Modular Medium Power Unit - terma

Modular Medium Power Unit
SPACE
The Modular Medium Power Unit concept is dedicated to
observation, navigation, science or low power
communication spacecrafts.
The design concept was qualified by it first application
in Rosetta and has been reused in Mars Express, Venus
Express, Galileo and Small Geo.
The concept is designed for Low, Medium and
Geostationary orbits as well as for interplanetary
missions.
Main Features:
• A convenient range of electrical functions is
available within the modular concept that allows
reuse of the functions. They can be combined into
either a PCU, a PDU or a PCDU
• When the needed functions have been determined
for new application, the selected modules are
integrated into a standard mechanical concept with
the length of the unit as the only adjustment.
• All modules are plugged in a backplane
motherboard and screwed to a common baseplate
without any internal wiring.
Technical features:
• Bus Power: 250 W to 5000 W
• Bus Voltage:
• Unregulated: 22 – 37 volt
• Regulated: 28 or 50 volt
• Conditioning:
• Solar Array Regulation: Shunt or MPPT
• Battery charge: BCDR or S4R (@ regulated bus)
• Lithium cell management: cell charge balancing,
by-pass actuation
• Distribution
• Equipment power: LCL, R-LCL, FCL
• Heater power: LCL + HSW
• Actuation: Pyro, Thermal knives
• TM/TC: MIL-STD-1553, ML/TM
• Redundancy: tolerant to anyone single failure
• Low unit mass
• Any single module can be removed or replaced
without unit disassembly
The Galileo PCDU is built on this concept and is included here as an example:
Space Engineering and Knowledge
Galileo Power Conditioning and Distribution Unit Flight Model
The Galileo PCDU provides a power capability up to 3000 watt based on a 50 volt regulated bus. The unit is comprised of the
following module types:
3 x Shunt Regulator (S3R / S4R) modules, in total 20 shunt sections
4 x Battery Discharge Regulation (BDR) modules, including cell balancing, by-pass actuation
3 x Equipment Power Distribution (EPD) modules, providing 48 LCL’s
6 x Heater Power Distribution (HPD) modules, providing 96 HSW
1 x Propulsion Power Distribution (PPD) module, providing two independent 28V supplies + LCL’s
2 x Thermal Knives Actuation (TKA) modules
2 x Command and Monitoring (CM) modules, based on MIL-STD-1553 I/F
1 x Backplane module

Specifications:
Unit volume:
Width, exclusive feet :
Height:
Length:, exclusive feet:
Unit mass ~
235 mm
156 mm
No of modules x 25 mm + 4 mm
∑ module mass + No of modules x 0.27 kg
Unit Mechanical Concept
The available module functions are described in separate flyers and can be combined as follows:
• Any number of different module functions
• Any number of specific modules
• Minimum of three APR’s to form a failure tolerant MPPT
• The total maximum number shall not exceed 21 plug-in modules.
Terma A/S Space
www.terma.com