A Study on the Planning of Photovoltaic-hydropower Complementary and Self-consistent Microgrid System for Road Transportation

Since China proposed the"carbon peak and carbon neutrality"goals in September 2020, green transformation and development in road transportation have become pressing. Utilizing clean energy along freeways to create self-consistent micro-network systems and integrating transportation with energy are vital for reducing carbon emissions and achieving clean energy usage in transportation. This paper focuses on independent transportation micro-networks in remote western regions of China, where are featured by abundant solar and water resources but limited access to the main power grid. It proposes a photovoltaic complementary system framework based on small hydropower and establishes a planning model for a self-consistent micro-network system for road transportation. Moreover, the paper proposes a control and operation strategy for the complementary system, with small hydropower as the main source and photovoltaics as an auxiliary source. By optimizing the system economy and stability of power supply, the particle swarm optimization (PSO) algorithm is used to solve typical cases and conduct a comparative analysis of different schemes, resulting in a recommended planning scheme for a self-consistent micro-network system of road transportation. The research results indicate that: under the complementary scheme, the stable power supply rate can reach 99.64%; the overall annual cost is reduced by 430 500 CNY and the power shortage rate is reduced by 2.5% comparing to a single photovoltaic power supply scheme; the overall annual cost increases by only 15 300 CNY but the system's power shortage rate is reduced by 1.59% comparing to a single small hydropower station supply scheme. These results validate the effectiveness of the proposed planning model for the complementary and self-consistent micro-network system and provide a reference for subsequent engineering practices.