The total oscillation energy in the system is consistent with the oscillation amplitude. The element dissipating energy has positive contribution to the damping of the oscillation and has positive damping. A damping control scheme aiming at dissipating oscillation energy is proposed, and supplementary damping control strategies of high voltage direct current (HVDC) and static var compensator (SVC) are designed. The method unifies a large class of damping control design methods based on energy function descent and constructs strict mathematical foundation for them. The influences on the energy dissipations of other elements should be considered when designing control strategies. Considering the influence of SVC control on load, frequency deviation term is introduced into the supplementary control to increase the energy dissipation of load and enhance the effect of damping control. The validity of control strategy is verified by simulation results.