Micro power grid time-delay margin calculating method based on critical characteristic root tracking

Abstract

The invention discloses a micro power grid time-delay margin calculating method based on critical characteristic root tracking, which belongs to the micro power grid operation control technology field. The method is based on the static input feedback to create a micro power grid closed-loop small signal model containing the communication time-delay voltage feedback control amount so as to obtain a characteristic equation containing a transcendental item; performing the critical characteristic root tracking of the transcendental item of the characteristic equation of the system; searching the possible purely virtual characteristic root so as to calculate the maximum delay time to stabilize the micro power grid; and carrying out research on the relationship between the controller parameters and the delay margin to guide the design of control parameters and to effectively improve the stability and dynamic performance of the micro power grid.

Description

technical field [0001] The invention discloses a micro-grid delay margin calculation method based on critical characteristic root tracking, and in particular relates to a calculation method for a micro-grid secondary voltage control delay margin, which belongs to the technical field of micro-grid operation control. Background technique [0002] With the depletion of the earth's resources and people's attention to environmental issues, the access to renewable energy has attracted more and more attention from all over the world. Microgrid is an emerging energy transmission mode that increases the penetration rate of renewable energy and distributed energy in the energy supply system, and its components include micro gas turbines, wind turbines, photovoltaics, fuel cells, energy storage devices, etc. Distributed Energy Resources (DER), user terminals of various electric loads and / or heat loads, and related monitoring and protection devices. [0003] The power supply inside the...

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Problems solved by technology

[0004] Droop control has attracted attention because it can achieve power sharing without communication, but the output voltage of each distributed power supply will have a steady-state deviation. Therefore, it is necessary to adopt microgrid secondary voltage control to improve reactive power sharing effect and voltage performance

At present, the coordinated voltage control designed is a centralized control structure. The centralized voltage controller of the microgrid generates control signals and sends them to the local controllers of each distributed power supply. This centralized control structure relies on communication technology, but the communication process is usually controlled by The impact of information delay and data packet loss, information delay, data packet loss and other effects lead to poor dynamic performance of the microgrid and even endanger system stability

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