Design,Control And Implementation Of Mission Profile Emulator For Power Electronics

As power electronic devices have gradually gained important status in power system,reliability has become a very important research direction.The research of reliability needs the power electronics modules and devices tested under various conditions,especially under actual operating conditions.In this context,this thesis designs a platform to emulate the mission profile for DC/AC converters in power system.The traditional mission profile emulators are based on the back-toback topology.The output of the two converters are connected together by an inductor.In this platform,only the grid-connected inverter with single inductor filter can be emulated.This thesis,based on the traditional one,uses an LC-LCL filter network to replace the L filter.The LC filter and its converter are used as a voltage source converter and to supply an AC voltage to the other side,which can be used to emulate actual operating conditions like UPS in power system.While,the LCL filter and its converter are used as a current source converter and to supply an AC current to the other side,which can be used to emulate actual operating conditions like grid-connected inverter in power system.With such improvements,the emulator can emulate more kinds of mission profiles and more real,and it is very economical and flexible.This thesis establishes a Two-Input and Two-Output mathematical model for the filter network and analyzes the coupling relationship between the output voltage and current.On the basis,the thesis studies the stability of the closed-loop system,finds the main factors affecting the stability and the corresponding solutions.In addition to the theoretical analysis,this thesis also finished the hardware and software design,verified the stability and other related analysis through experiments,and realized the emulator for various conditions.Moreover,the hardware also realized some measurement function such as the switching current of IGBT.