Patent ID: 8125807
Filing Date: 2012-02-28
Classification: H02J,H02M,Y02E,Y10S

Abstract:
1. A transformerless photovoltaic grid-connecting inverting device comprising: a boosting unit connected to a solar cell, for boosting an output voltage of the solar cell and then outputting a direct voltage; an inverting unit connected to the boosting unit, for converting the direct voltage output by the boosting unit into an alternating voltage; a grid-connecting unit connected between the inverting unit and an alternating power grid, which includes, two serially connected relays, each relay connects or disconnects the electrical connection between the inverting unit and the alternating power grid based on a control signal; and a control unit connected to the grid-connecting unit and the inverting unit, which samples the direct voltage of the boosting unit and the alternating voltage and phase of the alternating power grid, and determines a drive signal output to the inverting unit and a grid-connecting signal output to the grid-connecting unit based on the direct voltage and the alternating voltage and phase of the power grid, wherein the phase of the drive signal is synchronous with the phase of the alternating current in the power grid, wherein the control unit comprises: wherein the inverting unit comprises: