GE P642 Technical Manual page 7

P64x
6.3 CLO Implementation
6.4 Application Notes
6.4.1 CLI Setting Guidelines
6.4.2 CLO Setting Guidelines
Chapter 8 Restricted Earth Fault Protection
1 Chapter Overview
2 REF Protection Principles
2.1 Resistance-Earthed Star Windings
2.2 Solidly-Earthed Star Windings
2.3 Through Fault Stability
2.4 Restricted Earth Fault Types
2.4.1 Low Impedance REF Principle
2.4.2 High Impedance REF Principle
3 Restricted Earth Fault Protection Implementation
3.1 Enabling REF Protection
3.2 Selecting the Current Inputs
3.3 Low Impedance REF
3.3.1 Setting the Bias Characteristic
3.3.2 Delayed Bias
3.3.3 Transient Bias
3.3.4 Restricted Earth Fault Logic
3.4 High Impedance REF
3.4.1 High Impedance REF Calculation Principles
4 Second Harmonic Blocking
4.1 REF 2nd harmonic Blocking Logic
5 Application Notes
5.1 Star Winding Resistance Earthed
5.2 Low Impedance REF Protection Application
5.2.1 Setting Guidelines for Biased Operation
5.2.2 Low Impedance REF Scaling Factor
5.2.3 Parameter Calculations
5.2.4 Dual CB Application with Different Phase CT Ratios
5.2.5 Dual CB Application with Same Phase CT Ratios
5.2.6 CT Requirements - Low Impedance REF
5.3 High Impedance REF Protection Application
5.3.1 High Impedance REF Operating Modes
5.3.2 Setting Guidelines for High Impedance Operation
5.3.3 Use of Metrosil Non-linear Resistors
5.3.4 CT Requirements - High Impedance REF
Chapter 9 Current Protection Functions
1 Chapter Overview
2 Overcurrent Protection Principles
2.1 IDMT Characteristics
2.1.1 IEC 60255 IDMT Curves
2.1.2 European Standards
2.1.3 North American Standards
2.1.4 Differences Between the North american and European Standards
2.2 Principles of Implementation
2.2.1 Timer Hold Facility
2.3 Magnetising Inrush Restraint
3 Phase Overcurrent Protection
3.1 Phase Overcurrent Protection for Power Transformers
3.2 Phase Overcurrent Protection Implementation
3.3 Selecting the Current Inputs
P64x-TM-EN-1.3
Contents
161
163
163
163
165
167
168
169
169
170
170
170
171
173
173
173
174
174
175
175
175
175
176
177
177
178
178
179
179
179
179
180
181
181
183
183
185
187
189
191
193
194
194
195
196
198
199
199
200
200
202
202
202
203
v