Synchronous Reluctance Motor (Synrm) - Eaton PowerXL DC1 20 Series Installation Manual

2 Engineering
2.11 Three-phase motors

2.11.5 Synchronous reluctance motor (SynRM)

58
￫
In order to use vector control with brushless DC motors, the
values for parameters P-60, P-61, and P-62 on DC1 variable
frequency drives need to be changed:
• Change the value for P-60 to 3 ("Brushless DC motor speed
control").
• Change the value for P-61 to 1 ("Motor identification").
Automatic autotune to determine the motor parameters
when the motor is stationary.
• P-62 ("MSC gain"). Adjust the gain factor for the speed
controller.
Synchronous reluctance motors have the same configuration as a three-
phase asynchronous motor. In order to prevent eddy currents, their rotor is
made of a soft magnetic material such as electrical steel, and in general
terms can have one of two different sheet cross-sections.
In the case of reluctance motors intended to be run as grid-connected
systems, the rotor additionally features a rotor cage (similar to that used in
asynchronous motors). This cage makes it possible for the motor to start
asynchronously on the grid until it synchronizes ("falls into step") to it and is
able to follow the rotating field.
In the case of reluctance motors with a rotor that features salient poles with
flux directing sections and flux barrier sections, a variable frequency drive
with sensorless vector control is required (DC1-...E1). This combination
makes it possible to have a rotor speed that is synchronous with the rotating
field and achieve optimum operation even when there are load changes. The
losses in the rotor will be practically negligible within this context.
Synchronous reluctance motors have better efficiency than conventional
asynchronous motors and, in contrast to them, can meet the requirements
for the IE4 international efficiency class. Synchronous reluctance motors are
primarily used in turbomachinery (rotating equipment) in process
engineering, where they are used to drive pumps, fans, compressors, and
turbines, as well as mixers, centrifuges, and conveyor systems.
￫
In order to use vector control with synchronous reluctance
motors, the values for parameters P-60, P-61, and P-62 on DC1
variable frequency drives need to be changed:
• Change the value for P-60 to 4 ("SyncRel motor speed
control").
• Change the value for P-61 to 1 ("Motor identification").
Automatic autotune to determine the motor parameters
when the motor is stationary.
• P-62 ("MSC gain"). Adjust the gain factor for the speed
controller.
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