P13271: AMSAT
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Detailed Design

Table of Contents

The Detailed Design section contains finished and working documents pertaining to the detailed design of the Maximum Power Point Tracker to be delivered to AMSAT for potential use in the Fox-2 satellite.

Prototyping, Engineering Analysis, Simulation

No prototyping was performed, this circuit is largely too complex to do so effectively. Many of the circuits implemented are constructed using SMD components and are layout dependent. Due to the sheer amount of analysis performed on the design with secondary review by outside parties, we are confident that our solution is correct and will have minimal issues during board bring-up. Our constant communications with our guides and volunteer consultants familiar with our project requirements have been very helpful in defining this circuit.

We have performed an extensive amount of simulation with LTSpice:

P13271 LTSpice Simulations (Directory)

Please download LTSpice and open our .ASC files we have generated in the above link to our simulations folder.

A great resource for learning more about LTSpice and its powerful functionality can be found on the SwitcherCAD/LTSpice Yahoo Group. This is where much of the documentation can be found for LTSpice.

AMSAT MPPT Hardware Revision 1.0

These KiCAD files are those which were used to order Rev. 1.0 of the PCB and all schematics/bill of materials are those which do not represent anything added during or after the PCB bring-up. There are issues present in these files which were mitigated during PCB bring-up.

MPPT Rev. 1.0 Directory

MPPT Rev. 1.0 Archive (ZIP)

Library Files (ZIP)

AMSAT 7 Watt Maximum Power Point Tracker

These files represent the fully functional hardware and firmware that was delivered to Tony Monteiro of AMSAT following the conclusion of the senior design project at the end of the RIT Spring quarter (May 2013).

System Level Diagram

For reference when reviewing detailed documentation.

High Level MPPT Block Diagram (PDF)

Hardware Files

Opening the KiCAD files may result in the default libraries to be used. It has been observed that some components will be incorrectly displayed if libraries are not correctly used. Some BJT devices have been observed to be displayed with incorrect pin placement. When in doubt, refer to the PDF schematics.

AMSAT 7W MPPT Files All KiCAD files (Zip).

Schematics

Fox-2 MPPT Schematics (PDF)

Bill of Material (BOM)

Fox-2 MPPT BOM (PDF)

Fox-2 MPPT BOM (XLSX)

Health and Status Firmware

All Health and Status firmware documentation can be found on the following EDGE wiki page

Health and Status Firmware (Directory).

Block Diagrams

Project Scope

This diagram details the scope of our project as implemented in the red box:

Fox-2 MPPT Full System Diagram (PDF)

Fox-2 MPPT Full System Diagram (VSD)

Detailed Control System Diagram

This is a detailed control systems diagram only pertaining to the MPPT control circuitry:

MPPT Detailed Control Block Diagram (PDF)

MPPT Detailed Control Block Diagram (VSD)

Input/Output Voltage Control Diagram

This block diagram shows the input and output voltage control loop. Our MPPT will allow the output voltage to swing between 3.3V and 4.1V with a regulated input solar panel voltage. This is not a power supply. The output voltage is "regulated" only when the 4.1V maximum is reached:

Input/Output Voltage Control System (PDF)

Input/Output Voltage Control System (VSD)

Output Voltage "Soft" PWM Limit Block Diagram

Duty Cycle Control (PDF)

Duty Cycle Control (VSD)

Obtaining KiCad EDA Software

If you would like to use KiCad EDA, the software this project was created with, please download the latest version from the KiCad EDA project website.

KiCad EDA Project Website

The version of KiCad used for P13271 is indicated in the bottom-right corner of each schematic page.

Theory Of Operations Documents

The theory of operations documents aim to explain in detail the operation of individual subcircuits which are critical to the operation of the Fox-2 prototype maximum power point tracker.

Theory of Operations Directory

Theory of Operations Software Directory

PWM Soft-Start

Soft-Start (PDF)

Soft-Start (DOC)

RTD Driver

RTD Driver Circuit Theory Of Operation (PDF)

RTD Driver Circuit Theory Of Operation (DOC)

RTD Voltage Scaling

RTD Scaling Vmpp Matching Theory Of Operation (PDF)

RTD Scaling Vmpp Matching Theory Of Operation (DOC)

Output Voltage "Soft" PWM Limit

UC2524 "Soft" PWM Output Voltage Limit Theory Of Operation (PDF)

UC2524 "Soft" PWM Output Voltage Limit Theory Of Operation (DOC)

Output Voltage Clamp

Output Voltage Clamp (PDF)

Output Voltage Clamp (DOC)

PWM Soft-Start

Pulse-Width Modulator Soft-Start (PDF)

Pulse-Width Modulator Soft-Start (DOC)

DC/DC Buck Converter

Non-Synchronous Buck Converter (PDF)

Non-Synchronous Buck Converter (ODS)

Level-Shifting MOSFET Driver

Level-Shifting MOSFET Driver (PDF)

Level-Shifting MOSFET Driver (DOC)

Test Plans

Please see the DDR presentation for our slide on test plan preparations. Actual plans will be added to this section once available.

Risk Assessment

The document from our SDR is still relevant to the DDR risks

Risk Assessment (PDF)

Risk Assessment (DOC)

Detailed Design Review

The presentation used during the P13271 Detailed Designe Review (DDR) held on February 15th, 2013.

P13271 MPPT DDR Presentation (PDF)

P13271 MPPT DDR Presentation (PPT)

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