Abstract :
The purpose of this overview is to offer an introduction of the so-called ancillary services which have been heard much about in recent times. There are people, including some well-known veterans in the electricity supply industry, who, upon hearing the term “ancillary services” for the first time, think that it is a new technology, or a new management technique that marketing or personnel departments of the company have just invented. When the meaning of the term is explained, they realise that ancillary services are simply what was known as “reactive power and regulation”