APPLICATIONS

Motor drives are used in a wide range of power values, from few watts up to many thousands of kilowatts, in applications ranging from high precision position control in robotics to variable speed drives for regulating the rate of flow in pumps.

In all drives where speed and position must be controlled, a power electronics converter is needed as interface between input power and motor.

Constant, or slightly variable according to load, speed drives use almost exclusively induction motors, thanks to their simple, robust and cheap construction, in addition to the fact that they do not need special maintenance.

However, the multi-phase motors supplied at constant network voltage and frequency have a rigid relationship between supply frequency and speed.

Direct current motor drives are mainly used in applications requiring the control of the speed of the motor (DCA 205.1).

In variable speed drives direct current machines are used everywhere; however, today, with the development of power electronics, induction motor drives are also widely used .


In these cases, the speed of the motor can be varied in three different ways: by varying the number of polar couples, by varying the slip speed (DCA 205.2), by varying the supply frequency (DCA 205.3).

DCA 205.1 DC MOTOR DRIVE

LIST OF EXPERIMENTS

  • Single-quadrant drive with converter B2C
  • Single-quadrant drive with converter B2C and armature voltage feedback
  • Single-quadrant drive with converter B2C and armature voltage feedback with RI compensation
  • Single-quadrant drive with converter B2C and tacho-voltage feedback
  • Single-quadrant drive with converter B2C and tacho-voltage feedback with inner current loop
  • Two-quadrant drive (I-IV) with converter B2C
  • Two-quadrant drive (I-III) with converter (B2C)2I
  • Two-quadrant drive (I-III) with converter (B2C)2I and tacho-voltage feedback with inner current loop
  • Four-quadrant drive with converter (B2C)2I
  • Four-quadrant drive with converter (B2C)2I and tacho-voltage feedback with inner current loop
  • Single-quadrant drive with converter B6C
  • Single-quadrant drive with converter B6C and tacho-voltage feedback with inner current loop

DCA 205.2 AC SLIP-RING MOTOR DRIVE

LIST OF EXPERIMENTS

  • Control of stator voltage with transformer
  • Control of stator voltage with controller W3C
  • Control of stator voltage and tachovoltage feedback
  • Rotor starter
  • Rotor pulsed resistor
  • Rotor pulsed resistor and tachovoltage feedback
  • Scherbius static drive
  • Scherbius static drive and tachovoltage feedback

DCA 205.3 AC SQUIRREL CAGE MOTOR DRIVE

LIST OF EXPERIMENTS

  • Preliminary investigation of the squirrel cage motor
  • Six-pulse PAM
  • Pulsed square-wave triggering
  • Trapezoidal modulation
  • Pulse width modulation (PWM)
  • Voltage vector control (VVC)
  • Motor magnetisation for linear U/f characteristic
  • Extra start magnetization
  • IxR compensation
  • Operation in standard converter setting
  • Slip compensation
  • Motor operation in star connection
  • Brake chopper
  • Speed control with tachovoltage feedback