Digital twin-enhanced opportunistic maintenance of smart microgrids based on the risk importance measure

•Develop the digital twin-enhanced opportunistic maintenance of microgrid systems.•Measure the consequences of equipment failure with CM costs, PM costs.•Analyze the maintenance sequence and number of devices under limited resources.•Give a risk model of the microgrid system after equipment failure.•Introduce a risk importance measure to guide opportunistic maintenance. Smart microgrids face more diverse and frequent risks than traditional grids due to their complexity and reliance on distributed generation. Ensuring the reliable operation of smart microgrids requires effective maintenance. Traditional maintenance methods, based on periodic inspections and fault diagnosis, struggle to adapt to the dynamics and complexity of microgrid systems. The introduction of digital twin technology provides a new solution for the opportunistic maintenance of microgrid systems. This paper presents a digital twin microgrid architecture for real-time monitoring and decision-making in opportunistic maintenance. Meanwhile, this paper introduces a risk importance measure to aid to optimize opportunistic maintenance strategies when resources are limited. Finally, a wind-solar-storage microgrid is used to illustrate the proposed method. Experimental results show that the proposed method significantly reduces maintenance costs and improves system reliability, effectively supporting microgrid maintenance.