kWh counter for wind mill by LOGO
Created by: Matti Niemi / Solar-Wind Automation at: 8/14/2009 3:48 PM (11 Replies)
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| 8/14/2009 3:48 PM | |
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Posts: 9 Rating:
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Any good idea, how to make kWh counter for LOGO. I have problems topick upanalog merger values to analog math I get voltage and current via analog inputs |
| 8/14/2009 10:26 PM | |
Joined: 1/5/2007 Last visit: 4/7/2023 Posts: 1690 Rating:
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Hi, before ask here,please search in the forum, e.g. under "kwh LOGO" most it can help fast!!! By this way you can find the following link: "Energy meter (kWh)" Best regards Betel _________________________________________________ Perhaps helpful links: |
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| 8/15/2009 4:52 PM | |
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Joined: 1/5/2007 Last visit: 4/7/2023 Posts: 1690 Rating:
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Hi Matti, ok, you have two analog inputs for V and I and you want to calculate V * I over a smal (defined) time window in a cyclic manner...means an integrtation of the calculated value "V * I" must programed... Please let me/us know the type of your analog input signals (V or mA) and there interpretation/scaling (in V and A); witch are the real ranges for the input values? Witch resolution you want to have for the result in Wh or kWh (perhaps for a display)? What range (0 to biggest value) must that result in Wh or kWh have (perhaps for a display)? What do you want to do with the result pulses? How are the speed of the changing of the input values for V and A; how often are the changing of the input values for V and A (perhaps V is nearely constant? and only A is changing?...) And what other details, facts, parametersyou can tell us? ...A solution should be possible, but that is a function of the asked parameters - and a solution is a little bit complex - ... Best regards Betel _________________________________________________ Perhaps helpful links: |
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| 8/17/2009 7:48 PM | |
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Joined: 1/5/2007 Last visit: 4/7/2023 Posts: 1690 Rating:
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Hi Matti, thanks for the infos! Because the matematical functionality of the LOGO-function-blocks are restricted, i have some additional questions: a) I think the current can have the range from 0 Ato 100 A, but the range of a battery can (at function of a "consumer equipment") only a range from n V to m V (m = 28 V from your last posting)... n = ? What type of battery (data) you have? b) My question beforeabout the changing speed of the voltage and current means the following: I think the voltage of the battery should only change there value slow (in normal function) but the currend can change with different speedas a funktion of the consumer equipment(s)..What equipment you have to drive?....This info is helpfull to define the needed speed (or measuring time) for the calculation of the valueWh or kWh.. Please remember, that i need some more time to create a concept and then a cirkuit as a solution - please have patience! Some ideas you can get from my answers at the followig links: CO2 calculation - Math equations with LOGO! Flow Totalization Best regards Betel ___________________________________________ Perhaps helpful links: |
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| 8/22/2009 11:52 PM | |
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Joined: 1/5/2007 Last visit: 4/7/2023 Posts: 1690 Rating:
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Hi Matti, look at my solution at the attachment...Please remember that this circuit not work correct in a PC-simulation without parameter changes: set the values of B015 "TimeBase" to higher values (1:15 s) to simulate the circuit correct and to look how it works....(of course in real time the interpretation of the counters is not more correct) The concept: a) integration of the measured values U*I over a smal time window cyclic: d(U*I)/dt [VA/300ms] That means: measuring voltage (U) and current (I) at one time, calculate "U * I" (/ 1000 because the value scaling) and hold this value constant for a smal time window dt (here = 300 ms). Do this cyclic.. b) ..addition of 4 or more measured parts of d(U*I)/dt and if the sum > 4 * 3000 = 12000 [VA/300ms] then build asignal witch stands for "1 Wh is used/measured" c) If this signal comes, build an output puls for "1Wh" (if softkey "En_Q1" is "ON") and set a counter_1" cnt + 1" d) If the counter_1 = 1000, then build an output puls for "1kWh" (if softkey "En_Q2" is "ON") and set a counter_2" cnt + 1" I1: enable (start/stop) the measurung of power consumption (kWh) I2: clear/reset the power consumption counters I3: clear/reset the power consumption day counters (as example -circuit part not needed for main function!!) 300 ms TimeBase is the smallest value of the actualisation time of the analog inputs of the LOGO! basic modules! This value as "dt" give us a measuring resolution of 0,25 Wh. Outside (Q1)you get a resolution of 1 Wh as pulses. Because only the counters can hold values retentiv, the maximum error by every powerfail is 1 Wh lost! U = 30,00 V; A = 100,0 A are the maximum values: If they are present for 1 h we must measure 3000 Wh. If we measure only 1,2 s we get a portion of 1 Wh and we measure this 3000 times... I hope you understand how the circuit works and you can use it inside your own cirkuit...B001 and B018 should there too... Caution: If you copy my circuit into yours, then you must redefine all parameters witch contain pointers to other blocks (in my orginal) - only then works it correct!!! Best regards Betel ___________________________________________ Perhaps helpful links: AttachmentDEMO_Sensorauswertung_kWh_V1 (0BA6).zip (849 Downloads) |
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| 8/23/2009 12:58 AM | |
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Posts: 12 Rating:
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I can unzip the file, but can't open it. Using Ver 6.0.17 on both MAC and PC. |
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