Electrospray power processing unit for a monopropellant-electrospray multimode thruster

Eisen, Jacob

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https://hdl.handle.net/2142/117846 Copy

Description

Title

Electrospray power processing unit for a monopropellant-electrospray multimode thruster

Author(s)

Eisen, Jacob

Issue Date

2022-12-08

Director of Research (if dissertation) or Advisor (if thesis)

Rovey, Joshua L

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Electrospray
• Converter
• PPU
• Multimode
• Propulsion
• Power electronics
• High-voltage

Abstract

Multimode space propulsion combines two or more propulsive methods into a single system with a shared propellant, the goal of which is to offer spacecraft improved maneuver flexibility and efficiency. A power processing unit (PPU) is described and developed here to meet the high-voltage low-power needs of the electrospray mode of a monopropellant-electrospray multimode thruster. The PPU is resilient to the variable-load nature of electrospray thrusters, producing a consistent output voltage regardless of the thruster’s current draw. The PPU consists of a two-phase interleaved boost converter, transformer, and Cockcroft-Walton voltage multiplier. By designing a transformer magnetizing inductance of at least 1 mH and using a 10 MΩ bleed resistor at the PPU output, discontinuous conduction mode is avoided during the thruster startup period before Taylor cone formation. This allows the desired thruster voltage of 3.25 kV to be maintained both during and after thruster startup. A 20 MΩ current-limiting resistor placed just before the thruster prevents PPU component damage during thruster shorts. The presence of this resistor also maintains the voltage multiplier output voltage even if the thruster voltage itself cannot be sustained without overcurrent, allowing nominal electrospraying to resume if the thruster recovers from the short. The PPU is integrated with a real multimode thruster for a ground-based test to prove its suitability for the application, marking the first time a purpose-built electrospray PPU has been successfully applied to a monopropellant-electrospray multimode thruster.

Graduation Semester

2022-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Jacob Eisen

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