Noise Immunity of Cable Networks in the Control System of Power Plants

Problems of an estimation of currents and voltages induced in the shields of low-voltage cables are considered. The estimation was carried out on the basis of calculation of magnetic flux induced in the contours constituted by the conductors of the ground system of the power plants and the shields of the cables. Measurements of the currents flowing in the cables shields are executed for the Zhigulevskaya hydroelectric power plant and observed data agrees well with the calculation results. The estimation of magnitudes of currents and voltages induced in the-cables shields during emergency situations is given. Also the possibility and the mechanism of failures in hydrogenerator control system due to the emergency on the next nearest hydrogenerator are shown.