Normothermic machine perfusion(NMP)is an innovative technique used in solid organ transplantation that involves perfusing the organ with specialized solution or leukocyte depleted red blood cells at near-normal body temperature aiming at mimicking physiological conditions,and providing optimal conditions for organ preservation which leads to reduced risk of ischemia reperfusion injury(IRI)when compared to the standard static cold storage(SCS)(1).One of the key advantages of NMP is its ability to assess the quality of the organ in real-time and assessment of the organ performance prior to transplantation.By continuously monitoring parameters such as blood flow,oxygen consumption,and lactate production,clinicians can evaluate the viability of the organ and make more informed decisions about its suitability for transplantation.This real-time assessment can help reduce the risk of transplanting organs that may not function optimally or have a higher likelihood of complications post-transplant.Additionally,NMP may expand the pool of donor organs by allowing for the use of organs that may have been deemed marginal or unsuitable for transplantation using traditional methods(1,2).
Transient voltage stability analysis(TVSA)of power systems is one of the most computationally challenging tasks in dynamic security assessment.To reduce the complexity of TVSA,this paper proposes an improved expanding annular domain(improved EAD)algorithm to estimate the domain of attraction(DA)of power systems containing multiple induction motors(IMs),whose improvements are concerned with relaxing the restriction on critical value and simplifying iteration steps.The proposed algorithm can systematically construct Lyapunov function for lossy power systems with IMs and their slip constraints.First,the extended Lyapunov stability theory and sum of squares(SOS)programming are presented,which are powerful tools to construct Lyapunov function.Second,the internal node model of IM is developed by an analogy with that of a synchronous generator,and a multi-machine power system model by eliminating algebraic variables is derived.Then,an improved EAD algorithm with SOS programming is proposed to estimate the DA for a power system considering the slip constraint of IM.Finally,the superiority of our method is demonstrated on two modified IEEE test cases.Simulation results show that the proposed algorithm can provide a better estimated DA and critical clearing slip for power systems with multiple IMs.
Lei ChenTianhao WenYuqing LinYang LiuQ.H.WuChao HongYinsheng Su