Efficiency optimization control method for bidirectional converter in microgrid energy storage system

Abstract

The invention discloses an efficiency optimization control method for a bidirectional converter in a microgrid energy storage system, which combines traditional light-load phase switching control, multi-degree of freedom frequency modulation control and a phase-shifting magnetic technology. The energy storage system adopts a six-phase interleaved parallel bidirectional converter main circuit. The efficiency optimization control method comprises the steps of firstly building a load current loss model, and deducing load current corresponding to an optimal phase switching point; secondly, seeking the optimal operating frequency under phase switching control by adopting multi-degree of freedom frequency control; and finally, suppressing ripple deterioration under the light load, the switched phase and the low frequency by adopting a phase shifting technology and a magnetic integration design to achieve a control target of higher efficiency operation under light load conditions. Compared with a bidirectional converter in the microgrid energy storage system in the prior art, the efficiency optimization control method can effectively improve low light-load efficiency of the bidirectional converter in the microgrid energy storage system and solve a problem of ripple deterioration easily caused by traditional phase switching control, greatly expands a high-efficiency operation range of the bidirectional converter and improves the stability and reliability of the system.

Description

technical field [0001] The invention relates to the field of microgrid technology, in particular to a method for optimizing the efficiency of bidirectional converters in a microgrid energy storage system. Background technique [0002] As the key to connect the microgrid bus and each distributed energy module, the bidirectional converter is the core device of the energy storage system. With the demand for high-efficiency and large-capacity bidirectional converters in large-scale energy storage systems, and the maturity of high-voltage battery technology, in recent years, many scholars have applied interleaved parallel non-isolated bidirectional topologies to new energy power generation systems, and achieved excellent results. However, due to the diversification of the energy input of the microgrid system, the load in its island operation mode is complex and changeable. If the multi-phase parallel operation of the converter is under light load conditions, the large switching ...

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Problems solved by technology

[0006] In order to solve the problems that the light-load efficiency of the bidirectional converter in the current microgrid energy storage system is low, and the traditional phase-cut control easily causes ripple deterioration, the present invention provides an efficiency optimization method for the bidirectional converter in the microgrid energy storage system Control Method

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