Principle of operation.  Equivalent circuits. No-load and short-circuit tests. Transformer at load. Transformers in three-phase systems. Transformer characteristics. Instrument transformers. Common methods for transformer cooling.

  Principle of conservation of energy. Expressions of mechanical force and energy. Simplified expressions - Linear magnetic circuits. Multiple Excited electromagnetic systems. Application to systems with permanent magnets. Systems with several degrees of mechanical freedom.

  Field created by a concentrated winding. Field created by distributed windings. Field created by three-phase sinusoidal windings- rotating field.

 Structure of polyphase machines. Equivalent circuit of induction machines. Using the T-equivalent circuit. The Gamma equivalent circuit. Torque speed curve of induction machines. Induction motors in electrical networks. Induction generators. Testing induction machines. Induction rotor speed adjustment. Starting three-phase induction motors.

   Description. Synchronous machine modeling. Testing synchronous machines. Synchronous generators isolated from the network. Synchronous machines connected to an infinite bus. Rotor speed adjustment of synchronous motors and generators.