There are many examples publically available. Otherwise, contacting your sales rep is the best path forward to get access to these materials. They are not always available and may be out of date if they are not shipping examples.
Here is this one: https://www.mathworks.com/matlabcentral/fileexchange/66599-ieee-123-node-test-feeder-in-simscape-power-systems
This answer is part of a MATLAB Answers cleanup effort for unanswered questions that are outstanding.