Download The Sun Devil Satellite Laboratory: Re

Electrical Power Subsystem Design –
Sun Devil Satellite Laboratory
Andrew Menicosy
http://sdsl.club.asu.edu/
Presentation Structure
• What is EPS?
• Designing the Subsystem
– Power Budget
– Hardware
• Questions
Sun Devil Satellite 1 (SDS-1)
1
What is EPS?
•
•
EPS is a big part of
the mission, as it is
the subsystem
ensuring the
components on SDS-1
have enough energy
throughout the
mission
According to
requirements, EPS
must be able to
regulate and supply
energy to the rest of
SDS-1
Electrical Power Subsystem
2
SDS-1 Net Power Production
Timing
Normal
Downlink
During Sun (W)
6.42
5.47
During Eclipse (W)
-4.92
-5.86
Max load with 5% wire loss and 8% loss from the 14cell solar array and a 1.2W payload draw during
sunlight and 0.05W standby power draw during eclipse
Power Produced During Sun W
12.4
Instantaneous power produced during sunlight
This table is broken down into the four different power consumption SDS-1 will
experience. Each cell is the instantaneous power draw during the specified time
period. EPS is accounting for a single 10-minute downlink per orbit.
3
Power Profile
Battery Energy (Wh)
Battery Energy Over Four Orbits
• By determining worst-case
power draw for each
component on SDS-1,
analysis can be performed
as to whether or not the
mission is sustainable
• Looking at this graph, it is
apparent EPS is capable of
sustaining SDS-1 for the
planned mission lifespan
Time (min)
4
EPS Hardware – Energy Production
and Storage
• Solar Array
– Consists of 2 solar panels
– Capable of supplying up
to 14.3W of power in
direct sunlight
– Deployable
• Battery
– 10Wh (1.25Ah) capacity
10Wh Standalone Battery
(Courtesy of Clydespace Ltd.)
Clydespace 3U Solar Panel
(Courtesy of Clydespace Ltd.)
5
EPS Hardware – Energy Regulation
• EPS Board
– Regulates energy from both
the battery and solar array
– Supplies voltages of both 3.3V
and 5V
– Fault detection circuitry
EPS Board (Courtesy of Clydespace Ltd.)
6
SDS-1 Photodiode Board
• Designed in-house
• A total of 5 will be used on
SDS-1 for attitude
determination
• Simple circuit designed to
amplify voltage to levels the
microprocessor can read
Photodiode Board
7
Attitude Control Subsystem Board
• Designed in-house
• Houses algorithms for SDS-1
attitude control
• Transceiver and magnetometer
will be mounted on the board as
well as connectors for the inertial
measuring unit, sun sensor,
photodiodes and reaction wheels
ACS Board
8
Questions?