Grid-connected resonance analysis method and system based on photovoltaic virtual synchronous generator

Abstract

The invention discloses a grid-connected resonance analysis method and system based on a photovoltaic virtual synchronous generator. An information module is used for establishing a photovoltaic virtual synchronous generator grid-connected small signal model; the analysis module analyzes the grid-connected resonance mechanism of the photovoltaic virtual synchronous generator by using a state spacestrategy in combination with the small signal model, and constructs a state space matrix; the calculation module is used for solving characteristic values and left and right characteristic vectors ofthe state space matrix, obtaining resonance participation factors of all nodes when grid-connected resonance of the photovoltaic virtual synchronous generator occurs, and respectively carrying out calculation processing; and the analysis module analyzes the influence of element parameters on resonance stability by using a Lyapunov analysis strategy and a resonance participation factor to obtain aresonance influence rule. According to the method, the influence of the grid-connected resonance mechanism, accurate parameters and elements of the photovoltaic virtual synchronous generator on the stability is analyzed through a state space strategy, and a theoretical basis is provided for parameter design and optimization of the photovoltaic virtual synchronous generator in actual engineering and evaluation of the photovoltaic grid-connected electric energy quality.

Description

technical field [0001] The invention relates to the technical field of grid-connected stability of new energy sources, in particular to a method and system for grid-connected resonance analysis based on photovoltaic virtual synchronous generators. Background technique [0002] Large-scale photovoltaic power plants must meet the requirements for stable operation of the power grid before they are put into operation, that is, photovoltaic power plants must have power supply performance characteristics, and can participate in the regulation of system frequency and voltage. Traditional photovoltaic inverters are connected to the grid. The rotating parts provide inertia response characteristics for the system, and cannot perform self-regulation and self-regulation of voltage. Through the coordination and cooperation of photovoltaic and energy storage, the photovoltaic virtual synchronous generator realizes the function of primary frequency modulation of the system, improves the da...

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Problems solved by technology

[0003] The existing photovoltaic grid-connected resonance analysis has the following problems: At present, the research on large-capacity photovoltaic power plants at home and abroad mainly focuses on: 1. The stability analysis of traditional photovoltaic inverter grid-connected; 2. The stability of multi-inverter grid-connected Modeling the interaction with the large power grid; the established model is relatively simple, and rarely considers the parameters of the virtual synchronous generator and the influence of the special and complex structure of the photovoltaic virtual synchronous generator on the stability of the grid-connected system

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