研製一降壓-升壓轉換器驅動馬達換流器

Abstract

本研究為研製一降壓-升壓轉換器驅動無人搬運載具(Automated Guided Vehicle, AGV)上的馬達換流器。電源級採用降壓-升壓轉換器(Buck-Boost converter)，其輸入電源來自於電池，所轉換的輸出電源用於驅動無人搬運載具的馬達換流器。其次，本研究利用一控制晶片(LM5118)控制降壓-升壓轉換器，控制晶片將利用峰值電流控制模式，偵測輸出電壓及電感電流從而控制開關的責任週期比例(Duty cycle)。本研究利用PSIM模擬軟體建構出降壓-升壓轉換器電路與控制晶片的內部電路，並將設計的參數利用所建構的模擬電路，調整降壓-升壓轉換器的電路參數，進而評估轉換器的效能與穩定性，從而進行必要的調整與優化，再與實作電路相互驗證。本研究設計之降壓-升壓轉換器連接於無人搬運載具的電池以及兩顆驅動馬達換流器之間，藉此達到增加驅動馬達換流器輸入電源的穩定性與可靠性。本研究所研製之降壓-升壓轉換器，其直流輸入電壓範圍為20~29 V，輸出直流電壓為24 V，輸出電流為10 A的條件下，轉換器皆可穩定工作。其次，無人搬運載具使用工業電腦AmITX-SL-G作為主控端，進而透過RS-485通訊界面下達控制兩顆驅動馬達的轉速信號，達成轉速與前後轉動控制之目的。This thesis developed a buck-boost converter to drive the motor inverter in the automated guided vehicle (AGV) application. The power stage used a buck-boost converter, the input power source was from a battery, and the output power could drive the motor inverter of the AGV. Moreover, this study used a control chip (LM5118) to control the buck-boost converter, and the peak-current mode control was applied to regulate the duty cycle of the power switches.The circuit simulation software - PSIM was employed in this study to establish the buck-boost converter and the internal circuit of the control chip. The designed circuit parameters were applied to the simulation circuit to adjust the practical circuit parameters of the buck-boost converter. The simulation results could be verified with the implemented circuit.The designed buck-boost converter was between the battery and the motor inverter supplying a stable direct-current voltage to drive the motor inverter on the AGV.The developed buck-boost converter was operated in the DC input voltage range of 20 to 29 V, its output voltage and current were 24 V and 10 A, respectively. Moreover, the AGV had an industrial computer - AmITX-SL-G as the main control unit, which could control the motor drivers through the communication interface - RS-485 to manipulate the speed and forward/reverse rotation of the motors.