Advanced Functional Descriptions; Voltage Event Detection - ABB PCS100 UPS-I User Manual

PCS100 UPS-I User Manual
—

9 ADVANCED FUNCTIONAL DESCRIPTIONS

9.1 Voltage Event Detection

The PCS100 UPS-I is classified as a single conversion UPS of the type VFD according to IEC62040-3. That is, the
voltage and frequency are protected but are dependent on the supply in normal operation.
In the event of an outage, sag, surge, overvoltage, undervoltage, excessive phase and frequency deviation on the
utility supply the PCS100 UPS-I will transfer the load to the backup energy storage via an inverter (Discharge
mode).
The PCS100 UPS-I incorporates an advanced Voltage Event Detector control block with function to identify when
to transfer the load from the utility supply voltage (Online mode) and on to the inverter system (Discharge mode).
This must be done quickly to limit the exposure of the load to out of tolerance utility voltage but should not be so
sensitive to normal utility supply disturbances such as switching transients, background voltage harmonics or
events caused by the load causing unnecessary transfers. Excessive transfers to the inverter and energy storage
supply should be avoided as these can shorten the life of the energy storage element, create additional
disturbance, and leave the energy storage in a discharged state where it is not prepared to manage a true event.
The PCS100 UPS-I Voltage Event Detection is a combination of three complementary voltage event detection
methods targeting different voltage event characteristics:
RMS detector
–
Transient detector
–
Frequency detector
–
69