ALLSHIFT/docs/04-simulations/pv-battery-simulink.md

PV + Battery Simulink Model

Markdown report consolidating two non-markdown sources plus one duplicate markdown file.

Sources	Shift Matlab Drive/.../Simulations/PV+Battery Simulink/PV+Battery.docx Shift Matlab Drive/.../Simulations/PV+Battery Simulink/PVBatteryRead.mlx Shift Matlab Drive/.../Simulations/PV+Battery Simulink/Constants.mlx
Also duplicated as	PV+Battery.md at the repository root — retired to superseded/
Owner	Simulations cluster
Status	Current — model has a known unresolved bug (see Known issue)
Report generated	2026-07-25

What this is

The Simulations cluster's first end-to-end vertical slice: read real profile data out of a spreadsheet, hand it to Simulink, and run coupled PV and battery models against it. It is a methodology trial as much as a model — the closing question in the source is "Discuss if this is a good standard for all parts."

Components

1. Profiles SHIFT (spreadsheet)

• A new tab has been added to the existing Excel data sheet.
• Quick-search data has been filled in for fast experimentation with the Simulink models.

See Generation Profiles Workbook for the sheet contents.

2. PVBatteryRead.mlx

• Code developed with large assistance from ChatGPT.
• Originally intended to read everything off the spreadsheet; it currently reads dynamic data and prepares it for Simulink use.
• The constants reading would not function, for reasons not established — so constants are set in Constants.mlx instead.

What the script actually does, step by step:

Step	Behaviour
File settings	Reads Profiles SHIFT(Generators Factors + Battery).xlsx, sheet Fake Simulink Data, with HeaderLines = 1 and VariableNamingRule = 'preserve'
1 — Type conversion	Converts cell-text numbers to double, replacing , with . for decimal commas; converts duration columns to hours
2 — Trim	Detects the last valid signal row (any non-NaN numeric, and a date after 2000-01-01) and truncates the table there
3 — Extract	Parses variable names out of headers of the form Name - var (unit) via the regex -\s*(.*?)\s*\(, then matlab.lang.makeValidName. Time (t) is converted to seconds — a max ≤ 1 is treated as fraction-of-day, otherwise as hours. A column whose values are all identical becomes a constant; otherwise a time series
4 — Simulink signals	For every numeric variable of the same length as t, creates <name>_simulink = [t, values] in the base workspace — the two-column [time, data] format Simulink's From Workspace block expects

The sheet name is literally Fake Simulink Data — placeholder data for wiring up the pipeline, not a real profile.

3. Constants.mlx

Remember to run this and PVBatteryRead.mlx before attempting to run the Simulink models.

A_PV     = 3060;      % PV Area (m2)
mu_PV    = 0.2;       % Panel Efficiency (%)
V_PV     = 24;        % PV Voltage (V)

P_ele    = 1500000;   % Electrolyzer Power Consumption (W)
E_t0     = 0;         % Initial Battery Energy (Wh)
E_rated  = 170000;    % Battery Rated Energy (W)
Q_rated  = 100000;    % Battery Rated Charge Capacity (W)
Charge_max    = 1;    % Maximum Charge (%)
Disharge_max  = 2;    % Maximum Discharge (%)
SoC_max  = 1;         % SoC limit (%)
SoC_t0   = 0;         % Initial SoC (%)

P_B_int  = 0;         % Initial Battery power (W)
I_B_int  = 0;         % Initial Battery current (A)

Parameter cross-check against the project spec:

Constant	Value here	Project spec	Comment
A_PV	3060 m²	2,300 m² (Simulator I/O §1.4)	33% larger than spec
mu_PV	0.2	—	Reasonable for commercial silicon
P_ele	1.5 MW	—	Large relative to a 2,300 m² × 20% array (~460 kW peak)
E_rated	170000, commented W	Rated energy capacity in Wh	Unit comment is wrong; should be Wh
Q_rated	100000, commented W	Rated charge capacity in Ah	Unit comment is wrong; should be Ah
Disharge_max	2	—	Commented "%" but a discharge limit of 2 with SoC_max = 1 is dimensionally inconsistent. Also a typo for Discharge_max
SoC_t0	0	—	Starting from an empty battery

None of these break the model — they are annotation errors and a not-yet-calibrated parameter set — but they should be reconciled with the simulator contract before results are quoted.

4. SolarPanel.slx + Battery.slx (and SolarPanel_n_Battery.slx)

• Two individual models using the equations from paper 1 to derive the desired outputs over time.
• Both do this in two different ways, using different variables, to compare consistency.
• Most SoC-related quantities are handled in %. The dynamic data found is likely in another unit — that is what Q_rated and E_rated are for, to be used according to paper 1.

Known issue — model is not time-dependent

"An issue was encountered where this code does not appear to be time dependant despite drawing the appropriate _simulink matrices from the workspace. This is most likely some kind of conversion issue between time in seconds in code and time measured in the simulinks themselves."

This is unresolved and is the first item on the to-do list. The author's diagnosis is consistent with what PVBatteryRead.mlx does: it converts t to seconds in step 3, so any Simulink block configured in hours — or a solver whose stop time is set in hours — will see a signal that appears constant across the run because the simulated interval covers only the first few samples.

Where to look first: the [t, values] matrices are built with t in seconds; check the Simulink model's configured stop time and the From Workspace block's sample-time interpretation match that unit.

To be continued

Carried forward verbatim from the source:

• Fix the aforementioned time-dependency issue.
• Test and see if these values make sense. Compare the two versions for both.
• Discuss if this is a good standard for all parts.

File locations

All of these files were submitted on MATLAB Drive and ClickUp under Simulations → PV+Battery Simulink. In this repository:

File	Size	Note
PV+Battery.docx	1.6 kB	Source of this report
PVBatteryRead.mlx	—	Data import script
Constants.mlx	—	Parameter definitions
SolarPanel.slx	—	PV model
Battery.slx	—	Battery model
SolarPanel_n_Battery.slx	—	Combined model
SolarPanel.slxc	—	Simulink cache — build artefact
Profiles SHIFT(Generators Factors + Battery).xlsx	—	Byte-identical to the copy in Current Framework/
slprj/	—	Simulink build cache — machine-generated

Duplicate source note

The repository root contained PV+Battery.md, a markdown transcription of PV+Battery.docx with the same content. Since this report supersedes both, the root markdown copy is retired to superseded/ and the .docx remains in place as the original.

Related

• Generation Profiles Workbook — the spreadsheet this reads
• MATLAB Live Scripts — inventory of all .mlx files
• Simulink Model Inventory — all .slx files and their lineage
• Simulator I/O Interface §1.4–1.5 — the parameter spec these constants should match