Comparative analysis of different types of generator voltage controllers

The problem of providing consumers with electric power of appropriate parameters is nowadays a very important issue. Rapid increase of demand for electric energy makes it difficult to be up to quality requirements. Voltage level, beside frequency is the most important parameter of electric power. This is the reason why engineers and scientist search for new methods and algorithms of generator voltage control in a power system. Synchronous generators, which are usually used to produce electrical energy must be equipped with voltage regulators. These control units are responsible for keeping the output voltage at specified level under different operating conditions (e.g. various load levels). The control systems traditionally used PID type controllers. The main advantages of controllers of this type are simple structure and low implementation costs. Usually, PID type controllers are tuned using hit and miss procedure, which may be problematic and time consuming. The progress in computer and microprocessor technology makes it possible to implement new and more sophisticated algorithms. The performance of traditional control structures is not good enough for present-day requirements. An improvement of system performance can be made using adaptive of self-tuning regulators. The controller parameters can be changed to give optimal performance under varying operating conditions. The other solution is to use elements of artificial intelligence in designing voltage regulation systems. Fuzzy controllers and controllers based on neural networks became more popular recently and they are widely accepted by engineers and scientists as an alternative for classical regulation structures. The processes involved in fuzzy controllers closely imitate human control processes human responses to stimuli is not described by transfer functions, the same can be said about responses of fuzzy controllers. In this paper a comparative analysis of different types of generator voltage controllers is presented. Traditional regulation structures, based on PID type controllers are taken into consideration. A new type of voltage controller based on Force Dynamic Control is proposed. In contrary to traditional control structures or fuzzy controller FDC is model-based control technique. Basing on data obtained from simulations conducted using programs like ATP-EMTP and Matlab, the performance of presented in the paper control structures in different configurations is analysed, evaluated and compared.