Estimation of power system voltage with limited measurements

In power systems it is often impractical to place monitors on all buses for recording power quality events. Therefore the accurate determination of the origin of power quality events, such as voltage sags requires unmonitored bus voltages to be estimated based on available measurements. However, available measurements are not always from an optimistic monitoring scheme. Hence a method is required to determine an estimate of unmonitored bus voltages within a power system with only limited voltage measurements. This paper proposes the use of the voltage sensitivity of a power system to estimate the missing bus voltages. The study is based on a nine bus system. The estimation of bus voltage measurements are applied in the case of voltage sags produced from load switches.