UPS response to power disturbances-a proposed method for determination of UPS response to power disturbances

The time it takes for a backup power system (BPS) to transfer to battery power (i.e. "transfer time") is difficult to measure. No industry standard exists describing a reasonable test for this measurement. A technique for inducing power interruptions and then measuring BPS output voltage response is described. Power interruptions at reduced voltage are recommended because data analysis from a North American Power Quality Study by National Power Laboratory show that 81 percent of all interruptions occur during a low voltage condition. Examples of the proposed measurement technique are shown for a variety of BPS topologies. Experimental results illustrate the difference between uninterruptible and standby power systems.<<ETX>>