Spring term update
As the spring term gets underway, the team‘s work is concentrated on the building of a prototype of an MPPT solar array regulation system and computer simulation of various mechanical aspects of the EPS design.
The documentation that the team will need to deliver for the Preliminary Design Review in April 2011 is close to completion. A large proportion of the work that has been done concerns planning the course of the future design and validation process in considerable detail, and this has lead to the exploration of new relationships with organisations that may be able to provide support or testing facilities in future years.
Design Development: Electrical Prototyping
The electrical team have begun building a prototype power regulation system. This first prototyping iteration has seen the circuits being constructed on breadboards. The testing of the MPPT system required
the design and build of a Solar Array Simulator (mimicking the I-V characteristic of a string of solar cells) and a battery. The next iteration will involve closing the feedback loop of the MPPT using a
microcontroller. NI Labview is being used to assist with this development. A revised Solar Array Simulator will also be constructed to give a more accurate representation of the solar array. Ultimately the team hope to manufacture a PCB prototype before the end of term. Please see our monthly newsletters for images and further details.
Mechanical: Battery Validation
Under the guidance of ABSL (who will supply the battery for ESMO), Oliver Sedden has been conducting vibration simulations to validate the battery design for the forces expected during launch and deployment. Initial results for random vibration in the x-plane (along the length of the battery) show a peak acceleration of 32.19grms, just meeting the qualification requirement of 32.2grms.
Mechanical: Solar arrays
Modelling of the solar arrays using the CFD package SolidWorks Flow Simulation has produced some useful results. Knowing how the photovoltaic cell temperatures vary with time as the spacecraft goes into
and out of eclipse is essential for calculating the power output of the arrays (the efficiency of the cells decreases with temperature).
Mechanical: Power Conditioning and Distribution Unit (PCDU)
The half microtray design will accommodate all electronic components required for several MPPT systems. Adam is currently refining a thermal model of these components, ensuring that they will not overheat in various conditions. If necessary a heat sink will be added to aid with the dissipation of some of the heat. The heat will mainly come from the relatively high powered MOSFETs. Other teams will need to be sure that the PCDU stays within a range of -20°C to +50°C at all times. This thermal model is runin Solidworks simulation, however future development may require an ESATAN model for better integration with the thermal and other teams.
PMU: Electronics design
Andre is researching possibilities for FPGA design, which will be addressed in a future news release
***Sponsors presentation day***
The team has sent out invitations to all of our project sponsors for what promises to be another informative occasion. This will be on the 12th May at 10am in the School of Engineering, University of Warwick. A 3-course lunch will follow the presentation and networking session. This event is generously sponsored by Harwin.
The team hope to release project updates to the local, national and international media in the near future. Please look out for these - updates will of course be posted on this website.