mppt vs pwm
Hi, A nice little video comparing mppt vs pwm with the batteries in bulk mode. mppt vs pwm
Forum Discussion
So even some pwm's have over current protection. Nice.
That raises the question, though, how does the pwm clip amps? I'm guessing thru the same sort of modulation it does during abs? In that case, pwm does sometimes happen during bulk?
BFL, that was the whole debate, it seems. If the "reconnect voltage", or "low set point" was too low, that would decrease the rate of frequency of on/off. So some early (low frequency) pwm's spent too much time in 'off' and were unsuccessful at keeping Vbatt up, which is necessary for proper finish charging,(not to mention the lack of current going to the batteries). But apparently, the most important factors were number of pulses per day and the reconnect voltage. The promotion by Morningstar made claims that these type would only get the batteries up to 60% soc in a day... clearly a poorly calibrated controller, but perhaps not representative of all such type controllers, as they are still in use today.
With your Landstar, perhaps you could not see the voltage going up and down because it would be doing so at a rather high frequency... say 300x/sec.
http://pvdepot.com/media/pwm-solar-charge-controllers.pdf
That raises the question, though, how does the pwm clip amps? I'm guessing thru the same sort of modulation it does during abs? In that case, pwm does sometimes happen during bulk?
BFL, that was the whole debate, it seems. If the "reconnect voltage", or "low set point" was too low, that would decrease the rate of frequency of on/off. So some early (low frequency) pwm's spent too much time in 'off' and were unsuccessful at keeping Vbatt up, which is necessary for proper finish charging,(not to mention the lack of current going to the batteries). But apparently, the most important factors were number of pulses per day and the reconnect voltage. The promotion by Morningstar made claims that these type would only get the batteries up to 60% soc in a day... clearly a poorly calibrated controller, but perhaps not representative of all such type controllers, as they are still in use today.
With your Landstar, perhaps you could not see the voltage going up and down because it would be doing so at a rather high frequency... say 300x/sec.
http://pvdepot.com/media/pwm-solar-charge-controllers.pdf
