Emerson unidrive m200 - Motor Rated Current; Motor Rated Speed; Motor Rated Voltage

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If slip compensation is required MotorRatedSpeed (05.008) should be set to the motor nameplate value, which should give the correct compensation for a

hot motor providing the nameplate value is correct. Slip compensation can be used throughout the speed range of the motor, i.e. below base speed and in the

flux weakening region, to correct the motor speed to minimise the change of speed with load. SlipCompensationLevel (05.027) is provided for the user to be

able to set the amount of compensation applied. At its default value of 100.0% Ratedslip is applied and reducing it below 100.0% will reduce the amount of

slip compensation, which may be required if some instability is experienced. Setting SlipCompensationLevel (05.027) negative causes the motor frequency to

reduce as load is applied introducing speed droop, which can be used to aid load sharing with mechanically coupled motors.

Slip Compensation = RatedSlip x TorqueProducingCurrent (04.002) / ITrated x SlipCompensationLevel (05.027) / 100

where I

Trated

= Torque Rated Current (see TorqueProducingCurrent (04.002) )

The amount of slip compensation applied can be limited by SlipCompensationLimit (05.033)

In Ur modes of operation the amount of slip can be increased at low output frequecies to boost torque capability at these frequencies. Also when Open-

loopVoltageMode (05.014) is set to mode 6 (Fixed Tapered) the slip can be tapered to 0 at very low frequencies to prevent creep at standstill,see

LowFrequencyEstimatorThreshold,LowFrequencyTorqueadjustment (05.084) .

Slip compensation is disabled under the following conditions:

1. MotorRatedSpeed (05.008) = 0

2. MotorRatedSpeed (05.008) = MotorRatedFrequency (05.006) x 60 / Pole pairs, i.e. synchronous speed.

3. SlipCompensationLevel (05.027) = 0.0%

4. SlipCompensationLimit (05.033) = 0.00Hz

It should be noted that MotorRatedSpeed (05.008) is used to calculate the rotor time constant of the motor which is then used to determine the flux build-up

time at the start of the catch a spinning motor algorithm. If spinning start is required (i.e. CatchASpinningMotor (06.009) ≥ 1) then MotorRatedSpeed

(05.008) should be set up correctly for the motor. If slip compensation is not required, it can be disabled by setting SlipCompensationLevel (05.027) to 0.0%.

Parameter 05.007 Motor Rated Current

Short description Set to the rated current rated of the motor

Mode Open‑loop

Minimum −VM_RATED_CURRENT Maximum VM_RATED_CURRENT

Default 0.00 Units A

Type 32 Bit User Save Update Rate Background read

Display Format Standard Decimal Places 2

Coding RW, VM, RA

MotorRatedCurrent is used as follows:

1. To define the rated operating conditions for motor thermal protection. See ThermalProtectionMode (04.016).

2. To define the range of the current limits.

3. In the motor control algorithm for Open-loop and Closed Loop asynchronous modes.