[Objective] To address the issues of high switching capacity requirements and significant maintenance costs in traditional bidirectional interlinking converters within active distribution networks

this paper proposes a hybrid converter consisting of a three-phase active converter (TAC) and a three-phase diode rectifier (TDR). [Methods] Firstly

the operating mechanism and control architecture of the hybrid converter were designed: when a power deficit occurred on the DC side

electrical energy flowed through the TDR to the DC side

and the TAC operated as an active filter. Conversely

when there was a power surplus on the DC side

the hybrid converter could feed energy back to the AC grid. Secondly

to address the issue of circulating currents caused by the parallel structure

which led to additional losses

the generation mechanism and influencing factors of the circulating current were analyzed in depth. Accordingly

a circulating current suppression strategy based on multi-carrier pulse width modulation (PWM) was proposed. Among the evaluated strategies

the active zero-state pulse width modulation (AZSPWM) strategy demonstrated the best performance. [Results] Test results showed that

compared with the traditional sinusoidal PWM

the proposed AZSPWM strategy effectively reduced the circulating current. Besides

the total harmonic distortion of the grid-side current was significantly reduced under both rectifier-filter and energy-regeneration modes

and the overall power loss of the system was also cut down markedly. [Conclusion] The proposed hybrid converter topology demonstrates strong feasibility

and the circulating current suppression strategy effectively addresses the inter-module circulation issue

confirming the correctness and effectiveness of the proposed AZSPWM strategy.