The team is using 11 Nomura mppts (same model as used on MS12). Unlike in MS12 in which solar sense was broken up into two boards (a solar sense slave that was placed beneath each mppt and a solar slave master that brought the power from each solar sense slave in series for each array → two masters for each array of solar cells in series were paralleled to provide a power path to the batteries), for MS14 it will be combined into one board for the following advantages:
- Easier to assemble and debug two boards as opposed to 11 different solar slaves
- Easier wiring as we will need to only harness the thermistors going to each solar panel section, isolated spi communication, and each power line going to each mppt from solar sense board
Other features of solar sense:
- current, voltage and temperature sense of the outputs of each mppt
- isolated spi communication between the board and the mppts
Block Diagram:
Testing the Nomura MPPTs
In MSXII, the MPPTs were never fully validated to source the error for inconsistent charging of the battery. If the above below block diagram is to be implemented, extensive testing must be conducted to verify the MPPTs are not the source of the issues. The following will be the testing procedure:
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After obtaining a SPI logic analyzer, we will record the SPI messages given by the SPV1020 MPPT IC.
The team is using 11 Nomura mppts (same model as used on MS12). Unlike in MS12 in which solar sense was broken up into two boards (a solar sense slave that was placed beneath each mppt and a solar slave master that brought the power from each solar sense slave in series for each array → two masters for each array of solar cells in series were paralleled to provide a power path to the batteries), for MS14 it will be combined into one board for the following advantages:
- Easier to assemble and debug two boards as opposed to 11 different solar slaves
- Easier wiring as we will need to only harness the thermistors going to each solar panel section, isolated spi communication, and each power line going to each mppt from solar sense board
Other features of solar sense:
- current, voltage and temperature sense of the outputs of each mppt
- isolated spi communication between the board and the mppts
Block Diagram: