Power balance control method for direct-current microgrid system

Abstract

The invention relates to the field of micro-grids. The invention discloses a power balance control method for a direct-current microgrid system. The method comprises: selecting one of a plurality of direct-current converters in parallel droop control as a host power distribution unit, and the host power distribution unit being responsible for monitoring the power states of the load side and the energy storage battery side, comprehensively calculating an equilibrium power reference value which should be output by each direct current converter according to the real-time power of the load, the SOC values of the multiple groups of energy storage batteries and the rated power of the multiple direct current converters, and issuing the equilibrium power reference values to the corresponding direct current converters. Master-slave and battery SOC control is added on the basis of direct-current droop control, so that the stability of the voltage on the direct-current bus side can be effectivelyensured, the dynamic response capability of the system is improved, and the cycle service life of the energy storage unit storage battery is prolonged.

Description

technical field [0001] The invention relates to the field of micro-grids, in particular to a method for power balance control of a DC micro-grid system. Background technique [0002] Microgrid technology represents the development trend of distributed energy supply systems in the future and is an important part of the future intelligent power distribution system. It is of great significance to promote energy conservation and emission reduction and achieve sustainable energy development. Most of the electric energy generated by photovoltaics, wind turbines, and battery energy storage units in the microgrid is direct current or non-power frequency alternating current. Commonly used electrical equipment, such as personal computers, mobile phones, LED lighting, air conditioners, and electric vehicles, are all driven by DC power through corresponding adapters. If the above power generation unit or load is connected to the AC microgrid, it needs to pass through a multi-level ener...

AI Technical Summary

Problems solved by technology

The main disadvantage of this control method is that the dynamic response capability of the entire system depends entirely on the response capability of the master as a voltage source, and the dynamic performance of the system is poor. Once the master fails and shuts down, the entire system will not work, and the number of slaves in the parallel system will affect Stability of Parallel System

The DC bus voltage stability of this control method is very poor, and the system is prone to oscillation and shutdown

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