI

• Device Information
• Relay Hardware and order code
• Set the relay date and time in the web UI
• Monitor Relay Displays
• Monitor binary inputs
• Monitor Binary outputs
• Monitor LEDs
• Access to all LOGs and download LOGs
• Runtime Data
• Monitor the recorded fault in the web UI
• Manual Recording trigger
• Download relay fault records
• Measurements
• Check the relay setting values
• Change settings
• Apply settings

Relay measurements

• Operational measured values
• Fundamental Components
• Symmetrical Components
• Function-specific measured values
• Energy metered values
• Statistical values
• Primary values
• Secondary values
• Snapshot
• Inject the three-phase values into the relay and monitor the relay measurements

Logs and Indications

• Reading Indications from the PC
• Operational Log
• Fault Log
• Ground-Fault Log
• User-defined Logs
• Config Logs in the matrix
• Download Logs
• Time stamp
• Relative time
• Entry Number
• Function Structure
• Signal name
• Signal Value
• Signal Quality

Fault Recorder

• Fault Recorder Function
• Fault recording with Pickup (find in digis and mention parameter ID)
• Fault recording with Pickup & AR cycle (why this setting)
• Storage settings
• Pre-fault time parameter
• Post-fault time parameter
• Sampling Frequency
• Fault recorder config
• Download fault records
• Comtrade format
• COMTRADE Viewer
• Time signals
• Harmonic signals
• Binary signals
• RMS and Instantaneous values

Overcurrent and Earth fault

• Overcurrent DT 50
• Overcurrent IT 51
• Overcurrent curves
• How to configure OC protection
• How to test OC protection
• IE calculation
• IE measurements
• Config earth fault protection
• How to test EF protection

Directional Overcurrent and Earth fault

• Why Directional overcurrent protection
• How to configure Directional overcurrent protection (ANSI67)
• Simulate a fault in the forward direction
• Simulate a fault in the backward direction
• How to Test Direction OC Protection
• Directional overcurrent fault logs and records
• How does 67N work?
• Config Directional Earth Fault overcurrent (ANSI67N)
• Fault simulation to test 67N
• Test 67N with simulated signals
• Fault logs with 67N operation
• Fault record with 67N operation

HARDWARE CONNECTIONS

• Power supply connections
• Current Transformer Terminals
• 4 protection-class current transformers
• 3 protection-class current transformers + 1 sensitive protection-class transformer
• 4 instrument transformers.
• Connection Diagrams
• 3 Phase + IN
• 3 Phase
• 3 Phase + IN separate
• Set test sequence & Monitor Current signals
• Phase sequence
• Neutral point in dir. Of object
• Inverted phases
• Connection Examples of Voltage Transformers
• 3-phase to ground voltages
• 3-phase to ground volt. + VN
• 2 ph-ph volt.
• 2 ph-ph volt. +VN

SYMBOL & TEXT STRUCTURE

• Parameters with setting values
• State logic
• Health
• External binary input signal with an indication number
• External output signal with indication number and additional information
• Measured output value
• Binary input signal derived from an external output signal
• Internal input signal
• Internal output signal
• Analog input signal
• Reset/block a logic element
• AND / OR / XOR / Negation
• Threshold stage exceeded
• Threshold stage exceeded with reset of input
• Threshold stage shortfall
• Threshold stage shortfall with reset of input
• Threshold stage exceeded with dropout delay
• Threshold stage exceeded with dropout delay and reset of input
• Threshold stage shortfall with dropout delay
• Threshold stage shortfall with dropout delay and reset of input
• Comparators
• Pickup delay
• Dropout delay
• Pickup and dropout delay
• Trigger the pulse of duration T with a positive signal edge
• Trigger the pulse of duration T with a negative signal edge
• SR-flip-flop, RS-flip-flop, D-flip-flop
• Characteristic curve
• Minimum operating time

COMTRADE VIEWER (SIGRA OR OTHER TOOLS)

• Comtrade format
• Import and configure the fault record in SIGRA
• Time signals
• Harmonic signals
• Binary signals
• RMS and Instantaneous values
• Structure of the function group Voltage-current 3-phase

FB General

• Operational measured values
• Process monitor
• Output logic of the function group
• Reset the LED group
• Rated current
• Rated voltage
• Rated apparent power
• Power-sys. neutral point
• P, Q sign

FUNCTION-GROUP CIRCUIT-BREAKER

• Interfaces with Measuring Points
• Rated normal current
• Current thresh. CB open
• Trip logic
• Trip/open cmd.
• Close command
• Acquisition of the Circuit-Breaker Information
• Acquisition blocking
• Manual Updating
• CB Ready
• Output time
• Indication of breaking values
• Manual Closure
• Action time
• Control

FAULTS

• Normal Operation of Power System
• Abnormal Condition of Power System
• Types of faults
• Cause of the fault in the power system equipment
• Short circuit type fault
• Short circuit with impedance
• Broken conductor fault
• Inter-circuit fault
• Cross-country fault
• Faults in overhead transmission lines
• Generator Stator Winding Faults
• Generator Rotor Circuit Faults
• Transformer faults
• Motor Thermal Failure
• Failure rate of power system equipment

FAULT SIMULATIONS

• Single line simulation
• Single-phase fault simulation
• Earth fault simulation
• Fault location effect on signals
• Phase-to-phase fault simulation
• RMS and Instantaneous signals
• Ph-Ph-E fault simulation
• 3-phase fault simulation
• 3-phase-E fault simulation
• Fault Zero sequence values
• Fault Negative sequence values
• Effect of fault impedance
• Fault impedance values
• Load effect
• Effect of source Impedance in fault signals
• Primary and secondary values

Transformer Protection

• Why Transformer Protection
• Earth Fault on H.V. External Connections
• Phase-to-Phase Fault on H.V. External Connections, Internal Earth Fault on H.V. Windings
• Internal Phase-to-Phase Fault on H.V. Windings Short Circuit Between Turns H.V. Windings
• Earth Fault on L.V. External Connections
• Phase-to-Phase Fault on L.V. External Connections, Internal Earth Fault on L.V. Windings
• Internal Phase-to-Phase Fault on L.V. Windings Short Circuit Between Turns L.V. Windings
• Transformer Protection Scheme
• SIPROTEC 7UT8 config
• Application templates
• Two-winding transformers
• Three-winding transformer basic (87T)
• Three-winding transformer 1.5CB
• Function Group Differential
• Function Group Side

Line Protection

• Transmission Line Faults
• Line protection functions
• Why Use Distance Protection?
• How Distance protection works
• Distance Protection
• Distance measurement (principle)
• phase- phase -loop
• phase- ground -loop
• Load and short-circuit impedances
• Distance characteristics
• Stepped Distance protection
• SIPROTEC 7SA8 Configuration
• SIPROTEC 7SA8 Application templates
• BI Config: Under Voltage blocking
• BI Config: PUTT receive signal
• BI Config: Channel PUTT faulty
• BI Config: DEF receive
• BI Config: DEF channel faulty
• BI Config: DS position for release STUB (DS Open)
• BI Config: CVT MCB Fail
• BI Config: CB Position
• User-defined: SUB II Faulty
• BO Config: 1/3 pole Trip
• BO Config: Close Cmd
• BO Config: 85-21 PUTT send
• BO Config: 85-21 DEF send
• Distance Protection in SIPROTEC 7SA8
• Pickup method
• Distance zones (quadrilateral characteristic curve preconfigured)
• Ground-fault detection
• Direction Determination

Generator Protection

• Generator Introduction
• Synchronous Generator
• Generator construction
• Stator
• Rotor
• Salient pole rotor
• Cylindrical rotor
• Synchronous Generator Operation
• Equivalent circuit of a synchronous generator
• Generator connection
• Direct Connected Generators
• Unit Connected Generator
• Faults in Generators
• Stator Earth Faults
• Rotor Earth Faults
• Stator Short Circuits
• Stator Interturn faults
• External faults
• Stator Winding Faults
• Control System and Field Winding/Rotor Circuit Faults
• Abnormal Operating Conditions
• 32 Reverse Power
• 40 Loss of Excitation
• 46 Negative Sequence
• 49 Thermal Overload
• 51V voltage restraint
• 51G Ground over current
• 64 Ground Relay
• 87 Differential
• Generator Stator Earth Fault Protection
• 87GD Generator Ground Differential
• 59N overvoltage protection
• 95 % of the stator winding protection