From 4b1a76541d3b0d3d9ace2bf039b3cd2608ebfe89 Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Sun, 9 Feb 2025 11:00:30 +0100
Subject: [PATCH] Initial commit

---
 README.md |  0
 mppt.py   | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 README.md
 create mode 100644 mppt.py

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/mppt.py b/mppt.py
new file mode 100644
index 0000000..20a74c9
--- /dev/null
+++ b/mppt.py
@@ -0,0 +1,61 @@
+import random
+
+from matplotlib import pyplot as plot
+import numpy as np
+
+def calc_p(U0, Ri, Rl):
+	I = U0 / (Ri + Rl)
+	Ul = I * Rl
+	P = Ul * I
+
+	return P
+
+
+U0 = 10
+Ri = 3.14
+Rl_min = 0.1
+Rl_max = 10.
+Rl_step_start = 1
+Rl_step_stop = 0.01
+
+Rl = np.linspace(Rl_min, Rl_max, 100, dtype=float)
+
+# --------------------------------------------------
+# MPPT search
+Rl_s = np.random.uniform()*(Rl_max - Rl_min) + Rl_min
+Rl_step = Rl_step_start
+dir = "inc"
+dir_last = dir
+while Rl_step > Rl_step_stop:
+	p0 = calc_p(U0, Ri, Rl_s)
+	p1 = p0
+	if "inc" in dir:
+		Rl_s = min(Rl_max, Rl_s + Rl_step)
+		p1 = calc_p(U0, Ri, Rl_s)
+		if p0 > p1:
+			if 'inc' in dir_last:
+				Rl_step /= 2
+			dir = 'dec'
+
+	elif "dec" in dir:
+		Rl_s = max(Rl_min, Rl_s - Rl_step)
+		p1 = calc_p(U0, Ri, Rl_s)
+		if p0 > p1:
+			if 'dec' in dir_last:
+				Rl_step /= 2
+			dir = 'inc'
+
+	dir_last = dir
+	print(f"p1 = {p1}, Rl_s = {Rl_s}, Rl_step {Rl_step}")
+
+# --------------------------------------------------
+
+P = calc_p(U0, Ri, Rl)
+plot.plot(Rl, P)
+
+plot.ylabel("Power [W]")
+plot.xlabel("RL [Ohms]")
+plot.title("Power vs RL")
+plot.legend("RL [Ohms]")
+plot.grid()
+plot.show()