Optimal planning of renewable energy source and energy storage in a medium- and low-voltage distributed AC/DC system in China

Abstract

As the quantity of DC load and distributed generation system increases in China, AC/DC distribution system is arousing more and more research interest for its high-efficiency distribution ability. In this study, the optimal size and location of renewable energy source (RES) and energy storage in a medium- and low-voltage distributed AC/DC system is studied. A modelling method for the optimisation of such hybrid AC/DC system is developed. The objective of the proposed optimisation method is to minimise the life cycle cost of the system with consideration of the life span of RES. The planning method is based on energy balances and constraints of system operation. The utility requirements and subsidy in China for such system are also considered in the planning process. The method is demonstrated in a 10 kV and low-voltage distributed AC/DC system considering installing photovoltaic system, wind turbines, and electric storage system. The provided results indicate that the method is effective and applicable for the optimisation of the size and location of RES in distributed AC/DC system. The life cycle cost of such system is significantly reduced with the subsidy of the Chinese government compared with the system without RES.

Keywords

• distribution networks
• renewable energy sources
• optimisation
• photovoltaic power systems
• wind turbines
• life cycle costing
• energy storage
• distributed power generation
• renewable energy source
• energy storage
• distributed AC/DC system
• distributed generation system
• AC/DC distribution system
• high-efficiency distribution ability
• hybrid AC/DC system
• system operation
• photovoltaic system
• electric storage system
• voltage 10.0 kV