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KEB COMBIVERT F5-A,-E,-H 4.0. APPLICATION MANUAL (2008) - page 10

Motor Data and Controller Adjustments of the Asynchronous Motor

The parametrisation of the controller (KP flux / dS.11, KI flux / dS.12, magnetising current limit/ dS.13) is carried

out automatically by Fr.10 and after the motor identification (dr.48).

dS.04 Flux / rotor adaption mode

Bit

Meaning

Value

Explanation

Flux controller always off (these adjustment is not allowed for the ope-

0: off

ration with motor model)

flux controller always on (must be used for control with motor model

32: on

and encoder feedback)

Flux control

5,6

64:on,

flux controller active, speed-dependent limit of the controller (at speed

(ASM)

n^3/dr.17^3

0 = 0 / at speed dr.17 = dS.13)

as value 64, exception: start of the drive:

96:on, start a.

here, (despite speed 0) the limit of the flux controller is set to the value

n^3/dr.17^3

dS.13 for the magnetisation.

During operation with speed feedback, the flux controller must be activated over the whole speed range, i.e.,

the value 32 must be chosen in dS.04 in the item "flux control" .

During operation without speed feedback, the value 64 or 96 should be selected.

With Fr.10, the parameter dS.13 "Magnetising current limit" is set to half the rated motor current. If the flux build-

up time is to be shortened or if particularly high demands are made on the dynamics in the field weakening

range, this value can be changed to the rated motor current (dr.00).

The inverter can only provide the standstill current at speed 0. Error OL2 is released shortly if the current is

higher. Thereby this can lead to problems during magnetizing at some motor/inverter combinations. In these

cases, the setting dS.04 Bit 5, 6 = 64 "flux controller not active during boot" must be chosen.

7.5.2.3.3.1

Dead time compensation

The drive has also measured the dead time compensation characteristic during automatic identification. The

calibrated characteristic must be activated for the control with motor model by the setting "dead time compen-

sation mode" (uF.18) = 3: "automatic".

uF.18 Dead time compensation mode

Value

Explanation

0: off

Deactivates the dead time compensation

1: linear

Default setting for u/F characteristics open loop operation

2: e function

Only required for special applications

3: automatical-

Activation of the identified characteristic. Shall always be used at control of asyn-

ly

chronous motors with motor model

Further available kinds of the dead time compensation are only required for special applications (applications

with high frequencies, some special motors) or in other operating modes (e.g. V/f characteristics controlled).

The dead time compensation can be switched off via a digital input. The digital input is selected with parameter

uF.21. This disconnection is only required for special applications with high frequency.

Page7.5 - 22

Motor Data and Controller Adjustments of the Asynchronous Motor

The parameter dS.21 indicates the speed range for which the start ramp applies. dS.22 indicates the accele-

ration-/ deceleration time.

Ramp output display

(ru.02)

Example:

ud.02 = 4 (4000 rpm mode)

dS.21 = 200 rpm

200 min^-1

dS.22 = 1s

0,2 s

Time

ASCL model shutoff during deceleration (dS.19, dS.20)

If the drive is to be stopped, the critical range of low frequencies must be traversed again.

The additional problem of the drive not stopping completely, but instead running permanently at a low frequency

with a very high current occurs here, leading to a miscalculation of the speed.

Under the following conditions, therefore, the mode is switched from vector controlled to current regulated,

frequency controlled operation:

- Drive decelerates

- the estimated output frequency is smaller than dS.19 ("limit uf-control dec ASCL")

The drive then shows the following behaviour:

- the output frequency is ramped down according to the adjusted deceleration ramp

- the current is held constant from the switching time on

The parameter dS.19 is loaded with a default value by the identification or by Fr.10 "Load mot. dependent pa-

rameter". Should problems still occur during deceleration, the value for dS.19 can be increased.

If the drive is stopped by switching off the rotation direction release, the modulation is switched off after rea-

ching output frequency 0.

If the drive is stopped by setting the setpoint to 0, the current is reduced to the magnetising current after rea-

ching the output frequency = 0.

At this point, the real speed of the motor is not yet 0 in some cases.

Therefore, the time for which the higher constant current is set can be increased with parameter dS.20 "delay

time uf-control".

Page7.5 - 24

Motor Data and Controller Adjustments of the Asynchronous Motor

ds.19: limit uf-control

deceleration ASCL

=> switching into

frequency-controlled

operation

ds.20: ASCL

delay time

Apparent current (ru.15)

uf-control

Overshoot current

Actual speed (ru.07)

Frequency (ru.03)

Magnetizing current

Time [ms]

Actual torque display (ru.12)

Attention: The actual torque display (ru.12) is invalid after switching to the frequency controlled operation!

ASCL / reversing

If one wants to run the drive through zero speed without stopping to change (reverse) the direction of rotation,

switching to the frequency controlled mode can be disruptive.

7

Therefore, this switching can be deactivated by setting bit 2 in parameter "function mode" (dS.18).

dS.18 Function mode

Bit

Meaning

Value

Explanation

Model switch-

0: activated

Deactivate switching to the frequency driven, current-controlled

2

off

4: deactivated

operation

To utilise the open loop mode for stopping, but, on the other hand, avoid negative effects during reversal, the

inverter must be programmed so that stopping of the motor always follows in the same set.

Then, one can let the switch to the open loop mode be activated for this set (the stop-set) (dS.18 = 0), and avoid

interfering effects during reversal for other sets with dS.18 = 4.

The, it is only necessary to ascertain that the range of low frequencies is traversed quickly.

This can be achieved by suitably setting parameter "start-up time" (dS.22) and parameter "start-up speed"

(dS.21), which apply to acceleration as well as deceleration.

ASCL / constant run with low speeds

Speed setpoints lying within the critical range must be avoided.

To avoid continuous operation in low frequency range, the minimum setpoint (oP.06 / oP.07) should be set to

speeds outside the critical range.

Alternatively, too-small setpoints may also be masked by parameter oP.65...oP.68 (blocked setpoints).

Page7.5 - 25

Motor Data and Controller Adjustments of the Asynchronous Motor

7.5.2.4.2

Switch to consecutive motor

If the motor is still rotating during addition of the modulation (e.g., "rundown" after malfunction), the calculation

of the actual speed from the motor model can become unstable.

Therefore, if there is a risk that the motor has not reached speed 0 for the start, there are two alternative starting

methods:

Speed search condition (Pn.26) or DC braking (Pn.28 / Pn.33)

During speed search, the drive attempts to determine the current speed via its mathematical model. The ope-

ration corresponding to the setpoint settings is re-established starting at this speed. For many standard motors,

this type of addition can be used.

For some motors or applications, e.g., for spindles, application of the speed search will be unsuccessful. In

these cases, speed is calculated incorrectly, the drive can vibrate, or the inverter can malfunction.

In these cases, the motor must be stopped by DC braking before the drive can be restarted. During DC braking,

a DC voltage is connected to the motor´s clamps. The small braking torque while the motor is still running at

high speed is a disadvantage.

For more (appropriate parameters, settings, etc.) see in 7.13.4 speed search and 7.15.1 DC braking, respec-

tively.

7.5.2.4.3

Model adaption

Some auxilliary functions can be activated via the parameter dS.18.

Adjustment of this parameter is not necessary and should only be carried out by authorised KEB service per-

sonnel.

Value 4 is an exception: Model deactivation (see "ASCL model deactivation during deceleration" / subsection

"reversal"). This chapter can therefore be skipped and reading continued in 7.5.2.4.4 "parametrisation of the

speed estimation control".

dS.18 Function mode

Bit

Meaning

Value

Explanation

Current offset/

0: off

0

activates a permanent current offset adjustment

Adaption

1: on

Stator resistance/ ad-

0: off

activates setpoint tracing of the stator resistance, which may

1

aption

2: on

change during operation due to temperature effects

0: activated

Switching in the frequency controlled, current regulated operati-

2

Model switch-off

4: deactiva-

on during stopping

ted

0: measured

Selection of the actual value source of the current controller: 0:

3

Current control

8: calculated

measured current 8: current calculated from the model

Observer /

0: off

4

Activation of an observer for high frequency applications

Motor model

6: on

5

reserved

Voltage output for Hf-

0: off

Activation of a faster voltage output. Only important for high fre-

6

applications

64: on

quency applications

Page7.5 - 26

Motor Data and Controller Adjustments of the Asynchronous Motor

The KP (dS.14) and the KI (dS.15) of the speed calculation controller are calculated automatically during the

identification of the motor parameters and may not be changed.

Only the parameter dS.17 "Speed PT1 time ASCL" can be adapted to a specific application. In non-dynamic

applications, a higher PT1 time (up to 32ms for large motors) leads to a steadier calculated speed, without

degradation of the control characteristics of the drive.

In contrast, a lower speed frequently permits a more dynamic setting of the speed control parameters.

If parameter dS.17 "Speed PT1 time ASCL" is changed, a previously conducted adaption of the speed control-

ler must be checked.

If the automatic calculation of the speed control parameters is used, it must be reactivated.

7.5.2.5Special function: Rotor adaption

In speed control with speed feedback, the motor model can be used to adapt the rotor time constant. The rotor

time constant is dependent on the rotor resistance, among others. Due to the temperature change of the motor

rotor, the rotor resistance can change significantly compared to the identified value. This also changes the rotor

time constant. This change leads to a less accurate torque display and an inferior performance of the drive.

The rotor adaption compensates for the temperature deviations of the resistance. It is activated by bit 1 in pa-

rameters dS.04 "Flux / rotor adaption mode".

dS.04 Flux / rotor adaption mode

Bit

Meaning

Value

Explanation

Rotor

adaption

0: off

1

Activation of the rotor adaption

(ASM)

2: on

Rotor adaption/

0: no

Storage of the last rotor adaption value obtained during ope-

2

store (ASM)

4: yes

ration

Bit 2 determines whether the drive stores the rotor adaption value on modulation switch-off. If memory is acti-

vated (memory: yes), the inverter starts with the last value obtained during operation, after reactivation of the

modulation. If memory is deactivated (memory: no), the inverter starts with the value 100%. After"net on",the

inverter always starts with the value 100%.

In parameter ru.59 "rotor adaption factor", the status of the rotor adaption can be read: 100% means that the

drive is working with the identified values.

Page7.5 - 28

Motor Data and Controller Adjustments of the Asynchronous Motor

7.5.3

Block diagram

Figure 7.5.3.a Block diagram ASCL

7

Page7.5 - 29

Motor Data and Controller Adjustments of the Asynchronous Motor

Figure 7.5.3.b Block diagram M

Page7.5 - 30

Motor Data and Controller Adjustments of the Asynchronous Motor

Figure 7.5.3.c SMM

7

Page7.5 - 31

Motor Data and Controller Adjustments of the Asynchronous Motor

Figure 7.5.3.d Field weakening

ds8 KP Max. voltage

ds9 Ki Max. voltage

ds04.Max. voltage controller

ds10 Maximum voltage (max. -2% of max. output voltage)

0

imr_ref

+

-

1ms

Usd

=SQR(Usd^2+Usq^2)

Usq

-0,75

Imrsoll

omega_1

n

dr.18,dr.20, Imrnenn

Page7.5 - 32

Motor Data and Controller Adjustments of the Synchronous Motor

The maximum permissible speed is also calculated from the EMK which is displayed in ru.79 (abs. speed

[EMK]) corresponding to the DC link voltage: The maximum DC link voltage, UZKmax, can be found in the

power circuit manual.

Max. UDC_link x 1000

rpm

ru.79 =

—————————

dr.26

Parameter dr.63 (DSM EMK HR) can be used for higher accuracy.

This parameter is also used after identification of the EMK. To insure downward compatibility with older para-

meter lists, this parameter can be deactivated with "0: Off".

Parameter dr.26 is further valid for the absolute value encoder !

DSM current for zero speed (dr.28)

The stand still current affects the electronic motor protective function (see chapter 7.13.).

7.6.1.2Controller configuration

For controlled operation, the parameter cS.00 must be set to the value 4: "speed control".

cS.00 Speed control configuration

Bit

Description

Value

Function

4: Speed control

0...3

Control mode

5: Torque control

(description see chapter 7.9)

6: Torque/ speed

7.6.1.3Actual value source

The actual value source for speed control must be selected in parameter cS.01 .

Possible values for regulated drives are 0 (speed measurement via encoder interface channel 1) or 1 (speed

measurement via encoder interface channel 2).

Description of the correct parameter setting of the encoder interfaces is made in chapter 7.11 "speed measure-

ment".

S.01 = 2 (calculated actual value) must be selected at operation without speed encoder (only SCL).

cS.01 Actual source

Bit

Description

Value

Function

0: Channel 1

Control to encoder interface 1

0...1

Actual value source

1: Channel 2

Control to encoder interface 2

2: calculated actual value

Control to estimated speed

0: off

2

System inversion

4: an

With activation of the system inversion it is reached that the motor with selected rotation direction "clockwise"

(e.g. by setpoint- or rotation setting) has the physically direction "counter clockwise" respectively at setting

"counter clockwise" the physical rotation "clockwise". Precondition is a correct wiring of motor and speed feed-

back (if available).

Page7.6 - 4

Motor Data and Controller Adjustments of the Synchronous Motor

7.6.1.4Load motor dependent parameter

Fr.10 = 2 (for some applications Fr.10 = 1 /explanation see below) must be entered once after input of the motor

data.

The parameter can only be written in "nop" status !

Fr.10 load motor dependent parameter

Value

Function

0: finished

1:uf.09

Calculation depending on uF.09 respectively voltage class

2: actual DC link

Calculation depending on act. DC link voltage

voltage

The calculation at Fr.10 = 1 is depending on the voltage entered in parameter uF.09 "voltage stabilisation". If

this parameter displays "off" (standard adjustment), then the voltage class of the frequency inverter (400V or

230V) is used.

The current DC link voltage of the frequency inverter, which is proportional to the supply input voltage, is con-

sidered for the calculations at Fr.10 = 2.

However this only applies if uF.09 is on "off".

Thus the following parameter are pre-charged dependent on the motor and inverter data:

Current controller

- dS.00

Kp current

- dS.01

Ki current

7

Torque limits:

- cS.19

Absolute torque reference

- cS.20...23

Torque limits forward / reverse , motoring- generating

- Pn.61

Quick stop torque limit

- dr.33

DSM max. torque

Motor type (only at SCL):

- nn.01

Stabilisation current

- nn.02

Min. speed for current

- nn.03

Max. speed for current

- nn.10

Standstill current

- nn.11

Stabilisation time

Page7.6 - 5

Motor Data and Controller Adjustments of the Synchronous Motor

7.6.2

Speed-controlled operation with encoder feedback

7.6.2.1Controller Structure

Diagram of the controller structure for operation with encoder feedback, see chapter 7.6.4.

7.6.2.2Absolute position (encoder 1)

The system position acquires the mechanical misalignment between rotor and zero position of the mounted

encoder system. This system position is preset at standard KEB motors in factory setting.

In order to operate a customer motor with encoder system it is necessary to make the automatically calibration

to detect the system position.

The following steps must be done:

-

open control release ST (terminal X2A.16)

-

Initial settings described in chapter 7.6.1 must be done.

-

Enter increments per revolution in Ec.01/ Ec.11

-

Check direction of rotation. The speed display ru.09/ ru.10 must be positive in case of manual clockwise

rotation. Otherwise the direction of rotation can to be changed as defined in chapter 7.11.7.

-

Attention has to be paid to in-phase connection (connect inverter clamps U, V, W on the motor terminal

board with the appropriate contacts) If the cabling is correct, the setting "clockwise rotation" will lead to

the following sense of rotation:

-

Motor must mandatory run with no load.

-

Enter "2206" in In Ec.02/ Ec.12 and confirm message (depending on encoder interface).

-

Close control release

-

The motor is excited with motor current dr.23. Subsequently a forward-/reverse running identification is

executed. On successful conclusion the inverter state displays ru.00 = 127 (drive data calculated).

-

If the motor is unable to rotate freely, or if the direction of rotation does not correspond to the phase po-

sition, the error E.ENC (ru.00 = 32: ERROR! Encoder 1) is triggered.

-

Open control release after successful trimming (ru.00 = 127 drive data calculated).

The current system position is written into the respective parameter (Ec.02/ Ec.12).

Page7.6 - 6

Motor Data and Controller Adjustments of the Synchronous Motor

Parameter dr.48 must be written again in order to start a new measurement.

For safety reasons the output signal "brake release" is not set during measurement, since the motor cannot

generate a defined torque in this time.

Since the identification in the automatic mode is very reliable and for the user the most pleasant method it is

recommended to use generally this method according to chapter 7.6.3.3.1.

dr.48 Motor identification

Bit

Description

Value

Function

0: off

1: Calculation EMK *

Calculation of the EMK from motor data

2: Inductance *

Measurement of the winding inductance respec-

tively

3: Resistance *

Winding resistance

5: Model-/controller parameterisa-

Calculation of the current controller from equiva-

tion *

lent circuit data

!Attention: requires motor rotation!

6: EMK with rotation *

EMK measurement

7: Automatically sequence without

Start of the automatic measurement without

rotation

EMK

8: Automatically sequence with

Start of the automatic measurement with EMK

rotation

0...4

Measurement

9: Dead time detection 2 kHz *

10: Dead time detection 4 kHz *

Measurement of dead time compensation cha-

11: Dead time detection 8 kHz *

7

racteristics for different switching frequencies

12: reserved

13: Dead time detection 16 kHz *

14: Torque detection 2 kHz

15: Torque detection 4 kHz

Detection of the no-load torque at different swit-

16: Torque detection 8 kHz

ching frequencies. During operation this torque is

subtracted from torque display ru.12.

17: reserved

18: Torque detection 16 kHz

19: Current offset detection

Detection of the current offset in phase U and V

20: reserved

0:

1000Hz

32: 500Hz

64: 250Hz

The measuring frequency is changed indepen-

Output fre-

96: 125Hz

dently during measurement.

5...7

quency

128: 62,5Hz

Keep the value at 0: 1000Hz!

160: 32,25Hz

192: 15,625Hz

224: 7,8125Hz

* at dr.48 = 8 auto-identification

Page7.6 - 9

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