Regulation and control method for improving transient frequency stability of low-voltage micro-grid

Abstract

The invention discloses a regulation and control method for improving transient frequency stability of a low-voltage micro-grid, and provides a control strategy for improving transient frequency response for the problem of transient impact on a system due to quick frequency change caused by disturbance of the low-voltage micro-grid, such as sudden load change. According to the method, on the basis of a virtual synchronous power generator model, an electrical angular speed deviation delta omega and a virtual damping coefficient D are taken as regulating indexes for P / omega droop control in an isolated island running state of the low-voltage micro-grid, the low-voltage micro-grid adopts different droop coefficients under different frequency deviation conditions, the impact on the system caused by transient response of an inverter after disturbance is reduced, and the frequency change rate is delayed; meanwhile, a secondary frequency modulation module for Q-omega and Q / T coordinated control is designed, so that no-deviating frequency regulation can be realized, control reference voltage can be provided for the inverter, and power oscillation is inhibited; the method is suitable for reducing the influence of the frequency on the system due to quick change under the circumstance that the low-voltage micro-grid is disturbed by sudden load change, state transition and the like, and is favorable for stable running of the low-voltage micro-grid.

Description

technical field [0001] The invention relates to a control method for the frequency of a low-voltage micro-grid, in particular to a control method suitable for improving the instantaneous frequency stability of the low-voltage micro-grid in an island operation mode of the low-voltage micro-grid. Background technique [0002] In recent years, with the development of Distributed Generation (DG), low-voltage microgrids containing DG have received more and more attention in the context of increasingly severe energy consumption and environmental problems. How to achieve efficient and stable frequency control in the case of a large number of DGs has become one of the important research directions of low-voltage microgrids in the future. The large-scale penetration of DG in the microgrid makes it difficult for the frequency modulation control strategy of the traditional power system to adapt to the frequency regulation after the low-voltage microgrid is disturbed. In the prior art,...

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