Leeson Micro Series Compact Inverters Manual do Utilizador descarregar pdf (Página 61)

20 AC BOOST (ACBOOST)

AC BOOST is similar to FX BOOST, but is only active when the drive is accelerating. During acceleration,

theoutputvoltageisincreasedaccordingtothesettingofACBOOST,whichincreasesmotortorque.Refer

tothediagrambelow.ACBOOST,likeFXBOOST,isusedinapplicationswithhigh-inertialoads.

 ThediagrambelowillustrateshowFXBOOSTandACBOOSTaltertheV/Hzratiotoincreasemotor

torque.

 FX BOOST sets the boost at 0 Hz (approximately 15% in the example above), and as the output

frequencyapproaches30Hz,theboostdecreasestozero.

AC BOOST only functions during acceleration. Inthediagramabove,thedriveisoperatingat35Hzandis

thencommandedto50Hz.TheoutputvoltageisincreasedbytheACBOOSTsetting(approximately15%

intheexampleabove)duringaccelerationtothenewspeedsetpoint.Oncethenewsetpointisreached,the

output voltage returns to normal.

21 SLIP CMP (SLIPCOMPENSATION)

 SLIPCOMPENSATIONisusedtocompensateforchangesinmotorspeed(“slip”)whichoccurdueto

changes in load. In a standard AC induction motor, as the load on the motor increases, the motor cur-

rentincreasesandthemotorshaftspeeddecreases.Byincreasingtheoutputfrequencyinresponsetothe

increased motor current, SLIP COMPENSATION is able to counteract the reduction in motor speed due

to increased load. This parameter is useful in applications where precise speed regulation is needed, even

under changing load conditions. The use of SLIP COMPENSATION can result in speed regulation of

less than 1% of base speed in most applications. SLIP COMPENSATION is often set to 3%, which is the

standard slip rating of most AC induction motors.

FX AND AC BOOST

FREQUENCY (HERTZ)

OUTPUT VOLTAGE (%)

AC BOOST

FX BOOST

CONSTANT V/Hz

100

90

80

70

60

50

40

30

20

10

10 20

30 40 50 60

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Leeson Micro Series Compact Inverters Manual do Utilizador Página 61