Network construction and network following unified control method of distributed photovoltaic power generation system

Abstract

The invention provides a network construction and network following unified control method of a distributed photovoltaic power generation system. The method comprises the following steps: S1, constructing a network construction / network following unified control structure of the distributed photovoltaic power generation system; s2, constructing a constraint relation of the distributed photovoltaic power generation system according to the control structure in the S1; s3, designing a virtual distribution coefficient according to the constraint relation in S2, and deducing a virtual voltage synthesis equation; and S4, designing an additional active damping controller. According to the method, the power grid supporting capability of a network construction type control strategy and the rapid response capability of the network construction type control strategy facing system disturbance can be realized, and meanwhile, the damping adjustment capability of the distributed photovoltaic power generation system is improved through the active damping controller; and the operation reliability and stability of the distributed photovoltaic power generation system are further improved.

Description

technical field [0001] The invention belongs to the field of power systems, and in particular relates to a unified control method for network construction and network of a distributed photovoltaic power generation system. Background technique [0002] In order to reduce the global energy crisis and irreversible climate change, photovoltaic power generation and other renewable energy generation technologies have developed rapidly in the past decade, but with large-scale photovoltaic access to the grid, the inertia and damping of the system have dropped significantly. This problem leads to large voltage / frequency changes in the power grid when the power generation does not match the load, which easily triggers the protection scheme of the system and reduces the stability and reliability of the system. [0003] Distributed Photovoltaic Generation (DPG) structure is as follows: figure 1 shown, where U dc is the DC side input voltage, C dc is the DC side support capacitor, ...

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Problems solved by technology

[0004] However, most of the current distributed photovoltaic power generation systems use GFM for grid-connected control. With the increase of the number of grid-connected equipment, it is easy to cause power oscillation in the system due to the problem of low power control accuracy and damping drop.

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