Abstract：The micro-grid solves the problem that the intermittent and fluctuating power generation has

adverse effects on the stable operation of the distribution network when the distributed generation is connected to

the distribution network. In order to meet the economic operation of micro-grid under grid connected mode and

improve power supply reliability，a micro-grid energy dispatching strategy based on peak-valley price and energy

storage state of charge（SOC）was proposed. The strategy divided the whole day into three periods：peak，average and valley. During the real-time scheduling cycle，different scheduling strategies were applied based on different time interval and the SOC of energy storage. Reasonable energy storage charging and discharging penalty functions were designed in different time interval，and the maximum energy storage charging and discharging constraint factor was introduced to further improve the charging and discharging of the energy storage device. The minimum operating cost of micro-grid was took as the objective function and solved it through particle swarm optimization algorithm. The effectiveness of the strategy was verified by an example analysis.

      Key words：micro-grid；energy storage；peak-valley price；real-time scheduling；state of charge（SOC）