Anyone reading an electrical magazine of late can’t help but notice the rising interest in (and column inches devoted to) the subject of voltage optimisation.
In 1995, the European Union set out to harmonise the single-phase mains supply voltage across countries. Prior to that, variation existed country-to-country from 220, 230 or 240Vac 50Hz. It was down to manufacturers of electrical equipment to optimise their products for each country or region. 230Vac became the nominal standard (prior to which the UK operated at 240Vac). Three-phase mains nominal voltage was harmonised to 400Vac.
A problem arose because many large electricity consumers found that much of the electrical equipment they use to run their businesses now operates inefficiently at the new rating and thus wastes considerable electricity each year.
Voltage optimisation technology providers stepped in to stem the problem by developing technology that sits between mains power and connected loads to provide a steady-state 230Vac or 400Vac supply to ensure optimal load voltage efficiency, whether resistive or inductive/capacitive loads.
Firstly, UPS protect connected loads from breaks in mains supply AND from mains-borne power problems such as sags, surges, brownouts and so on, which a voltage optimisers cannot do as effectively.
Secondly, although most online UPS are installed as 230Vac (single-phase) or 400Vac (three-phase) output, they can be configured manually to provide other voltages such as: 220/230/240Vac or 380/400/415Vac. Loads are automatically supplied by a UPS with the level of voltage and current required to perform at their optimal frequency. UPS also provide battery back up and/or connection to an alternative energy source (such as a generator) to protect loads in the event of a mains failure. Today’s online UPS can also achieve operating efficiency figures of 96% and higher (if operated in certain power modes).
Voltage optimisers carry a lower capital cost compared with UPS but they do not provide the higher levels of power protection required by the critical loads that run today’s always on businesses. In my view, UPS are better at the job of both power protection and voltage optimisation.