Bidirectional buck-boost circuit for battery energy storage system and its digital control method

Abstract

The invention discloses a two-way boost-buck circuit for a storage battery energy-storage system and a digital control method thereof. The two-way boost-buck circuit consists of an energy storage inductor LP, a power tube Sbuck, a power tube Sboost, a snubber capacitor Cs, a resonant inductor Lr, a resonant capacitor Cr and a diode. A control device includes a control core, a drive circuit, a sampling circuit, an upper computer and an LCD display screen. The control core obtains the voltage, current, and output voltage of the storage battery set, the voltage of the snubber capacitor Cs, and the voltage of the power tube Sbuck by the sampling circuit; on the basis of a corresponding control algorithm, a drive wave form is outputted by the drive circuit so as to drive the power tube Sbuck and the power tube Sboost; the control core sends the voltage and the current of the storage set to the LCD display screen; the upper computer collects all variable values of the current working situation from the control core and the values are displayed by upper computer software; and the upper computer also can send a control command to the control core. According to the invention, the provided circuit and method can be applied to the storage battery energy storage system and two-way electric energy flowing can be realized well.

Description

technical field [0001] The invention relates to a bidirectional converter for an energy storage system, in particular to a bidirectional buck-boost circuit for a storage battery energy storage system and a digital control method thereof. Background technique [0002] In recent years, with the rapid development of new energy technologies, in order to solve the intermittent, volatile and unstable shortcomings of wind energy, solar energy, and ocean energy, the research and development of energy storage systems is particularly important. At this stage, battery energy storage systems It has the widest range of applications and has achieved good economic benefits. However, in order to improve the service life of the battery, the battery needs to be charged and discharged reliably, so it is necessary to have a suitable bidirectional conversion circuit and a corresponding control method. [0003] The circuit at this stage often has the following disadvantages: (1) The switching tub...

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Problems solved by technology

[0003] The circuit at this stage often has the following disadvantages: (1) The switching tube adopts a hard switch, and the switching loss is extremely large, which reduces the efficiency of the battery pack; (2) There is no soft-start control, and the energy storage inductor may It will be saturated due to excessive instantaneous current, and the reliability will be greatly reduced

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