Synchronous Machines-1 Study notes For Electrical Engineering

By Deepak Yadav|Updated : July 13th, 2023

Synchronous Machines-1 study notes offer a comprehensive exploration of synchronous machines, which are essential components in electrical power systems. These study notes provide electrical engineering students with a deep understanding of the principles, construction, and operation of synchronous generators. Topics covered include synchronous machine modelling, phasor diagrams, synchronous reactance, voltage regulation, and synchronization. By studying these notes, students gain a solid foundation in the theory and practical aspects of synchronous machines, enabling them to analyze and design power systems with synchronous generators.

Synchronous machines play a crucial role in electrical power generation and distribution, making them a focal point of study for electrical engineering students. Synchronous Machines-1 study notes delve into the intricacies of synchronous generators, providing students with a comprehensive overview of their working principles and characteristics. This study notes cover topics such as the synchronous generator equivalent circuit, armature reaction, voltage regulation, power-angle characteristics, and the impact of loading and excitation on machine performance. By immersing themselves in these study notes, students develop a strong understanding of synchronous machines, enabling them to contribute to the design, operation, and control of power systems.

Download Formulas for GATE Electrical Engineering - Signals and Systems

Table of Content

Synchronous Machines

Synchronous machines are vital components in electrical power systems, employed for power generation, transmission, and distribution. These machines operate in synchronism with the grid frequency, providing stable and reliable power. With their unique characteristics and capabilities, synchronous machines form an integral part of the infrastructure that powers our modern world.

  • Synchronous machines are one of two types: the stationary field or the rotating dc magnetic field. The stationary field synchronous machine has salient poles mounted on the stator—the stationary member. The poles are magnetized either by permanent magnets or by a dc current.
  • The armature, normally containing a three-phase winding, is mounted on the shaft. The armature winding is fed through three slip rings (collectors) and a set of brushes sliding on them. This arrangement can be found in machines up to about 5 kVA in rating.
  • For larger machines—all those covered in this book—the typical arrangement used is the rotating magnetic field. The rotating magnetic field (also known as revolving-field) synchronous machine has the field-winding wound on the rotating member (the rotor), and the armature wound on the stationary member (the stator).
  • A dc current, creating a magnetic field that must be rotated at synchronous speed, energizes the rotating field-winding. The rotating field winding can be energized through a set of slip rings and brushes (external excitation), or from a diode bridge mounted on the rotor (self-excited).
  • A synchronous generator is an electrical machine producing alternating emf (Electromotive force or voltage) of constant frequency.
  • The synchronous motor operates at a precise synchronous speed and hence is a constant-speed motor. Unlike the induction motor, whose operation always involves a lagging power factor, the synchronous motor possesses a variable-power-factor characteristic and hence is suitable for power-factor correction applications.
  • A synchronous motor operating without mechanical load is called a compensator. It behaves as a variable capacitor when the field is overexcited, and as a variable inductor when the field is under-excited. It is often used in critical positions in a power system for reactive power control.
Types of Synchronous Machines: According to the arrangement of the field and armature windings, synchronous machines may be classified as:
  • Rotating-armature type
  • Rotating-field type

Rotating-Armature Type

  • The armature winding is on the rotor and the field system is on the stator.
  • The generated current is brought out to the load via three (or four) slip rings.
  • Insulation problems, and the difficulty involved in transmitting large currents via the brushes, limit the maximum power output and the generated electromagnetic field (emf).
  • This type is only used in small units, and its main application is as the main exciter in large alternators with brushless excitation systems.

Rotating Field Type

Get complete information about the GATE exam pattern, cut-off, and all those related things on the BYJU’S Exam Prep official youtube channel.


write a comment

Follow us for latest updates