Project results
Public results from the EU-co-funded DEEP PPU project: a disruptive Power Processing Unit (PPU) for electrical propulsion gridded ion thrusters.
- Conference paper
Development of a multi-technology and Multi-Voltage Power Processing Unit (MVPPU)
Authors
- J. Torres Cabanuz, Airbus Crisa
- R. Gutiérrez, Airbus Crisa
- M. Prieto, Airbus Crisa
- J. Cortés, Airbus Crisa
- P. Alias, Airbus Crisa
- V. Romero
This paper presents the development and validation of the Modular Versatile Power Processing Unit (MVPPU) by Airbus Crisa, designed to bridge the gap between low-power SmallSat PPUs and high-reliability products for larger satellites. The MVPPU offers configurable powers between 1kW and 20kW, compatibility with major thruster technologies, in-flight output voltage reconfigurability and high-reliability using well-tested Components Off-The-Shelf (COTS). The paper discusses the MVPPU’s development approach, highlighting its cost competitiveness, reduced mass and volume, wide range of output beam voltages, and scalable design. The hardware status and test results of three MVPPU models—engineering models for a 6kW Hall-Effect Thruster (HET) and a 5kW Radio-frequency Ion Thruster (RIT), and an Elegant Bread-Board for a 5kW Applied Field Magnetoplasmadynamic (AF-MPD) thruster—are presented. The impact of generic modules on reusability, development times, and costs is also discussed. Airbus Crisa’s commitment to innovating PPU product lines to meet evolving space mission requirements and supporting all major thruster technologies. The successful characterization tests and coupling tests validate the MVPPU’s design and new technologies, demonstrating its flexibility and unprecedented performance in mass, volume, efficiency, and reliability.
Date of Conference: 14-19 September 2025, London, Imperial College London, United Kingdom
Published in: Presented at the 39th International Electric Propulsion Conference
- Presentation
Design of a RF Generator for a Gridded Ion Thruster: RF Harness Impact and Required Filter Network
Author: Guillermo Núñez Rodriguez, Universidad Politécnica de Madrid
Date: June, 2025
- Paper presented at APEC
Modeling, Control and Digital Implementation of a Buck converter Operating in Triangular Current mode for a Wide Output Voltage Range Space Application
Authors
- Regina Ramos Hortal, Universidad Politécnica de Madrid
- Sara Pérez Sánchez, Universidad Politécnica de Madrid
- Guillermo Núñez Rodriguez, Universidad Politécnica de Madrid
- Javier Torres Cabanuz, Airbus Crisa
- Pedro Alou Cervera, Universidad Politécnica de Madrid
This paper presents a simplified constant on time modeling and control of a buck converter operating in triangular current mode for space applications. The buck converter operates at a variable frequency to achieve ZVS in both transitions while minimizing the RMS current through the inductor. This control is implemented in a field-programmable gate array. Since the converter operates at a variable frequency, two different data acquisition alternatives are explored: sampling at a variable frequency (once per switching cycle) or sampling at a constant frequency (higher than the switching frequency). The proposed control is validated by simulation and experimental results with a 500 W prototype.
Date of Conference: 16-20 March 2025
Published in: 2025 IEEE Applied Power Electronics Conference and Exposition (APEC)
- Poster
Design and Control of a DC/DC Converter for RF Generator of a Power Propulsion Unit
Author: Sara Pérez Sánchez, Universidad Politécnica de Madrid
A Buck Converter is used as one of the stages of the Radio Frequency Generator (RFG) to regulate the power. The converter works in the operating mode TCM (Triangular Current Mode) to optimize the efficiency. The output voltage will be variable depending on the operation point requested, which means a different duty cycle, but also a variable switching frequency as the inductor current starts to increase from IZVS. The converter is controlled adjusting the on-time by a PI controller designed for all operating points.
Date: May, 2023
Presented: 16th CEI Annual Meeting, Madrid, Spain
- Poster
Design of a Resonant Inverter for the RF Generator of a Power Propulsion Unit
Author: Guillermo Núñez Rodríguez, Universidad Politécnica de Madrid
The Power Processing Unit (PPU) converts the spacecraft’s electrical supply into the high voltage needed to drive the ion thruster. Within the PPU, the Radio Frequency Generator (RFG) ionizes the propellant, enabling thrust control. To maximize efficiency, a resonant inverter aligns with the load’s frequency and phase, ensuring optimal power transfer.
Date: June, 2023
Presented: 16th CEI Annual Meeting, Madrid, Spain
- Poster
Analysis and Design of a Radio Frequency Generator for Gridded Ion Technology Thruster
Author: Astudillo, Miguel, Universidad Politécnica de Madrid
This poster analyzes the RF generator employed in Gridded Ion Technology thrusters for electric propulsion. Two implementation approaches—two-stage and single-stage architectures—are proposed and evaluated, with simulations confirming their correct operation. Compared to chemical propulsion, electric propulsion offers significant advantages, including higher specific impulse, improved efficiency, extended mission lifetime, greater payload capacity, and enhanced flexibility. Within this context, the RF generator is a key component, responsible for ionizing noble gases such as Xenon to produce the plasma required for thrust generation.
Date: June, 2023
Presented: 15th CEI Annual Meeting, Madrid, Spain
- Poster
Isolated DC/DC Converter for RF generator of a Power Propulsion Unit: Topology Comparison based on GaN
Author: Guillermo Núñez Rodríguez, Universidad Politécnica de Madrid
A Power Processing Unit (PPU) is required to convert the spacecraft’s electrical supply into the high voltage necessary to operate the ion thruster. Within the PPU, the Radio Frequency Generator (RFG) ionizes the propellant, enabling thrust control. The RFG consists of two stages: an isolated DC-DC converter that regulates power, and a resonant inverter that matches the load’s frequency and phase to achieve highly efficient power transfer.
Date: June, 2023
Presented: 15th CEI Annual Meeting, Madrid, Spain
- Conference paper & presentation ESPC 2023 at Elche, Spain
Isolated DC/DC Converter for RF generator of a Power Propulsion Unit: Topology Comparison Based on GaN Semiconductors
Authors
- Guillermo Núñez Rodríguez, Universidad Politécnica de Madrid
- Miguel Astudillo Martínez, Universidad Politécnica de Madrid
- Anja Zajc, FRAZA
- Franci Zajc, FRAZA
- Javier Torres Cabanuz, Airbus Crisa
Abstract
Four topologies (dual active bridge, phase shift full bridge, active clamp flyback and buck+LLC) have been compared for an isolated DC-DC converter used to regulate the output power of a radio frequency generator for a gridded ion electric propulsion system for satellites. The DC-DC converter has an input voltage of 100V, being required a demanding wide output voltage regulation, 20-200V, with a maximum current of 6.5A and a maximum output power of 1.1kW. All topologies have been compared at a high switching frequency, 500kHz, to reduce the size of passive components.
Date: October, 2023
Presented: 13th European Space Power Conference (ESPC)
- Conference paper ESPC 2023 at Elche, Spain
Analysis and Design of a Radio Frequency Generator for Gridded Ion Technology Thruster
Authors
- Miguel Astudillo Martínez, Universidad Politécnica de Madrid
- Guillermo Núñez Rodriguez, Universidad Politécnica de Madrid
- Javier Torres Cabanuz, Airbus Crisa
- Regina Ramos Hortal, Universidad Politécnica de Madrid
- Pedro Alou Cervera, Universidad Politécnica de Madrid
Abstract
This paper presents an analysis of the radio frequency generator used for ionizing the plasma in a Gridded Ion Technology Thruster. The operational principle is explained, and a single-stage architecture is proposed to simultaneously regulate power and synchronize with the load without the need for a separate control stage. Simulations are conducted to validate the functionality of the proposed architecture, demonstrating its ability to regulate power and maintain synchronized current at a constant frequency for different output power levels and load inductances. In addition, a two-stage architecture inverter prototype is presented, showing the results of the inverter operation at low load. The findings from this study contribute to the advancement of radio frequency generators for Gridded Ion Technology Thrusters, enabling efficient plasma ionization and propulsion in space applications. Radio frequency generator, Gridded Ion Technology Thruster, Power regulation, Load synchronization, single-stage architecture, Space applications.
Date: October 2023
Presented: 13th European Space Power Conference (ESPC)