Toshiba G9000 User Manual

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Guide Specification – 3-Phase Static Uninterruptible Power Supply 
 
10 
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 
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 varies from maximum to 
minimum: 
  0% to 100%Unbalanced load 
  0% to 100%Balanced load 
 
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 1Hz/sec) and track the 
bypass AC source until synchronization is achieved without causing any disturbance to 
the load.  
 
5.3.4  Output Control 
The Inverter can be manually started and stopped using the LCD touch screen controls.