Fault Analysis In Electrical Networks and Distribution Cables

Introduction

The detection and identification of faults on an electrical network have been and still is one of the problems facing Transmission and Distribution companies. The characteristics and operation of a network system are major considerations in creating or reducing the effects of electrical faults on the system. Effective modern protective systems are designed to sense faults and send a warning signal or initiate a disconnection of the faulty system in an appropriate time.  Delegates are encouraged to participate by active involvement in group discussions and sharing experiences.

Objectives

By the end of the training, participants will be able to:

• Understand the various types of fault currents
• Determine the causes of overcurrent and short circuit current
• Explain the differences between symmetrical and unsymmetrical faults
• Analyze the common faults in a power system
• Interpret manual calculation versus software aided fault current calculations

Training Methodology

This is an interactive course. There will be open question and answer sessions, regular group exercises and activities, videos, case studies, and presentations on best practice. Participants will have the opportunity to share with the facilitator and other participants on what works well and not so well for them, as well as work on issues from their own organizations. The online course is conducted online using MS-Teams/ClickMeeting.

Who Should Attend?

Course Outline

Day 1: Power System Components and System Grounding

• Introduction
• 1.1.1 General

1.1.2 Importance of Continuity of Supply

1.1.3 Power System Components

1.1.3.1 Causes of Faults

1.1.3.2 Types of Faults

1.2 System Grounding

1.2.1 Introduction

1.2.2 Ungrounded Generation Units & Transformers

1.2.3 Transient over Voltages in Ungrounded Systems: Generators and Transformers

1.2.4 Grounded Detection Methods for Ungrounded Systems: Generators & Transformers

1.2.5 High Impedance Grounding Systems: Generators & Transformer

1.2.6 System Grounding for Mine or Other Hazardous Type Applications

1.2.7 Low Impedance Grounding: Generator & Transformers

1.2.8 Solid (Effective) Grounding Generators & Transformers

1.2.9 Ferro--resonance in 3-Phase Power Systems: Distribution Systems

1.2.10 Ferro-resonance in 3-Phase Power Systems: Transmission Systems

1.2.11 Arrangements of Grounding in Power Systems

1.2.12 Grounding Summary and Recommendation

1.2.13 Electric Shock and Its Effects on Humans

1.2.14 Ground Resistance

1.2.15 Transmission Line Grounds

1.2.16Substation Grounding

Day 2: Analysis of Power Generation & Transformer Systems and Analytical Tools for Fault Analysis

2.1 Power Generation Systems

2.1.1 General

2.1.2 Factors Affect the Fault Current Contribution & Continuity of Supply

2.1.2.1 General

2.1.2.2 Balanced Three–Phase Faults at No Load Generator

2.1.3 Relation between Substation Equipment’s Connections and the Fault Contribution

2.2 Transformers

2.2.1 Vector Group

2.2.2 Parallel Transformers with Different Vector Groups

2.2.3 Grounding Transformers

2.2.4 Common & Separate Grounding Resistance (High & Low Values)

2.3 Fault Calculations

2.3.1 System Configuration

2.3.2 Per-Unit Values

2.3.3 Symmetrical Components

2.3.4 Symmetrical & Unsymmetrical Fault Calculations

2.3.5 Short Circuit Level

2.3.6 Effect of Induction Machines on Short Circuit Level

2.3.7 Rupture Capacity of Circuit Breakers

2.3.8 Methods to Reduce the Short Circuit Level & Peak Current Limiters

2.3.9 Numerical Examples

2.4 Fault Analysis in Power Generation Plants

2.4.1 Generation Plants Outline

2.4.2 Types of Electrical Faults in Generating Plants

2.4.3 Methodology of Generator Fault Analysis

Day 3: Mal & False Operation of Common Protective Relays Which Leads to Power System Disturbances

3.1 Introduction

3.2 Directional & Non-Directional over Current and Earth Fault Relays

3.3 Sensitive Earth Fault, Differential & Restricted Earth Fault, Directional and  

      Distance Relays

3.4 Gas Actuating Relays

3.4.1 Buchholz Relay

3.4.2 Sudden Pressure Relays

3.5 Over Fluxing Relays

3.6 Case Study

3.6.1 A Case of a False Operation for an Out–Of–Step Relay (OS)

3.6.2 A Case of a False Operation of a Circuit Breaker

Day 4: System Behavior due to some Abnormal Operational Conditions

4.1 Introduction

4.2 Shortage of Active Power & Frequency Deviation

4.3 Shortage of Reactive Power

4.3.1 Introduction

4.3.2 Voltage Deviations & Voltage Rise

4.3.3 Voltage Stability and Voltage Collapse with Case Studies

4.4 Maintenance Management and Fault Forecast

4.4.1 Maintenance Strategies

4.4.1.1 Run to Failure (RF)

4.4.1.2 Scheduled Maintenance (SM)

4.4.1.3 Condition Based Maintenance (CM)

4.4.2 Fault Forecast (Fault Detection)

Day 5: Faults due to Unavoidable Causes and Network Improvement

5.1 Faults due to the Following External & Internal Influences

5.1.1 Lightning

5.1.2 Switching

5.1.3 Pollution

5.1.4 Harmonics

5.2 Network Performance Evaluation

5.3 Cause of Blackouts in Electrical Networks

5.4 Blackout in Power Systems

5.5 Preventive Measures of Blackout (Network Improvement Methods)

5.6 Case Studies Discussions