FIELD: electricity.
SUBSTANCE: neutral grounding device of the three-phase electrical network consists of a grounding resistor connected between the network neutral and the conditional anode of the resistor triac, the conditional cathode of which is connected to the ground. Between the neutral of the three-phase electrical network and the ground, a capacitive voltage divider consisting of two capacitors is included. In parallel to the capacitor, included between the midpoint of the capacitive divider and the ground, the terminals of the primary winding of the starting transformer are connected. The first output of the secondary winding of the triggering transformer is connected to the control electrode of the resistor triac, and the second -to the ground. A protective nonlinear overvoltage limiter is connected to the conditional anode and cathode of the resistor triac. Phase non-linear overvoltage limiters are connected to the three-phase terminals of the supply transformer of the electrical network, the second terminals of which are connected to the corresponding conditional anodes of the phase triacs, and their conditional cathodes are connected to the ground. The first terminal of the secondary winding of the triggering transformer is connected to the three control electrodes of the phase triacs. Parallel to the phase triacs, protective nonlinear surge arresters are connected to their conditional anodes and cathodes.
EFFECT: reducing arc overvoltage on the equipment of the entire network, reducing losses in the grounding device and the power of the grounding resistor.
2 dwg
