User Manual

Table Of Contents
Brushless Motor Connections and Operation
124 Advanced Digital Motor Controller User Manual V2.1, December 3, 2020
if (FluxSetpoint > 100) then FluxSetpoint = 100 ‘ Cap to 10.0 Amps
setcommand(_GID, 1, FluxSetpoint) ‘ Apply Flux setpoint
wait(10)
goto top ‘ repeat every 10ms
Interior Permanent Magnet Motor Operation
IPM (interior permanent magnet) motor is an Alternating Current (AC) synchronous motor,
where the permanent magnets are inserted inside the rotor, while in brushless dc motors
the permanent magnets are mounted on the surface of the motor, as illustrated in figure
8-29.
FIGURE 8-29. (a) IPM motor (b) brushless dc motor configurations
Below the basic structural and operating differences between the IPM and BLDC motor:
IPM
Reduce the risk of a magnet being peeled off by centrifugal force
Higher total torque (IPM motor produces both magnetic and reluctance torque)
Higher speed range (IPM motor has higher field weakening capability, due to the
insertion of the permanent magnets inside the rotor)
Reduce the risk of Permanent Magnets demagnetization
Higher efficiency (lower permanent magnet eddy current losses)
BLDC
The permanent magnets are mounted on the surface of the rotor
PMs are glued (provokes aging due to centrifugal forces and heat) or banded
Lower total torque (BLDC produces only magnetic alignment torque)
Lower speed range (BLDC motor has lower field weakening capability, due to the
PMs location at the airgap)
Lower efficiency (higher PM eddy current losses)
Due to the different IPM magnetic circuit and produced torque mechanism compared to
brushless dc motors, both torque (Iq) and field weakening (Id) currents needed for optimal
Maximum Torque Per Ampere (MTPA) operation as shown in the following figure.