Fair determination of mandatory capacity of reactive power using generalized tracing method

In most of reactive power markets, a part of reactive power capacity of each generator must be mandatory used for generation or absorption of reactive power. There is not any clear rule for determination of mandatory reactive capacity of each generator and it is determined by system operators´ experiences. Determining mandatory capacity of each unit by considering its contribution in reactive losses will increase the transparency of reactive market and consequently the competition. In this paper a fair approach for determining mandatory capacity of each generator is presented. In this approach reactive power of each generator is decomposed into two components. The first component is necessary to support the units´ active power and the second is used to supply loads. A generalized tracing method for determining these components is presented. The first component is considered as the mandatory part of reactive power generation of each unit. The proposed method is applied to a 7 bus test system and Khuzestan electric utility and the results are analyzed.