Interactional Influence Analysis of DC Bus Voltage Versus Servo Systems and Stabilization Technology for Aerospace Combined Power Supply Systems

With rapid developments in aerospace science and technology, higher requirements are being placed on the control accuracy of aircraft. As the power source of aircraft servo systems, the power quality of the combined power supply system directly affects the control accuracy of aircraft. Therefore, it is crucial to improve the performance of this combined power supply system. In this article, a method based on nonsingular terminal sliding mode control (NTSMC) is proposed to suppress the DC bus voltage fluctuation of the combined power supply system, which is caused by servo motor loads. First, the mutual influences of the servo motor running state and the DC bus voltage on one another are analyzed. Then, the mathematical model of the DC bus voltage regulation module, based on a bidirectional DC-DC converter and ultracapacitor, is established. The NTSMC algorithm is adopted, and the sliding mode surface and control law are designed to suppress the DC bus voltage fluctuation of the combined power supply system. Finally, simulation and experimental research are carried out to verify the effectiveness of the method. The results show that the proposed method can effectively suppress the fluctuation of DC bus voltage, and that NTSMC is superior to the traditional PID control method for aerospace combined power supply systems.