Chapter 7 Parameter Explanation
Shanghai Sigriner STEP Electric Co., Ltd.
- 124 -
Speed loop – zero speed Ti (ms)
Speed loop - low speed Ti (ms)
Speed loop - high speed P
Speed loop - high speed Ti (ms)
Switching frequency f0 (%)
Switching frequency f1 (%)
For the PID adjustment of the velocity loop, P0, I0 are used as zero-servo section adjustable
parameters, and the other three groups are divided into three groups by P60.12 and P60.13. P1, I1 are
used as low-velocity section adjustable parameters; P3, I3 are used as high-velocity section
adjustable parameters.
The P60 parameter group mainly adjusts the proportional gain and integration time of the velocity
regulator.
Proportional gain P:
Please adjust it according to the size of the rotational inertia of the mechanical device connected with
motor. For mechanical devices with large moment of rotational inertia, please increase P gain; for
mechanical devices with small moment of rotational inertia, please decrease P gain.
When P gain is greater than inertia, the motor may oscillate or overshoot, although the control
response can be accelerated. On the contrary, if the P gain is lower than inertia, the control response
will slow down and the time to adjust the velocity to stable value will become longer.
Integration time I:
Setting it to 0 means that the integral is invalid (controlled by P alone). In order to make the
deviation between velocity command and actual velocity in steady state zero, the integration time I is
set to a non-zero value. When I is set to a small value, the system responds quickly; but if it is too
small, it may oscillate; when I is set to a large value, the system response is slow.
PID setting value adjustment at high velocity and low velocity:
When the motor velocity is higher than the switching frequency P60.10, P60.06 - P60.07 work,
which makes the system achieve better dynamic response and no oscillation; when the motor
velocity is lower than the switching frequency P60.09, P60.03 - P60.04 work. In general, in order to
obtain better dynamic response at low velocity, the proportional gain P60.03 can be appropriately
increased and the integration time P60.04 can be reduced. When the velocity is lower than the
switching frequency P60.10 and higher than the switching frequency P60.09, P60.03 - P60.07 work.
Feedback curve P is large
Feedback curve P is small
Figure 7-30 Effect of the proportionality constant P on the feedback tracking
To Next Page
Loading...