Improved Sufficient Conditions for Exact Convex Relaxation of   Storage-Concerned ED
  To avoid simultaneous charging and discharging of storages, complementarity constraints are introduced to storage-concerned economic dispatch (ED), which makes the problem non-convex. This letter concerns the conditions under which the convex relaxation of storage-concerned ED with complementarity constraints is exact. Two new sufficient conditions are proposed, proved and verified to significantly reduce the conservatism of recent results [3], [4]. 
Chao Duan, Lin Jiang, Wanliang Fang, Xin Wen, Jun Liu
math.OC