Wenxin Zhao

TL;DR: It is pointed out that the bandwidth of the power loop should be far less than twice the line frequency for the purpose of avoiding the VSG output voltage to be severely distorted, and the line-frequency-averaged small-signal model of theVSG is derived for system analysis and parameters design.

TL;DR: An adaptive tuning method of the virtual resistor is proposed, which can automatically regulate thevirtual resistor to the critical value to stabilize the system, and thus reduce the power loss.

TL;DR: In this article, a virtual series impedance was introduced to increase the output impedance of the grid-connected inverter only at the dominated lower harmonic frequencies to improve the injected grid current quality.

TL;DR: Three improved control schemes are proposed, namely, notch-filter-incorporated inductor current feedback scheme (NF-ICFS), proportional resonant cascaded regulator plus inductorCurrentFeedback scheme (PR+ICFS, and neutral current feed-forward plus inducter current Feedback scheme (NCFF+IC FS), which not only ensure system stability, but also maintain a small neutral point voltage ripple.

TL;DR: In this paper, the operation principle of the three-phase four-wire inverter with split dc-link capacitors when a neutral inductor is introduced was analyzed, and an optimized design of the neutral inductors and filter inductors was proposed with the considerations of the inductor current ripple, the ability of supplying unbalanced loads, and the total energy stored in the inductors.