说明：  四机两区算例(4机2区算例),与昆德(Kunder)书中参数一致，包含详细的发电机模型，算例在PSCAD4.2中可以运行，是学习PSCAD难得的资料。
(The four-machine two-zone example (4-plane 2-zone example) is consistent with the parameters in Kunder s book, including detailed generator model. The example can be run in PSCAD4.2, which is a rare learning material for PSCAD.)