Hitachi's new photovoltaic inverter: Using a chopper circuit to output power even when there is little sunshine

Hitachi's 300kW photovoltaic inverter "HIVERTER-NP203i-300" supporting medium-sized photovoltaic power generation systems was launched on July 1, 2015. Its feature is that it has a built-in boost chopper circuit that can convert even when the amount of sunshine is small and the output voltage is low, and can reduce the DC lower limit of the photovoltaic inverter operating voltage range from 360V to 230V.

In recent years, as more and more medium-sized photovoltaic power stations are built on the roofs and idle land of commercial facilities, factories and schools, Hitachi has added models suitable for medium-sized photovoltaic power stations to its product line in addition to the photovoltaic inverters (output power of 500kW and 660kW) previously designed for large-scale photovoltaic power generation.

This product is equipped with two chopper circuits, which can perform MPPT (Maximum Power Point Tracking) independently. The operating voltage range of MPPT is DC 230-600V. By using the chopper circuit to boost the variable voltage of the photovoltaic power generation module into a stable DC voltage, more power can be output even in the morning and evening hours and on cloudy days when there is less sunshine.

The new product has a maximum power conversion efficiency of 97.5% (at 500V DC, 50% output, and a power factor of 1.0). It is also available as an outdoor system that integrates a photovoltaic inverter, a collector cabinet, a high-voltage box, and a dedicated transformer. The maintenance service (regular inspection, fault recovery) is for 20 years. The price is about 6 million yen (depending on performance parameters).