- #1
solvejskovlund
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- TL;DR Summary
- How could we stop house wires to act as antennas for the pwm charging pulses from the solar charge controller?
After we got the solar array working, we made all lamps, laptop chargers, most kitchen appliances... run on 48vDC (so that we can have the inverter switched off unless we're running any 220v appliances). Then everyone in the house got a headache. We traced this down to being indoors at daytime. Further we traced this to be caused by constantly changing electric fields being stronger than if we lived under the most powerful power line around here. We have measured up to 1400V/m in the living room. This all seems to be caused by the mppt (pwm with some extra logic) solar charge controller making high frequency pulses to charge the battery. All wires in the house seems to be acting like antennas for this high frequency pulses, causing our headaches.
How can we stop these pulses from spreading out to all cabels in the house?
The current workaround is that we manually disconnect all house wires when the solar array is connected. That is - either we have the battery connected to solar for charging, or connected to the house wires for consumption. Never both connections at the same time.
(It turns out that the 220V wires from the inverter does not have this problem. Problem is only related to the cables that are connected directly to the battery.)
I'd like to know if anyone has some ideas of how to leave both the charger and the house wires connected without getting these pulses around the house.
We've tried:
* using shielded wires (grounding the shield) - did help some, but not enough to be worth the effort to replace all house wires.
* put a constant voltage (45v) circuit between the battery and the house wires - did nothing.
We've thought about putting a huge capacitor in parallel to the battery bank, but we're worried this will confuse the mppt logic.
What could work (when we get more batteries) is to pull one battery out of the bank for consumption, leave the others for solar charging. When this battery is drained, pull another out of the bank, put the first one into recharging mode (from the bank) and once charged, return it into the bank. Circulating the batteries this way would probably solve the problem, but it would require an electrical engineer to switch on a light bulb, or some arduino setup controlling 30ish relays (planning for 6 batteries requiring least 5 relays for each battery (positive to bank, positive to recharge, positive to house wires, negative to bank/recharge, negative to house wires). Besides I'm not sure how to do the recharge in order to return the battery to the bank.
Just to avoid any confusion. The headache is felt at first. Then traced to be related to house wires being connected/disconnected. Then this all has been confirmed using a EMF meter "GQ EMF-390". The meter sets off an alarm in the living room while solar is charging. Once solar array (or the house wires) is disconnected the meter shows 0.
How can we stop these pulses from spreading out to all cabels in the house?
The current workaround is that we manually disconnect all house wires when the solar array is connected. That is - either we have the battery connected to solar for charging, or connected to the house wires for consumption. Never both connections at the same time.
(It turns out that the 220V wires from the inverter does not have this problem. Problem is only related to the cables that are connected directly to the battery.)
I'd like to know if anyone has some ideas of how to leave both the charger and the house wires connected without getting these pulses around the house.
We've tried:
* using shielded wires (grounding the shield) - did help some, but not enough to be worth the effort to replace all house wires.
* put a constant voltage (45v) circuit between the battery and the house wires - did nothing.
We've thought about putting a huge capacitor in parallel to the battery bank, but we're worried this will confuse the mppt logic.
What could work (when we get more batteries) is to pull one battery out of the bank for consumption, leave the others for solar charging. When this battery is drained, pull another out of the bank, put the first one into recharging mode (from the bank) and once charged, return it into the bank. Circulating the batteries this way would probably solve the problem, but it would require an electrical engineer to switch on a light bulb, or some arduino setup controlling 30ish relays (planning for 6 batteries requiring least 5 relays for each battery (positive to bank, positive to recharge, positive to house wires, negative to bank/recharge, negative to house wires). Besides I'm not sure how to do the recharge in order to return the battery to the bank.
Just to avoid any confusion. The headache is felt at first. Then traced to be related to house wires being connected/disconnected. Then this all has been confirmed using a EMF meter "GQ EMF-390". The meter sets off an alarm in the living room while solar is charging. Once solar array (or the house wires) is disconnected the meter shows 0.