Hunan University

Changsha Boli Electric Corporation

An Luo

Zhikang Shuai

Chunming Tu

Xuan Liu

Zheng Shen

Wen Huang

Qingchang Zhong

Leming Zhou

Yuan Huang

Zhiyong Chen

Xiaoping Zhou

Yandong Chen

Huimin Kuang

Mingyue Wang

Mingshen Li

The present invention provides a method, a system and a storage medium for frequency adjustment of an islanded virtual synchronous micro-grid. The method includes: performing frequency adjustment on inverters in the micro-grid in a cyclic manner until the respective inverters reach rated frequencies; where each cycle includes: determining, in a differential delay manner, an inverter with a highest active output in the micro-grid as a reference unit, and sending a local output factor of the reference unit as a maximum output factor of a current cycle to other inverters; determining, for each inverter in the micro-grid, an active power adjustment amount of the inverter according to the maximum output factor, a preset rated frequency, a local output factor and an actual angular frequency of the inverter; and performing frequency adjustment on the inverter according to the active power adjustment amount.

Frequency adjustment method for islanded virtual synchronous micro-grid

A steady state control method for a three-phase double-mode inverter. Off-grid steady state control is composed of outer loop power droop control, voltage feed-forward quasi-resonant control, and inner current loop dead-beat control. Therefore, the response speed of the inverter is raised, and the influence caused by the load fluctuation of a micro-grid is inhibited. Based on the off-grid steady state control, grid-connected steady state control introduces phase lead control to the power droop control. Therefore, the output voltage of the inverter is always slightly ahead of the power grid voltage, which avoids the energy pour backward phenomenon of the inverter due to a phase error, and realizes stable and reliable running in the grid-connected mode.

Phased lock loop control for multiple inverters connected to a polyphase grid

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Changsha, China

An Luo