A Parallel Power Balance Method for Three-phase Inverters Based on Zero-sequence Components

Abstract

The invention discloses a three-phase inverter power supply parallel power balancing method based on zero-sequence component. The method herein includes: interconnecting zero wires of three-phase inverter power supplies to form a zero-sequence loop bus; allowing each inverter power supply to send a minor zero-sequence component, and using amplitude and phase information of the zero-sequence component to characterize reactive and active information respectively; thus detecting comprehensive information of the zero-sequence component of the zero-sequence loop bus to provide active and reactive closed-loop balance control for equipment. The method provided herein has no need for commutation and signal buses in conventional balance schemes or additional complex communication or bus logic devices; the zero wires of the equipment itself can be used to allow power information interaction, the anti-interference performance is great, power dividing speed is high, and the method herein is simple, feasible and evidently effective.

Description

technical field [0001] The invention relates to a DC-AC power conversion device operating in parallel, in particular to a zero-sequence component-based parallel power equalization method for three-phase inverter power supplies. Background technique [0002] The inverter power supply can convert the DC system to the AC system and provide various AC power with good quality. With the development of micro-grid and smart grid technology, the capacity demand of micro-grid is gradually expanding. Therefore, there are usually multiple inverters distributed inside the micro-grid. In order to achieve stable operation and higher economic benefits of multiple distributed inverters , multiple inverters are required to achieve balanced distribution of power between each other. This requires that in addition to its own voltage control, the inverters also need to interact with each other to help realize power sharing control. [0003] The traditional power equalization method of inverter ...

AI Technical Summary

Problems solved by technology

However, using a communication network or signal bus to realize power information interaction requires additional communication and bus devices, and second, the speed of power sharing is affected by communication speed and signal transmission delay. Electromagnetic interference affects the correctness of information interaction. Finally, when the network or bus device fails, it will cause errors in power information interaction and affect the effect of power sharing control.

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