3.2.5 Monitoring method for feedback amount. Toshiba E6580772

E6580772③

3.2.5 Monitoring method for feedback amount

Motor rotation speed can be monitored.

The motor is equipped with status monitor which is displayed on the panel and analog monitor which used analog output terminals (FM, AM terminals)

Set items① and② for motor speed monitoring.

① Speed feedback (real-time value) (Unit: Hz/free unit)

The real-time display of motor speed can be made (Monitor display setting: 6).

② Speed feedback (one-second filter) (Unit: Hz/free unit)

The filtered motor speed (feedback value) is displayed. (Monitor display setting: 7).

The monitoring for the above① and② is possible also in cases except for =8 (PG feedback vector control operation). For example, the monitoring can be used for confirmation of the initial PG feedback amount in open loop (V/F operation and the like).

<Setting method for status monitoring>

In order to monitor motor rotation speed in condition monitoring, it is necessary to change the setting for extended parameters (f711 to f714).

Refer to <Monitoring Operating Condition) section of the inverter manual.

<Setting method for analog monitoring>

In order to monitor motor rotation speed by the analog output terminal, it is necessary to change the setting for basic parameter (fmsl,fm ) and extended parameter (f670, f671).

Refer to (Meter Setting and Calibration) section of the inverter manual.

3.2.6 Accuracy of speed control

The accuracy of speed control with the PG feedback can be obtained by the following formulae.

Accuracy of speed control = Command frequency accuracy + feedback detection accuracy

Command frequency accuracy＝±

0.01(Hz)

×100×

1

2

［％］

(using digital command)

Feedback detection accuracy＝±

F

P

C

PG

PH

0.04

1

( 2 )

×

PG PH

×

0 04

× 100 ×

1

2

［％］

: Inverter output frequency

: Number of motor poles

: Number of PG pulses/rotation

: Single Phase = 1, Two-Phase = 4

: Response speed of 40ms

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