Design of a novel digital automatic voltage regulator

In the control of synchronous machines excitation, automatic voltage regulators (AVRs) have been used for many years. AVRs have evolved from the early electromechanical types to the solid state AVRs controlled with analogue circuits found most commonly in service today. With recent advances in microprocessor technology making faster and more powerful processors readily available it is now possible to implement more complex forms of adaptive and fixed parameter based controllers. However these more complex forms of control have some limitations and it will take more time to develop them into widely acceptable products. The conventional forms of control used in most digital AVRs are the same as in their analogue equivalents and hence no improvement in dynamic performance will result from a move to digital. However there are many advantages for both the customer and supplier in changing to a digital AVR. The digital AVR illustrated in this paper can be looked upon as equivalent in performance to the more sophisticated of the analogue AVRs available