An improved balance control method for multiple energy storage units in a DC microgrid

Abstract

The present invention relates to the field of electrical control, in particular to an improved balanced control method for multiple energy storage units in a DC microgrid, including constructing a balanced control circuit for multiple energy storage units in a DC microgrid, and constructing a monotonically increasing function according to its own state of charge parameters. It introduces an energy storage unit to improve the droop control loop to form the reference voltage of the control system; the reference voltage and the sampled output voltage and input current form a double closed-loop control system, and the digital controller outputs a duty ratio control signal to drive the switching power device , to realize the non-communication adaptive droop control of the energy storage unit; the present invention adopts an algorithm to apply to the two working modes of charging and discharging of the energy storage unit, without switching, and without sampling the output current of the interface converter, which simplifies Controller design.

Description

Technical field [0001] The present invention relates to the field of electrical control, and more particularly to an improved equalization control method of multi-energy storage units of DC microgrid. Background technique [0002] In recent years, as the power supply system of integrated distributed energy, energy storage components and power converters, microgrids are widely concerned by academia in various countries. The DC microgrid is an important form of a future intelligent power distribution system as a reliable and efficient power supply method, with high transport efficiency and high transmission efficiency, and the advantage that the phase, reactive and harmonic problem is required. [0003] The DC microgrid is used as a small inertial weak support system, usually small capacity, and does not have better anti-interference ability. In order to meet the stable operation of the system, increasing capacity configuration, ENERGYSTORAGE Units, ESUSs in the energy storage syst...

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Problems solved by technology

[0005] However, the control method proposed in the above literature ignores the line resistance between the converter output terminal and the DC bus, and the droop control expressions corresponding to the charging and discharging process are different. During the dynamic conversion process of the energy storage unit, the controller Frequent switching is required, which not only increases the difficulty of controller design, but also adversely affects the control effect of the system

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