Eaton Power Xpert Solar 1500 User Manua

Power Xpert Solar 1500/1670 kW Inverter12 Power Xpert Solar 1500/1670 kW Inverter MN141001EN—October 2014 www.eaton.comInverter Output CircuitInductors and capacitors, working as LC filters on the outputstage of the power-stacks, removes (filters) the carrierfrequency and smooth’s the voltage waveform, resulting in anominal 320 AC (357 for the 1670 kW inverter) sinusoidal ACwaveform, ready to be transmitted to the step-up mediumvoltage transformer.The final components of the individual power-stacks andLC-filter are the isolation contactors, K8, K9, and K10,illustrated in Figure 4. Each isolates the power-stackand LC-filter from the utility-AC before the power-stackoutputs are combined in a parallel-output manner prior tothe main circuit breaker CB1. Located on the inverter sideof CB1, these contactors are opened to isolate the inverterstacks and LC-filters during sleep-mode, faults, and whenturned off.A 3-phase AC surge suppressor (transient voltagesuppression) protects the inverter from voltage spikesstemming from the utility-side connection. In areas prone tolightning, utility-side medium voltage suppression isrecommended, as is the typical practice for utility-scaleprojects.The main AC disconnect is an Eaton Magnum® circuitbreaker, noted as CB1 in Figure 4. The circuit breaker CB2,connected on the utility side of CB1, supplies the inverter’scontrol power. It must be closed prior to inverter operation.When CB2 is off (open/tripped), the inverter will not operate,regardless of whether utility voltage is connected to themedium voltage transformer.Cooling-SystemThe inverter’s power stacks are liquid cooled. In concert witha coolant circulation pump, a blower forces air through a heatexchanger. The inlet-air vents are along the top-front edge.Outlet-air is vented along the top-back edge of the inverter.In Figure 8, cool air (blue arrows) is passed through theliquid-cooling system’s heat exchanger where it is furtherpassed through the AC output-filter magnetics (inductors)and exits the inverter in the rear-top edge (red arrow). Theresult is an efficient cooling and ventilation system whereforced-air exiting the heat-exchanger is utilized to cool theinductor and capacitors (LC cabinet) before exiting theinverter.As shown in Figure 8, cool air also passes through the ACcabinet, exiting directly into the exhaust duct.The cooling-loop is self-contained within the inverter andsealed. Pressure and flow sensors constantly monitor thehealth of the cooling system.The standard coolant is anenvironmentally friendly 30/70 mix of propylene-glyco/distilled-water.No on-site coolant and plumbing installation is required.The inverter is delivered with the cooling system complete.Serviceable air-filters are fitted to both the air-inlet and outletvents, as well as immediately before the coolant radiatorlocated in the cooling/blower cabinet.Figure 8. Schematic of the Ventilation-PrincipleCool AirInletAC SectionAir InletHot AirExhaustBlowerFront Rear