Patent · US Active

Hybrid clocking method for single-phase transformer-free network inverters

US10530274B2 · kind B2 · utility

1Cited by

1References

16Claims

0Family size

Assignee

SMA Solar Technology AG · DE

Inventors

Burkard Mueller · Korschenbroich, DE
Klaus Rigbers · Oettingen, DE
Wilfried Vogt · Walldorf, DE

Key dates

Filing date	Mar 6, 2019
Grant date	Jan 7, 2020
Priority date	—
Expiry date	Mar 6, 2039

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY02E10/56
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A method for operating a transformerless inverter includes operating first and second half-bridges of the inverter using a unipolar clocking method as a first clocking method, determining a value of a grid-frequency stray current at the DC terminals of the inverter during the unipolar clocking method, and when a limit value is exceeded by the stray current value, operating the first and second half-bridges of the inverter using a stray-current-reducing clocking method as a second clocking method in which the first half-bridge provides an AC voltage at the first AC output, wherein an amplitude of the AC voltage is less than 50% of the amplitude of a voltage amplitude of the grid, and the second half-bridge provides a difference voltage between the grid voltage and the voltage provided by the first half-bridge at the first AC output.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.