power monitor wu

8/3/2019 Power Monitor Wu

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John Kinsella Power Monitor BE(SEE)

Contents

Introduction: .......................................................................................................................1Siemens Sentron PAC3200 .............................................................................................1

Objectives:..........................................................................................................................1Methodology: .....................................................................................................................1Solution: .............................................................................................................................2

Configuring the hardware................................................................................................2Writing the code: ............................................................................................................5Variable table: ................................................................................................................9Configuring the VSD and MM440 for testing ............................................................... 11

Testing: ............................................................................................................................ 11Questions: ......................................................................................................................... 12Discussion: ....................................................................................................................... 13Conclusion: ...................................................................................................................... 13Table of figures................................................................................................................. 14


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Introduction:

Power monitoring is essential for all parts of most manufacturing facilities, it enables plants

and machinery to run safe and efficiently. Power monitoring is not only subject to just

motors but also to a wide range of electric, hydraulic and pneumatic equipment. In thispractical a VSD (variable speed drive) will be monitored. When a motor is involved in a

process it is vital to know and be able to predict the performance of that motor. If the

performance is diminished, which will happen over time due to wear and tear, and then the

motor will be costing the user more than it should. By monitoring its performance the user

can predict if the motor will need changing or adjusting. Sensors are installed which can

monitor motors and send signals back to the user if necessary indicating a shift in

performance of that motor.

Siemens Sentron PAC3200

The power monitoring device used in this practical is the Siemens Sentron PAC3200

device; this compact and powerful electric device is used where the desire to monitor

electric attributes precisely wherever electricity is consumed. As well as displaying the

recorded data the Sentron PAC3200 unit can also be linked up with an automation and

power management system. Such a system would have massive benefits on an electrical

heavy plant and studies have shown that BAS (building Auditing systems) and CMMS

(computer maintenance management systems) can generate financial savings by simply

monitoring and targeting specific machines.

Objectives:Set up the hardware as specified by the practical specification.

Write up a piece of code using stl as set out by the project specification.

Test the program and both with a simulator and actual hardware.

Methodology:

An understanding of the stl language and how its attributes work was first needed.

The original piece of code was first changed as to allow five pieces of data and a bigger

storage space of 3000.

The hardware was called in and the clock parameters changed and address assigned for the

relevant information.

The old function block was called and used to assign the start stop function.

Switch i1.6 and i1.7 where assigned to control the reset of the pointers and control if the

data is recorded or not.

The code was then downloaded and the system tested using the simulator.


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The parameters on the VSD where changed using the interactive controls.

The system was then tested using the hardware.

Solution:

Configuring the hardware

Figure 1 hardware Configuring page

The power monitoring device used in this practical was the Siemens Sentron PAC3200. It

was found using the search function. It was then dragged over onto the network and

inserted. The specified parameters where selected using the scroll down function under thePAC3200 heading. The default address had to be changed as they were all over 100 and

would not be recognized by the CPU. The addresses reassigned are shown below.


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Figure 2 list of selected parameters and addresses

Figure 3 how to change the clock memory

The CPU clock memory properties had to be changed this was done using the properties

function and Cycle/ clock memory tab used. The help function was then used to input the

100 value. The screen shot of the table used is shown below.


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Figure 4 selection criteria for period duration

Figure 5 connecting and disconnecting the hardware

The hardware was then added as shown above.


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Writing the code:

Firstly an understanding for the terminology used for programming was needed.

The Pointer function is a method of storing a reference or pointing to a memory location for

something such as a reading for voltage, current etc.

Figure 6 pointer explanation

Above is a screen shot of the F1 help function explaining how to utilize the pointer

function?

Figure 7 OPN function help page


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The OPN code was used because we had to tell the program which address or location we

will be sending the data too. In this case the data was sent to DB2 (data block 2), a screen

shot of DB2 is shown below.

Figure 8 DB2


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Below is a screen shot of the developed code.

Figure 9 developed code not showing address for voltage

Figure 10 first line of code showing the open DB2 function

The first (OPN) part of the code opened the datablock DB2.

Figure 11 second piece of code

Figure 12 L (load) help function


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Next the L address was employed to load the static pointer (#pointer1) which tells the data

where to go. In this case DB2. The limit is then set to 3000 because thats the calculated

number of bytes we will calculate over the 5 minute period in total. Such that 5 x 4 samples

= 20 therefore 20 x 150 (150 = how many times in 5 minutes) = 3000.The >D function was then employed which says if the #pointer1 is less than 3000 then

continue however if it is more than3000 then jump( JC = jump conditional) to the end of

the cycle.

Figure 13 third piece of code

The code above says load up the static pointer as in show the temporary pointer where to goand transfer it over. L = load, T = transfer.

Figure 14 fourth piece of code showing address for voltage

The piece of code above says load the value form address 54 (ID 54 = input double word

from address 54 the voltage). Transfer the double word (recorded value for voltage) into theaddress specified from the static pointer. Then add 4 (4 bytes = 2 words) to the pointer to

go to the next address. Then transfer the temporary pointer into DB2.

Next the above piece of code was then copy and pasted another four times, each time

changing the input double word address so it will call up the different piece of information.

The corresponding addresses are as follows.

Figure 15 Assigned address


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Figure 16 end of code

Above is a screen shot of the end of the written program.

Variable table:

Figure 17 variable table

The above is a screen shot of the variable table with the address called in for the specific

parameter needed such as voltage current etc. The display format was then changed to a


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floating point. Floating point terminology is used to tell the computer that the values will

have decimal places or that they are not integers.

Next in FB1 a previously written function block was called in to assign the start and stop of

the motor to the switches. I0.0 and I1.0

Figure 18 called in function block

Figure 19 code for restart function

As can be seen in the above code description the switch I1.6 was assigned to tell the pointer

to restart the cycle and start rewriting the code when activated.


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Figure 20 code for turn on or off saving of recorded values

As can be seen in the above piece of code the switch I1.7 was assigned to tell to program

whether or not to start recording the data. This was not a momentary switch and must be

left on in order to record the data.

M100.7 (originally M100.5) was the reassigned value which governed the frequency of the

recording which was set by the specification at one reading every half second.

DB2 was called in and renamed store as this is where the information or data gathered is

sent.

Configuring the VSD and MM440 for testing

Before testing the program the settings on the VSD had to be changed to tell it where the

commands where coming from such as start stop and speed or frequency. This was done

using the MM440 interface as shown below.

From the MM440 (micro master 440) manual section 3.8 governing the default settings of

the VSD the settings where changed as follows:

Using the P button to access the settings and using the directional buttons the value was of

700 was arrived at. Then by double pressing P and using the direction buttons a value of 6

was inputted. As specified by the manual this setting told the VSD that the commands for

stop and start will come from the switches assigned earlier (I0.0 for start and I0.1 for stop).

Then in the same manner as before the value of 1000 was arrived at and the a setting of 2

set which tells the VSD to use the potentiometer on the VSD unit itself.

Testing:

The system was tested using the VSD which worked as specified however it would only

record the data once and not rewrite it when the pointer was turned on using I1.6.


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When simulating the hardware the address for the switches where changed to ms and also

in the variable table the address where changed. By doing so enabled the user to input the

values as the machine was not connected to a profibus or motor. When simulating the

system it would only start recording the data after the value of 80. The cause for this

problem was realized to be a pointer issue and not an issue with the written code, however

due to time constraints the issue was not resolved.

Questions:

What data typically can be gathered from a power monitor?

The data gathered in this practical was the phase voltage, phase current, power

factor (actual), Minimum power factor and operating hours however power

monitors are capable of monitoring all sorts of characteristics such as temperature,

simple and complex harmonics etc. the specific model used in this practical can

meter up to 50 different parameters.

What are the advantages of having the power monitor connected on a fieldbus like

profibus?

Using the power monitoring device with profibus allows the data to be sent both

ways as the data can be sent in two directions at the same time, this enables the

controller to receive data whilst also make changes if necessary to the equipment.

Give six examples of useful VSD parameters that are configurable on the VSD hardware

drive unit. (List the parameter number and function).

Lists of the available parameters are shown in the table below.


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Figure 21 list of available parameters

How is a power monitor such as the PAC3200 wired? (Sketch a typical wiring diagram for

power monitoring of a single phase motor)

Below is a sketch of how the wiring is done.

Figure 22 wiring configuration taken from power monitor.

What is indirect addressing and what are its advantages?

This is when an address mode points to another pointer rather than the actual

address or data where the information will be sent. Indirect addressing allows the

programmer to increase or decrease the address of the operand either before or after

use by a specified number. In this case as there was five bits of data the value was 5.

Discussion:

During this practical the hardest part was initially getting started and understanding the

STL language. Once this was achieved writing the code was still tricky however having an

original piece of code to rewrite was a big help.

Conclusion:

This practical was very much so hands on as such which enabled the student to gain a better

understanding as they could see exactly what was happening when the motor was running


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and the relevant pieces of code stored in DB2. Perhaps a better understanding of the STL

language could have implemented before jumping straight in as it was felt the language and

code was the most time consuming part of this practical.

Table of figureshardware Configuring page .................................................................................................2list of selected parameters and addresses .............................................................................3how to change the clock memory ........................................................................................3selection criteria for period duration....................................................................................4connecting and disconnecting the hardware ........................................................................4pointer explanation .............................................................................................................5 OPN function help page ......................................................................................................5DB2 ....................................................................................................................................6developed code not showing address for voltage .................................................................7first line of code showing the open DB2 function ................................................................7second piece of code ...........................................................................................................7L (load) help function .........................................................................................................7third piece of code ..............................................................................................................8fourth piece of code showing address for voltage ................................................................8Assigned address ................................................................................................................8end of code .........................................................................................................................9variable table ......................................................................................................................9called in function block ..................................................................................................... 10code for restart function .................................................................................................... 10code for turn on or off saving of recorded values .............................................................. 11list of available parameters................................................................................................ 13wiring configuration taken from power monitor. ............................................................... 13


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power monitor wu

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