Paralleling Power Supply Units Made Easy ???
I am considering paralleling a couple of 20a variable adjustable psu's for 40a charging. According to what I have read on the world wide inter-web, it can be done quite easily, provided the following ...
Forum Discussion
There is a huge difference between
Current SHARING
and
Current HOGGING
pnichols, I am not familiar with the system that Ford uses. On commercial fishing vessels the larger ones I frequently had to deal with as many as four paralleled 32 volt units. One brand and type of alternator the LHA 40006U Motorola 100 ampere did not have a voltage regulator that liked to be paralleled. Neither did certain models of Niehoff. And of course the 9000 series of Delco mentioned earlier. Alternator voltage regulators have a pair of large inductors to deal with, the rotor and stator. To end compatibility issues I often neutered the OEM regulators and substituted self-excited stator triggered regulators that relied on residual magnetism in the rotor to develop enough stator voltage to trigger a transistor. The paralleling object was not to perfectly "balance" the alternators but to prevent load hogging meaning a particular alternator doing 90% of the work 100% of the time.
With programmable computer regulator control field load current-sharing should be a snap. This is what is missing in doing it with discrete components meaning separate voltage regulators. ECU's in today's vehicles routinely rely on a computer alternator voltage regulator connection that is labelled "Field Report". This is used mostly for diagnostic analysis of the health of the charging system. An ambiguity seen between field voltage and output voltage will result in a "Check Engine" light, and an open loop condition (limp home) mode in the ECU.
Most technicians do have have the experience necessary to develop compatible field load (meaning amperage flowing through the rotor winding) sharing in a multiple alternator scenario. It isn't necessary -unless- total load burden approaches or exceeds individual unit ultimate charging potential.
Exactly what I am dealing with on the cheapskate power supplies. The additional circuitry, the extra weight of the Meanwell and component count as noted by landyacht versus the cheapo isn't there for the fun of it. It would be foolish of me to not individually current protect each unit, and current protection has to come in the form of individual 25-ampere ATO fuses. One fault at full load will decade fault all the fuses. I may try ganged marine circuit breakers, a pair of three phase 25 ampere AC/DC breakers.
But I cannot afford three hundred forty dollars for five Megawatt units never mind uograding to Meanwell units.
And to top it off, I have to come up with incoming line voltage protection that deals with line voltage spikes, sags and surges that are mostly absent in USA power distribution systems. What happens to these units when 20VAC is presented to them? When we had a situation here day before yesterday it BLEW OUT three brand new wall socket type TENERGY AA and AAA chargers. I am not worried about problems back in Michoacan as I have a 6KW rated Sola ferroresonant line regulator that shuts off when a threshold of 111 volts output is exceeded. With the cheapowatt charger in a hotel room I will not have this advantage. Fun city. And BTW unlike the USA there are repair shops who deal exclusively in repairing flat screen television and audio systems down here. They rebuild the circuit boards, and the price is not inexpensive.
Current SHARING
and
Current HOGGING
pnichols, I am not familiar with the system that Ford uses. On commercial fishing vessels the larger ones I frequently had to deal with as many as four paralleled 32 volt units. One brand and type of alternator the LHA 40006U Motorola 100 ampere did not have a voltage regulator that liked to be paralleled. Neither did certain models of Niehoff. And of course the 9000 series of Delco mentioned earlier. Alternator voltage regulators have a pair of large inductors to deal with, the rotor and stator. To end compatibility issues I often neutered the OEM regulators and substituted self-excited stator triggered regulators that relied on residual magnetism in the rotor to develop enough stator voltage to trigger a transistor. The paralleling object was not to perfectly "balance" the alternators but to prevent load hogging meaning a particular alternator doing 90% of the work 100% of the time.
With programmable computer regulator control field load current-sharing should be a snap. This is what is missing in doing it with discrete components meaning separate voltage regulators. ECU's in today's vehicles routinely rely on a computer alternator voltage regulator connection that is labelled "Field Report". This is used mostly for diagnostic analysis of the health of the charging system. An ambiguity seen between field voltage and output voltage will result in a "Check Engine" light, and an open loop condition (limp home) mode in the ECU.
Most technicians do have have the experience necessary to develop compatible field load (meaning amperage flowing through the rotor winding) sharing in a multiple alternator scenario. It isn't necessary -unless- total load burden approaches or exceeds individual unit ultimate charging potential.
Exactly what I am dealing with on the cheapskate power supplies. The additional circuitry, the extra weight of the Meanwell and component count as noted by landyacht versus the cheapo isn't there for the fun of it. It would be foolish of me to not individually current protect each unit, and current protection has to come in the form of individual 25-ampere ATO fuses. One fault at full load will decade fault all the fuses. I may try ganged marine circuit breakers, a pair of three phase 25 ampere AC/DC breakers.
But I cannot afford three hundred forty dollars for five Megawatt units never mind uograding to Meanwell units.
And to top it off, I have to come up with incoming line voltage protection that deals with line voltage spikes, sags and surges that are mostly absent in USA power distribution systems. What happens to these units when 20VAC is presented to them? When we had a situation here day before yesterday it BLEW OUT three brand new wall socket type TENERGY AA and AAA chargers. I am not worried about problems back in Michoacan as I have a 6KW rated Sola ferroresonant line regulator that shuts off when a threshold of 111 volts output is exceeded. With the cheapowatt charger in a hotel room I will not have this advantage. Fun city. And BTW unlike the USA there are repair shops who deal exclusively in repairing flat screen television and audio systems down here. They rebuild the circuit boards, and the price is not inexpensive.
