Merge pull request #13 from NREL/develop

Include rated power in yaw correction to master
NREL · Jun 13, 2019 · c23fd0e · c23fd0e
2 parents 20094e0 + a17dba3
commit c23fd0e
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Showing 5 changed files with 28 additions and 9 deletions.
diff --git a/floris/simulation/turbine.py b/floris/simulation/turbine.py
@@ -402,6 +402,7 @@ def average_velocity(self):
         """
         return np.cbrt(np.mean(self.velocities**3))
 
+
     @property
     def Cp(self):
         """
@@ -413,6 +414,8 @@ def Cp(self):
         calculated as the cube root of the mean cubed velocity in the 
         rotor area.
 
+        Note, the velocity is scalled to an effective velocity by the yaw
+
         Returns:
             float: The power coefficient of a turbine at the current 
             operating conditions.
@@ -422,7 +425,11 @@ def Cp(self):
 
             >>> Cp = floris.farm.turbines[0].Cp()
         """
-        return self._fCp(self.average_velocity)
+        # Compute the yaw effective velocity
+        pW = self.pP / 3.0 # Convert from pP to pW
+        yaw_effective_velocity = self.average_velocity * cosd(self.yaw_angle) ** pW
+
+        return self._fCp(yaw_effective_velocity)
 
     @property
     def Ct(self):
@@ -460,12 +467,24 @@ def power(self):
 
             >>> power = floris.farm.turbines[0].power()
         """
-        cptmp = self.Cp \
-            * cosd(self.yaw_angle)**self.pP \
-            * cosd(self.tilt_angle)**self.pT
+
+        # Update to power calculation which replaces the fixed pP exponent with
+        # an exponent pW, that changes the effective wind speed input to the power 
+        # calculation, rather than scaling the power.  This better handles power
+        # loss to yaw in above rated conditions
+        # 
+        # based on the paper "Optimising yaw control at wind farm level" by
+        # Ervin Bossanyi
+
+        # Compute the yaw effective velocity
+        pW = self.pP / 3.0 # Convert from pP to w
+        yaw_effective_velocity = self.average_velocity * cosd(self.yaw_angle) ** pW
+
+        # Now compute the power
+        cptmp = self.Cp #Note Cp is also now based on yaw effective velocity
         return 0.5 * self.air_density * (np.pi * self.rotor_radius**2) \
             * cptmp * self.generator_efficiency \
-            * self.average_velocity**3
+            * yaw_effective_velocity**3
 
     @property
     def aI(self):

diff --git a/tests/curl_regression_test.py b/tests/curl_regression_test.py
@@ -39,7 +39,7 @@ def baseline(self, turbine_index):
 
     def yawed_baseline(self, turbine_index):
         baseline = [
-            (0.4632707, 0.7626735 , 1780240.6778116, 0.2559082, 7.9727208),
+            (0.4632734, 0.7626735, 1780250.9240069, 0.2559082, 7.9727208),
             (0.4539774, 0.8325224, 761784.3584749, 0.2953798, 6.0342075)
         ]
         return baseline[turbine_index]

diff --git a/tests/gauss_regression_test.py b/tests/gauss_regression_test.py
@@ -39,7 +39,7 @@ def baseline(self, turbine_index):
 
     def yawed_baseline(self, turbine_index):
         baseline = [
-            (0.4632706, 0.7626695, 1780851.3400887, 0.2559061, 7.9736330),
+            (0.4632733, 0.7626695, 1780861.5909742, 0.2559061, 7.9736330),
             (0.4519389, 0.8403914, 696267.1270400, 0.3002448, 5.8647976)
         ]
         return baseline[turbine_index]

diff --git a/tests/jensen_jimenez_regression_test.py b/tests/jensen_jimenez_regression_test.py
@@ -39,7 +39,7 @@ def baseline(self, turbine_index):
 
     def yawed_baseline(self, turbine_index):
         baseline = [
-            (0.4632706, 0.7626695, 1780851.3400887, 0.2559061, 7.9736330),
+            (0.4632733, 0.7626695, 1780861.5909742, 0.2559061, 7.9736330),
             (0.4554894, 0.8266861, 813067.4207660, 0.2918451, 6.1598540)
         ]
         return baseline[turbine_index]

diff --git a/tests/multizone_jimenez_regression_test.py b/tests/multizone_jimenez_regression_test.py
@@ -39,7 +39,7 @@ def baseline(self, turbine_index):
 
     def yawed_baseline(self, turbine_index):
         baseline = [
-            (0.4632706, 0.7626695, 1780851.3400887, 0.2559061, 7.9736330),
+            (0.4632733, 0.7626695, 1780861.5909742, 0.2559061, 7.9736330),
             (0.4420041, 0.8650277, 535742.2576472, 0.3163071, 5.4141570)
         ]
         return baseline[turbine_index]