To deal with uncertainties of renewable energy, demand and price signals in real-time microgrid operation, this paper proposes a model predictive control strategy for microgrid economic dispatch, where hourly schedule is constantly optimized according to the current system state and latest forecast information. Moreover, implicit network topology of the microgrid and corresponding power ?ow constraints are considered, which leads to a mixed integer nonlinear optimal power ?ow problem. Given the nonconvexity feature of the original problem, the technique of conic programming is applied to ef?ciently crack the nut. Simulation results from a reconstructed IEEE-33 bus system and comparisons with the routine day-ahead microgrid schedule suf?ciently substantiate the effectiveness of the proposed MPC strategy and the conic programming method.