Implementation Of CC mode in EVAL_3KW_2LLC_C7_20 DC_DC converter

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Bandarikarthik
Level 3
Level 3
25 replies posted 100 sign-ins First like given

Hi all  Good day 

I am working on 3.3 kw DC DC Converter  evaluation board (EVAL 3 K W 2 L L C C 7 20) 

I want to implement battery profile Constant Current (CC mode) and Constant Voltage (CV mode)

I have a source code with CV mode  need your guidance for implementing  the CC mode  in the existing Source Code for Battery charging Profile please guide me.

I want to re-adjust the output voltage and output current  from the default state to different Voltages and Currents

 

Please Help me  need your'e Guidance 

Reagrds,

Karthik.

 

Bandari Karthik Kumar
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1 Solution
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @Bandarikarthik  and @User21479 ,

  There are several ways to implement the current loop needed in order to shape a given charging profile, including e.g. CC, CV and floating mode, such as in the  typical “IUoU” lead acid battery charging profile.

psb_0-1642877729208.png

A typical way is to do it in HW by a dedicated current feedback loop on the secondary side, put in “OR” with the voltage loop. The current loop will limit the current in CC mode, when the battery is fully discharged and tends to draw the max possible current. This happens until the current typically reduces below 80% of Imax, then the CV follows, regulated by the voltage loop. Again, this is a possible way.

Actually, a current reading is, in our board,  available in the primary side, and already used by the MCU,  as the you have already rightly pointed out. This can be also used for the CC management.

So, you have several ways to implement it: kindly decide based on the need.

From our side we do not have any specific version of the SW to support the CC mode, and there is no plan to do it. Kindly be informed that we provide demo boards customer support about the operation based on the original design.

Thanks and Regards,
Sai

 

Best Regards,
Sai

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @Bandarikarthik ,

  Typically in battery charging applications, in the CC mode, the outer voltage loop gets saturated and the inner current loop gets the maximum possible value for current reference corresponding to the given reference voltage input and the CC mode output current required. Similar thing happens if both CC and CV mode loops are separate. These can be changed accordingly either through GUI or in the source code.

We'll also look into the source code and get back to you accordingly.


Thanks, 
Sai

Best Regards,
Sai
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Bandarikarthik
Level 3
Level 3
25 replies posted 100 sign-ins First like given

Hello @psb 

the Module is shutting Down after reaching the max current 55A it has over current protection 

I have source code for this  I need the guidance for Implementing the CC mode 

the module which I have is CV mode only its a DCDC convertor ( EVAL_3KW_2LLC_C7_20 DC_DC converter )

I would like to implement the CC mode for this Module Help me 

so, at last final Both CC and CV loops can give us the battery profile at the end 

regards 

Karthik

 

Bandari Karthik Kumar
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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hi @Bandarikarthik ,

The 3kW Dual Phase LLC Demo Board is not intended to be used as a battery charger, so with the current hardware on the board, there is no way to implement CC and CV mode functionalities only by simple software adaptation something similar as described above. This can be implemented only with additional dedicated hardware according to the charging profile you would like to implement. In other words, the design of these additional functionalities has to be done by deciding on the kind of closed loop control and adding in the required hardware accordingly. 

Thanks,

Sai

Best Regards,
Sai
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User21479
Level 1
Level 1
10 sign-ins 5 sign-ins First reply posted

Sai,

The current feed back (converter 1 (I12)+ converter 2(I22) = total(It)  and volatge feed back available with this application. Hence we can implement the code for out side voltage loop and inside current loop.i dont think no separate hardware is required.provide your clarificartions in case any.

Requesting to provide a reference code for cc and cv in case any avaialble.

Regards,

Bhima Prasad.

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @Bandarikarthik  and @User21479 ,

  There are several ways to implement the current loop needed in order to shape a given charging profile, including e.g. CC, CV and floating mode, such as in the  typical “IUoU” lead acid battery charging profile.

psb_0-1642877729208.png

A typical way is to do it in HW by a dedicated current feedback loop on the secondary side, put in “OR” with the voltage loop. The current loop will limit the current in CC mode, when the battery is fully discharged and tends to draw the max possible current. This happens until the current typically reduces below 80% of Imax, then the CV follows, regulated by the voltage loop. Again, this is a possible way.

Actually, a current reading is, in our board,  available in the primary side, and already used by the MCU,  as the you have already rightly pointed out. This can be also used for the CC management.

So, you have several ways to implement it: kindly decide based on the need.

From our side we do not have any specific version of the SW to support the CC mode, and there is no plan to do it. Kindly be informed that we provide demo boards customer support about the operation based on the original design.

Thanks and Regards,
Sai

 

Best Regards,
Sai
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