explainning the Design of substation grounding grids from hazard analysis and soil charectristics to parts of ground sys and setup of ground system with explanning factors that affect ground resistance and the effect of grid number and grid depth
Electrical installations require grounding systems, which provide protection against electric shocks. In most industrial cases, grounding systems consist of grids integrated with rods at each comers. in some cases, non-insulated reinforcing bars in concrete foundations may also serve as vertical ground electrodes.
index of Design of substation grounding grids book
1. Introduction 6
2. Electric shocks and protection 11
2.1. Hazard Analysis 11
2.2. A safe grounding design has two objectives: 11
2.3. Soil Characteristics 12
2.4. RESISTANCE OF GROUNDING SYSTEMS 14
2.5. Resistance of a Grounding Point Electrode 17
2.7 Resistance of Driven Rods 21
3. SUBSTATION GROUNDING SYSTEM 26
3. SUBSTATION GROUNDING SYSTEM 27
3.1. PRINCIPLES OF DESIGN OF ASUBSTATION GROUNDING 27
3.2. NEUTRAL GROUNDING 30
3.3. GROUNDING OF LOW-VOLTAGE (LV) SYSTEMS 33
3.4. GROUNDING OF GAS-INSULATED SUBSTATIONS 35
3.5. Grounding of Enclosures 36
3.5.1. Touch Voltages for GIS 37
3.5.2. Transient Impedance of GIS Grounding Grid 37
3.6. Transmission-line tower grounding 38
3.7. Safety ground 39
3.8. Range of Tolerable Currents 39
3.9. Tolerable Step, Touch, and Transferred Voltages 40
3.9.1. Electric Shock Hazard in Hospitals 43
3.10. Methods Of Decreasing Ground Resistance 43
3.11. Cracks with Low-Resistivity Materials (LRM 44
3.11.1. Chemical Rods 44
3.11.2. Grounding Augmentation Fill (GAF 46
3.11.3. Cracks with Low Resistivity Materials (LRM) 46
4. Experimental setup 48
4. Experimental setup 49
4.1. Introduction 49
4.2. Experimental layout 50
4.3. Touch voltage calculation 53
4.4. Electric resistivity Measurement by 4 electrode method 54
4.5. Test procedures 57
5. Results And Discussion 58
5. Results And Discussion 59
5.1. Effect of grid number 59
5.2. Effect of grid depth 63
6. Conclusions 67
7. Future work
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