Continuing the saga of "And now for Something Completely Different".... Otherwise known as "PLC's, Auto Start Generators and Inverters, Getting them to play nicely!"
Here is a link to the Logo Software - Demo version, fully functional with simulator et al, just cannot download a project to a PLC:
https://w3.siemens.com/mcms/programmable-logic-controller/en/logic-module-logo/demo-software/pages/default.aspx#Demo_20softwareand attached hereto is the little proggie I wrote... in zip format... The umpteenth revision thereof, shoehorned into the few memory places the little Logo has, with a few extra features I managed to include after hacking out a few things and changing some push buttons to SPST switches, allowing me to add a little more useful logic into it....
Basic info needed to run this thru the simulator is (a little imagination required here chaps):
Genset:
The genset will autostart if mains power drops away from the mains input, it will continue running until mains power re presents itself again.
The genset can be switched from auto-start to manual mode, this is what I will use to turn the gennie on with by using a plc output/relay instead of turning an ignition key.
The inverter has a single "Normally Open" contact that will close on low battery, remaining closed until the battery level is back up to a predefined preset.
Things are pretty much connected in a straight stripe -
Mains in -> Mains Sensing Relay -> Mains Input Isolating Contactor -> Genset Proper -> Mains Output Sensing relay -> Inverter/Solar Mains Input -> Inverter -> Inverter Output to the rest of the DB Board
For mains sensing relays, there is simply 220v on the coil of a relay...If the 220v buggers off, the relay goes to open state, the plc picks this up and responds accordingly.
As far as controls go, there are only three -
A start Fault reset - If the gennie doesn't start within the preset time, start and further operation is aborted.
Enable System - When this is off, the gennie will not start or run, unless it is switched to manual on the gennie itself.
Isolate Mains input to gennie - When off, the mains input into the gennie is....well ...not there.....
Indicators and Idiot Lights:
Controller Enabled
Start Fault
Relays/Contactors:
One relay to sense power from the mains.
One relay to sense power out the ass end of the gennie.(when mains is present, and the gennie isn't running, the mains power is bridged through the gennie automatically as one of its internal functions)
One relay to control the auto start feature on the Gennie
One Contactor to make the mains input to the gennie... be.... uhhh ....not there...
If you get around to running the sim, Its quite a bit of fun, if you're into this sort of thing, set all the inputs and outputs and watch what happens when you present a myriad of thing to my little proggie that I never thought about... Break it and tell me how you did, so I can make it idio....sorry, operator proof!
Have fun!!
(And should you find this proggie useful, please do not hesitate to send me a pint via email!)
Keep it switching...
Cheers
Ed