THDi

mathieucarbou · Feb 24, 2024 · 417bb5c · 417bb5c
1 parent cf052b2
commit 417bb5c
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/src/MycilaPZEM004Tv3.h b/src/MycilaPZEM004Tv3.h
@@ -96,11 +96,20 @@ namespace Mycila {
       float getPowerFactor() const { return _powerFactor; }
       float getApparentPower() const { return _powerFactor == 0 ? 0 : _power / _powerFactor; }
       float getVoltage() const { return _voltage; }
+
       float getResistance() const {
         const float c = _current;
         return c == 0 ? 0 : _voltage / c;
       }
 
+      float getTHDi(float phi) const {
+        const float pf = _powerFactor;
+        if (pf == 0)
+          return 0;
+        // https://fr.electrical-installation.org/frwiki/Indicateur_de_distorsion_harmonique_:_facteur_de_puissance
+        return sqrt(pow(cos(phi), 2) / pow(pf, 2) - 1);
+      }
+
       // get the uptime in milliseconds of the last successful read
       uint32_t getTime() const { return _lastReadSuccess; }