Merge branch 'merge-cps' into 'master'

Merge cps

See merge request acs/public/simulation/dpsim!124

Former-commit-id: 1880c5ef

.gitmodules

-[submodule "Dependencies/libcps"]
-	path = Dependencies/libcps
-	url = ../cpowersystems.git
 [submodule "Examples/CIM/grid-data"]
 	path = Examples/CIM/grid-data
 	url = ../../grid-data/cim-grid-data.git

CMake/FindCIMpp.cmake

+set(CIMPP_DIR Dependencies/libcimpp)
+option(WITH_CIM_SUBMODULE "Build with CIMpp as submodule" OFF)
+
+set(CIM_VERSION "16v29a")	
+set(USE_CIM_VERSION "IEC61970_16v29a")
+
+include(FindPackageHandleStandardArgs)
+
+if(WIN32 AND NOT WITH_CIM_SUBMODULE)
+
+	set(CIMPP_INCLUDE_DIR 
+		${CMAKE_CURRENT_SOURCE_DIR}/${CIMPP_DIR}/src 
+		${CMAKE_CURRENT_SOURCE_DIR}/${CIMPP_DIR}/${CIM_VERSION}
+	)
+
+	find_library(CIMPP_LIBRARY
+		NAMES libcimpp.lib
+		PATH_SUFFIXES
+			Debug
+			Release
+		PATHS
+			${CMAKE_CURRENT_BINARY_DIR}/${CIMPP_DIR}	
+	)
+
+	set(ARABICA_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/${CIMPP_DIR}/thirdparty/arabica/include)
+
+	find_library(ARABICA_LIBRARY
+		NAMES arabica.lib
+		PATH_SUFFIXES
+			Debug
+			Release
+		PATHS
+			${CMAKE_CURRENT_BINARY_DIR}/${CIMPP_DIR}/thirdparty/arabica	
+	)
+
+	find_package_handle_standard_args(CIMpp DEFAULT_MSG CIMPP_LIBRARY CIMPP_INCLUDE_DIR)
+	mark_as_advanced(CIMPP_INCLUDE_DIR)
+
+	if(CIMPP_LIBRARY AND ARABICA_LIBRARY)
+		set(WITH_CIM_SUBMODULE OFF)
+	else()
+		set(WITH_CIM_SUBMODULE ON)
+		set(CIMPP_INCLUDE_DIR "")
+		set(CIMPP_LIBRARY "")
+		set(ARABICA_INCLUDE_DIR "")
+		set(ARABICA_LIBRARY "")
+	endif()
+endif()
+
+if (WITH_CIM_SUBMODULE)
+	# When adding CIMpp via a subdirectory, all the neccessary
+	# details about include directories, library name and path
+	# are associated with the CIMpp target 'libcimpp'
+	# We therefore do not need to keep track of CIMPP_INCLUDE_DIR
+	# seperately
+
+	if(NOT WIN32)
+		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")
+	endif()
+	add_subdirectory(Dependencies/libcimpp)
+	set(CIMPP_LIBRARY libcimpp)
+	set(CIMPP_LIBRARIES ${CIMPP_LIBRARY})
+	set(CIMPP_INCLUDE_DIR "")
+
+	find_package_handle_standard_args(CIMpp DEFAULT_MSG CIMPP_LIBRARY)
+
+elseif(NOT WIN32)
+	find_path(CIMPP_INCLUDE_DIR
+		NAMES CIMModel.hpp
+		PATH_SUFFIXES
+			cimpp/${CIM_VERSION}
+			${CIM_VERSION}
+			include/src
+	)
+	find_library(CIMPP_LIBRARY
+		NAMES cimpp${CIM_VERSION}
+		PATH_SUFFIXES
+			lib/static
+	)
+
+	# handle the QUIETLY and REQUIRED arguments and set CIMPP_FOUND to TRUE
+	# if all listed variables are TRUE
+	find_package_handle_standard_args(CIMpp DEFAULT_MSG CIMPP_LIBRARY CIMPP_INCLUDE_DIR)
+	mark_as_advanced(CIMPP_INCLUDE_DIR)
+
+endif()
+
+mark_as_advanced(CIMPP_LIBRARY)
+
+set(CIMPP_LIBRARIES ${CIMPP_LIBRARY} ${ARABICA_LIBRARY})
+set(CIMPP_INCLUDE_DIRS ${CIMPP_INCLUDE_DIR} ${ARABICA_INCLUDE_DIR})

CMake/FindEigen3.cmake

+option(WITH_EIGEN_SUBMODULE "Build with Eigen as submodule" OFF)
+
+if (WITH_EIGEN_SUBMODULE OR WIN32)
+	# This could be used when an optimized version of eigen is required
+	# add_subdirectory(Dependencies/eigen)
+	find_path(EIGEN3_INCLUDE_DIR
+		NAMES signature_of_eigen3_matrix_library
+		PATHS
+		  Dependencies/eigen
+	)
+else()
+	set(TEMP_PATH ${CMAKE_MODULE_PATH})
+	# We temporarily clear the module path to avoid recursion
+	set(CMAKE_MODULE_PATH "")
+	find_package(Eigen3 REQUIRED)
+	set(CMAKE_MODULE_PATH ${TEMP_PATH})
+endif()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Eigen3 REQUIRED_VARS EIGEN3_INCLUDE_DIR)

CMakeLists.txt

@@ -47,6 +47,19 @@ check_symbol_exists(getopt_long getopt.h HAVE_GETOPT)
 include(GetVersion)
 GetVersion(${PROJECT_SOURCE_DIR} "DPSIM")
 
+find_package(Eigen3 3.0 REQUIRED)
+option(SPDLOG_BUILD_TESTING "Build spdlog tests" OFF)
+option(SPDLOG_BUILD_BENCH "Build spdlog benchmarks" OFF)
+option(SPDLOG_BUILD_EXAMPLES "Build spdlog examples" OFF)
+# Workaround for spdlog in Windows
+# A custom FindSpdlog does not work currently
+option(WITH_SPDLOG_SUBMODULE "Build with Spdlog as submodule" OFF)
+if (WITH_SPDLOG_SUBMODULE OR WIN32)	
+	set(SPDLOG_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/Dependencies/spdlog/include)
+else()
+	find_package(spdlog REQUIRED)
+endif()
+find_package(CIMpp)
 add_subdirectory(Dependencies/libcps)
 
 find_package(PythonInterp 3.6)

libcps @ 811f480b

-Subproject commit 811f480b1b3eea0971f432e551c8e30aebbc954c

Dependencies/libcps/CMake/FindGSL.cmake

+include(FindPackageHandleStandardArgs)
+
+if (WIN32)
+    # GSL is currently not supported for Windows
+else()
+    find_path(GSL_INCLUDE_DIR
+        NAMES gsl_version.h
+        PATH_SUFFIXES gsl
+    )
+
+    find_library(GSL_LIBRARY NAMES libgsl.so)
+    find_library(GSL_CBLAS_LIBRARY NAMES libgslcblas.so)
+
+
+    set(GSL_LIBRARIES
+        ${GSL_LIBRARY}
+        ${GSL_CBLAS_LIBRARY}
+    )
+
+   # handle the QUIETLY and REQUIRED arguments and set SUNDIALS_FOUND to TRUE
+    # if all listed variables are TRUE
+    find_package_handle_standard_args(GSL DEFAULT_MSG GSL_LIBRARY GSL_INCLUDE_DIR)
+    mark_as_advanced(GSL_INCLUDE_DIR)
+endif()

Dependencies/libcps/CMake/FindGraphviz.cmake

+find_library(CGRAPH_LIBRARY
+    NAMES
+        cgraph
+    PATH_SUFFIXES
+        lib
+)
+
+find_library(GVC_LIBRARY
+    NAMES
+        gvc
+    PATH_SUFFIXES
+        lib
+)
+
+find_path(GRAPHVIZ_INCLUDE_DIR
+    NAMES
+        graphviz/cgraph.h
+    PATH_SUFFIXES
+        include
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Graphviz REQUIRED_VARS CGRAPH_LIBRARY GVC_LIBRARY GRAPHVIZ_INCLUDE_DIR)
+
+mark_as_advanced(GRAPHVIZ_LIBRARY GRAPHVIZ_INCLUDE_DIR)
+
+set(GRAPHVIZ_LIBRARIES ${CGRAPH_LIBRARY} ${GVC_LIBRARY})
+set(GRAPHVIZ_INCLUDE_DIRS ${GRAPHVIZ_INCLUDE_DIR})

Dependencies/libcps/CMake/FindNumPy.cmake

+# - Find the NumPy libraries
+# This module finds if NumPy is installed, and sets the following variables
+# indicating where it is.
+#
+# TODO: Update to provide the libraries and paths for linking npymath lib.
+#
+#  NUMPY_FOUND               - was NumPy found
+#  NUMPY_VERSION             - the version of NumPy found as a string
+#  NUMPY_VERSION_MAJOR       - the major version number of NumPy
+#  NUMPY_VERSION_MINOR       - the minor version number of NumPy
+#  NUMPY_VERSION_PATCH       - the patch version number of NumPy
+#  NUMPY_VERSION_DECIMAL     - e.g. version 1.6.1 is 10601
+#  NUMPY_INCLUDE_DIR         - path to the NumPy include files
+#
+# Source: https://raw.githubusercontent.com/BVLC/caffe/master/cmake/Modules/FindNumPy.cmake
+
+unset(NUMPY_VERSION)
+unset(NUMPY_INCLUDE_DIR)
+
+if(PYTHONINTERP_FOUND)
+  execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c"
+    "import numpy as n; print(n.__version__); print(n.get_include());"
+    RESULT_VARIABLE __result
+    OUTPUT_VARIABLE __output
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+  if(__result MATCHES 0)
+    string(REGEX REPLACE ";" "\\\\;" __values ${__output})
+    string(REGEX REPLACE "\r?\n" ";"    __values ${__values})
+    list(GET __values 0 NUMPY_VERSION)
+    list(GET __values 1 NUMPY_INCLUDE_DIR)
+
+    string(REGEX MATCH "^([0-9])+\\.([0-9])+\\.([0-9])+" __ver_check "${NUMPY_VERSION}")
+    if(NOT "${__ver_check}" STREQUAL "")
+      set(NUMPY_VERSION_MAJOR ${CMAKE_MATCH_1})
+      set(NUMPY_VERSION_MINOR ${CMAKE_MATCH_2})
+      set(NUMPY_VERSION_PATCH ${CMAKE_MATCH_3})
+      math(EXPR NUMPY_VERSION_DECIMAL
+        "(${NUMPY_VERSION_MAJOR} * 10000) + (${NUMPY_VERSION_MINOR} * 100) + ${NUMPY_VERSION_PATCH}")
+      string(REGEX REPLACE "\\\\" "/"  NUMPY_INCLUDE_DIR ${NUMPY_INCLUDE_DIR})
+    else()
+     unset(NUMPY_VERSION)
+     unset(NUMPY_INCLUDE_DIR)
+     message(STATUS "Requested NumPy version and include path, but got instead:\n${__output}\n")
+    endif()
+  endif()
+else()
+  message(STATUS "To find NumPy Python interpretator is required to be found.")
+endif()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(NumPy
+  REQUIRED_VARS NUMPY_INCLUDE_DIR NUMPY_VERSION
+  VERSION_VAR NUMPY_VERSION
+)
+
+mark_as_advanced(NUMPY_INCLUDE_DIR)
+set(NUMPY_INCLUDE_DIRS ${NUMPY_INCLUDE_DIR})
\ No newline at end of file

Dependencies/libcps/CMake/FindSundials.cmake

+include(FindPackageHandleStandardArgs)
+
+if (WIN32)
+    message(STATIS "Sundials is currently not supported in Windows")
+else()
+    find_path(SUNDIALS_INCLUDE_DIR
+        NAMES sundials_version.h
+        PATH_SUFFIXES sundials
+    )
+
+    find_library(SUNDIALS_ARKODE_LIBRARY NAMES sundials_arkode)
+    find_library(SUNDIALS_CVODE_LIBRARY  NAMES sundials_cvode)
+    find_library(SUNDIALS_CVODES_LIBRARY NAMES sundials_cvodes)
+    find_library(SUNDIALS_IDA_LIBRARY    NAMES sundials_ida)
+    find_library(SUNDIALS_IDAS_LIBRARY   NAMES sundials_idas)
+    find_library(SUNDIALS_KINSOL_LIBRARY NAMES sundials_kinsol)
+
+    set(SUNDIALS_LIBRARIES
+        ${SUNDIALS_ARKODE_LIBRARY}
+        ${SUNDIALS_CVODE_LIBRARY}
+        ${SUNDIALS_CVODES_LIBRARY}
+        ${SUNDIALS_IDA_LIBRARY}
+        ${SUNDIALS_IDAS_LIBRARY}
+        ${SUNDIALS_KINSOL_LIBRARY}
+    )
+
+    # handle the QUIETLY and REQUIRED arguments and set SUNDIALS_FOUND to TRUE
+    # if all listed variables are TRUE
+    find_package_handle_standard_args(Sundials DEFAULT_MSG SUNDIALS_ARKODE_LIBRARY SUNDIALS_INCLUDE_DIR)
+    mark_as_advanced(SUNDIALS_INCLUDE_DIR)
+endif()

Dependencies/libcps/CMakeLists.txt

+cmake_minimum_required(VERSION 3.6)
+project(CPowerSystems CXX)
+
+if(${CMAKE_VERSION} VERSION_GREATER "3.12.0")
+  # Allow setting Graphviz_ROOT for windows builds
+  cmake_policy(SET CMP0074 NEW)
+endif()
+
+# Enable C++11 support
+set(CMAKE_CXX_STANDARD 11)
+
+set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMake")
+
+include(CheckCXXCompilerFlag)
+if(MSVC)
+	check_cxx_compiler_flag("/W4 /WX" CXX_SUPPORTS_WERROR)
+
+	if(CXX_SUPPORTS_WERROR)
+	# TODO activate this again after fixing warnings
+	#	set(CPS_CXX_FLAGS /W4 /WX)
+	endif()
+else()
+	check_cxx_compiler_flag("-Wall -Werror" CXX_SUPPORTS_WERROR)
+
+	if(CXX_SUPPORTS_WERROR)
+		set(CPS_CXX_FLAGS -Wall -Werror)
+	endif()
+endif()
+
+set(Python_ADDITIONAL_VERSIONS 3.5 3.6 3.7)
+
+find_package(Threads REQUIRED)
+find_package(PythonInterp 3.5)
+find_package(PythonLibs 3.5)
+find_package(Graphviz)
+find_package(Sundials)
+find_package(GSL)
+find_package(NumPy)
+
+if(PythonInterp_FOUND AND PythonLibs_FOUND)
+	set(Python_FOUND ON)
+endif()
+
+if("${CMAKE_SYSTEM}" MATCHES "Linux")
+	set(Linux_FOUND ON)
+elseif("${CMAKE_SYSTEM}" MATCHES "Darwin")
+	set(MacOS_FOUND ON)
+endif()
+
+include(CMakeDependentOption)
+cmake_dependent_option(WITH_NUMPY    	"Enable NumPy"							ON "NumPy_FOUND"		OFF)
+cmake_dependent_option(WITH_GSL			"Enable GSL"        					ON "GSL_FOUND"			OFF)
+cmake_dependent_option(WITH_SUNDIALS	"Enable sundials solver suite"			ON "Sundials_FOUND"		OFF)
+cmake_dependent_option(WITH_PYTHON		"Enable Python support"					ON "Python_FOUND"		OFF)
+cmake_dependent_option(WITH_CIM			"Enable support for parsing CIM files"	ON "CIMpp_FOUND"		OFF)
+cmake_dependent_option(WITH_GRAPHVIZ	"Enable support for Graphviz Graphs"	ON "Graphviz_FOUND"		OFF)
+
+# Show feature summary
+include(FeatureSummary)
+
+add_feature_info(CIM       WITH_CIM       "Loading Common Information Model Files")
+add_feature_info(Graphviz  WITH_GRAPHVIZ  "Graphviz Graphs")
+add_feature_info(Python    WITH_PYTHON    "Use DPsim as a Python module")
+add_feature_info(Sundials  WITH_SUNDIALS  "Sundials solvers")
+
+if(${CMAKE_PROJECT_NAME} STREQUAL ${PROJECT_NAME})
+	feature_summary(WHAT ALL VAR enabledFeaturesText)
+	message(STATUS "Feature summary for CPS")
+	message(STATUS "${enabledFeaturesText}")
+endif()
+
+configure_file(
+	${CMAKE_CURRENT_SOURCE_DIR}/Include/cps/Config.h.in
+	${CMAKE_CURRENT_BINARY_DIR}/Include/cps/Config.h
+)
+
+set(INCLUDE_DIRS
+	${CMAKE_CURRENT_SOURCE_DIR}/Include
+	${CMAKE_CURRENT_BINARY_DIR}/Include
+	${EIGEN3_INCLUDE_DIR}
+	${SPDLOG_INCLUDE_DIR}
+)
+
+set(LIBRARIES
+	Threads::Threads
+)
+
+if(Linux_FOUND OR MacOS_FOUND)
+	# TODO This doesn't actually depend on which OS or compiler is used, but which
+	# stdlib. For now, under Linux only GNU's libstdc++ seems to work anyway.
+	# With LLVM's libc++, -lc++fs should probably be used
+	list(APPEND LIBRARIES stdc++fs)
+endif()
+
+add_subdirectory(Source)
+add_subdirectory(Examples)
+add_subdirectory(Tests)

Dependencies/libcps/Documentation/Latex/.gitignore

+*.synctex.gz
+*.log
+*.toc
+*.aux
+*.pdf
+*.bbl
+*.blg
+*.dvi
+*.out

Dependencies/libcps/Documentation/Latex/DPsim_Documentation.tex

+ %----------------------------------------------------------
+% Packages and other configurations
+%----------------------------------------------------------
+
+\documentclass{report}
+
+\usepackage{graphicx} % Needed to insert images into the document
+\graphicspath{{img/}} % Sets the default location of pictures
+
+\usepackage{amsmath}
+
+\usepackage{hyperref}
+
+\usepackage{xcolor}
+
+\newcommand{\todo}[1]{\textcolor{red}{[TODO: #1]}}
+
+\title{Documentation of the Dynamic Phasor Simulator - DPsim}
+\author{Markus Mirz, Jan Dinkelbach, Viviane Sapucaia, Antonello Monti}
+
+\begin{document}
+
+\maketitle
+
+\tableofcontents
+
+%----------------------------------------------------------
+% Content
+%----------------------------------------------------------
+
+\include{content/introduction} 
+\include{content/dynamic_phasors}
+\include{content/nodal_analysis}
+\include{content/powerflow}
+
+\chapter{Models}
+\include{content/branches}
+\include{content/synchronous_machine}
+\include{content/induction_machine}
+\include{content/power_converters}
+
+\include{content/appendix}
+
+%----------------------------------------------------------
+% Bibliography
+%----------------------------------------------------------
+\bibliographystyle{ieeetr} 
+\bibliography{bibliography}
+
+%----------------------------------------------------------
+% End
+%----------------------------------------------------------
+
+\end{document}

Dependencies/libcps/Documentation/Latex/bibliography.bib

+%----------------------------------------------------------
+% Books
+%----------------------------------------------------------
+@book{kundur1994power,
+  title={Power system stability and control},
+  author={Kundur, Prabha and Balu, Neal J and Lauby, Mark G},
+  volume={7},
+  year={1994},
+  publisher={McGraw-hill New York}
+}
+
+@article{krause2002,
+  title={Analysis of Electric Machinery and Drive Systems},
+  author={Krause, Paul and Wasynczuk, Oleg and Sudhoff, Scott and Pekarek, Steven},
+  journal={IEEE Press},
+  year={2002}
+}
+
+@book{maas2003nonlinear,
+  title={Nonlinear microwave and RF circuits},
+  author={Maas, Stephen A},
+  year={2003},
+  publisher={Artech House}
+}
+
+@book{suarez2009analysis,
+  title={Analysis and design of autonomous microwave circuits},
+  author={Su{\'a}rez, Almudena},
+  volume={190},
+  year={2009},
+  publisher={John Wiley \& Sons}
+}
+
+@book{haykin2009communication,
+  title={Communication Systems, 5th Edition},
+  author={Haykin, Simon and Moher, Michael},
+  year={2009},
+  publisher={Wiley}
+}
+
+@book{proakis2001communication,
+  title={Communication Systems, 5th Edition},
+  author={Proakis, John and Salehi, Masoud},
+  year={2001},
+  publisher={Prentice Hall}
+}
+
+@book{schreier2010statistical,
+  title={Statistical signal processing of complex-valued data: the theory of improper and noncircular signals},
+  author={Schreier, Peter J and Scharf, Louis L},
+  year={2010},
+  publisher={Cambridge University Press}
+}
+
+%----------------------------------------------------------
+% Papers
+%----------------------------------------------------------
+
+@article{wang2010methods,
+  title={Methods of interfacing rotating machine models in transient simulation programs},
+  author={Wang, L and Jatskevich, J and Dinavahi, V and Dommel, HW and Martinez, JA and Strunz, K and Rioual, M and Chang, GW and Iravani, R},
+  journal={IEEE Transactions on Power Delivery},
+  volume={25},
+  number={2},
+  pages={891--903},
+  year={2010},
+  publisher={IEEE}
+}
+
+@article{sanders1991generalized,
+  title={Generalized averaging method for power conversion circuits},
+  author={Sanders, Seth R and Noworolski, J Mark and Liu, Xiaojun Z and Verghese, George C},
+  journal={IEEE Transactions on Power Electronics},
+  volume={6},
+  number={2},
+  pages={251--259},
+  year={1991},
+  publisher={IEEE}
+}
+
+@article{venkatasubramanian1995fast,
+  title={Fast time-varying phasor analysis in the balanced three-phase large electric power system},
+  author={Venkatasubramanian, Vaithianathan and Schattler, Heinz and Zaborszky, John},
+  journal={IEEE Transactions on Automatic Control},
+  volume={40},
+  number={11},
+  pages={1975--1982},
+  year={1995},
+  publisher={IEEE}
+}
+
+@article{strunz2006frequency,
+  title={Frequency-adaptive network modeling for integrative simulation of natural and envelope waveforms in power systems and circuits},
+  author={Strunz, Kai and Shintaku, Rachel and Gao, Feng},
+  journal={IEEE Transactions on Circuits and Systems I: Regular Papers},
+  volume={53},
+  number={12},
+  pages={2788--2803},
+  year={2006},
+  publisher={IEEE}
+}
+
+@inproceedings{demiray2008evaluation,
+  title={Evaluation study for the simulation of power system transients using dynamic phasor models},
+  author={Demiray, T and Andersson, G and Busarello, L},
+  booktitle={Transmission and Distribution Conference and Exposition: Latin America, 2008 IEEE/PES},
+  pages={1--6},
+  year={2008},
+  organization={IEEE}
+}
+
+@article{mattavelli1999ssr,
+  title={SSR analysis with dynamic phasor model of thyristor-controlled series capacitor},
+  author={Mattavelli, Paolo and Stankovic, Aleksandar M and Verghese, George C},
+  journal={IEEE Transactions on Power Systems},
+  volume={14},
+  number={1},
+  pages={200--208},
+  year={1999},
+  publisher={IEEE}
+}
+
+@article{stefanov2002modeling,
+  title={Modeling of UPFC operation under unbalanced conditions with dynamic phasors},
+  author={Stefanov, Predrag C and Stankovic, Aleksandar M},
+  journal={IEEE Transactions on Power Systems},
+  volume={17},
+  number={2},
+  pages={395--403},
+  year={2002},
+  publisher={IEEE}
+}
+
+@inproceedings{demiray2007dynamic,
+  title={Dynamic phasor modeling of the doubly-fed induction generator under unbalanced conditions},
+  author={Demiray, Turhan and Milano, F and Andersson, G{\"o}ran},
+  booktitle={Power Tech, 2007 IEEE Lausanne},
+  pages={1049--1054},
+  year={2007},
+  organization={IEEE}
+}
+
+@article{stankovic2000analysis,
+  title={Analysis of asymmetrical faults in power systems using dynamic phasors},
+  author={Stankovic, Aleksandar M and Aydin, Timur},
+  journal={IEEE Transactions on Power Systems},
+  volume={15},
+  number={3},
+  pages={1062--1068},
+  year={2000},
+  publisher={IEEE}
+}
+