Servosila-Device-Reference-0xA020192

experimentally determines the Poles Number.
4
Phase
Resistance
(Line-to-Line)
Ohm The phase-to-phase electrical resistance parameter should be taken from the
motor's datasheet, or it can be measured using the controller itself. Even if the
parameter is provided in the motor's datasheet, it is still recommended to
measure it and re-confirm the value.
Electrical resistance generally increases as the temperature of the motor
increases. As such, do not be surprised if the measured value differs from a value
taken from the datasheet.
FLOAT32,
0x2000,
0x04,
rw
5
Phase
Inductance
(Line-to-Line)
H The phase-to-phase inductance parameter should be taken from the motor's
datasheet, or it can be measured using the controller itself.
Even if the parameter is provided in the motor's datasheet, it is still
recommended to measure it and re-confirm the value for a given motor.
FLOAT32,
0x2000,
0x05,
rw
6 Back-Emf
Constant (Ke)
V/
(rad/
s)
The Back-Emf Constant (Ke) parameter defines how much voltage a motor
generates whenever an external force spins its rotor thus turning the motor into
an electric generator.
Although not immediately apparent from the definition, the Back-Emf Constant
(Ke) tells how much torque the motor produces given an electric current that
flows through the motor. There is a well-known relationship between an electric
current flowing through a motor and a torque produced by the motor. The Ke
constant plays a prominent role in a formula that details the relationship.
The Back-Emf Constant (Ke) should generally be MEASURED using the
controller itself. It is usually not a good idea to take the value of Ke straight from
a motor's datasheet as there are so many ways the value can be measured by the
manufacturer, and there are so many units the value can be expressed in, that it is
very easy to make a mistake when configuring the controller. It is better to allow
the controller to measure the constant, than risking to misconfigure it.
Many manufacturers of the motors provide alternative constants called Velocity
Constant (Kv) or Torque Constant (Kt) instead of the Back-Emf Constant (Ke)
that the controller expects. However, there is a simple way to convert one
constant into another (Ke, Kv, Kt). The "Servoscope" software comes with a tool
that performs the conversions. It is wise to first measure Ke using the controller,
and then compare it to a Ke value taken from a datasheet or derived from either
Kv or Kt constant, assuming that at least one of those constants is provided by
the manufacturer.
The controller expects that the Back-Emf Constant (Ke) is configured in units
called "V (peak, line-to-neutral) per electrical rad/s". The controller measures
Back-Emf Constant (Ke) in those units, so one do not have to worry about units
conversion. If one still wants to venture into converting between various units
used to define the Back-Emf (Ke) constant, the "Servoscope" software comes
FLOAT32,
0x2000,
0x06,
rw
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