APPARATUS FOR AND METHOD OF OPERATION OF A POWER INVERTER SYSTEM

摘要

A power inverter system consists of a connection to a primary DC power source, a connection to an AC grid or load, a plurality of switching elements and filter elements to connect the DC power source to the AC grid or load, three power rails internal to the inverter, and a buck/boost circuit to provide a third power rail. The invention allows for simple transformerless grounded or ungrounded connection of a DC power source to an AC grid or load. The voltage rail that is not directly connected to the primary DC power source can be connected to an auxiliary DC power source without any significant additional hardware.

主权项

1. An apparatus comprising
a connection to a DC power source; a connection to an AC grid or AC load; and an inverter that contains
1) a positive DC voltage rail,2) a negative DC voltage rail,3) a voltage rail whose DC voltage is between the voltages on the positive and negative rails,4) a plurality of switching elements that can connect each leg of the AC grid or load to either the positive or negative rail, and5) a buck/boost circuit that drives voltage on one of the rails from the two rails connected to the DC power source, by driving current to and from the between-rail through an inductor connected to the positive and negative rails through switching devices.