| Buck-Boost matrix converter(BBMC)is a new type of power converter,which has a series of advantages such as simple topological structure,adjustable voltage output ratio and direct output of high-quality sine wave voltage,etc.,so it is very suitable for variable frequency speed regulation of asynchronous motors In the system.However,because the BBMC inverter stage is a strong nonlinear system with variable structure,it will produce bifurcation and chaos under certain conditions,which directly affects the stability of the speed control system.Therefore,the stability of the asynchronous motor speed control system based on BBMC Analysis and research to determine the stability zone of relevant parameters will be of great significance to ensure the stable operation of the speed regulation system.By establishing a mathematical model of the asynchronous motor speed control system based on BBMC,the thesis studies the influence of BBMC main circuit parameters,finite time control parameters and segmented delay feedback control parameters on the system stability,and studies and determines the relevant parameters when achieving stable system operation The value range of the paper mainly includes the following aspects:Firstly,the basic characteristics of BBMC are briefly introduced,and the domestic and foreign research on the stability of DC/DC converters is described.Since the establishment of an effective mathematical model is the basic premise for the study of DC/DC converter stability,a further overview The research status of DC converter mathematical modeling,and finally the paper structure and research work are explained.Second,the topology and basic working principle of BBMC are introduced,the voltage transmission characteristics of BBMC are described,and the control methods adopted by BBMC rectifier stage and inverter are introduced respectively.Third,the mathematical model of the asynchronous motor speed control system based on BBMC is established.The influence of the BBMC main circuit parameters inductance L and capacitor C on the system stability is analyzed.The range of values,and the correctness of the above analysis was verified by the time domain waveform chart and the folded chart.Fourth,the discrete iterative mapping model of the asynchronous motor speed control system based on BBMC is established,the control function of the BBMC speed control system based on finite time control is determined,the influence of each control parameter of the finite time control on the system stability is analyzed and determined The range of values of each control parameter when the system is running stably.Finally,the correctness of the above analysis is verified by the BBMC output voltage waveform.Finally,aiming at the chaotic phenomenon existing in the BBMC inverter stage under the action of the PWM pulse input voltage,a segmented delay feedback control method is proposed;the basic principle and specific design method of the control method are described,and the stability region of its control parameters is studied and determined.Finally,the correctness of the above analysis is verified. |
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