Efficient method for calculating the reactive power supply by applying analytical load flow calculations

The reactive power supply of power plants is regulated at the European and national levels. This paper presents an analytical load flow calculation approach to calculate the reactive power supply. Based on the requirements at the point of connection, the minimum required reactive power supply at the generator terminals is calculated. The calculation methods also consider the effects of a step-up transformer with a tap changer. One advantage of this approach is that the generator’s capability diagram in relation to the terminal voltage does not need to be modelled.