6.3.2Boost Converter and Neutral Regulator
A Boost Converter converts the raw DC IN to a regulated DC Link of approximately 400 volts DC. It is operated in current mode and controlled using a variable frequency modulation technique at approximately 18---20 kHz. An artificial neutral is generated by the Neutral Regulator (Buck/Boost configuration in current mode control), which balances the center point to 1/2 the DC Link (+/--- 200 Volts).
6.3.3Inverter and Filter
The Inverter is a traditional (current mode controlled) hard---switched IGBT 3---phase topology. The IGBTs are modulated by a variable frequency,
current---mode control technique at approximately 18---20 kHz. An output filter filters out the high frequency switching components (line to neutral).
6.3.4Battery and Battery Charger
The Battery is comprised of a string of 144 cells, made up of twenty---four 12 volt Battery blocks. The Battery Charger is configured as a simple Buck or Boost current mode controlled converter (mode auto selected based on I out), powered by the raw DC IN, which regulates the battery charge voltage/current. The unit utilizes Advanced Battery Management (ABM) technology, which essentially isolates the Battery from the electrical environment, except for periodic charging or reserve mode operation, extending its life.
6.3.5Bypass
The Bypass has a continuously rated SCR switch in the Bypass circuit and a contactor in the Inverter leg. In normal mode, the Contactor connects the Inverter to the output. A backfeed contactor is also provided.
6.3.6Maintenance Bypass
A user accessible shrouded 4---wire Mechanical Maintenance Bypass switch is provided.
6.3.7External Batteries
External Batteries connect in parallel to the Internal Battery via an internal breaker. The internal charger charges the Batteries in parallel or in conjunction with an optional external charger
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Powerware 9330 (10 kVA--40 kVA) Installation and Operation | 6--13 |
164201300 REV. G 061502 | | |
