Power coordination control method of direct-current micro-grid group

Abstract

The invention relates to a power coordination control method of a direct-current micro-grid group. A direct-current micro-grid power autonomous control system and an isolation bidirectional DC-DC (Direct Current-Direct Current) common power control system are used; each direct-current micro-grid is provided with an independent power autonomous control system; a power unit adopts a constant-power control model; a balance unit is composed of secondary control, namely direct-current voltage recovery, direct-current voltage droop control and voltage / current double-closed-loop control. The isolation bidirectional DC-DC common power control system comprises two parts: external loop control is interconnected power autonomous control and communication with two interconnected direct-current micro-grid secondary control systems is carried out to obtain droop control characteristic parameters; then direct-current bus voltage at two sides are actually measured and an interconnected power error signal can be obtained through calculation; then a power reference value of an internal loop control system is obtained through a PI (Proportion Integration) controller, and internal loop control is power closed-loop control.

Description

technical field [0001] The invention belongs to the technical field of DC micro-grid power group power coordination control, and relates to a DC micro-grid group power coordination control method based on isolated bidirectional DC-DC interconnection. Background technique [0002] In the form of DC microgrid, it provides high reliability and high power quality power supply for future smart homes, commercial buildings, and even industrial parks, and realizes flexible access and efficient application of distributed power generation units and energy storage systems. It is a future distributed energy supply system The development trend is an important part of the future intelligent AC-DC hybrid power distribution system [1-2]. If multiple adjacent DC microgrids can be interconnected and operated in the form of a cluster, each sub-microgrid can support each other through energy dispatching and coordinated control of the DC microgrid group [3-4]. Under normal circumstances, the ec...

AI Technical Summary

Problems solved by technology

Due to the mutual coupling and influence between the power coordinated control of each sub-grid and the normal DC voltage control system of the DC microgrid, it will not only reduce the control flexibility of the transmission power between the interconnected DC microgrids, but also be detrimental to the DC microgrid and its control system. plug and play[3-4]

In addition, there is no electrical isolation between interconnected DC microgrids. If a fault occurs anywhere in the DC bus in the system, even if the DC circuit breaker can quickly isolate the fault point, the fault will inevitably affect the reliable operation of the DC microgrid group as a whole. impact, and it is not conducive to the rapid restoration of power supply of the system after the fault is eliminated [5]

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