Low Voltage problem What type PLC use?

Voltage stabilizer. large one
Am American product for 120volts is the Monster AVS2000.
Which is a huge reostate iike device which keeps the voltage at 120.
I am certain industrial models exist for 220 volts
Or medical use devices.. I would Google
"Medical Voltage stabilizer"

is it a stable 208VAC? or does if fluctuate between 220VAC and 208VAC? This is important. First, call the local utility and complain loudly so that they will do something about the low voltage problem. Most utilities will fix the problem if you complain both vocally and more importantly, in writing. You apparently are at the end of the line or transformer drop for your neighborhood and have a voltage support problem. They need to either add another line transformer for you or add capacitors to boost the voltage support. But, if you don't complain in writing, nothing will happen. Second, PS audio makes power conditioners/generators where you can actually increase the output voltage to your system. Look on PS Audio's web site. But answer the first questions first. does your voltage fluctuate? if so, you must have the local utility fix the problem. You need voltage support for your area. They will fix this.

208V doesn't seem to be an issue.