Master Follower Aqua Aqua 0113

7/26/2019 Master Follower Aqua Aqua 0113

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DD-OSA/ JL 2012-02-2

Master Follower Aqua-Aqua

Note: Before starting this program please configure the master drive with the text NA-05

Master / Follower applicationswiththeFC202 VLT AQUADrive(Sof tware Version 1.53)

1. Abstract

The Master-Follower cascade control mode offers the best performance, the most precise contr ol and

maximum energy savings. It controls multiple equal sized pumps in parallel, running all pumps at the same

speed and stages the pumps on and off according to the system r eq uir ements. Compared to traditional

cascade control the number of running pumps is controlled by s peed instead of feedback. To obtain the

highest energy saving the stage on and off speed must be set correctly according to the system. The ter minal

27 of the master drive is used as pulse output for the reference. The terminals 29 of the f ollower drives are

used as pulse input for this reference. While the master drive is running in closed loo p, the follower(s) are

running in open loop. All follower drives are connected to mains and motor the same way as the master d r ive.

Figure 1:Basic Wiring Principle

The advantages and benefits of this conf iguration

Maximum per f or mance:

In old and weak pipe system where huge pressure surges can lead to leakage, the high

performance of the Master / Follower mode can be a real benef it.

Maximum energy savings:

In constant pressure water systems the pumps can be operated in the most energyefficient way by using Master / Follower o per ation.

In systems with large variances in flow, the fast reacting Master / Follower mode

will safely and fast maintain a constant pr essur e.

Lowest costs for installation:

Very easy installation - no need for external equipment. The drives can be delivered in

IP55 or even IP66, which means no need for panels, except f or fuses.

Reduced wear and tear :

Runtime Balancing of the pumps and all motors operate at the same frequency when in use.

Master Drive contains the cascade CTL option MCO 101 or MCO 102

Follower units are “standard” drives (without the need for extra eq ui pment)

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DD-OSA/ JL 2012-02-28

2. Example for the configuration of a Master-Follower application

The application of the following example consists of 3 variable speed pumps. It is assumed that the pressure transmitter used as feedback sensor, has a range

from 0-10 bar. An internal reference is used .

Remark: Even if a lot of the above listet settings have their default values it is recommended to

check them in order to avoid a misconf iguration.

The necessary steps for the configuration ar e

Basic Settings for the Master and for the Follower (Motor d ata, Display etc.)

Configuration of the Master

Configuration of one of the Followers

Copying the settings with the LCP from this Follower to the other Fo llowers

2.1 Basic Settings for the Master and the Followers

Basic Settings (Master and Follower) Example / Remarks

0-02 Motor Speed Unit Hz [1]

1-20 Motor Power [k W]

1-22 Motor Voltage [V]

1-23 Motor Frequency [Hz] 60

1-24 Motor Current [A]

1-25 Motor Nominal Speed [RPM]

1-29 Automatic Motor Adaptation (AMA)

3-41 Ramp 1 Ramp up Time [s]

3-42 Ramp 1 Ramp down Time [s] Settings must be the same f or

Master and Followers 4-11 Motor Speed Low Limit [RPM] 4-12 (HZ)

4-13 Motor Speed High Limit [RPM] 4-14 (HZ)

It is very important that the motor is properly running before the master drive is

set to closed loop operation.

Display settings - Master drive Example 0-20 Display Line 1.1 Small Reference [1652]

0-21 Display Line 1.2 Small Feedback [1614]

0-22 Display Line 1.3 Small Motor current [1611]

0-23 Display Line 2 Large Frequency [1613]

0-24 Display Line 3 Large Cascade System Status [2581] Display settings - Follower drives Example 0-20 Display Line 1.1 Small External Reference [1650]

0-24 Display Line 3 Large Frequency [1613]




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2.2 Settings for the Master

While the Follower are running in Open Loop and get their reference by an pulse input the master has to

be configured for Closed Loop. In this example it is assumed, that the Analogue Input 54 is used for the

feedback which is the default setting.

Please note: The format of the analogue input is set using switch S201(0=Current, 1=Voltage)

below the LCP.

Par. 16-63 (Terminal 54 Switch Setting) is a read out of the actual switch position.

If an external reference is used, the analogue input (terminal 53 by default) for this signal need s also to be

conf igur ed .

Please have a look at the Programming Guide for further inf or mation.

(MASTER)Closed Loop Settings Example

1-00 Configuration Mode Closed Loop [3] 3-02 Minimum Reference 0 ( bar )

3-03 Maximum Reference 10 ( bar )

6-00 Live Zero Timeout Time 10 (s)

6-01 Live Zero Timeout Function OFF

6-20 Terminal 54 Low Voltage 0 (V) or 6-22, if 16-63 = Curent

6-21 Terminal 54 High Voltage 10 (V) or 6-23, if 16-63 = Curent

6-24 Terminal 54 Low Ref/Feedb Value 0 ( bar )

6-25 Terminal 54 High Ref/Feedb Value 10 ( bar )

20-12 Reference/Feedb.Unit Bar

(MASTER)

Closed Loop Settings Example

20-79 PID Autotuning Enabled [1]*

20-81 PID Normal/Inverse Control Normal [0]

20-83 PID Start Speed [RPM] 0

20-21 Setpoint 1 4 ( bar )

20-93 PID Proportional Gain 3.2

20-94 PID Integral Time 2

* It's recommended to perform a PID Autotuning (par. 20-79) after the whole

application has been configured in order to find the best PID settings for the application.

Please note that PI Auto tune has to be enabled with the LCP.

Setting the reference for the Follower drives, it is assumed that terminal 27 is used as by d ef ault.

(MASTER)

5-* Digital Output Example

5-01 Terminal 27 Mode Output [1]

5-30 Terminal 27 Digital Output Pulse output [55]

5-60 Terminal 27 Pulse Output Variable Cascade Reference [116]

5-62 Pulse Output Maximum Frequency #27 5000 (Hz)




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2.3 Basic settings in the Master drive for the Master/Follower application

The parameters in group 27 are only visible if the MCO101 (or MCO 102) is mounted .

When the system is set to operation, the master drive will automatically run time balance with all

drives running with the needed number of pumps depending on the demand. If, for some reason

the user wants to prioritize which motors should be preferred, it is possible to prioritize each

pump in par. 27-16 in three levels. (Priority 1, Priority 2 and spare pump).

Pumps with priority 2 will only be staged on when there is no priority 1 pump available.

It might be necessary to fine adjust the stage on/off speed to optimise the energy consumption,

if not auto tuned.

(MASTER)

27-1* Configuration Example

27-10 Cascade Controller Master/Follower [1]

27-11 Number Of Drives 3

27-16 Runtime Balancing Array, Balanced Priority 1 [0]

27-19 Reset Current Runtime Hours Do reset [1]

27-2* Bandwidth Settings Example

27-21 Override Limit 100 (%)

27-23 Staging Delay 5 (s)

27-24 Destaging Delay 5 (s)

27-3* Staging Speeds Example / Remarks

27-30 Auto Tune Staging Speeds Enabled [1]

27-31 Stage On S peed [R PM]

27-32 Stage On S peed [Hz]

27-33 Stage Off S peed [RPM]

27-34 Stage Off S peed [Hz]

Arrays for the staging s peed s,

see example below in chapter 3.2

(Example settings for 27-3* , 3 pumps

with Sleep Mode ena bled)

In Master-Follower applications the Lead Pump is defined as the last variable speed pump running.

Even if the cascade controller tries to runtime balance the pumps it may be the case that the system

demand stays below the maximum capacity of the Lead Pump and no alternation takes place. If it is

intended to force the alternation of this pump it can be d one at a Time Interval or at Time of Day.

27-5* Alternate Settings Example

27-52 Alternation Time Interval 0 (min), Disa bled

27-54 Alternation At Time of Day Disabled [0]

27-56 Alternate Capacity is < 0 (s), Off

An array parameter is used to configure the output of the master drive for the s tar t signal of the

follower dr ives.

27-7* Connections Example

27-70.0 Relay 1 Drive 2 Enable [1]

27-70.1 Relay 2 Drive 3 Enable [2]




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2.4 Settings for the Followers

Because the follower drives get their reference from the master as a pulse signal they have to be

configured for Open Loop o per ation.

In order to make sure that all follower drives have got the same settings it is a good idea ton

configure only one of the followers and to copy the settings by using the LCP.

(Follower)

Open Loop Settings (Follower) Example / Remarks

1-00 Configuration Mode Open Loop [0]

3-02 Minimum Reference 0

3-03 Maximum Reference 60 (Hz)

3-15 Reference 1 Source Pulse Input 29 [7]

Sleep mode based on the detection of low speed

• Enable low speed detection P22-22

• Choose low-speed function P22-23 (Sleep Mode)

• Choose low-speed delay P22-24 (the time it will run at low speed before entering sleepmode)

• Adjust the level of feedback to wake P22-44

(10% means that the team woke up when the value of the feedback is 10% below the set

point)

To enable reinforcement, follow these steps:

• Select the pressure at which P22-45 will increase the pressure in% of setpoint

• Select the maximum time reinforcement. P22-46

The terminal 29 is used as a pulse input for the reference signal and has to be scaled . (Follower)

5-* Digital Input (Follower) Aqua Example / Remarks

5-02 Terminal 29 Mode Input [0]

5-13 Terminal 29 Digital Input Pulse Input [32]

5-50 Terminal 29 Low Frequency 0 (Hz)

5-51 Terminal 29 High Frequency 5000 (Hz)

5-52 Term. 29 Low Ref. Value 0

5-53 Term. 29 High Ref. Value 60 (Hz)

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3. Enhancement of the Application: Sleep Mode since SW Version 1.53

The new software will also de-stage the last variable speed pump in applications with mor e than one

drive. Until version 1.53 the last pump will not always enter the sleep mod e pr o per ly

(if not configured ind ivid ually).

3.1 Necessary steps to configure the SleepMode

The sleep function is enabled if P27-34.01 is set higher than the minimum speed.

This will de-stage the last pump using the normal de-stage timer P27-24.

Setting it to zero will disable the function.

Important: P27-10 must be in “Mixed Pumps” to display all of the necessary parameters.

P27-20 and P27-21 must be set (at least one of them). Ether of these will cause the Cascade Controller to wake up a pump.

Upon wake up it will start the pump with the least r unning hours.

There is no boost f unction.

There is no minimum run time or minimum sleep time.




44 (i.e. par . 2732.1) 30 (i.e. par. 2734.1)

46 (i.e. par . 2732.2) 40 (i.e. par. 2734.2) X (i.e. par. 2732.3) 42 (i.e. par. 2734.3)

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3.2 Example settings for 27-3* , 3 pumps with Sleep Mode enabled

Stage 1

Stage 2

Stage 3

Stage ON (Hz) Stage OFF (Hz)

Stage X refers to the stage the cascade is running in

(Stage 1 -> Cascade is running in stage 1, only 1 pump is running)

Pump 2 is started on 44Hz, Pump 3 is started on 46Hz

Pump 3 is stopped on 42Hz, Pump 2 is stopped on 40Hz and Pump 1 is stopped on 30Hz

Par. 2732.3 is irrelevant in this case, because there's nothing left to stage on in stage 3

It might be necessary to fine adjust the stage on/off speed to optimise the ener gy consumption, if

not auto tuned .

3.3 Important detail regarding the current implementation of the Sleep Mode

While the Master-Follower application is in Sleep Mode the stop signal (i.e. removing the start signal

from DI 18) is ignored as long as the Master is "slee ping", meaning the sto p signal does not have

highest priority.

You would see that the Cascade wakes up again (even if there is no start signal active),

switches the drives on and de-stages immediately afterwards and sto ps the cascad e.

The following shows how any unintended motor start during the Sleep Mode can be avoided.

This will be changed within the follow-up release of the software version 1.53 and the described

workaround won’t be necessary anymor e.

Workaround using the SLC The following workaround by using the Smart Logic Controller has been tested to work.

The basic idea is to coast the cascade if there is no start signal and if the motor s peed

is almost 0.

Par. 13-01 (Start Event): Logic rule 0




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The event above becomes true if the Digital Input 18 (programmed as Start) is LOW and

if the Motor speed is almost 0 (Comparator 0):

Par. 13-51.0 and 13-52.0 (SL Controller Event and SLController Action)

The SLC program consists of only this one pair :

Par. 13-02 (Stop Event): Digital Input 18

As soon as a Start signal is active the drive should leave the Smart Logic Contr oller .

4. MCT10 file with example settings

The settings (Master and Follower) in the attached file show the configuration f or a similar

a pplication.

Please be aware that a lot of the settings depend on the application (e.g. its dynamic behaviour)

and will have to be adapted in order to match the special requirements.


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Master Follower Aqua Aqua 0113