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Electrical Passivation - PCDU upgrade for power passivation

Programme Reference
Prime Contractor
Start Date
End Date
Electrical Passivation - PCDU upgrade for power passivation
Develop and test a passivation technique to provide the isolation of the solar arrays embedded in the PCDU. Development and manufacture of electric breadboard for demonstration of proposed approach
For passivation, it is required that the electrical power sources on-board a spacecraft after its operational phase are depleted or made safe. This requirement is driven by the fact that some accidental satellite breakups have been caused by the battery in the past. One of the drivers of such battery explosion is being at high state of charge. At the end of mission, the solar panels continue to provide charge to the battery, particularly if the satellite once uncontrolled ends up sun pointing, which increases the chance of battery explosion. As such, it is necessary to isolate the solar panels in order to ensure that no further charge is provided to the battery. The simplest and more effective way to implement this is within the PCDU. The development of reliable passivation methods is considered of high priority by the LSIs.
Preliminary studies have shown that many solutions exist to provide the passivation function within the PCDU. The scope of this study will be to select the best passivation technique, taking into account robustness, PCDU design impact but also impacts on the performance and at system level.
During the CleanSat Concurrent Engineering Phase a set of harmonized requirements has been agreed among the European LSIs. The coordinated work between supplier and integrators is a key aspect of CleanSat, guaranteeing that the technology is developed in line with the needs of the end users. The consolidated requirements establish a solid basis to support this development.
In this activity design, manufacture and test a full electrical breadboard of the PCDU module will be performed in a phased approach:
Phase 1  Passivation Technique Selection and Testing (300 Keuro, 9 months)
  • Selection of at least two passivation techniques
  • Design maturation of the selected passivation techniques
  • Testing of the passivation solutions
  • Testing to ensure the robustness of the proposed solutions to the severe conditions possible during the entire mission. As a minimum the following tests should be performed: Thermal cycling, Shock and vibration tests.
  • Electrical characterization shall be performed out to measure the isolation of the passivation solution.
  • Based on the test results, a tradeoff shall be done between the passivation techniques. In this tradeoff the following aspects shall be considered: converter efficiency, control electronics (analog, digital), complexity, development risk, cost, dimension/mass, flexibility to various missions, impact on overall PCDU
  • Architecture review of the selected solution
Phase 2  Design and development of electrical breadboard 
  • Detailed design of the module hardware, including FDIR and FMEA analysis, performance assessment, routing constraints and thermal constraints
  • Manufacture of EBB
  • Testing of EBB
  • Definition of future qualification steps
A coordinated approach with the LSIs will be continued during this activity in order to guarantee a seamless introduction of this equipment in their future platforms.
Application Domain
Generic Technologies
Technology Domain
23 - Electrical, Electronic and Electro-mechanical (EEE) Components and Quality
Competence Domain
4-Electric Architecture, Power and Energy, EMC
32-Clean Space
Initial TRL
Target TRL
Achieved TRL