Adjustable LCL filter optimization design method of T-type three-level energy storage converter

Abstract

The invention provides an adjustable LCL filter optimization design method based on fuzzy control T-type three-level PCS. The method comprises the steps: replacing the AC side inductor of an LCL filter with the leakage inductor of an AC side isolation transformer in order to reduce the size of the LCL filter as much as possible; and establishing a filter model, solving a transfer function and establishing a function clear limiting condition, designing a parameter calculation module through the limiting condition, calculating parameters of an LCL filter by the parameter calculation module according to collected correlation values, determining actual parameters by combining the parameters with actual empirical values, and designing a filter capacitor and a filter inductor which are adjustable capacitors and inductors. The parameters of the filter can be adjusted to a certain extent according to the change of actual output power, and the network access electric energy quality can be further improved. The design method is simple, the purpose is clear, the complex filter design process is simplified, the filter parameters can be further optimized according to the output power change, the network access harmonic content is further reduced, and meanwhile the loss is reduced.

Description

technical field [0001] The invention relates to the technical field of energy storage converters, in particular to an optimal design method for an adjustable LCL filter of a T-type three-level energy storage converter based on fuzzy control. Background technique [0002] Energy storage is a key link in the integration of new energy into the grid. During the operation of the power grid, it can realize the functions of peak shaving and valley filling, power grid dispatching, power grid frequency regulation, and new energy consumption. Since the voltage between the energy storage device and the grid is inconsistent, it is necessary to design a power storage converter (Power Conversion System, referred to as PCS) system to realize energy conversion, so that the grid can operate safely and reliably while providing high-quality power to the grid. energy. PCS can effectively regulate the power resources in the smart grid, well balance the difference in power consumption between da...

AI Technical Summary

Problems solved by technology

However, there are still some problems at present. The overall volume of the LCL filter is too large, which makes the overall volume of the converter too large; There is a resonance peak in the characteristics, which will have a negative impact on the stability of the system and the output current, and the design process is complicated, and usually requires a certain design experience; when the output power of the converter changes, it will often produce large harmonics, which is Since the filter is designed according to the rated power of the converter, although the output power changes slightly, it has a greater impact

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