Research On Key Technologies Of Space Solar Array Simulator

The space solar array simulator(SSAS)is a key test device of the spacecraft power supply system replacing the real space solar panel to provide the DC bus power for the spacecraft power supply system during the ground test period,and its performance directly affects the spacecraft power supply ground testing reliability.In this article,the key technical problems of SSAS are researched deeply,and the proposed improvement schemes and optimization methods are verified by the corresponding hardware experiment platforms.The experimental results are compared with the SAS modular products E4360-SAS from Keysigh show that the proposed SSAS has a significant performance advantage.Firstly,with the test reliability problem caused by the low dynamic response performance of SAS modular products used in the testing of spacecraft power system currently,a new topology suitable for parallel connection linear current source is proposed,and 20 linear current source paths are in parallel.The proposed SSAS has a high dynamic response capability,that can response to step switching between short-circuit operating point and rated operating point at a high step switching frequency with excellent dynamic response performance and dynamic simulation accuracy.Secondly,due to the limited output power and low efficiency of the space solar array simulator,it is proposed to use the multi-level bus tracking converter to track the output voltage to reduce the power consumption of the linear unit,it can improve the system efficiency significantly also with high dynamic response ability.In addition,with the non-linearity problem and the conditional convergence or low convergence speed of the high frequency switching between the different operating points using the single table method of the digital I-U out loop control of the space solar array simulator,this article proposed a UI-RI hybrid look-up table method is an effective solution to solve the nonlinear problem of I-U digital out loop control,and have the characteristics of high-speed convergence to the target operating point under high frequency step switching between different working points conditions that could improve the SSAS dynamic response performance further.Finally,a novel cascade JFET three-port composite linear power transistor is proposed to dissipate the power dissipation of the linear current source,which can optimize the volume and reliability of the linear power stage unit of the space solar array simulator.This optimized method can reduce the number of parallel linear current source paths that would simplifies the linear power unit circuit structure greatly,and improve the reliability of the SSAS.