Kim Chaek
In 2015, Kim Jong-un rode a newly manufactured four car train set which was reported to have been developed and built at Kim Chong-t'ae Electric Locomotive Works in North Korea, although the cars appeared to be significantly renovated D-class cars. This set is named 'Underground Electric Vehicle No. 1'. It features a VVVF control and initially fitted with an asynchronous motor but later replaced with a permanent magnet synchronous motor developed by the Kim Chaek University of Technology. It usually runs on the Chollima Line but has also ran on the Hyoksin Line.