The basic elements are described in four main sections:
AC Motors
Frequency converters
Frequency converters and motors
Protection and safety when using frequency converters
CHAPTER 0: Introduction
Advantages of infinitely variable speed regulation
Control or regulation?
CHAPTER 1: 3-Phase AC Motors
Asynchronous motors
Stator
Magnetic field
Rotor
Slip, torque and speed
Efficiency and losses
Magnetic field
Equivalent circuit diagram
Speed change
Changing the number of poles
Slip control
Frequency regulation
Motor data
Types of load
Synchronous motors
Reluctance motors
Control or regulation?
Many people use the terms control and regulation interchangeably. However, they do have precise definitions – largely as a result of developments in the field of automation.
!!! The terms “control” and “regulation” depend on the type of plant. With speed “control” a signal which is expected to produce the required speed is sent to the motor. With speed “regulation” a feedback signal is given from the process.
If the speed does not correspond to the requirements, the signal to the motor is regulated automatically until the motor speed is as it should be
