2.7.1.4 The Magnetic Energy in Terms of the Currents and Inductances -- 2.8 The Magnetic Energy for a Solenoid Carrying a Current I -- 2.9 Energy Flow Diagram -- 2.9.1 Power Flow Diagram of DC Generator and DC Motor -- 2.9.1.1 Power Flow Diagram and Losses of Induction Motor -- 2.9.1.2 Rotational Losses -- 2.10 Multiple Excited Systems -- 2.11 Doubly Excited Systems -- 2.11.1 Torque Developed -- 2.11.1.1 Excitation Torque -- 2.11.1.2 Reluctance Torque -- 2.12 Concept of Rotating Magnetic Field -- 2.12.1 Rotating Magnetic Field due to Three-Phase Currents -- 2.12.1.1 Speed of Rotating Magnetic Field -- 2.12.1.2 Direction of Rotating Magnetic Field -- 2.12.2 Alternate Mathematical Analysis for Rotating Magnetic Field -- 2.13 Summary -- Problems -- References -- Chapter 3 Single-Phase and Three-Phase Transformers -- 3.1 Preliminary Remarks -- 3.2 Classification of Transformers -- 3.2.1 Classification Based on Number of Phases -- 3.2.1.1 Single-Phase Transformers -- 3.2.1.2 Three-Phase Transformers -- 3.2.1.3 Multi-Phase Transformers -- 3.2.2 Classification Based on Operation -- 3.2.2.1 Step-Up Transformers -- 3.2.2.2 Step-Down Transformers -- 3.2.3 Classification Based on Construction -- 3.2.3.1 Core-Type Transformers -- 3.2.3.2 Shell-Type Transformers -- 3.2.4 Classification Based on Number of Windings -- 3.2.4.1 Single-Winding Transformer -- 3.2.4.2 Two-Winding Transformer -- 3.2.4.3 Three-Winding Transformer -- 3.2.5 Classification Based on Use -- 3.2.5.1 Power Transformer -- 3.2.5.2 Distribution Transformer -- 3.3 Principle of Operation of the Transformer -- 3.3.1 Ideal Transformer -- 3.4 Impedance Transformation -- 3.5 DOT Convention -- 3.6 Real/Practical Transformer -- 3.7 Equivalent Circuit of a Single-Phase Transformer -- 3.8 Phasor Diagrams Under Load Condition -- 3.9 Testing of Transformer -- 3.9.1 Open-Circuit Test -- 3.9.2 Short-Circuit Test.

4.3.1 Coil Construction -- 4.3.1.1 Coil Construction: Distributed Winding -- 4.3.1.2 Coil Construction: Concentrated Winding -- 4.3.1.3 Coil Construction: Conductor Bar -- 4.3.2 Revolving (Rotor) Winding -- 4.3.3 Stationary (Stator) Winding -- 4.3.4 DC Armature Windings -- 4.3.4.1 Pole Pitch (Yp) -- 4.3.4.2 Coil Pitch or Coil Span (Ycs) -- 4.3.4.3 Back Pitch (Yb) -- 4.3.4.4 Front Pitch (Yf) -- 4.3.4.5 Resultant Pitch (Y) -- 4.3.4.6 Commutator Pitch (a) -- 4.3.5 Lap Winding -- 4.3.5.1 Lap Multiple or Parallel Windings -- 4.3.5.2 Formulas for Lap Winding -- 4.3.5.3 Multiplex, Single, Double, and Triple Windings -- 4.3.5.4 Meaning of the Term Re-entrant -- 4.3.5.5 Multiplex Lap Windings -- 4.3.6 Wave Winding -- 4.3.6.1 Formulas for Wave Winding -- 4.3.6.2 Multiplex Wave or Series-Parallel Winding -- 4.3.6.3 Formulas for Series-Parallel Winding -- 4.3.7 Symmetrical Windings -- 4.3.7.1 Possible Symmetrical Windings for DC Machines of a Different Number of Poles -- 4.3.8 Equipotential Connectors (Equalizing Rings) -- 4.3.9 Applications of Lap and Wave Windings -- 4.3.10 Dummy or Idle Coils -- 4.3.10.1 Dummy Coils -- 4.3.11 Whole-Coil Winding and Half-Coil Winding -- 4.3.12 Concentrated Winding -- 4.3.13 Distributed Winding -- 4.4 Electromotive Force (emf) Equation -- 4.4.1 emf Equation of an Alternator -- 4.4.1.1 Winding Factor (Coil Pitch and Distributed Windings) -- 4.4.2 Winding Factors -- 4.4.2.1 Pitch Factor or Coil Pitch (Pitch Factor (Kp) or Coil Span Factor [Kc]) -- 4.4.3 Distribution Factor (Breadth Factor (Kb) or Distribution Factor (Kd)) -- 4.4.3.1 Distribution Factor (Kd) -- 4.5 Magnetomotive Force (mmf) of AC Windings -- 4.5.1 mmf and Flux in Rotating Machine -- 4.5.2 Main Air-Gap Flux (Field Flux) -- 4.5.3 mmf of a Coil -- 4.5.3.1 mmf -- 4.5.3.2 mmf of Distributed Windings -- 4.5.3.3 mmf Space Wave of a Single Coil.