S7300 plc PID control for modulating burner motor

[Tweed]

Hi
can anybody help with the PID control of the modulation motor for gas burners.The system at the moment is controlled with eurotherm 818 controls but we are upgrading the whole system on to siemens s7 300 plc and would like to do away with the eurotherms and use the plc with a HMI screen.Would be greatfull for any help on the function blocks required etc.

 

[pocowork]

tweed,

how many burners?
are the motors controlled with analog positioning?
what and how many feedback devices?

It really depends on how it was controlled before but it could be a simple as embedded PID commands being cascaded. that is the output from one PID as the Setpoint for another.

I have done submersable burners for Vat control.

pocowork

 

[nbucska]

What is the specs? Motor and sensor data ? or types and where we can find them?

<nbucska@pcperipherals DOT com> subj: eng-tips

 

[ozmosis]

Tweed
Is this a boiler? If yes and they are up upgrading a burner control system, what about looking at the Siemens Building Technologies [SBT](Landis & Staefa as was) new LMV52...
This is a new miroprocessor based burner management controller that incorporates all burner functions (load controller, O2 sensor,infrared flame detector, control of up to 6 actuators as well as a 4-20mA siganl to control a VSD/VFD via a 4-20mA). More importantly, it is approved by all major worldwide bodies and meets all the safety specs demanded in this industry. You can also plug in a HMI as well.
If it is a boiler, I'm not sure the S7-300 would meet the global approvals.
I actually work for SBT on the drives side so I'm no expert on the LMV other than having to work with the LMV experts more an more with drives on the FD fans. I've come across a few companies who wish to use PLC's on main boiler management but fall foul of the authorities.

 

[CARF]

This is what we use:

* Standard PID control (6ES7860-2AA21-0YX0)

The Standard PID Control software package enables the integration of

? continuous PID controllers,
? pulse controllers, and
? step-action controllers

into the user program.

The parameterizing tool with integrated controller adjustment permits time-saving configuring and optimal adjustment of the controller, thus reducing engineering costs. The innovative control algorithm used in the step-action controller contributes to an increased lifetime of the actuators. Standard PID Control can be used in the S7-300 (CPU 313 and higher), S7-400, and C7.

Standard PID Control consists of a parameterization tool and standard function blocks with the different controllers. The parameterization tool has an easy to understand and easy to use Windows user interface.

The following turnkey application examples are supplied with the software:

? Fixed-setpoint controllers with continuous output for continuous actuators;
? Multi-loop feedback ratio control;
? Compound controllers;
? Cascade controllers.

PID_CP PID controller with continuous control output (continuous controller) or pulse output (pulse controller); in addition to the functions in the setpoint and actual value branches, it implements a predefined PID controller with continuous control output. The control output can also be varied manually; sub functions can be activated or deactivated.

Hope this helps,
C.