TabularModelDMVsForDocumentation

//list available DMVs
Select * from $SYSTEM.DBSCHEMA_TABLES where table_type = 'Schema' order by table_name

//Useful DMVs for 2016 SSAS Tabular Models
Select * from $SYSTEM.TMSCHEMA_ATTRIBUTE_HIERARCHY_STORAGES //distinct data count for each column
Select * from $SYSTEM.TMSCHEMA_ATTRIBUTE_HIERARCHIES  //ties hierarchy id to column
SELECT * from $SYSTEM.TMSCHEMA_COLUMN_STORAGES //has order by column, row count is inaccurate
Select * from $SYSTEM.TMSCHEMA_COLUMNS //column name, ID for table, data type, category, hidden, iskey, isunique, is nullable, summarize by, expression for calc columns, hierarchy id, refresh time, modify time. source provider type, display folder
SELECT * from $SYSTEM.TMSCHEMA_DATA_SOURCES //connection string, account, impersonation mode, name
Select * from $SYSTEM.TMSCHEMA_HIERARCHIES //hierarchy name, display folder
Select * from $SYSTEM.TMSCHEMA_HIERARCHY_STORAGES //user hierarchy definitions
Select * from $SYSTEM.TMSCHEMA_KPIS //KPI definition
Select * from $SYSTEM.TMSCHEMA_LEVELS //hierarchy level and model source column
Select * from $SYSTEM.TMSCHEMA_MEASURES //measure and expressions, formatt, hidden, display folder
Select * from $SYSTEM.TMSCHEMA_MODEL //name of each model
Select * from $SYSTEM.TMSCHEMA_PARTITIONS //source queries for each table
Select * from $SYSTEM.TMSCHEMA_PERSPECTIVE_COLUMNS //perspective table to perspective column maps
Select * from $SYSTEM.TMSCHEMA_PERSPECTIVE_HIERARCHIES // perspective table to hierarchy id map
Select * from $SYSTEM.TMSCHEMA_PERSPECTIVE_MEASURES // perspective table id to measure id map
Select * from $SYSTEM.TMSCHEMA_PERSPECTIVE_TABLES //perspective to table map
Select * from $SYSTEM.TMSCHEMA_PERSPECTIVES //list of perspectives
Select * from $SYSTEM.TMSCHEMA_RELATIONSHIPS //active , type, crossfilter, table, colmn, cardinality
Select * from $SYSTEM.TMSCHEMA_ROLE_MEMBERSHIPS //member name, ID, Modified time, role id,
Select * from $SYSTEM.TMSCHEMA_ROLES //model, name, description, permission
Select * from $SYSTEM.TMSCHEMA_TABLE_PERMISSIONS // role, rable, filter expression, modified time
Select * from $SYSTEM.TMSCHEMA_TABLES  //tables, description, hidden, 
Select * from $SYSTEM.DBSCHEMA_CATALOGS //Catalog name, description, compatibility level, type, database id, version

//Other DMVs
Select * from $SYSTEM.TMSCHEMA_ANNOTATIONS 
Select * from $SYSTEM.TMSCHEMA_COLUMN_PARTITION_STORAGES 
Select * from $SYSTEM.TMSCHEMA_CULTURES 
Select * from $SYSTEM.TMSCHEMA_DICTIONARY_STORAGES 
Select * from $SYSTEM.TMSCHEMA_LINGUISTIC_METADATA 
Select * from $SYSTEM.TMSCHEMA_OBJECT_TRANSLATIONS 
Select * from $SYSTEM.TMSCHEMA_PARTITION_STORAGES 
Select * from $SYSTEM.TMSCHEMA_RELATIONSHIP_INDEX_STORAGES 
Select * from $SYSTEM.TMSCHEMA_RELATIONSHIP_STORAGES 
Select * from $SYSTEM.TMSCHEMA_SEGMENT_MAP_STORAGES 
Select * from $SYSTEM.TMSCHEMA_SEGMENT_STORAGES 
Select * from $SYSTEM.TMSCHEMA_STORAGE_FILES 
Select * from $SYSTEM.TMSCHEMA_STORAGE_FOLDERS 
Select * from $SYSTEM.TMSCHEMA_TABLE_STORAGES
Select * from $SYSTEM.DBSCHEMA_COLUMNS

See Microsoft documentation at https://msdn.microsoft.com/en-us/library/mt719260(v=sql.105).aspx
Note that $SYSTEM.TMSCHEMA_COLUMN_STORAGES is reserved for internal use only. Two of the most useful columns on that table for row counts and discount column counts are incorrect and should not be used.