As Joe states there is no 'current' portal when installing a module - but if you 'just' need a valid portal id you can fetch the first available. Fill in the rest of the fields as needed - and remember to take the database scheme into consideration (the curly brackets part).
INSERT INTO {YourDatabase}.{dbo}.[PortalSettings]
([PortalID]
,[SettingName]
,[SettingValue]
,[CreatedByUserID]
,[CreatedOnDate]
,[LastModifiedByUserID]
,[LastModifiedOnDate]
,[CultureCode]
,[IsSecure])
VALUES
((SELECT TOP (1) [PortalID] FROM {YourDatabase}.{dbo}.[Portals] ORDER BY [PortalID])
,@SettingName, nvarchar(50),
,@SettingValue, nvarchar(max),
,@CreatedByUserID, int,
,@CreatedOnDate, datetime,
,@LastModifiedByUserID, int,
,@LastModifiedOnDate, datetime,
,@CultureCode, nvarchar(10),
,@IsSecure, bit,)