Two energy management modes for diesel generators (DGs) in microgrid are proposed

which takes into consideration the stepped time-of-use price

the timing sequence characteristics of different types of loads and distributed generators

and the operating characteristics of DGs. An optimization model used for dispatching diesel generators in the microgrid is developed. An actual microgrid is taken as an example to analyze the unit investment costs for energy-saving and emission reduction in different management modes. The particle swarm optimization (PSO) algorithm is employed to optimize the management mode with relatively better economy

further reducing the unit investment cost for energy-saving and emission reduction of microgrid. The results of a case study show that DG adopting the energy management of deficiency power supply to the important load is best so that it can provide a reference for optimal proportion of DG capacity and its energy management in the actual microgrid system.