Voltage sensitivity analysis in radial MV distribution networks using constant current models

The paper presents some results of studies conducted on the development of analytical tools useful to allow real time control of voltages and power fluxes in active distribution networks in presence of distributed generation (DG) in the framework of Smart Grids implementation. The analytical tools can nevertheless be useful at the planning stage to guide some choices made by distribution planners. Specifically, a simple approach for calculating voltage sensitivity indexes with respect to active and reactive power changes at any node in a radial distribution network is investigated. The paper presents first stage results obtained by using two constant current models for loads and generators to obtain node voltages and their sensitivities. Subsequent stages of the study will perform a comparison with different models, such as the constant power one, and will assess the viability of the various approaches. Then, in this paper voltage sensitivity indexes are formulated with respect to active and reactive components of net node currents and the influence of some simplifying assumptions has been assessed. Numerical results are provided as the outcome of calculations performed on a test distribution network using MATLAB^®.