Design Of Control Strategy For PWM Boost Converter Under Denial-of-service Attack

As the core device of power electronic equipment,the stable operation of pulse width modulation(PWM)boost converter power chip is related to the safe and effective operation of the whole electronic equipment.However,as a kind of nonlinear time-varying system,PWM boost converter faces many difficulties in its analysis and design,which restricts its application range.Therefore,simplifying the modeling process of PWM boost converter and designing reasonable control strategy have very high theoretical and engineering value in the application analysis and control design of PWM boost converter.For this reason,this paper attempts to model the PWM boost converter as a switched system with both continuous state variables and discrete switched variables,and studies the network switched model and control strategy design of PWM boost converter under denial-of-service(Do S)attack based on switched system theory and linear matrix inequality(LMI).The main work is as follows:(1)According to the topology and working characteristics of the PWM boost converter,the differential equation of the PWM boost converter is obtained.Then,using the state averaging method,a switched linear system model of the PWM boost converter is established.(2)Based on the established switched system model of PWM boost converter,the influence of network attack,bandwidth limitation and event-triggered transmission mechanism on the system performance in the remote control process is considered.Firstly,an event-triggered mechanism is designed based on the switched time,attack end time and driving error to reduce the network transmission volume,and at the same time ensure the modal matching between the system side and the controller side under the condition of no attack.Secondly,a novel quantization coding method is designed by introducing a monotonically increasing sequence,which guarantees the unsaturation of the quantizer in the unreliable transmission environment.Thirdly,coupled with the impact of event triggering and network attacks,an observer-based dynamic feedback control algorithm is designed based on the received quantized signal(when there is no attack)or empty signal(when there is an attack).Finally,the sufficient conditions to ensure the exponential convergence and Lyapunov stability of the closed-loop system are obtained.(3)Aiming at the PWM boost converter switched system,the Model Predictive Control(MPC)method under the event-triggered mechanism and Do S attacks is studied.The eventtriggered mechanism is designed based on the dwell time and driving error,and the predictive observer is designed for the two cases of attack and non-attack respectively,and the predictive control algorithm is designed based on the state of the observer.Under the influence of attack and trigger coupling,the system mode and controller mode appear complex mismatch phenomenon,which brings difficulties to the transformation of MPC optimization problem.In order to solve this problem,this paper designs a new performance index coefficient by using the increase/decrease law of Lyapunov function,and realizes the transformation of the optimization problem based on this.Then,the controller gain and observer gain in the case of no attack are designed to ensure the exponential convergence of the closed-loop system.For the attack situation,this paper obtains the upper limit of the attack duty cycle,and verifies that the exponential convergence of the system is still valid below the upper limit.