Igbt Inverter - Toshiba T90S3S08KS6XSN Manual

Guide Specification – 3-Phase Static Uninterruptible Power Supply
The Converter logic shall provide DC for controlled battery charging. The battery current
sensing shall be independent of the Converter DC Output current sensing to provide
precise battery recharging control. The DC/DC Charging Converter shall include a circuit
to regulate the battery charging current to between 100% and 125% of maximum battery
charging current..
5.2.3 Battery Protection
The converter shall be provided with monitoring and control circuits to protect the battery
system from damage due to excessive discharge. Converter shutdown shall be initiated
when the battery voltage reaches a discharge cutoff voltage of 400 VDC. Automatic
shutdown based on discharge time is not acceptable.
5.2.4 DC Ripple (Without batteries)
AC Ripple on the DC Bus shall be less than 0.2%.
AC Ripple on the Battery charging circuit shall be less than 0.23% for the 80/100/160
kVA UPS, and less than 0.29% for the 225 kVA UPS.

5.3 IGBT Inverter:

5.3.1 General
The inverter shall be composed of multi-level IGBT power transistors controlled utilizing
an Advanced Technology PWM logic. The Inverter shall continuously convert DC power
from the IGBT Rectifier to AC power for the critical loads. When the utility voltage or
frequency exceeds the specified UPS input tolerances, the inverter shall continuously
convert DC power from the battery source to AC power for the critical load.
The inverter shall be capable of providing rated output while operating at any battery
voltage within the battery operating range. When the DC battery voltage reaches the
operational low voltage limit during a loss of utility AC power, the inverter shall
automatically shut off.
5.3.2 Output Voltage
The Inverter output voltage shall not deviate by more than +/- 1.0% RMS under the
following steady state conditions as the Inverter DC input voltage varies from maximum
to cutoff:
5.3.3 Synchronization
The Inverter output voltage shall be automatically synchronized with the bypass AC
source as long as the source is within the tolerable frequency and voltage range. If the
bypass AC source is not within the range, the control circuitry will stop synchronization
and operate the inverter in free running mode. When the bypass AC source recovers to
within tolerance, the inverter shall change its frequency (slew rate 1 to 5 Hz/sec,
selectable) and track the bypass AC source until synchronization is achieved without
causing any disturbance to the load.
10
0% to 100%Unbalanced load
0% to 100%Balanced load
March 2009