Computer aided analytical study of the transient operation of an exciter-alternator-rectifier set

The transient operation of a rectified output double-star synchronous machine excited by a single-star rectified output synchronous generator is studied. An equivalent transient three-phase impedance is defined. It accounts for the particular structure of the rectifier bridge, including the effect of overlapping. All quantities are given by rational transfer functions including polynomials of high degree (up to 27). All expressions are analytically derived from Park equations of the machines and their loads. This is achieved by means of a program which can handle the multiplications and additions of the polynomials, and step-by-step integration techniques are avoided. Experimental verification was obtained in two cases. The field voltage of the exciter was suddenly varied, and the load impedance was suddenly changed. In both cases, theoretical results tally with experimental curves