UM1040 Datasheet, PDF (9/19 Pages) STMicroelectronics – STEVAL-SPIMD20 demonstration kit based on the SPIMD20 integrated motor drive

UM1040
Connection and initialization
● Calculate S_LOOP gains
To be used only on rotary motors and if the “Check Motor Wiring” test was terminated
without errors.
It calculates the speed loop gains by generating a speed square wave with the
reference value changing from 0% and 10% of the max. speed parameter.
A very low proportional gain is entered at first, the integral gain = 0 and the speed filter
“Number of Speed Samples” = 1.
The proportional gain is doubled from time to time until the speed loop oscillates.
The proportional gain is progressively reduced by 10% of the oscillation value, until the
oscillation disappears.
The correct value for the proportional gain is therefore obtained.
This operation is repeated for the integral gain.In the case of a too high speed ripple,
the number of speed samples is automatically increased and the test is repeated.
● Execution of the motor tests
Supply the DC-BUS to the SPIMD20 (ensure that the bulk capacitors are correctly
wired to the connector).
Enter the “Live” mode and set the NMT state machine in “Operational” mode.
Select the current or speed test menu:
UTILITIES > TORQUE TEST or UTILITIES > SPEED TEST
When the test is activated, its parameters are re-initialized with their default values and
their setpoints are zeroed
● Torque test
It is possible to generate a torque reference using a wave form synthesizer capable of
generating a constant value, a sinusoidal wave, a square wave, or any combination of
these.
If a square wave is selected, the generator returns a value +1 (if high state) or -1 (if low
state) which is multiplied by the reference. The frequency and duty cycle are
programmable.
If a sinusoidal wave is selected, the generator returns a sinusoidal wave whose value
ranges from +1 to -1 and which is multiplied by the reference. The frequency is
programmable.
If a combination of the two waves is selected, the square wave is added to the
sinusoidal wave.
Finally, a constant value can be added.
If working for a “forced” electrical angle, the value read by the position transducer is not
used. Instead, the angle value is read from the “Requested Electrical Angle”.
Value 30 corresponds to the vector positioned on the U phase, value 150 corresponds
to the vector positioned on the V phase, and value 270 corresponds to the vector
positioned on the W phase.
If you do not force the electrical angle, the motor will follow the transducer read-out and
will start running at the max possible speed.
It is also possible to generate a turning current vector turning the forced angle.
The motor will then rotate. To get such behaviour, select a "Speed for forced electrical
Angle" different from 0 and check that the flag "Requested speed on forced Electrical
Angle".
● Speed test
Doc ID 18362 Rev 3
9/19