A minimal movement phasing test is performed each time the drive is enabled (i.e. changes from the inhibit state to either the stop or run state). The

test can be used to determine the phasing angle for an absolute or non-absolute type encoder. If the test is completed successfully the drive changes

to the stop or run state as appropriate. The phasing angle parameter is updated to the correct value, but it is not saved to EEPROM or the SMART

card.

2: Ph Init

A minimal movement phasing test is performed the first time the drive is enabled after power-up. The test will only be performed again on enable if the

position feedback device(s) have been re-initialized. Re-initialization occurs for example after a trip specifically related to an encoder where position

information may have been lost. Initialization occurs when parameter 03.48 changes from zero to one. The phasing angle parameter is updated to the

correct value, but it is not saved to EEPROM or the SMART card.

5.15

Low frequency voltage boost

Drive modes

Open-loop, Closed-loop vector

Bit

Coding

Range

Open-loop, Closed-loop vector

Default

Open-loop, Closed-loop vector

Update rate

Background read

The voltage boost is used in fixed boost mode and square law mode for Open-loop mode, and during the rotating auto-tune test in Closed-loop vector

mode.In open-loop mode the default is dependant on the frame size as given in the table below.

Drive sizes

SP0xxx,SP1xxx, SP2xxx, SP3xxx

SP4xxx, SP5xxx

SP6xxx to SP9xxx, SPMxxxxx

5.16

Rated rpm auto-tune

Drive modes

Closed-loop vector

Bit

Coding

Range

Closed-loop vector

Default

Closed-loop vector

Update rate

Background read

The motor rated full load rpm parameter (Pr 5.08) in conjunction with the motor rated frequency parameter (Pr 5.06) defines the full load slip of the

motor. The slip is used in the motor model for closed-loop vector control. The full load slip of the motor varies with rotor resistance which can vary

significantly with motor temperature. When this parameter is set to 1 or 2 the drive can automatically sense if the value of slip defined by Pr 5.06 and

Pr 5.08 has been set incorrectly or has varied with motor temperature. If the value is incorrect Pr 5.08 is automatically adjusted. Pr 5.08 is not saved

at power-down, and so when the drive is powered-down and up again it will return to the last value saved by the user. If the new value is required at

the next power-up it must be saved by the user. Automatic optimization is only enabled when the frequency is above rated frequency/8, and when the

load on the motor load rises above

correct values of stator resistance (Pr 5.17), transient inductance (Pr 5.24), stator inductance (Pr 5.25) and saturation breakpoints (Pr 5.29 and Pr

5.30) should be stored in the relevant parameters. Rated rpm auto-tune is not available if the drive is not using external position/speed feedback

(RFC mode).

The gain of the optimizer, and hence the speed with which it converges, can be set at a normal low level when Pr 5.16 is set to 1. If this parameter is

set to 2 the gain is increased by a factor of 16 to give faster convergence.

The rated rpm optimizer is automatically disabled when closed-loop vector RFC mode is selected (Pr 3.24=1 or 3).

Unidrive SP Advanced User Guide

Issue Number: 10

Parameter

Advanced parameter

description format

descriptions

VM DP

0 to 2

Txt VM DP

0.0 to 25.0 % of motor rated voltage