Merge pull request #93 from cuihantao/develop

Prepare for v1.2.2 release.

Author: cuihantao

andes/cases/GBnetwork/README.md

@@ -1,4 +1,4 @@
 GBnetwork power flow case downloaded from
-https://www.maths.ed.ac.uk/optenergy/NetworkData/fullGB/
+<https://www.maths.ed.ac.uk/optenergy/NetworkData/fullGB/>
 
 Dynamic data is randomly generated and does not represent the actual system.

andes/cases/ieee14/README.md

@@ -2,7 +2,7 @@ IEEE 14-Bus System
 
 Power flow data is created by J. Conto.
 
-Data is available at https://drive.google.com/drive/folders/0B7uS9L2Woq_7YzYzcGhXT2VQYXc
+Data is available at <https://drive.google.com/drive/folders/0B7uS9L2Woq_7YzYzcGhXT2VQYXc>
 
 Dynamic data is created by H. Cui for ANDES.
 

andes/cases/ieee14/ieee14_pvd1.xlsx

@@ -0,0 +1,14 @@
+"""
+An empty pert file.
+"""
+
+
+def pert(t, system):
+    """
+    Perturbation function called at each step.
+
+    The function is named "pert" and takes two arguments:
+    ``t`` for simulation time, and ``system`` for the system object.
+
+    """
+    pass

andes/cases/ieee14/pert.py

@@ -1,5 +1,5 @@
 Nordic 44-Bus System
 
-Source: https://github.com/ALSETLab/Nordic44-Nordpool/tree/master/nordic44/models
+Source: <https://github.com/ALSETLab/Nordic44-Nordpool/tree/master/nordic44/models>
 
 Most dynamic models in this system have not been supported.

andes/cases/kundur/kundur_vsc.xlsx

@@ -1467,14 +1467,16 @@ class GainLimiter(Block):
              │     │ _____/
              └─────┘ lower
 
+    TODO: Add an extra gain block "R" for y.
+
     Parameters
     ----------
     u : str, BaseVar
         Input variable, or an equation string for constructing an anonymous variable
 
     """
 
-    def __init__(self, u, K, upper, lower, no_upper=False, no_lower=False,
+    def __init__(self, u, K, lower, upper, no_lower=False, no_upper=False,
                  name=None, tex_name=None, info=None):
         Block.__init__(self, name=name, tex_name=tex_name, info=info)
         self.u = dummify(u)
@@ -1518,6 +1520,66 @@ def define(self):
         self.y.e_str += f' - {self.name}_y'
 
 
+class LimiterGain(Block):
+    """
+    Limiter followed by a gain.
+
+    Exports the limited output `y`, unlimited output `x`, and HardLimiter `lim`. ::
+
+                   upper ┌─────┐
+                  /¯¯¯¯¯ │     │
+        u  ->    /   ->  │  K  │ -> y
+           _____/        │     │
+           lower         └─────┘
+
+    The intermediate variable before the gain is not saved.
+
+    Parameters
+    ----------
+    u : str, BaseVar
+        Input variable, or an equation string for constructing an anonymous variable
+
+    """
+
+    def __init__(self, u, K, lower, upper, no_lower=False, no_upper=False,
+                 name=None, tex_name=None, info=None):
+        Block.__init__(self, name=name, tex_name=tex_name, info=info)
+        self.u = u
+        self.K = dummify(K)
+        self.upper = dummify(upper)
+        self.lower = dummify(lower)
+
+        if (no_upper and no_lower) is True:
+            raise ValueError("no_upper or no_lower cannot both be True")
+
+        self.no_lower = no_lower
+        self.no_upper = no_upper
+
+        self.lim = HardLimiter(u=self.u, lower=self.lower, upper=self.upper,
+                               no_upper=no_upper, no_lower=no_lower,
+                               tex_name='lim')
+
+        self.y = Algeb(info='Gain output after limiter', tex_name='y', discrete=self.lim)
+
+        self.vars = {'lim': self.lim, 'y': self.y}
+
+    def define(self):
+        """
+        TODO: write docstring
+        """
+        self.y.e_str = f'{self.K.name} * {self.u.name} * {self.name}_lim_zi'
+        self.y.v_str = f'{self.K.name} * {self.u.name} * {self.name}_lim_zi'
+
+        if not self.no_upper:
+            self.y.e_str += f' + {self.K.name} * {self.name}_lim_zu*{self.upper.name}'
+            self.y.v_str += f' + {self.K.name} * {self.name}_lim_zu*{self.upper.name}'
+        if not self.no_lower:
+            self.y.e_str += f' + {self.K.name} * {self.name}_lim_zl*{self.lower.name}'
+            self.y.v_str += f' + {self.K.name} * {self.name}_lim_zl*{self.lower.name}'
+
+        self.y.e_str += f' - {self.name}_y'
+
+
 class Piecewise(Block):
     """
     Piecewise block. Outputs an algebraic variable `y`.

andes/cases/nordic44/README.md

@@ -203,8 +203,10 @@ class Limiter(Discrete):
         True to only use the upper limit
     no_upper : bool
         True to only use the lower limit
-    equal: bool
+    equal : bool
         True to include equal signs in comparison (>= or <=).
+    no_warn : bool
+        Disable initial limit warnings
     zu : 0 or 1
         Default value for `zu` if not enabled
     zl : 0 or 1
@@ -224,7 +226,8 @@ class Limiter(Discrete):
     """
 
     def __init__(self, u, lower, upper, enable=True, name=None, tex_name=None, info=None,
-                 no_upper=False, no_lower=False, equal=True, zu=0.0, zl=0.0, zi=1.0):
+                 no_upper=False, no_lower=False, equal=True, no_warn=False,
+                 zu=0.0, zl=0.0, zi=1.0):
         Discrete.__init__(self, name=name, tex_name=tex_name, info=info)
         self.u = u
         self.lower = dummify(lower)
@@ -233,6 +236,7 @@ def __init__(self, u, lower, upper, enable=True, name=None, tex_name=None, info=
         self.no_upper = no_upper
         self.no_lower = no_lower
         self.equal = equal
+        self.no_warn = no_warn
 
         self.zu = np.array([zu])
         self.zl = np.array([zl])