Parker 590+ series Frame 1, 2, 3, 4, 5, 6 & H. Product Manual (2012) - page 10

4-20 Operating the Drive

Starting and Stopping Methods

Stopping Methods

• If the Drive is “non-regenerative” (2-quad - 591+) it effectively coasts to a stop once the current demand reverses.

• If the Drive is “regenerative” (4-quad - 590+) then it can stop faster because it uses energy from the load, i.e. reverse current is allowed to flow.

Normal Stop and Program Stop are only relevant for a “regenerative” controller.

The parameters STOP TIME and PROG STOP TIME have associated timers which initiate a Coast Stop after the timed

period.

MMI Menu Map

1 SETUP PARAMETERS

The Coast Stop has direct control of the Run relay with no intervening electronics.

2 STOP RATES

All associated parameters can be found in the STOP RATES menu.

Terminal

Description

Function

Parameter

Priority

Coast Stop

Motor coasts to rest

Overrides Program Stop and Normal Stop

Program Stop

Motor decelerates at Program Stop rate

PROG STOP TIME

Overrides Normal Stop

Start/Run

Motor decelerates at Normal Stop rate

STOP TIME

(Normal Stop)

Normal Stop (C3)

MMI Menu Map

This is achieved by removing 24V from Terminal C3.

1 SETUP PARAMETERS

The motor speed is brought to zero in a time defined by the STOP TIME parameter.

2 STOP RATES

STOP TIME

MMI Menu Map

During Normal Stop, the current is limited by the MAIN CURR. LIMIT parameter

1 SETUP PARAMETERS

2 CURRENT LOOP

MAIN CURR.LIMIT

Operating the Drive 4-21

NORMAL STOP

SPEED SETPOINT (100%)

Control Signals

START / RUN (C3)

SPEED DEMAND

100% = SPEED SETPOINT

Speed Demand

STOP TIME

DEFAULT 10.0 SEC

SPEED FEEDBACK

= SPEED SETPOINT

Actual Speed

ACTUAL STOPPING RATE

DEPENDS ON LOAD INTERTIA,

MOTOR HP AND OVERLOAD

CAPABILITY OF MOTOR/DRIVE

DRIVE IS DISABLED BELOW

STOP ZERO SPEED

IF SET > 0.25%

STOP ZERO

SPEED

(DEFAULT 2%)

DRIVE REMAINS ENABLED

FOR CONTACTOR DELAY

IF STOP ZERO SPEED < 0.25%

Enable

DRIVE ENABLE =ENABLED

(DISPLAY DIAGNOSTIC)

DRIVE ENABLE = DISABLED

Indicators

DRIVE RUN LED

AND START CONTACTOR

CONTACTOR DELAY

(DEFAULT 1.0 SECS)

4-22 Operating the Drive

TIME-OUT IN NORMAL STOP

SPEED SETPOINT

Control Signals

START/RUN (C3)

SPEED SETPOINT

SPEED DEMAND

Speed Demand

CONTACTOR WILL DROP OUT

IF SPEED FEEDBACK > STOP ZERO SPEED

= SPEED SETPOINT

WHEN STOP LIMIT TIMED OUT

SPEED FEEDBACK

Actual Speed

STOP ZERO SPEED

(DEFAULT 2% )

STOP LIMIT ( DEFAULT 60.0 SEC )

Indicators

DRIVE RUN LED

AND START CONTACTOR

DRIVE ENABLE =ENABLED

DRIVE RUN LED & START CONTACTOR

DRIVE ENABLE =DISABLED

Operating the Drive 4-23

MMI Menu Map

Program Stop (B8)

1 SETUP PARAMETERS

This is achieved by removing 24V from Terminal B8.

2 STOP RATES

The motor speed is brought to zero under conditions defined by the PROG. STOP TIME (ramp rate) and PROG. STOP I

PROG. STOP TIME

LIMIT parameters.

PROG. STOP I LIMIT

4-24 Operating the Drive

PROGRAM STOP TIMING

SPEED SETPOINT ( 100% )

Control Signals

PROGRAM STOP

LED ON ( PROGRAM STOP FALSE )

LED

(PROGRAM STOP IS A

OFF

LATCHED FUNCTION)

SPEED DEMAND

100% = SPEED SETPOINT

Speed Demand

PROG STOP TIME

DEFAULT 0.1 SEC

SPEED FEEDBACK

= SPEED SETPOINT

CURRENT LIMIT SET BY

Actual Speed

PROG STOP I LIMIT

( DEFAULT 100% )

ACTUAL STOPPING RATE DEPENDS

STOP ZERO

ON LOAD INERTIA, MOTOR HP AND

SPEED

OVERLOAD CAPABILITY OF MOTOR/DRIVE

(DEFAULT 2%)

DRIVE IS DISABLED

AND CONTACTOR

TURNS OFF BELOW

Indicators

DRIVE RUN LED

STOP ZERO SPEED

AND START CONTACTOR

DRIVE ENABLE =ENABLED

DRIVE RUN LED AND START CONTACTOR

DRIVE ENABLE =DISABLED

Operating the Drive 4-25

TIME-OUT IN PROGRAM STOP

SPEED SETPOINT

Control Signals

LED ON (PROGRAM STOP FALSE )

PROGRAM STOP

LED

OFF

SPEED DEMAND

SPEED SETPOINT

Speed Demand

CONTACTOR WILL DROP OUT IF

SPEED FEEDBACK

SPEED SETPOINT

SPEED FEEDBACK > STOP ZERO SPEED

WHEN PROG STOP LIMIT TIMED OUT

Actual Speed

STOP ZERO SPEED

( DEFAULT 2% )

PROG STOP LIMIT

(DEFAULT 60.0 SEC)

Enable

DRIVE RUN LED AND START CONTACTOR

DRIVE ENABLE =ENABLED

DRIVE RUN LED & START CONTACTOR

DRIVE ENABLE =DISABLED

4-26 Operating the Drive

Coast Stop (B9)

This is achieved by removing 24V from Terminal B9.

The stack is automatically quenched and the contactor is opened. The motor coasts to a stop.

NOTE The motor coast stop rate is dictated by the motor inertia - the drive does not control the motion.

MMI Menu Map

SETUP PARAMETERS

Standstill

Refer to Appendix D: “Programming” - STANDSTILL.

STANDSTILL

STANDSTILL LOGIC

ZERO THRESHOLD

The Trip Condition

When a trip condition is detected, a similar stopping method to Coast Stop is used. The power stack cannot be re-enabled until the trip condition has

been cleared and successfully reset.

Refer to Chapter 7: “Trips and Fault Finding” for further details.

Normal Starting Method

To achieve a normal start of the Drive:

1. Apply 24V to Terminal C5 (Enable)

2. Apply 24V to Terminal C3 (Start)

NOTE The Drive will not start if there are alarms present, or if Terminals B8 (Program Stop) or B9 (Coast Stop) are low, 0V.

Ensure that Program Stop and Coast Stop are valid before Start/Run is applied.

Operating the Drive 4-27

Advanced Starting Methods

Starting Several Drives Simultaneously

1. Apply 24V to Terminal C3 (Start)

2. Use Terminal C5 (Enable) to synchronise the start-up of the Drives

Jog

NOTE The Drive will not start if there are alarms present.

This facility provides two dedicated jog setpoints (or perhaps an Inch Forward/Inch Reverse). Activating Jog runs the

motor at speeds set by JOG SPEED 1 or JOG SPEED 2. The JOG/SLACK::MODE parameter selects JOG SPEED 1 or 2.

1. Apply 24V to Terminal C5 (Enable)

2. Apply 24V to Terminal C4 (Jog Mode)

Refer to Appendix D: “Programming” - JOG/SLACK for further information. Also refer to the STOP RATES function

block: the CONTACTOR DELAY parameter is used to prevent multiple operations of the main contactor from rapid use of

the Jog switch.

Crawl

NOTE The Drive will not start if there are alarms present.

This facility provides a dedicated crawl setpoint. Activating Crawl runs the motor at the speed set by CRAWL SPEED.

1. Apply 24V to Terminal C5 (Enable)

2. Set JOG/SLACK::MODE parameter (Tag No. 228) to TRUE.

3. Apply 24V to Terminal C3 (Start) and Terminal C4 (Jog Mode) simultaneously to start the Drive using the crawl

speed, in Forward or Reverse.

When selecting CRAWL, apply Start (C3) and Jog (C4) simultaneously, otherwise you may experience Modes 3 or

6 momentarily. Refer to Appendix D: “Programming” - JOG/SLACK for further information (see the Setpoint

Selection Table).

4-28 Operating the Drive

Take Up Slack

NOTE The Drive will not start if there are alarms present.

This facility provides two additional Take Up Slack setpoints. Activating Take Up Slack runs the motor at the speed set by

"speed setpoint + TAKE UP1" or "speed setpoint + TAKE UP 2".

TAKE UP SLACK 1:

1. Apply 24V to Terminal C5 (Enable).

2. Apply 24V to Terminal C3 (Start) to accelerate to set speed.

3. Set JOG/SLACK::MODE parameter (Tag No. 228) to FALSE.

4. Apply 24V to Terminal C4 (Jog Mode) to run the motor at "speed setpoint + TAKE UP 1".

5. Remove 24V from Terminal C4 (Jog Mode) to run the motor at speed setpoint.

TAKE UP SLACK 2:

6. Apply 24V to Terminal C5 (Enable).

7. Apply 24V to Terminal C3 (Start) to accelerate to set speed.

8. Set JOG/SLACK::MODE parameter (Tag No. 228) to TRUE to run the motor at "speed setpoint + TAKE UP 2".

9. Set JOG/SLACK::MODE parameter (Tag No. 228) to FALSE to run the motor at speed setpoint .

Refer to Appendix D: “Programming” - JOG/SLACK for further information (see the Setpoint Selection Table).

Operating the Drive 4-29

External Control of the Drive

Remote Sequencing Command

REM. SEQUENCE : Tag 536, Mnemonic "ow", Default = 0x0000 ("0x" denotes a Hexadecimal value)

This is a control word that allows the device to be operated remotely over a field bus. REM. SEQ. ENABLE must be TRUE to enable this function.

NOTE

Refer to the RS485 Communications Interface Technical Manual, HA463560 on the website, for information about the EI Bisynch ASCII

communications protocol.

Reserved bits are undefined when read and should be set Zero when written.

Bit Number

Mask

Name

Comment

0 (lsb)

0x0001

Remote Enable

0x0002

Remote Start

0x0004

Remote Jog

0x0008

Remote Jog Mode

Selects Jog Speed

0x0010

Reserved

0x0020

Reserved

0x0040

Reserved

0x0080

Reserved

0x0100

Remote Alarm Ack

Alarm Acknowledge

0x0200

Remote/Remote Trip

Remote Trip (High for OK)

0x0400

Reserved

0x0800

Reserved

0x1000

Reserved

0x2000

Reserved

14 (msb)

0x4000

Reserved

15 (msb)

0x8000

Validation

This bit must be zero for the command word to be accepted

4-30 Operating the Drive

Useful Commands using EI Bisynch ASCII - REM. SEQUENCE

Tag 536, Mnemonic "ow", for example:

/Remote Trip

Alarm Ack

Jog Mode

Jog

Start

Enable

Command

Start Drive

ow>0203

Stop Drive

ow>0201

Disable Drive

ow>0200

Jog Setpoint 1

ow>0205

Jog Setpoint 2

ow>020D

Remote Trip

ow>0000

Reset Alarm a)

ow>0300

Healthy Output Bit 11 goes high

Reset Alarm b)

ow>0200

Operating the Drive 4-31

Sequence Status

SEQ STATUS : Tag 537, Mnemonic "ox" (Read Only)

Reserved bits are undefined when read.

Bit Number

Mask

Name

Comment

0 (lsb)

0x0001

Coast Stop

Coast Stop demanded

0x0002

Program Stop

Program (Fast) Stop demanded

0x0004

Disable

/Enable demanded

0x0008

Run

Drive Start demanded

0x0010

Jog

Drive Jog demanded

0x0020

Reserved

Undefined

0x0040

Alarm

Unacknowledged alarm

(Health Store != 0)

0x0080

Reserved

Undefined

0x0100

Running

Contactor in and drive ready to be enabled

0x0200

Enabled

Drive is enabled

0x0400

Zero Speed

Zero speed Output TAG 17

0x0800

Healthy Output

Healthy Output TAG 12

0x1000

Ready

Ready Output TAG 559

0x2000

Reserved

Undefined

0x4000

Reserved

Undefined

15 (msb)

0x8000

Reserved

Undefined

Typical Bit Patterns reported via SEQ STATUS

Tag 537, Mnemonic "ox" (Read Only) - for example:

Sequence Status

Comment

0x1B0B

Running

0x044B

Tripped, Run High

0x0447

Tripped, Run Low, Enable Low

0x0C47

Trip Acknowledged, Healthy output TRUE Alarm stays high until drive is restarted.

Chapter 5 Control Loops

This chapter explains the principle of operation, and provides help on setting up the control loops correctly.

Control Loops - Principle of Operation

• Current Loop

• Speed Loop

• Field Control

Control Loops

5-1

Control Loops - Principle of Operation

MMI Menu Map

SETUP PARAMETERS

NOTE Selection between Current Control or Speed Control (default) is made by the I DMD ISOLATE (current demand

isolate) parameter using Digital I/P3 (Terminal C8). If ENABLED the Drive operates as a current controller, and if

CURRENT LOOP

DISABLED (the default) it operates as a speed controller.

I DMD ISOLATE

Current Loop

The current loop accepts a demand from either the speed loop, or directly from the plant, and forms an error signal which is the difference between

demand and average value of feedback. The error signal is fed into a Proportional + Integral compensator which produces the output of the current

loop, i.e. the firing angle signal.

In the Drive, the error signal is created in two different forms:

1. The average error is computed as the difference between demand and average value of feedback and fed into the Integral part of the P + I

algorithm.

2. The instantaneous error is computed as the difference between demand and instantaneous value of feedback and is fed into the Proportional part of

the P + I algorithm. This gives higher transient performance since it does not contain any time lag, unlike the average which has a built-in lag of 1/6

of mains cycle. However, the average is the true measurement of torque which is the objective of the current control and this is not affected by the

small time lag in achieving zero steady-state error.

The firing angle signal is translated into a certain time delay from the mains zero cross point (obtained via a Phase-Lock-Loop) and this results in a

firing command being issued to the thyristor stack every 1/6 of a mains cycle in steady-state.

Some special features of the current controller are discussed separately below.

Adaptive Current Control

The gain of a thyristor 6-pulse converter (voltage-time area over firing angle) drops dramatically at discontinuous values of armature current.

Therefore a gain boost is required in the current controller to compensate for that.

In the Drive, this is handled by an adaptive algorithm which allows the current to follow the demand in one step (firing) within the discontinuous

region of operation.

Back EMF (BEMF) Estimate

With the motor at standstill, the firing angle for zero current is 120 degrees. When the motor is rotating at different speeds the firing angle for zero

current follows a cosine locus.

It is of paramount importance to track this locus as close as possible throughout the speed range if the current loop bandwidth is to be maintained at its

highest possible level during current reversals from master to slave bridge and visa-versa.

There are two reasons for the loss of bandwidth at current reversals:

5-2 Control Loops

1. The loss of converter gain needs to be compensated in an accurate way which is the objective of the adaptive algorithm.

2. The above algorithm also relies on the right start-up value of firing angle in the incoming bridge in order to minimise both the "dead-time"

(time interval of zero current referred to below) as well as the rise time to the required current demand.

In order to get the right start-up value of firing angle the knowledge of the operating BEMF is necessary. In the Drive, this is achieved by a

combination of a hardware peak current detector and appropriate software algorithm.

Bridge Changeover Delay

The bridge changeover "dead-time", i.e. time interval of zero current, is programmable from 1 to 1500 (via Reserved Menu) with a default value of 1.

For values from 1 to 6:

The delay can be set at multiples of 1/6 mains period, i.e. max. 6 x 3.33 = 20ms at 50Hz. This is relevant for use with large power converters where it

is advisable to allow more time for snubber currents to subside before reversal is enabled. It is also relevant for motors with very large armature

inductance where zero current detection is more sensitive and therefore a "factor of safety" in the bridge changeover delay is advisable.

For values from 7 to 1500:

The delay corresponds to 7 x 1.33μs up to 1500 x 1.33μs = 2ms maximum.

Manual Tuning

NOTE

This procedure is rarely used or required, if possible use Autotune.

If the motor is permanent magnet or (very rarely) wound-field of relatively high permanent magnetism, and the drive is a 4Q drive, then clamp the

shaft prior to using the 4Q Autotune process (default). This mode of Autotune produces current pulses on alternate thyristor bridges, and thus the net

rotational torque is very low.

There are two circumstances where a manual tuning process would be required:

1. The motor is permanent magnet or (very rarely) wound-field of relatively high permanent magnetism, and the drive is a 2Q drive.

2. The Autotune process has failed with AUTOTUNE ERROR message. The possible causes of an Autotune error are:

• The motor shaft was rotating, or was caused to rotate.

• The field current was seen to exceed 6%, when a field-off Autotune had been selected, or the field current stopped during a field-on

Autotune.

• The drive to armature wiring was open-circuit.

• The discontinuous current boundary was found to exceed 200% of either the stack rating or the nominated motor armature current rating

(see A below).

• Large imbalance in the three-phase voltages of the supply (see B below).

• A hardware fault relating to current feedback was detected on the control board.

If the cause of the Autotune failure can be determined and rectified then do so and simply repeat the Autotune process.

Control Loops

5-3

If a very high motor discontinuous current boundary was the cause of failure, then the discontinuous-region manual tuning process needs to

be applied as follows:

1. Set the DISCONTINUOUS parameter to 0, which selects adaptive current control off. When operating in this mode, disable the Missing

Pulse alarm, since it is normally masked in the discontinuous region, and it will otherwise give spurious trips at low currents.

2. Set PROP. GAIN to a low level (typically 1), since it is ineffectual in the discontinuous current operating region.

3. Set the INT. GAIN to a moderate level (typically 10), sufficient to give fast response throughout the discontinuous current region.

If imbalance in the three-phase voltages of the supply is the cause of failure then the PI-control manual tuning process needs to be applied as

follows:

1. Set FIELD ENABLE to Disabled and clamp the motor shaft, to prevent rotation.

2. Attach an oscilloscope to the control board armature current monitor test-point (test point IA [see page 5-5], scaled for 1.1V = 100%

rated armature current, +ve = reverse bridge, -ve = forward bridge). The scaled armature current value can also be seen in the CURRENT

FEEDBACK diagnostic.

3. Run the drive with a positive speed demand, gradually increasing MAIN CURR. LIMIT until the armature current pulses are seen to just

join up. At this point, enter the value of CURRENT FEEDBACK into the DISCONTINUOUS parameter.

4. Enable the I DMD. ISOLATE parameter (or supply 24V to terminal C8). Use a toggling square-wave (< 20Hz) on the direct demand

input (terminal A3) to generate current steps above the discontinuous region. Alternately increase PROP. GAIN and INT. GAIN, as far as

possible, until the current loop response is correct (see Tuning Hints below).

Current Loop controls incorrectly set.

Current Loop controls correctly set.

Rapid alternating oscillation = P gain

Slower oscillatory response = I gain

too high

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