Impact of the variation of the operational frequency and voltage on the Venezuelan interconnected system

As a consequence of the shortage of water in the hydroelectric reservoirs, the Venezuelan interconnected system decided to drop the operational frequency in order to save water. After analyzing the characteristics of the different types of loads of an electrical system, coefficients of sensitivity were adopted according to the Venezuelan reality for active and reactive loads versus voltage magnitude and frequency. This paper summarizes improvements on the studies of the impact of working at low frequencies by running a power flow over the Venezuelan interconnected system, showing a crossed and unavoidable effect of the frequency and voltage on the demanded and generated power. According to the results of the power flow, it is not advisable in the first instance to work at low frequency. In this conclusion stand out three fundamental factors, first of all the minor reduction in the demand, the damping effect of the transmission network and the existence of a not neglectable percentage of load that behaves as constant energy types, besides the classical limitation associated to the operation at under rated frequency.