Performance of a High-Fidelity 4kW-Class Engineering Model PPU and Integration with HiVHAc System

Abstract

The High Voltage Hall Accelerator (HiVHAc) propulsion system consists of a thruster, power processing unit (PPU), and propellant feed system. An engineering model PPU was developed by Colorado Power Electronics, Inc. funded by NASA's Small Business Innovative Research Program. This PPU uses an innovative 3-phase resonant converter to deliver 4 kW of discharge power over a wide range of input and output voltage conditions. The PPU includes a digital control interface unit that automatically controls the PPU and a xenon flow control module (XFCM). It interfaces with a control computer to receive highlevel commands and relay telemetry through a MIL-STD-1553B interface. The EM PPU was thoroughly tested at GRC for functionality and performance at temperature limits and demonstrated total efficiencies a high as 95 percent. Integrated testing of the unit was performed with the HiVHAc thruster and the XFCM to demonstrate closed-loop control of discharge current with anode flow. Initiation of the main discharge and power throttling were also successfully demonstrated and discharge oscillations were characterized.

Integration Tests of the 4 kW-class High Voltage Hall Accelerator Power Processing Unit with the HiVHAc and the SPT-140 Hall Effect Thrusters

“…To that end, NASA GRC is working with Colorado Power Electronics (CPE) to mature the design of a 4.5 kW PPU with an input voltage range of 70-140 V and an output voltage range of 200-700 V for implementation in NASA's HiVHAc propulsion system. 5,6 This paper will present recent test results of the integrated tests of the CPE PPU and VACCO xenon flow control module (XFCM) with NASA's HiVHAc thruster and the SPT-140 Hall Effect Thruster (HET) provided by Space Systems Loral (SSL). The paper is arranged as follows: Section II presents an overview of the Hall thruster propulsion system under development and test, Section III presents results from the integrated tests with the HiVHAc thruster, Section IV presents results from integrated tests with the SPT-140, and Section V presents the summary and future work.…”