High Voltage Wide Output Range Isolated DC-DC Converter for Micro-Newton Ion Thruster

This article proposed an active clamp flyback (ACF) converter with a single transformer with multiple output windings as a power processing unit (PPU) to provide energy for the ion thruster. The ACF converter has the advantages of the simple circuit structure and suitability for a wide range of input and output voltages. Through circuit mathematical model analysis, the parameters of the ACF converter are designed. In order to meet the thrust accuracy regulation, a high precision control circuit is designed with field programmable gate array (FPGA) and 24-bit external analog to digital converter (ADC) as the controller, and its operating analysis shows that its voltage accuracy meets the requirements. A 10 W/20 kHz with output voltage varying between 400-2000 V prototype is built to verify the effectiveness. The ion thruster experimental test shows that the proposed ACF converter meets the thrust requirements and voltage resolution adjustment. The maximum efficiency can reach 87.7% at normal input voltage.