I. Introduction
With the development of industrialisation, the scale of motorway construction has increased, which has led to economic development and also brought about huge energy consumption [1]. Therefore, the establishment of an expressway integrated energy system optimisation model and the rational scheduling and utilisation of multiple energy sources of the system are the inevitable requirements of expressway intelligence [2]. An integrated energy system for expressway will effectively promote the construction of” zero-carbon” expressway, and the use of renewable energy sources to replace traditional energy sources and achieve vertical substitution and horizontal complementarity of energy sources is the core content of the optimisation model [3]. China's expressway network has been constructed with consideration of natural variables and has the capacity to effectively utilize renewable energy sources like wind power and photovoltaic power for energy provision [4].