RESEARCH ON DROOP CONTROL STRATEGY OF COMBINED NON-ISOLATED THREE-PHASE INVERTER

Feng Zetao; Xia Yan; Yang Kai; Chen Renzhao; Li Ke; Shi Jinhui

doi:10.19912/j.0254-0096.tynxb.2024-0563

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Acta Energiae Solaris Sinica ›› 2025, Vol. 46 ›› Issue (8) : 625-633. DOI: 10.19912/j.0254-0096.tynxb.2024-0563

RESEARCH ON DROOP CONTROL STRATEGY OF COMBINED NON-ISOLATED THREE-PHASE INVERTER

Feng Zetao¹, Xia Yan¹, Yang Kai¹, Chen Renzhao², Li Ke³, Shi Jinhui¹

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Abstract

The combined non-isolated three-phase inverter consists of three single-phase inverters using a Heric topology, each of which can operate independently. To solve the problem of unbalanced output voltage of a combined non-isolated three-phase inverter during off grid operation due to asymmetric load carried by the three-phase, an improved droop control strategy based on the combined non-isolated three-phase inverter is proposed. Replace the traditional active-frequency （P-f） droop curve with the inverse square root unit （ISRU） curve of the neural network activation function, search for the active intermediate phase P_mid and the reactive intermediate phase Q_mid to improve the active-frequency （P-f） and reactive-voltage （Q-U） droop curves, thereby obtaining a three-phase balanced reference voltage. Meanwhile, introduce voltage amplitude compensation to further ensure the symmetry of the output voltage. The correctness and feasibility of the proposed control strategy were verified in Matlab/Simulink and StarSim HIL semi-physical platform. The results indicate that the strategy has good control performance and can effectively reduce the unbalance degree of output voltage.

Key words

droop control / unbalanced load / non-isolated / three-phase combined inverter / unbalance degree of voltage

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Feng Zetao, Xia Yan, Yang Kai, Chen Renzhao, Li Ke, Shi Jinhui. RESEARCH ON DROOP CONTROL STRATEGY OF COMBINED NON-ISOLATED THREE-PHASE INVERTER[J]. Acta Energiae Solaris Sinica. 2025, 46(8): 625-633 https://doi.org/10.19912/j.0254-0096.tynxb.2024-0563

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