Abstract:
As the deregulated electricity market is moving towards the competition, different services those are provided by the system operator are separated. Ancillary services like power factor control, frequency control, voltage control and reactive power management are secondary services to ensure that the system is more secured. It is required that the system voltage is always to be maintained with in the specified limits of the system. To achieve this, system operator has to provide the voltage control service using the reactive power sources. The function of the system operator is to identify the reactive power sources and loads. According to this, the payments are allocated to the customers and distributed among the providers. For this, a transparent reactive power cost allocation technique is to be identified.
In this paper, an existing reactive power cost allocation method i.e., modified Y bus method is compared with proposed method i.e., improved Y bus method of reactive power allocation and its cost including line charging admittance, proportional sharing and equal sharing. The sample 5 bus system and IEEE 24 bus system are used to illustrate the proposed method. The simulation of computation of reactive power and its cost has been carried out using MATLAB programming. The simulation results are presented and analyzed.

Keywords: Reactive Power Cost Allocation, Improved Y – Bus Method, Proportional Sharing, Equal Sharing and Line charging Admittance.