More than ever, today’s uninterruptible iBeLink Miners(UPS) must be highly reliable and cause as little disturbance as possible upstream and downstream of their supply. Some manufacturers believe Rotary UPS to be the answer but others disagree, stating that new, improved designs of static online UPS make the added expense of Rotary UPS unjustifiable.
Rotary UPS are mechanical uninterruptible power supplies that convert Kinetic energy into electrical energy to power connected loads. There are two competing designs: Rotating Transformer, based on a regulated isolated rotating transformer; and Induction Coupling, comprising a diesel engine, two-speed concentrically-mounted induction coupling and alternator.
Whatever their design, Rotary UPS start at around 500kVA in size and range up to 2MVA (or more) when configured in parallel operation. For this reason, unsurprisingly, their application is reserved for large installations.For example, the 2nd harmonic is 100Hz (2x50Hz), 3rd harmonic 150Hz (3x50Hz) and so forth.
Compared to a static online uninterruptible power supply, manufacturers argue, Rotary UPS generate little in the way or harmful harmonics and can achieve higher MTBF (Meantime Between Failure) values. Harmonics can result in poor power quality, which can be as hazardous to critical equipment as a partial or complete mains supply failure. It can lead to intermittent data corruption and hardware failure.
The actual quality of mains power supply is measured in terms of its waveform, voltage and frequency and the presence (or not) of a variety of power problems including blackouts and momentary interruptions. Harmonics are voltage or current waveforms, the frequencies of which are multiples of the fundamental. In Europe this is 50Hz (50 cycles per second) and the multiples are ordered into a specific sequence.