MPPT charger's design - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: July 01, 2023, 01:15:26 pm
content: I would like to learn more about the design of MPPT chargers so that I can repair them.I can repair various electronics ( e.g. SMPS power supplies, chargers, cell phones,etc.) but not MPPT chargers yet.Where can I find a good resources?Thank you for help

author: m k
author_rank: Super Contributor
timestamp: July 03, 2023, 03:58:02 pm
content: Maybe from reference designs of controller chips.Maybe the thing is so new that textbook approach is so last season.The principle is simple.It's just a DC/DC converter with source overload sniffer.

author: Grandchuck
author_rank: Super Contributor
timestamp: July 03, 2023, 04:08:32 pm
content: https://electricalacademia.com/renewable-energy/maximum-power-point-tracking-mppt-charge-controller-working-principle/Maybe you already know this much?

author: MrAl
author_rank: Super Contributor
timestamp: July 03, 2023, 07:52:35 pm
content: Quote from: Jane on July 01, 2023, 01:15:26 pmHello there,I worked with MPPT way back in the 1980's when it was done with logic chips like the 74LS00 series.A modern MPPT very likely will do it with a microcontroller that is programmed to perform the necessary measurements and adjustments.I am curious as to how you can obtain a replacement microcontroller with the right programming if that turns to be bad when you go to fix it. The algorithm could be proprietary.There are also other ways that this might be done. For example, back then the application was line tied converters/inverters, that provide power back into the line (like 120vac for example) and the customer gets paid back for that energy. One of the big customers was Sandia Labs and they did a study that suggested that the better way was to use a remote solar cell that monitored the insulation level and used that alone as feedback to select the max power point. That is not an algorithm per se, but simply feedback from a sensor that can perform the required measurements.It may have gotten a little more sophisticated than that though, using multiple cells and making a decision on which ones to use at the time and which ones needed to be cleaned.The hunting algorithm was not suitable for them because they found that the cloud cover can change so fast that it made it hard for the system to react to the changes fast enough to keep the converter/inverter online. It would have to drop out completely and then wait for a timeout to connect back to the line and provide energy again. Things could have progressed since then though but it's almost certain it will include using a microcontroller with a company produced program programmed into flash memory. I am not sure they would want to give that information out or even provides new chips for replacement, but you can look into that, I guess.The other point is that if they are not that expensive the simplest fix may be to just buy a new one. The most expensive element(s) would be the power passing elements which would be apart from the controller IC.

author: Jane
author_rank: Frequent Contributor
timestamp: July 04, 2023, 08:37:01 pm
content: Thank you ALL for the replies.@MrAl:Regarding the repair I am not going to repair firmware chips. I agree it is not repairable, if not having firmware. However, I think that ( mostly) if there is a problem with MPPT , then it is not a programmed flash.Or disagree?

author: MrAl
author_rank: Super Contributor
timestamp: July 05, 2023, 11:11:56 am
content: Quote from: Jane on July 04, 2023, 08:37:01 pmHi Jane,I mostly agree. I would think the power stages would be most vulnerable.