09-11-2016, 02:24 PM
1467779434-ELECTRICDRIVES.ppt (Size: 1.44 MB / Downloads: 41)
Components in electric drives
Control unit
Complexity depends on performance requirement
analog- noisy, inflexible, ideally has infinite bandwidth.
digital – immune to noise, configurable, bandwidth is smaller than the analog controller’s
DSP/microprocessor – flexible, lower bandwidth - DSPs perform faster operation than microprocessors (multiplication in single cycle), can perform complex estimations
Electrical isolation between control circuit and power circuit is needed:
Malfuction in power circuit may damage control circuit
Safety for the operator
Avoid conduction of harmonic to control circuit
Sensors
Sensors (voltage, current, speed or torque) is normally required for closed-loop operation or protection
Electrical isolation between sensors and control circuit is needed for the reasons previously explained
The term ‘sensorless drives’ is normally referred to the drive system where the speed is estimated rather than measured.