Output open‐circuit voltage control method with resistor–capacitor–diode dummy load branch for SSAS

Abstract

The current output type space solar array simulator (SSAS) is an important test equipment for a spacecraft power supply to achieve high dynamic output response performance and meet the power current high precision requirements of the power conditioning unit (PCU). However, the current output type SSAS cannot produce a stable open circuit voltage when the output terminal is completely disconnected from the load. Therefore, it is impossible to reliably test the PCU with different architectures. In this study, the open circuit voltage control output problem is analysed, and a parallel resistor–capacitor–diode (RCD) dummy load branch in the SSAS output port is proposed to ensure that the SSAS outputs high-precision open circuit voltage values and provides stable series switching performance without adversely affecting the shunt switching performance. The proposed solution yielded excellent experimental results for a 1 kW hardware power SSAS platform. The open circuit voltage control accuracy is 0.5%, and the series switching test and shunt switching test yielded stable performances with a high dynamic response that quickly converges to the target working points at 1.25 kHz switching frequency, indicating that the PCU can be reliably tested regardless of whether a series architecture or a shunt architecture is used.