add test cases descriptions

Signed-off-by: Peter Mitri <[email protected]>

src/tests/resources/modeler/epic2/us2.5/study_2.5.1/input/system.yml

@@ -1,6 +1,7 @@
 system:
   id: sys_example1
-  description: test system
+  description: one load of 100 MW, one cheap generator gen1 (max_p=80 MW, cost=0.5€/MWh), one expensive generator gen2  
+   (max_p=200 MW, cost=6€/MWh). Thus, gen1 must be used fully (80) and gen2 must complete (20), objective=80*0.5+20*6=160
   model-libraries: lib_example1
 
   components:

src/tests/resources/modeler/epic2/us2.5/study_2.5.2/input/system.yml

@@ -1,6 +1,8 @@
 system:
   id: sys_example2
-  description: test system
+  description: one load of 100 MW, one cheap generator gen1 (max_p=80 MW, cost=0.5€/MWh), one expensive generator gen2  
+   (min_p=40 MW, cost=6€/MWh). Thus, gen1 does not suffice, gen2 must be used at its min_p (40), and gen_1 must complete 
+   (60); on the 3 timestamps. Objective = 3 * (60 * 0.5 + 40 * 6) = 810
   model-libraries: lib_example2
 
   components:

src/tests/resources/modeler/epic2/us2.5/study_2.5.3/input/system.yml

@@ -1,6 +1,11 @@
 system:
   id: sys_example3
-  description: test system
+  description: in node1, gen is enough to fulfill load and is less expensive than gen1; thus gen1 must not be used (0)
+   and gen2 must be used at load level (100). Objective = 100 * 6 = 600 for node1.
+   In node2, load is 1000 MW and gen1 is cheap but not enough (max_p=650, cost=10€/MWh), and gen2 is large but more 
+   expensive (min_p=500, cost=20 €/MWh). Thus gen2 must be used at its minimum power (500) and gen1 should complete 
+   (500). Objective = 500 * 10 + 500 * 20 = 15000 for node2.
+   Total objective = 15600 for both nodes.
   model-libraries: lib_example1, lib_example2
 
   components:

src/tests/resources/modeler/epic2/us2.5/study_2.5.4/input/system.yml

@@ -1,6 +1,7 @@
 system:
   id: sys_example4
-  description: test system
+  description: a node with up to 10 similar generators (min_p=150, max_p=300, cost = 0.5 €/MWh + 10€/hour of up time).
+   Load is of 1000MW; thus 4 generators should be used. Objective = 1000*0.5 + 4*10 = 540.
   model-libraries: lib_example3
 
   components: