352 lines
11 KiB
Markdown
352 lines
11 KiB
Markdown
# MPPT Testbench
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Unified tool for testing and tuning MPPT (Maximum Power Point Tracking) converters. Combines three bench instruments with direct STM32 firmware access for closed-loop parameter optimization.
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| Instrument | Role | Interface |
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| **ITECH IT6537D** | DC power supply (solar panel simulator, 80V/120A/6kW) | USB-TMC / SCPI via PyVISA |
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| **Prodigit 3366G** | DC electronic load (600V/420A/6kW) | RS-232 (115200 8N1 RTS/CTS) |
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| **HIOKI 3193-10** | Power analyzer (efficiency measurement) | GPIB via UsbGpib / PyVISA |
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| **STM32G474** | Converter firmware (LVSolarBuck64) | Serial 460800 baud (debug protocol) |
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## Wiring
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```
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+------------------+
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IT6500D --(+/-)--> | MPPT Tracker | --(+/-)--> Prodigit 3366G
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| (DUT) |
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HIOKI Ch5 --(sense)-- | Input Output | --(sense)-- HIOKI Ch6
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+------------------+
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STM32 debug
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serial (COM28)
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HIOKI EFF1 = P6 / P5 x 100% (output power / input power)
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```
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## Installation
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Requires Python 3.12+, NI-VISA runtime, and [uv](https://docs.astral.sh/uv/).
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```bash
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git clone --recurse-submodules https://git.b4l.co.th/B4L/mppt-testbench.git
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cd mppt-testbench
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uv sync
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```
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The debug console (inside `code64/`) has its own environment:
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```bash
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cd code64
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uv sync
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```
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## Step-by-Step Guide
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### 1. Connect and verify instruments
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```bash
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# Check all bench instruments respond
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uv run bench identify
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# Check STM32 responds (reads params + telemetry)
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uv run bench stm32-read --stm32-port COM28
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```
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### 2. Configure instruments for MPPT testing
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```bash
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uv run bench setup
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```
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This sets wiring mode (1P2W), DC coupling, auto-ranging, efficiency formula (EFF1 = P6/P5), and display layout on the HIOKI.
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### 3. Basic measurements
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```bash
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# Single reading from all instruments
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uv run bench measure
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# Continuous text monitoring with CSV export
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uv run bench monitor --interval 1.0 --output data.csv
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```
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### 4. Launch the GUI
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```bash
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uv run bench-gui
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```
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The GUI provides:
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- Real-time readouts from all three instruments
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- Supply voltage/current control with ON/OFF indicators
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- Load mode (CC/CR/CV/CP) and setpoint control
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- HIOKI channel range selectors + degauss buttons
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- Meter format selector (scientific/normal)
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- 2D sweep panel with time estimate
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- Live-updating power, efficiency, voltage, and current plots
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- Console log panel
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### 5. Run efficiency sweeps
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#### Voltage sweep (1D)
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```bash
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uv run bench sweep \
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--v-start 30 --v-stop 100 --v-step 5 \
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--current-limit 20 \
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--load-mode CP --load-value 200 \
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--settle 2.0 -o voltage_sweep.csv
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```
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#### Load sweep at fixed voltage (1D)
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```bash
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uv run bench sweep-load \
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--voltage 60 --current-limit 20 \
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--i-start 0.5 --i-stop 15 --i-step 0.5 \
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--settle 2.0 -o load_sweep.csv
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```
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#### 2D voltage x load sweep (efficiency map)
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```bash
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# Constant Power mode
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uv run bench sweep-vi \
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--v-start 60 --v-stop 100 --v-step 5 \
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--l-start 50 --l-stop 500 --l-step 50 \
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--load-mode CP --current-limit 20 \
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--settle 2.0 -o map_cp.csv
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# Constant Current mode
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uv run bench sweep-vi \
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--v-start 35 --v-stop 100 --v-step 5 \
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--l-start 0.5 --l-stop 15 --l-step 0.5 \
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--load-mode CC --current-limit 20 \
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--settle 2.0 -o map_cc.csv
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```
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### 6. Analyze sweep results
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```bash
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# Generate efficiency overlay, heatmap, and power loss plots (no instruments needed)
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uv run bench plot-sweep map_cp.csv
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# Save plots without displaying
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uv run bench plot-sweep map_cp.csv --no-show -o plots/
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```
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Produces three PNG files:
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- `*_efficiency.png` -- efficiency vs load, one line per voltage, best point marked
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- `*_heatmap.png` -- 2D efficiency surface (voltage x load)
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- `*_loss.png` -- power loss vs load, all voltages overlaid
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### 7. Tune converter parameters
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The tuning commands combine the testbench instruments (ground truth efficiency from HIOKI) with direct STM32 parameter writes to find optimal settings.
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#### Read current STM32 state
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```bash
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uv run bench stm32-read
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```
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#### Write a single parameter
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```bash
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uv run bench stm32-write --param dt_10_20A --value 20
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```
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#### Sweep a parameter to find the optimum
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Sweeps a parameter from start to stop, measuring HIOKI efficiency + STM32 telemetry at each step. Plots the result.
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```bash
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# Optimize deadtime for the 10-20A bracket at 300W
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uv run bench tune-param \
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--param dt_10_20A --start 14 --stop 40 --step 1 \
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--voltage 60 --current-limit 20 \
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--load-mode CP --load-value 300 \
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--settle 3.0 -o dt_tune.csv
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# Tune Vfly proportional gain
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uv run bench tune-param \
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--param vfly_kp --start -2 --stop 2 --step 0.1 \
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--voltage 60 --current-limit 20 \
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--load-mode CP --load-value 200 \
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--settle 3.0
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```
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#### Auto-optimize all deadtime brackets
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Automatically sweeps deadtime for each of the 6 current brackets (0-3A, 3-5A, 5-10A, 10-20A, 20-30A, 30-45A), setting an appropriate load for each bracket.
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```bash
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# Sweep and report best values
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uv run bench tune-deadtime \
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--voltage 60 --current-limit 20 --load-mode CP \
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--dt-start 14 --dt-stop 50 --dt-step 1 \
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-o deadtime_results.csv
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# Sweep, report, and apply best values to STM32
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uv run bench tune-deadtime \
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--voltage 60 --current-limit 20 --load-mode CP \
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--load-values 20,50,100,250,400,600 \
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--apply
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```
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### 8. Shade / irradiance profile simulation
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Simulate cloud passing or partial shading with a CSV-driven sequence:
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```bash
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uv run bench shade-profile \
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--profile samples/cloud_pass.csv \
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--settle 2.0 -o shade_results.csv
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```
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Profile CSV format: `time,voltage,current_limit,load_mode,load_value`
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### 9. Real-time debug console (TUI)
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For live monitoring and parameter tuning via the Textual terminal UI:
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```bash
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cd code64
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uv run debug-console COM28
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```
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Keybindings: `p` ping, `r` read params, `f` toggle EMA filter, `l` show log path, `q` quit.
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### 10. Direct instrument control
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```bash
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# Supply
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uv run bench supply set --voltage 48 --current 10
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uv run bench supply on
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uv run bench supply off
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# Load
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uv run bench load set --mode CP --value 200
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uv run bench load on
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uv run bench load off
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# Emergency shutdown (load first, then supply)
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uv run bench safe-off
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```
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## CLI Reference
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```
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uv run bench [-h] [--supply-address ADDR] [--load-port PORT] [--load-baud BAUD]
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[--meter-address ADDR] [--timeout MS]
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[--stm32-port PORT] [--stm32-baud BAUD]
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{command}
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```
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| Command | Description |
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| `identify` | Show identity and status of all instruments |
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| `setup` | Configure all instruments for MPPT testing |
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| `measure` | Single measurement from all three instruments |
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| `monitor` | Continuous text monitoring with optional CSV |
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| `live` | Real-time 4-panel matplotlib graph |
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| `sweep` | Voltage sweep with efficiency recording |
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| `sweep-load` | Load current sweep at fixed voltage |
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| `sweep-vi` | 2D voltage x load sweep (efficiency map) |
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| `efficiency` | Averaged efficiency at a fixed operating point |
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| `shade-profile` | Run shade/irradiance profile from CSV |
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| `plot-sweep` | Generate analysis plots from sweep CSV (offline) |
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| `stm32-read` | Read all STM32 parameters and telemetry |
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| `stm32-write` | Write a parameter to the STM32 |
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| `tune-param` | Sweep an STM32 parameter while measuring efficiency |
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| `tune-deadtime` | Auto-optimize deadtime for each current bracket |
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| `supply` | Direct IT6500D control (on/off/set) |
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| `load` | Direct Prodigit 3366G control (on/off/set) |
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| `safe-off` | Emergency shutdown (load first, then supply) |
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### Global Options
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| Option | Default | Description |
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| `--supply-address` | auto-detect | IT6500D VISA address |
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| `--load-port` | `COM1` | Prodigit 3366G serial port |
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| `--load-baud` | `115200` | Prodigit 3366G baud rate |
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| `--meter-address` | auto-detect | HIOKI 3193-10 VISA address |
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| `--timeout` | `5000` | VISA timeout in milliseconds |
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| `--stm32-port` | `COM28` | STM32 debug serial port |
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| `--stm32-baud` | `460800` | STM32 debug baud rate |
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## Tunable STM32 Parameters
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| Parameter | Type | Range | Description |
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| `VREF` | uint16 | 3100-3700 | ADC reference voltage |
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| `vfly_kp` | float | -10 to 10 | Vfly proportional gain |
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| `vfly_ki` | float | -10 to 10 | Vfly integral gain |
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| `vfly_clamp` | uint16 | 0-10000 | Vfly integrator clamp |
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| `vfly_active` | uint8 | 0-1 | Vfly loop enable |
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| `cc_target` | float | 0-60000 | CC target (mA) |
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| `cc_gain` | float | -1 to 1 | CC proportional gain |
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| `cc_active` | int32 | 0-1 | CC loop enable |
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| `mppt_step` | float | 0-10000 | MPPT P&O step size (mA) |
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| `mppt_deadband` | float | 0-1 | MPPT deadband |
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| `mppt_active` | int32 | 0-1 | MPPT loop enable |
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| `dt_0_3A` | uint8 | 14-200 | Deadtime 0-3A (HRTIM ticks) |
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| `dt_3_5A` | uint8 | 14-200 | Deadtime 3-5A |
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| `dt_5_10A` | uint8 | 14-200 | Deadtime 5-10A |
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| `dt_10_20A` | uint8 | 14-200 | Deadtime 10-20A |
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| `dt_20_30A` | uint8 | 14-200 | Deadtime 20-30A |
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| `dt_30_45A` | uint8 | 14-200 | Deadtime 30-45A |
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## CSV Output Format
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Sweep CSV files contain:
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| Column | Description |
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| `voltage_set` | Supply voltage setpoint (V) |
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| `current_limit` | Supply current limit (A) |
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| `load_setpoint` | Load setpoint value (A for CC, W for CP) |
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| `supply_V/I/P` | Supply measured voltage, current, power |
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| `load_V/I/P` | Load measured voltage, current, power |
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| `input_power` | HIOKI P5 -- power into MPPT tracker (W) |
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| `output_power` | HIOKI P6 -- power out of MPPT tracker (W) |
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| `efficiency` | HIOKI EFF1 -- P6/P5 x 100 (%) |
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Tuning CSV files additionally contain `param_name`, `param_value`, and STM32 telemetry columns (`stm_vin`, `stm_vout`, `stm_iin`, `stm_iout`, `stm_eff`, `stm_vfly`, `stm_etemp`).
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## Project Structure
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```
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mppt-testbench/
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+-- IT6500D/ git submodule -- DC power supply driver
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+-- PRODIGIT-3366G/ git submodule -- electronic load driver
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+-- HIOKI-3193-10/ git submodule -- power analyzer driver
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+-- testbench/
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| +-- __init__.py exports MPPTTestbench
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| +-- bench.py orchestrator (sweeps, measurement, auto-range wait)
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| +-- cli.py unified CLI entry point
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| +-- gui.py tkinter GUI with live plots
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| +-- gui_workers.py background instrument I/O thread
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| +-- stm32_link.py synchronous STM32 debug protocol interface
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| +-- tuner.py automated tuning routines (param sweep, deadtime opt)
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+-- code64/
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| +-- Core/ STM32G474 firmware (C)
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| +-- Drivers/ HAL drivers
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| +-- debug_console/ Textual TUI for live debugging
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| +-- pyproject.toml uv-compatible package config
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+-- samples/ shade profile CSV examples
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+-- pyproject.toml package config, entry points: bench, bench-gui
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```
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## Dependencies
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- Python >= 3.12
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- [PyVISA](https://pyvisa.readthedocs.io/) + [pyvisa-py](https://pyvisa.readthedocs.io/projects/pyvisa-py/)
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- [pyserial](https://pyserial.readthedocs.io/)
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- [matplotlib](https://matplotlib.org/)
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- [numpy](https://numpy.org/)
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- NI-VISA runtime (for GPIB/USB-TMC communication)
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- [Textual](https://textual.textualize.io/) (debug console only, in code64/)
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