| Abstract |
A lot of interesting papers have already been published
on sensorless control for synchronous as well as for asynchronous
machines. High frequency carrier injection is a
promising approach for position control even at zero speed
because it does not refer to the fundamental machine model
which fails at standstill of the magnetic field. Industry, however,
is hesitating to apply these concepts – on the one hand many
published concepts depend on physical parameters of the machine
and on the other hand many sensorless control schemes
require voltage sensors in addition to the standard equipment of
an industrial drive. Both demands cannot be accepted by industry,
because they result in additional costs and mean a step-back
in comparison to existing industrial drives.
Recently a modified sensorless control scheme for synchronous
machines was published, which does not need any sensor to
measure voltage(s). As this concept is based on a tracking
scheme, it is also not depending on any physical parameter of
the drive or its components. The paper presented here discusses
the application of similar ideas on the line side of the drive. The
proposed method is applicable on pulsewidth modulated (PWM)
power supply rectifiers and neither needs voltage sensors on the
line side nor accurate parameters to adjust the algorithms.
New European (EU) Directives enforce the manufacturers of
power electronic products to reduce the harmonics in the mains
significantly. With respect to this development the use of controlled
PWM rectifiers will increase in the future, because they
provide very low harmonics. This paper is a contribution to
combine industry needs for cheap solutions (no additional
hardware components and no additional installation effort) with
the increase of technical and legal requirements. |
