Instrumentations for microalternator voltage and speed digital automatic control

The development of circuits necessary to implement speed and voltage digital regulators in a scaled-down synchronous generator of a research and teaching laboratory is presented in this work. The realization of the synchronous generator output voltage sensor and the shaft speed sensor of the dc machine (which represents the prime mover of the scaled-down power system model) are presented. The bridge rectifiers, which are the actuators in the two regulation loops, together with the thyristor firing circuits, are also shown. Some aspects related to the project and implementation of discrete PI controller of the synchronous generator output voltage and of the dc machine speed are also presented; such controller are implemented by software in C++. Results of operation tests of the implemented circuits, as well as performance of the regulators, with the synchronous generator feeding a local load, are commented.