Topology (electrical circuits)

Voltage

Mathematics

Integrator

Computer science

Engineering

Jitter

Synchronization (alternating current)

Control (management)

DC bias

Artificial intelligence

Grid

Geometry

Control theory (sociology)

Programming language

Electronic engineering

Electrical engineering

Phase-locked loop

Offset (computer science)

Frequency grid

IEEE Journal of Emerging and Selected Topics in Power Electronics

The second-order generalized integrator (SOGI) has been widely used to implement grid synchronization for grid-connected inverters, and from grid voltages, it is able to extract the fundamental components with an output of two orthogonal sinusoidal signals. However, if there is a dc offset existing in the grid voltages, the general SOGI's performance suffers from its generated dc effect in the lagging sine signal at the output. Therefore, in this paper, a mixed second- and third-order generalized integrator (MSTOGI) is proposed to eliminate this effect caused by the dc offset of grid voltages. A detailed theoretical analysis on the proposed MSTOGI is presented to reveal the mechanism of eliminating the dc offset. After that, the MSTOGI is applied to a phase-locked loop (PLL) and thereby establish an MSTOGI-PLL which is more adaptable to various grid conditions and power quality. Moreover, a frequency-adaptive control scheme is added to the proposed MSTOGI-PLL to eliminate the phase difference between the PLL ...

A Grid Synchronization PLL Method Based on Mixed Second- and Third-Order Generalized Integrator for DC Offset Elimination and Frequency Adaptability