Research On Nonlinear Control Of Three Phase Voltage Source Rectifier

The voltage source rectifier (VSR) has been widely used as its "green energyconvert", scholars have proposed a variety of nonlinear control strategies which haveexcellent control effect, but most of the nonlinear control strategy have their ownadvantages and disadvantages. In this thesis, two nonlinear control strategies areanalysed in the three-phase VSR.Passivity-based control’s algorithm is simple, it is easy to implement and has acertain robustness, so it is widely used in the control of the robot. Based on ELmathematical model in the dq coordinate system of the three-phase voltage-sourcerectifier, a system error energy function is designed based on the expected point of thesystem, and then the passivity-based controller is designed using damping injection sothat the system can be stabilized at the desired point, it can also solve the couplingproblem of the system, the power supply can be achieved "green transformation", andthe system performance can be improved by adjusting the damping injection.Backstepping control uses a recursive manner to derive the control law resultsfrom the desired control of the system, it can achieve the overall system stability andits control performance is relatively excellent, especially in the control of the robotand the aircraft, it has significant advantages. Based on the mathematical model ofthree-phase voltage-source rectifier, the entire system is treated as a number ofsubsystems, and design the first subsystem and its Lyapunov function from theexpected output voltage of DC side, then design the virtual control functions in orderto stabilize the subsystem, and so on, design the control for each subsystem until theactual control results of the system.Finally, the static and dynamic performance is analysed based on the Matlabsimulation results of passivity-based control and backstepping control of thethree-phase voltage source rectifier, and then the effects on the system performance ofthe control parameters is also analysed in the two control strategies based on thesimulation waveform, finally, a better combination of the parameters is designed sothat the indicators of the system to the best, at the last the two control strategies arecompared to analysis separately from the controller design process, the controlparameter settings and effect on performance of system parameters perturbation.