In certain applications where voltage fluctuation in the power supply is frequent and causing damage to loads, a voltage stabiliser can be an option.
It must however be remembered that a voltage stabiliser can only compensate for voltage variation to try keep the load voltage relatively constant but it can not generate power if the utility supply fails.
If you require power to be generated when the utility fails the only option for uninterrupted clean power is the use of a UPS and battery, with a backup generator feeding its rectifier.
If one is considering using a voltage stabiliser then certain selection criteria need to be followed.
A good quality voltage stabiliser must supply a stable output voltage for the connected load that is unaffected by harmonic distortion on the utility supply.
A high efficiency product will ensure low cost of running due to low losses.
A wide input voltage range is necessary to cover for voltage deviations in the utility supply
Each phase should operate independently as often a utility supply may only vary on one of its phases. Thus sensing on all three input phases is essential.
Modern voltage stabilisers should be fitted with a full electronic display to allow for interrogation