Analysis of synchronous generator excitation system operation at various kinds of non-symmetrical external short circuits

The synchronous generator excitation system with single- and multi-channel rectifier control systems at various kinds of non-symmetrical external short circuits is described. The rectifier control systems synchronized relative to line or phase voltages. The advantages and disadvantages of the synchronization methods are reviewed. For analysis generator operation, the mathematical expressions for the excitation voltage, field-forcing ratio and operating ranges are calculated.