A Novel Simulation Method for Power Electronics: Discrete State Event Driven Method

In the analysis of power electronics system,it is necessary to simulate ordinary differential equations(ODEs)with discontinuities and stiffness.However,there are many difficulties in using traditional discrete-time algorithms to solve such equations.Kofman and others presented the quantized state systems(QSS)algorithm in the discrete event system specification(DEVS)formalism.The discretization is applied to the state variables instead of time range in QSS.QSS is efficient to solve ODEs,but it is difficulty to be used when simulating actual power electronics systems with controller’s and other events.Based on the idea of this numerical algorithm and discrete event,a Discrete State Event Driven(DSED)simulation method is presented in this paper,which is fit for simulation of power electronics system.The method is developed to deal with non-linearity,stiffness and multi-time scale of power electronics systems.The DSED simulation method includes event definition,module seperation and modeling,event-driven mechanisms,numerical computation based on QSS,and some other operations.Simulation results verified the effectiveness and validity of the proposed method.

Sliding Mode Control in Power Converters and Drives: A Review

Sliding mode control(SMC)has been studied since the 1950s and widely used in practical applications due to its insensitivity to matched disturbances.The aim of this paper is to present a review of SMC describing the key developments and examining the new trends and challenges for its application to power electronic systems.The fundamental theory of SMC is briefly reviewed and the key technical problems associated with the implementation of SMC to power converters and drives,such chattering phenomenon and variable switching frequency,are discussed and analyzed.The recent developments in SMC systems,future challenges and perspectives of SMC for power converters are discussed.

Generic Modeling and Control Framework for Power Systems Dominated by Power Converters Connected Through a Passive Transmission and Distribution Grid

In this paper,a compact mathematical model having an elegant structure,together with a generic control framework,are proposed for generic power systems dominated by power converters that are interconnected through a passive transmission and distribution(T&D)grid,by adopting the port-Hamiltonian(pH)systems theory and the fundamental circuit theory.The models of generic T&D lines are developed and then the model of a generic T&D grid is established.With the proposed control framework,the controlled converters are proven to be passive and Input-to-State Stable(ISS).The compact mathematical model is scalable and can be applied to power systems with multiple power electronic converters with generic passive controllers,passive local loads,and different types of passive T&D lines connected in a meshed configuration without self-loops,so it is very generic.Moreover,the resulting power system is proven to be ISS as well.The analysis is carried out without assumptions on constant frequency/voltage,constant loads,and/or lossless networks,except the need of passivity for all parts involved,and without using the Clarke/Park transformations or the graph theory.To simplify the presentation,three-phase balanced systems are adopted but the results can be easily adapted for single-phase or unbalanced three-phase systems.

Guest Editorial:Special Section on Applications of Power Electronics in Power Systems

Power transformers and steam turbines were the key drivers in the development of the AC power system paradigm at the dawn of the 20 th century, characterized by huge synchronous generators feeding millions of passive loads through large interconnected systems, all of them supervised and controlled from a centralized energy management system(EMS). In the same way, thyristor valves and IGBTs, introduced