A Power Decoupling Control Method of Electric Spring with Current Inner Loop

Abstract

The invention discloses a power spring power decoupling control method with an inner current loop. A power spring system comprises a bidirectional DC power supply vdc, a single-phase voltage source inverter module and an LC low-pass filter. A bypass switch S controls switching of a power spring. The power spring is in series connection with a non-critical load through a filter capacitor C and thenis in parallel connection with a critical load, and then a line impedor Z1 and a power grid vG are connected, in this way, a practical application system of the power spring is formed. The inventionprovides the power spring power decoupling control method with an inner current loop to solve problems of voltage and power fluctuation of a microgrid caused by intermittency and instability of new energy power generation. Therefore, power fluctuation of new energy power generation can be transferred to a power spring device and the non-critical load to guarantee voltage and power stability of thecritical load. Moreover, the adoption of the inner current loop makes current waveforms of the grid tend to be sinusoidal, and the system can obtain the better dynamic performance.

Description

technical field [0001] The invention relates to the application field of power electronics in power systems, in particular to a power decoupling control method of an electric spring with a current inner loop. Background technique [0002] At present, my country has entered a critical period of energy low-carbon transformation. The contradictions in the development of new energy sources such as wind energy and solar energy are prominent, and the phenomenon of abandoning wind and light is prominent. The bottleneck of grid-connected consumption has not yet been effectively resolved. It has become a trend to shift the focus of energy structure transformation to distributed energy; on-site grid connection and on-site consumption will become the norm; the model of "spontaneous generation and self-use, surplus grid grid" will be gradually promoted. However, as the installed capacity of new energy generation such as rooftop photovoltaics and small wind power increases year by year, ...

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Problems solved by technology

However, as the installed capacity of new energy generation such as rooftop photovoltaics and small wind power increases year by year, the stable operation of the microgrid will be greatly affected

[0003] In order to ensure the reliable operation of microgrids with high penetration rate of new energy power generation, energy storage devices such as battery packs are generally used as an important means of peak shaving and valley filling, but this is a passive energy storage method, and more times of charging and discharging will affect its performance. Service life, and the use of larger capacity battery packs to improve reliability will lead to a significant increase in costs

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