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Recent content by bogdal

  1. bogdal

    SIEMENS STEP5 V6.6

    It worth to try with STEP 7, in my opinion. It has more features, it's an improved phylosophy and more important, you can programm the latest CPUs from SIMATIC.
  2. bogdal

    What I/O card to use???

    You can also try with some field ellements if you want only to monitor and not to control those signals. Check out for National Instruments - Field Point. Or, if you want to use the Siemens family, you can visit their site and check for SIMATIC ET-200.
  3. bogdal

    Temperature control using PLCs

    Hi You didn't tell if you have a boiler in each room. If You have a single boiler, I think it should be more confortable to use thermostate vanes for each room, so you can control individually the temperature. If you have a boiler for eache zone you want to control, I think a simple thermostate...
  4. bogdal

    droop setting of governors

    Ples escuse me, I've forgot to mention them: bp - permanent droop s - Laplacian operator
  5. bogdal

    droop setting of governors

    The droop is applied to the generator power value. The frequency error determines the gate movement to increase or decrease the active power, so the error at the inner loop (gate positioner) becomes zero. You can use the following formula: CV = [(df+dP*bp)(Kp+Ki/s)+df*Kd*s+setpoint] where: CV...
  6. bogdal

    droop setting of governors

    The speed governor actually makes the frequency error (frequency setpoint - actual frequency) to become zero at no load functioning. After the generator is coupled to the grid, you can assume that the grid power is infinite, compared to the generator's power. So in load or full load functioning...
  7. bogdal

    droop setting of governors

    Hi, Sailer 12000 It's right, you will use a PID algorithm, but not a compact one. For a electro-hydraulic governor, we have a cascade loop, so the functions of the PID are distributed on the feedback reactions, depending on the regulating principle. The governor's droop can be defined either as...
  8. bogdal

    ENCODER/PLC INTERFACE

    You can visit the site of Siemens :http://www4.ad.siemens.de/csinfo/livelink.exe?lang=en&aktprim=0&nodeID0=4000024&siteid=cs&SearchAction=csallprompt&SearchType=9000&func=cslib.csinfo Depending on the motion transducers You have, you can choose the right interface module, to control the position...
  9. bogdal

    Numeric derivation and integration

    Thank's again. After I made the translation from the Laplace form of the transfer function in the time domain, as an intermediar step, I used afterwards the Z-transform. I will reconsider the whole algoritm again.
  10. bogdal

    Numeric derivation and integration

    Thank You for the answers. I'll try to be more speciffic: I have to write the discrete differentiation and integrative for inputs wich are aqiered at a constant sample time. For the derivative I use for the moment the centered discrete differentiation formula. But I need to know how the...
  11. bogdal

    Numeric derivation and integration

    I'm looking for a discrete form of derivation and integration to use in a PLC program. I tried with the classic form af these operations but I encountered difficulties in defining time constants for them (Td,Tm, Ti)

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