GE Industrial Solutions AF-650 GP General Purpose Drive Programming Guide User Manual

Page 65

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H-43 Torque Characteristics

Option:

Function:

NOTE

This parameter cannot be adjusted while
the motor is running.

Select the torque characteristic required.

VT and Automatic Energy Savings are both

energy saving operations.

[0]

*

Constant

torque

Motor shaft output provides constant torque

under variable speed control.

[1]

Variable

torque

Motor shaft output provides variable torque

under variable speed control. Set the variable

torque level in SP-40 VT Level.

[2]

Energy

Savings

CT

Automatically optimises energy consumption by

minimising magnetisation and frequency via

SP-41 Energy Savings Min. Magnetization and

SP-42 Energy Savings Min. Frequency.

[5]

Constant

Power

The function provides a constant power in the

field weakening area.

The torque shape of motor mode is used as a

limit in the generatoric mode. This is done to

limit the power in generatoric mode that

otherwise becomes considerable larger than in

motor mode, due to the high DC link voltage

available in generatoric mode.

P

shaft

W

=

ω

mech rad /

s

×

T

Nm

This relationship with the constant power is

illustrated in Illustration 3.24:

Illustration 3.24 Constant Power

H-44 Constant or Variable Torque OL

Option:

Function:

NOTE

This parameter cannot be adjusted
while the motor is running.

[0]

*

High torque

Allows up to 160% over torque.

[1]

Normal torque For oversized motor - allows up to 110%

over torque.

H-45 Local Mode Configuration

Option:

Function:

Select which application configuration

mode (H-40 Configuration Mode), i.e.

application control principle, to use when a

Local (keypad) Reference is active. A Local

Reference can be active only when

F-02 Operation Method is set to [0] Linked to

Hand/Auto or [2] Local. By default the local

reference is active in Hand Mode only.

[0]

Speed open

loop

[1]

Speed Closed

Loop

[2]

*

As mode par

H-40

H-46 Back EMF at 1000 RPM

Range:

Function:

500

V

*

[0 -

9000 V]

Set the nominal back EMF for the motor when

running at 1000 RPM.

Back EMF is the voltage generated by a PM

motor when no frequency converter is

connected and the shaft is turned externally.

Back EMF is normally specified for nominal

motor speed or for 1000 RPM measured

between two lines. If the value is not available

for a motor speed of 1000 RPM, calculate the

correct value as follows. If back EMF is eg. 320 V

at 1800 RPM, it can be calculated at 1000 RPM

as follows:

Calculate RPM at 1000 RPM as follows: Back

EMF= (Voltage/RPM)*1000 = (320/1800)*1000 =

178.

This is the value that must be programmed for

H-46 Back EMF at 1000 RPM

This parameter is only active when P-20 Motor

Construction is set to [1] PM motor (Permanent

Magnet Motor).

NOTE

When using PM motors, it is recommended
to use brake resistors.

H-47 Motor Angle Offset

Range:

Function:

0

*

[-32768 -

32767]

Enter the correct offset angle between the PM

motor and the index position (single-turn) of the

attached encoder or resolver. The value range of

0 - 32768 corresponds to 0 - 2 * pi (radians). To

obtain the offset angle value: After frequency

converter start-up apply DC-hold and enter the

value of DR-20 Motor Angle into this parameter.

Parameter Descriptions

AF-650 GP Programming Guide

64

DET-618C

3

3

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