چكيده به لاتين
In this thesis, four algorithms are proposed to improve synchronous switching of transmission lines. The first algorithm, Assuming there is no trapped voltage, considering the coupling voltage, controls synchronous closing of each of the three phases of an uncompensated open-end transmission line. The first algorithm, considering the coupling voltages between phases and the residual voltage, controls the synchronous closing of all three phases of an uncompensated transmission whenever the other end of the line is open. In the next step, the mentioned algorithms that are designed assuming that CB is ideal are improved by taking into account the parameters of the real condition. The third algorithm provides a method for calculating the trapped voltage of the transmission line (for healthy and faulty phases) with opening of three-phase circuit breakers of the two sides of an uncompensated line. The The fourth algorithm, Assuming there is no trapped voltage, considering the coupling voltage, controls synchronous closing of each of the three phases of an compensated open-end transmission line. The results show that by applying the first algorithm and its improved algorithm each phase of CB is closed in the zero-voltage state with a maximum error of one sample. By applying the second algorithm and its improved algorithm each phase of CB is closed in the zero-voltage state with a maximum error of three sample. By calculating the trapped voltage using the third algorithm, the over voltages caused by synchronous closing of the CB are significantly reduced compared to other methods, and the fourth algorithm has a maximum error of 1 sample.
