Fixed issue in PWMsyn1ph: the equation "sigma = pre(sigma);" appeared to be used to cover the fact that sigma is only set during initialization, removed equation and changed sigma to a parameter with "fixed=false"
Set some parameters and constants to be declared as such for clarity
Removed use of non-standard function "classDirectory()" and replaced with modelica:// URL
Made partial model partial
Removed superfluous "import PowerSystems;" declarations
Replaced TableDir + "filename" with ModelicaServices.ExternalReferences.loadResource(TableDir + "filename") in order to handle URLs
Removed unspecified annotations "Window" and "DymolaStoredErrors"
Replaced __Dymola_checkBox with checkBox
Corrected hyperlinks in documentation