Introduction Economic dispatch is the main function of EMS To some extents,it is the generation plan, including unit commitment,hydro-thermal plan,exchange plan,repair plan and fuel plan. According to the period:short-term plan,i.e., AGC,short generation plan (in a day or a week);mid-term plan,one month to one year; long-term plan,several to tens of years, including the development plan of power sources and power grid 电力拿镜广城洲量写控制四川省童点实验蜜 家电网电力系统广域测量与控制四川省重点实验室 Introduction  Economic dispatch is the main function of EMS  To some extents, it is the generation plan, including unit commitment, hydro-thermal plan, exchange plan, repair plan and fuel plan.  According to the period: short-term plan, i.e., AGC, short generation plan (in a day or a week); mid-term plan, one month to one year; long-term plan, several to tens of years, including the development plan of power sources and power grid