METHOD FOR IMPLEMENTING ON/OFF-GRID DUAL-MODE OPERATION OF BIDIRECTIONAL CONVERTER IN MICRO POWER GRID

摘要

The present invention provides a method for realizing on/off-grid dual-mode operation of a bidirectional converter in a micro power grid, wherein an on/off-grid controller in the micro power grid detects if the large power grid loses power or the power supply is resumed, instructions of "prepare to go off-grid", "go off-grid", "prepare to go on-grid", or "go on-grid" are sent to the bidirectional converter in an interface form of two-bit binary code, meanwhile the on/off-grid controller communicates with the micro power grid control system, and the micro power grid control system sends instruction signal of "charge/discharge power" to make the bidirectional converter perform a corresponding operation. When the large power grid loses power, the bidirectional converter will immediately transfer from the on-grid operation state to the off-grid operation state and switch to the operating mode of voltage source. Without additional investment on facility, this method solves the problem that the energy storage system and photovoltaic on-grid inverter can not work after the large power grid loses power, and the problem that it's difficult to set up a micro power grid system, and meanwhile it realizes a fast and seamless conversion between off-grid operation and on-grid operation in the micro power grid control.