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Tracing Power System Weak Nodal Shifts Following Reactive Power Compensation


Bright. G. C. E , Dept. of Electrical/ Electronic Engineering, Chukwuemeka Odumegwu Ojukwu University, Uli. Anambra Stat; Uju, I. U., Dept. of Electrical/ Electronic Engineering, Chukwuemeka Odumegwu Ojukwu University, Uli. Anambra State; Onyedikachi, S. N., Dept. of Electrical/ Electronic Engineering, Nnamdi Azikiwe University, Awka. Anambra State


VDI, TVDI, Voltage-Reactive Power (V-Q)


The deficiency of reactive power especially at load buses result in poor voltage profile in these load buses which do not respond in the same measure owing to their individual reactive power need, adequacy of network reactive supply and their proximity to an adequate reactive source. The response of load buses to reactive power variation can be determines from various static methods suchas voltage drop index (VDI) or voltage-reactive power (V-Q) sensitivity analysis whose result provide a means to determine the choice location for reactive power compensation for voltage improvement and stability. This study using the Nigerian 330kV network determined the VDI of the networks load buses which was ranked based on the total VDI (TVDI). The work is an extension to the basic investigation for the optimal location of reactive power compensators within the Nigerian 330kV of 41 buses. In this case study, load bus active power is varied from a base case through five steps of 10% increments for which nodal voltages were determined. Using the result, TVDI for the load buses were computed and ranked with Yola, Omotosho and Maiduguri as the top three. Aided with this result, load flow analyses were executed for the individual and simultaneous shunt compensation at these buses and V-Q sensitivity analysis performed to ascertain how nodal weakness shifts between load bus following compensation. Each of the compensated cases when compared with the base case bus load flow result showed significant improvement in nodal voltage magnitude which justified the compensation but it did not eliminate bus voltage violation in the other previously violated buses. Following optimum nodal reactive compensation, the result from V-Q analysis shows that compensating a load bus of higher total voltage drop index shifts the bus participating in voltage instability to the next ranked load bus based on the TVDI. The deduction here is that independent shunt compensation for a higher ranked bus with respect to the bus participation factor or total voltage drop index shifts the responsibility of voltage instability to the next ranked load bus while compensating a lower ranked bus keeps the bus participation factor profile unchanged.

Other Details

Paper ID: IJSRDV7I60031
Published in: Volume : 7, Issue : 6
Publication Date: 01/09/2019
Page(s): 187-193

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