Abstract:Aiming at the large disturbance stability of hybrid energy storage DC microgrid with constant power load and the modeling of energy storage converter,based on deducing the equivalent model of hybrid energy storage system (HESS)PWM switching network.A stability criterion and analysis method of DC microgrid containing HESS based on mixed potential function theory is proposed.Firstly,considering the charge-discharge characteristics of HESS,the oper- ating states of the DC microgrid system containing HESS are divided into buck and boost operating modes.Then,the hybrid potential function models of DC microgrid system based on the equivalent model of pulse width modulated switc- hing network are established respectively under the above two operating modes.Finally,usingthe third stability theorem of the mixed potential function theory,the large disturbance stability criteria of the DC microgrid under buck and boost operating modes are derived respectively.Compared with the system stability criterion based on switching average model of buck operation mode,this paper proposes that the derivation method of stability criterion is more accurate to predict the dynamic behavior of the system.The simulation verifies the rationality of the proposed stability analysis method and the advancement of the hybrid potential function criterion.