A new series of converter + filter for high power photovoltaic plants was introduced. The Ax-Sun system consists of the Ax-W 400-400-4 400 A rated high efficiency single conversion inverter system coupled with the Fx-W high frequency two stage filter system, all designed for unlimited paralleling and direct connection to the photovoltaic array on one side and the medium voltage transformer on the other side. Each Ax-Sun module controls about 200 kW and any number of modules can be connected in parallel. The system is fully water cooled with water up to 50 C so that a simple heat exchanger can be located outside the conversion room, thus keeping the cabinets silent and tidy while the cooling plant can be easily and safely serviced. The conversion efficiency exceeds 97%; monitoring can be achieved via the RS 485, CanOpen or EtherCat connections, all available on the converter interface. Device PWM frequencies are synchronized when parallel operation is selected.