The highway service area, with facilities for electricity-hydrogen charging, includes multi-energy load energy demands and domestic waste process demands. Based on these needs, a fully renewable energy based multi-energy microgrid with electricity-hydrogen charging services and waste process capacity is proposed. This paper studies the energy input and output characteristics of multi-energy conversion and storage devices, and establishes the model for electricity-hydrogen charging microgrid (EH-CMG). The multi-energy conversion, storage characteristics and multi-energy flow coordination in the EH-CMG are then studied. An optimization model and its algorithm solution, based on constraints such as the charging time of vehicles, the reliability of multi-energy load energy supply and the available grid regulation performance in the EH-CMG, are established. The proposed optimization of EH-CMG is illustrated with the actual multi-energy operation data of a highway service area in northwest China. The results demonstrate that the proposed EH-CMG and its optimization method can achieve economic benefits for a multi-energy system with the ability of waste process, electricity-hydrogen charging, and also provide better regulation characteristics for the power grid.

In order to accurately assess the risk of the hybrid AC/DC network under fault, a risk assessment method for the hybrid AC/DC system based on the transient energy function is proposed. First, based on the energy transfer relationship of the hybrid AC/DC power system, the transient energy function model of the hybrid AC/DC system is established. Based on the operating data of the power grid, the energy function is used as an efficiency variable, and the efficiency variable is integrated into the prior risk probability calculation of nodes in the network, and a Bayesian network-based risk assessment model of hybrid AC/DC system is established. Considering the dynamic update model of network cascading failures, the clique tree propagation algorithm is used to dynamically calculate the posterior risk probability of the node to realize the dynamic assessment of the network risk. Finally, the improved IEEE-39 node hybrid AC/DC system is used as an example for analysis. The results show that the proposed model can not only effectively evaluate the overall safety of the network, but also has feasibility in predicting faults, which can provide a theoretical basis for the stability control of the hybrid AC/DC system.