SU433589A1 - DEVICE YES BL (PROTECTION TIPS FOR FAILURE IN THE SECONDARY CIRCUITS OF THREE-WATER TRANSFORMERS ^ VOLTAGES INPUT REFERENCE TO AREA-] [C]. interlocking devices based on the use of differential transformers. ^ Such devices have a significant consumption, which is due to the fact that, with operable secondary circuits of a transformer, Differential transformers operate in a short circuit mode. In addition, differential devices deduce protection from operating in the event of faults in both the star and the open circuit of the voltage transformer, although in the latter case the protection could remain in operation. devices use the transformer star's zero wire, voltage, and the integrity (the zero conductor does not control –101520 is faulty, then the following short circuit to ground prevents the interlock from acting incorrectly. The proposed device is characterized in that in order to increase the reliability, a three-phase rectifier bridge is connected to the phase outputs of the star of intermediate transformers, the output of which is connected to the comparison circuit of the absolute values of two voltages, and a three-phase rectifier bridge connected to the phase voltage is connected to the second input of the comparison circuit wires of the star transformer voltage transformer. The drawing shows the device diagram. The device is connected to the secondary windings of the transformer I, connected by one star, and the other - about the scheme open triangle. The device contains an intermediate two-winding I transformer 2, connected by - Google Patents

Description

open-delta star circuit, two three-phase rectifier bridge circuits -3 and 4, a comparison circuit of absolute values of rectified voltages 5, which includes two ballast resistors 6.7 and output relays a, y. Output relays are selected in such a way that they can react both to the magnitude and direction of the current in the windings (for example, polarized relays). The device operates as follows: 00 The switching circuit and the 1Y transformation factor of the intermediate transformers are chosen so that the three-phase voltage system at their output is exactly equal to the voltage system of the star winding of the voltage transformer. Therefore, in the case of serviceable secondary circuits, the rectifying circuits 3 and 4 always have equal output voltages, and the current in the windings of the y-8 relay does not flow. In case of short circuit and disconnection of automata in the circuits of the transformer star, the voltage emf. straightening circuitry becomes more emf. rectifying circuit 4, and a current flows through the relay in the direction causing the operation of the relay o. The indicated relay deactivates the protection and gives the fault status. In the event of faults in an open triangle circuit, the current in the output relay circuit will change direction, which will trigger the relay 8, which gives a fault signal. The 6.7 ballast resistors create a current path through the output relays. The subject of the invention is a device for blocking protection in case of malfunctions in the secondary circuits of three-winding voltage transformers, one of the secondary windings of which is connected by a star, and the other is in an open triangle circuit and connected to an intermediate voltage transformer, the windings of which are connected in an open circuit tre gon - star, distinguished in b. in order to increase reliability, a three-phase bridge circuit is connected to the phase outputs of the star of intermediate transformers, the output of which is connected to the comparison circuit of the absolute values of two voltages, and a three-phase bridge circuit connected to the second input of the comparison circuit to the phase wires of the transformer star winding.