SU662995A1 - Movable plant for testing and adjusting relay protection current circuits - Google Patents

Description

The invention relates to electrical engineering, in particular, to devices for checking current circuits of relay protection.

A known analogue of the proposed device, a portable device for testing relay protection, containing a series-connected autotransformer, a load transformer, in series with the secondary winding of which a partitioned primary winding of a measuring transformer connected to the ammeter by a secondary winding is connected, and the output of the autotransformer is connected via an isolation transformer and the device under test is connected electrical time meter 1.

The disadvantage of this device is that the control circuit of the electric time meter is connected to the contact of the device under test, which increases the electrical hazard of using the device and complicates the test (requires connecting two additional wires to the contact of the device under test). The absence of a metallic connection of the common lead of the secondary winding of the load transformer with the device case requires the use of an additional wire for grounding the case of it, which also complicates the test. The applied circuit for measuring load current has a relatively narrow range and limits the functionality of the device.

A known device for testing and setting up current circuits of relay protection, comprising a series-connected autotransformer, load transformer and instrument transformer with a partitioned primary winding, where the secondary winding of the load transformer is made multi-section, moreover, the conjugate sections of the load and measuring transformer are made of cross-section wires, corresponding to vuyuschego limit the sensed current, which is taken as the prototype as the closest in technical essence to the proposed 2.

Currently, industrial production does not yet produce mass production.

S-s. ; iK1X mobile installations for testing the adjustment of current circuits of protection devices, for example, substation feeders and circuit breakers, so the development of the optimal variant of such an installation is especially important. The functionality of the installation by aut. St. No. 521538 are limited, namely, Oia does not automatically determine the –ArryKG load current flow and the application of the string has a relatively narrow range for measuring the load current. For example, if it is possible to measure the protection currents of feeders with low earth fault currents of 3-ZOa, there is no possibility of measuring currents of several thousand amperes, since measuring transformers with such a wide limit of measurement are not available. For a known installation in 1, an additional wire is required to ground the installation case, which complicates the test. The purpose of the invention is to expand the functionality and simplify the use of the TM-1; -Plan-Thani; :: 1. „; L, -. ...,., -, „„. This is achieved by using in a well-known installation for testing and adjusting the current relay relay common circuit of the secondary winding of a load transformer as the primary winding of a pulse transformer, the secondary winding of which is connected to a control transition of a symmetrical thyristor connected directly to an electrical measuring instrument. the network, and in series with the high-current section of the secondary winding of the load transformer. The primary winding is included. ka additional measuring transformer with a partitioned secondary winding connected through a section switch to the ammeter, and the output terminal of the common output of the load transformer is connected to the installation body. ; ,,,: „.., ..,. ,,.,„..... The drawing is a schematic diagram of the proposed installation. FcTairtoBKa removes sequentially autotransformer 1, load transformer 2 with partitioned secondary winding, sections, for example, 3.4 which are connected in series with the mating sections 5.6 of measuring transformer 7, connected to ammeters 8.9 by the secondary winding. The high-current section 10 of the secondary o6fe 6fKlrHfffpp64WorO fpa for the pTyatora ip iR lChcheTa 1TcSlefto but with the primary winding of the additional measuring transformer 1 with the partitioned secondary winding 12 connected via the ceKi switch. ammeter 14. The overall output 15 of the secondary winding of the load transformer is used as the primary winding of the pulse transformer. 16, the secondary winding 17 of which is connected to the control switch of the symmetric thyristor 18 connected in series with the Electric time meter 19 between the power supply inputs 20, 21. The output terminal 22 of the common output of the secondary winding of the load transformer is connected to the housing 23 of the installation. The output of the autotransformer 1. is connected to a voltmeter 24 and an adjustable voltage outlet. A test load, for example, a current transformer 25 with a series-connected oil switch 26, is connected between terminal 22 and one of the terminals 27, 28, 29 of the secondary winding of the load transformer 2. The terminals 30, 31 of the secondary winding of the current transformer 25, when determining its transformation ratio, can Be connected via switch 13 to the ammeter 14. The installation works as follows. According to the required current value, the load of, for example, a current transformer 25 of an after-connected oil switch 26, grounded from one side to an external ground, is connected between terminal 22 and one of the terminals 27, 28, 29 of the secondary winding of the load transformer 2, and terminal 22 is connected. earthed: the oil switch 26 leads through the grounding terminal of the cell of the adjacent feeder it is under test, and thereby the installation housing 23 is automatically grounded. Inputs 20, 21 are connected to the mains. The autotransformer 1 establishes the required current in the load under test, which is measured by one of the ammeters 8, 9, 14. When a current flows in the common terminal 15 of the load transformer 2, the current pulses of the polar transformer 16 are applied to the secondary winding 17, which are supplied In the control circuit of the symmetric thyristor 18, it is opened and the time meter 19 automatically generates at the same time an account of the time of the switched on state of the test load. The use of an additional measuring transformer AND with a partitioned secondary winding 12 connected via a switch section 13 to an ammeter 14 provides for measuring TOKOV in the test load within wide limits from fractions of an ammeter to several thousand amperes, which is necessary when testing, for example, protection of substation feeders, and thereby greatly enhancing the functionality of the installation. It can be used, for example, to test how low-current ze-lous protection of feeders for high-voltage cut-offs and automatic switches.