Mitsubishi Electric FR-A700 Technical Manual page 290

2.12.3 Speed detection filter and torque detection filter [Pr. 823, 827, 833, 837]
Set the time constant of the primary delay filter relative to the speed feedback signal and torque feedback signal.
Since this function reduces the speed loop response, use it with the initial value.
[Pr. ] Name
Speed detection filter 1
823
827 Torque detection filter 1
Speed detection filter 2
833
837 Torque detection filter 2
(1) Stabilize speed detection [Pr. 823, 833]
Since the speed loop response reduces, use it with
the initial value.
Increase the setting value gradually and adjust the
value to stabilize the speed when speed ripples occur
due to high frequency disturbance, etc. A too large
value will run the motor unstably.
Speed detection filter is valid only during vector
control.
2.12.4 Excitation ratio [Pr. 854]
Decrease the excitation ratio when you want to improve
efficiency under light load. (Motor magnetic noise
decreases.)
[Pr. ] Name
854 Excitation ratio
Note that the rise of output torque becomes slow if
excitation ratio is decreased.
This function is appropriate for applications as machine
tools which repeat rapid acceleration/deceleration up to
high speed.
When 1 (magnetic flux with terminal) is set in [Pr. 858
Terminal 4 function assignment] or [Pr. 868 Terminal 1 function
assignment] , the [Pr. 854] setting is invalid.
Initial Value Setting Range
0
0.001s
0.001 to 0.1s
0
0s
0.001 to 0.1s
0 to 0.1s
9999
9999
0 to 0.1s
9999
9999
A700
)
(A700)
Initial Value Setting Range
100% 0 to 100%
324
Description
Without filter
Set the time constant of the primary delay filter relative to the
speed feedback signal.
Without filter
Set the time constant of the primary delay filter relative to the
torque feedback signal.
Second function of [Pr. 823] (valid when RT signal is ON)
Same as the [Pr. 823] setting
Second function of [Pr. 827] (valid when RT signal is ON)
Same as the [Pr. 827] setting
(2) Stabilize the torque detection [Pr. 827, 837]
Since the current loop response reduces, use it with
the initial value.
Increase the setting value gradually and adjust the
value to stabilize the speed when torque ripples
occur due to high frequency disturbance, etc. A too
large value will run the motor unstably.
(3) Use multiple primary delay filters
Use [Pr. 833 and 837] to change the filter according to
applications. [Pr. 833 and 837] are valid when the RT
signal is ON. Other second function is also valid.
Set the excitation ratio under no load.
Excitation
ratio [%]
100
(initial value)
[Pr. 854]
set value
0
PARAMETER
A700
(A700)
Description
100 Load [%]