- #753 Course Code
- Line protection with SIPROTEC 5 7SA8 (Basic to advanced level)
- Trainer: Dr. Saeed Roostaee (Profile)
- Course creation: Feb 2025
- Last update: September 2025
- Total time till now: 12 hours & 50 minutes
- Join our WhatsApp group for the latest updates on this training: https://elec-engg.com/updates/
Our video-recorded training on Line Protection based on SIPROTEC 5 7SA offers a convenient and flexible learning option for participants who prefer to study at their own pace. Our expert instructors deliver comprehensive training modules and cover all the essential aspects of line protection using the SIPROTEC 5 7SA8 relay IED. Participants can access the video recordings anytime, anywhere, allowing them to review the content as needed and learn at a time that suits their schedule.
The following sections provide an overview of the course structure and topics covered in our training package.
Line Protection
The training course begins by introducing the fundamental principles and concepts of line protection, including (Length: 1 hour and 54 minutes):
- Faults in transmission lines
- Over-current issues in the line protection
- Why distance protection function
- Line Distance Basic Principle
- Effect of fault resistance on distance protection function
- Distance characteristics (MHO & Quad)
- Directional determination
- Distance Measurement Principle (6 loops)
- Load area and fault area with resistance for phase-to-phase and phase-to-ground faults
- Stepped Distance
- Distance parameters in the SIPROTEC 7SA8 (an overview)
- Fault resistance with infeed effect (over-reach, under-reach)
- Zone-inclination angle
- Distance protection classic and RMD methods
- Tele-protection scheme
- Tele-protection config in SIPROTEC 5 7SA8
- Switch on to fault (SOFT)
- Auto-recloser (ANSI 79)
- STUB protection
- Power swing blocking



SIPROTEC 5 7SA Config
The second chapter provides detailed insights into SIPROTEC 7SA8 hardware and configuration with the below topics (Length: 1 hour and 12 minutes):
- SIPROTEC 5 7SA basic template
- SIPROTEC 5 7SA RMD config
- SIPROTEC 5 7SA config in 1.5 CB arrangement
- SIPROTEC 5 7SA Config case study config (functions and signals)

Distance Protection
Moving on to the next chapter, the distance protection function in the SIPROTEC 7SA8 is discussed, covering the topics highlighted below (Length: 2 hours and 12 minutes).
- Distance Protection for Grounded Systems
- Structure of the Distance Protection
- Ground-fault detection logic
- Supervision of the zero-sequence current 3I0
- Supervision of the ratio of the zero-sequence current and negative-sequence current (3I0/3I2)
- Supervision of the zero-sequence voltage V0
- Ground-fault detection parameters
- Pickup method
- Impedance pickup
- Overcurrent pickup
- V/I pickup
- V/I φ pickup
- Distance zones
- Loop Selection
- Direction determination
- Zone with Quadrilateral Characteristic
- Operate Curve with Quadrilateral Characteristic
- MHO Characteristic Curve
- Circular Characteristic Curve
- Output Logic of the Distance Protection



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Line Function Group
The Line Function Group encompasses the main protection and supervision functions available in SIPROTEC 5 7SA8 relays. Grasping the logic and parameters of this function block is crucial, as they are integral to all tasks required for line protection and monitoring. This chapter provides a comprehensive explanation of the structure and blocks within the line function group, focusing on the key topics highlighted below (Length: 1 hour and 6 minutes).
- Structure of the Function Group
- Operational Measured Values
- Line data
- Operational measurement
- Inversion of Power-Related Measured and Statistical Values
- The Kr and Kx parameters
- R0 Zero-sequence system resistance
- X0 Zero-sequence system reactance
- R1 Positive-sequence system resistance
- X1 Positive-sequence system reactance
- CT saturation detection
- Series compensation
- Process monitor
- Current-Flow Criterion Logic & Parameters
- Circuit-Breaker Condition for the Line
- Closure detection Logic & Parameters
- 1-Pole Open Detector
- Voltage criterion
- Cold-load pickup detection
- Output logic of the function group





Tele-Protection
Information exchange with the remote line end is applied throughout the line length to enable selective and non-delayed fault clearance of all faults. This chapter discusses the SIPROTEC 5 7SA8 Tele-protection functions and logic, highlighting the topics below (Length: 1 hour and 12 minutes).
- Why Teleprotection?
- Permissive Underreach Transfer Trip (PUTT)
- Direct Underreach Transfer Trip (DUTT)
- Permissive Overreach Transfer Trip (POTT)
- Teleprotection with Ground-Fault Protection
- 85-67N transient blocking
- Echo and Tripping in the Event of Weak Infeed
- Weak infeed parameters
- Detection of Weak Infeed Logic



Switch onto Fault (SOTF)
Logic Diagram of the Stage Instantaneous Tripping at the Switch onto the Fault

Power-Swing Blocking
- Functionality of Power-Swing Blocking
- Trajectory monotony
- Trajectory continuity
- Trajectory uniformity
Automatic Reclosing Function
- Automatic Reclosure function (AR) (AREC)
- Dead time
- Reclaim time
- Start AR
- Block AR
- multishot AR
- Signals between Protection Functions and Automatic Reclosing Functions
- Operating modes
- Cyclic Automatic Reclosing Function
- Operating mode 3: with op., w/o act. Time
- Operating Mode: With Tripping/With Action Time
- Action time
- Operating Mode: with Pickup/without Action Time
- Parameter: 102) CB ready check bef. start
- Parameter: CB ready superv. time
- Reclaim Time
- Parameter: 104) Block. time aft. man.close
- Parameter:105) Start signal supervis.time
- Parameter:107) 3-pole operate by 79
- Parameter: Evolving faults
- Parameter:108) Evolving-fault detection
- Parameter:109) Response to evolv. faults
- Parameter:109) Dead time aft. evolv. fault





Synchronization function (ANSI 25)
- Synchrocheck
- Switching synchronous power systems
- Switching asynchronous power systems
- Switching to the dead line/busbar
- Synchronization of Line and Busbar, Connection via 4 Voltage Inputs
- Synchronization of Line and Busbar, Connection via 6 Voltage Inputs
- Closing Conditions for the Synchrocheck Function
- The indication All sync. conditio. OK
- Synchrocheck Min. Max. operating limit
- The power transformer is located between the feeder and the busbar voltage transformers
- Angle adjust. (transform.)
- Max.durat. sync.process
- Direct close command
- Operating range
- Synchronous/Asynchronous (Sychr./Asycr.) stage



7SA Testing & Commissioning
SIPROTEC 5 7SA8 distance protection testing
- SIPROTEC 7SA8 distance protection testing procedure
- How to draw SIPROTEC 7SA8 characteristics
- RIO and XRIO
- Distance RIO parameters
- Testing of the SIPROTEC 5 7SA8 relay
- SIPROTEC 7SA8 PTL

Why this course?
- Learn at your own pace and on your own schedule.
- Revisit complex topics as needed without coordinating with an instructor.
- Comprehensive coverage including: Protection concepts, wiring diagrams, Configuration, commissioning steps, parameter sets, maintenance, troubleshooting, and safety notes
- Real-world scenarios
Sample Parts:
https://youtube.com/watch?v=Rzvejbui4-w%3Fsi%3DK9W1gqziJiicHK1v%26nbsp%3Bhttps%3A
Supplementary files

