System Start - ABB HiPerGuard MV UPS User Manual

8.1.1.6. Resynchronizing State
When the grid input voltage recovers and stabilizes within the specified thresholds:
– HiPerGuard MV UPS(s) transit(s) to "Resynchronizing state" and the output voltage(s) is (are) phase
locked to the grid input voltage.
– When synchronization has been achieved, the HiPerGuard MV UPS(s) command(s) circuit breaker(s)
Sin to close, and transits to "PCM_Normal state".
If a power quality event occurs while HiPerGuard MV UPS(s) is (are) in "Resynchronizing state", then the
MV UPS(s) will transit back to "Island state".
8.1.1.7. Stopping state
When in "Running state" and a STOP command or Fault trip occurs:
– MV input breaker (S
in
– MV bypass circuit breaker (S
– MV UPS is now in "Bypass isolate state".
8.2.

System Start

To start the MV UPS(s), the system needs to be precharged. The user shall confirm the system state
and either:
1. Precharging the system by following the precharge instructions till sufficient precharge conditions
are met (example: system start after maintenance)
2. Starting the system right away if the system was already precharged (example: system start after a
brief stop).
8.2.1. DC bus precharge
Before a MV UPS system can be started, the energy storage shall be precharged and connected.
Precharging is required if the converter DC bus has been disconnected from energy storage (batteries)
and its DC bus capacitors have been allowed to discharge. If the battery circuit breaker is closed while
the DC bus capacitors are in a discharged state, the resulting current inrush may cause damage or
clearing of protection devices.
The control logic shall be preset with the voltage threshold required on the converter DC bus to allow
connection to the battery DC bus.
Before commencing precharge, check to ensure the HiPerGuard MV UPS(s) is (are) in "By-pass isolate
mode", as shown in Figure 8.2 and Figure 8.3. Table 8.1 describes the precharging steps.
HI PE RG UA RD M V UP S U S E R M A N UA L
), output circuit breaker (S
) closes.
abp
) both open.
out
O P E R AT I O N
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