Eaton Power Xpert Solar 1500 User Manua

Power Xpert Solar 1500/1670 kW InverterPower Xpert Solar 1500/1670 kW Inverter MN141001EN—October 2014 www.eaton.com 11Inverter Power-Modules and StacksThe power stacks are the heart of the inverter, inverting thevariable direct voltage and current from the photovoltaicmodules into a grid-matching quasi-sinusoidal waveform andfrequency. Operating 1 power-module per phase, the 9power-modules form the 3 power-stacks and are identical.Each liquid cooled power-module assembly weighs less than23 kg (50 lbs) and is individually replaceable. Figure 7illustrates the power-module and power-stacks.The Power Xpert Solar’s power-stacks are nominally rated500 kW with a minimum of 500 Vdc input (Vmp). Operationto 555 kW is available whenever factory-configured foroperation with a minimum 555 Vdc input (Vmp). Combiningthe power-stacks outputs in a parallel fashion results in theinverter’s overall 1500/1670 kW rating. The actual power isdefined within the software, corresponding to the minimumDC input voltage and AC output voltage.The power-stacks feature the latest IBGT-module technologyand are liquid cooled. The IGBT module-technology allowstrue 1000 Vdc switching. Once the minimum PV voltage andenergy are available, the inverter’s control algorithms willsynchronize its output-AC waveform and frequency with theutility’s, controlling the exported power as current. Theinverter is grid-tie, therefore its actual (versus nominal)output voltage and frequency is established by the utility grid,via feedback based upon the MV transformer’s step-up ratio.The capacitors within the power stack store the energy forcontinuous millisecond operation during photovoltaicfluctuations (e.g., momentary irradiance fluctuations).Furthermore, they are sized to enable the inverter to meetLow Voltage Ride Through (LVRT) and Frequency RideThrough (FRT) required for utility-scale photovoltaic systems,as well as significant VAR support.Figure 7. Power Xpert Solar: Inverter Power Module and Power StacksPower StacksPower Xpert Solar 1500/1670 kW Inverter