I will discuss general formulas of generators of the center of the completed quantum affine algebra in type A at the critical level. They are associated with primitive idempotents of the Hecke algebra and parameterized by Young diagrams. The Harish-Chandra images of the Sugawara operators are identified with the eigenvalues of the operators acting in the q-deformed Wakimoto modules. The eigenvalues turn out to be some shifted deformation of Schur functions. This is joint work with Ming Liu and A. Molev.