Power quality regulators based on active filters

In many countries, there is now a big problem to ensure increasing quality standards of electric power. This aim can be achieved by many different methods. One of the prospective ways is by using active filters (AF). The well known functions of AC AF are limitation of the high current or voltage harmonics and the compensation of the reactive power. This paper presents information about expansion traditional functions. The new function is the stabilization of voltage in AC networks. A principle realizing this function and some aspects of design such AF with expanded functions are described here.