RU85672U1 - AC SHORT CONTROL DEVICE - Google Patents

Abstract

A short circuit monitoring device in the contact network of a two-track section of the contact network for alternating current of electric railways, containing 27.5 kV buses of the traction substation connected via controlled switches of the first and second track contact networks and a longitudinal power supply line of DPR-27.5 kV, the contact network being located in the zone of electromagnetic influence of the longitudinal power supply line DPR-27.5 kV and mutual influence between the contact network of the first and second paths, relay-repeaters of the disconnected state circuit breakers, a voltage transformer with primary and secondary windings, a voltage relay with a make contact, a low-pass filter and a signal device, the primary winding of a voltage transformer connected with one terminal to a rail, and a secondary winding connected to an input of a low-pass filter, a signal device through a make contact of the voltage relay is connected to “+110 V” and “-110 V” of the power source, characterized in that a spare bus is introduced, to which the contact network of the first and second paths are connected via the control removable bypass disconnectors with block contacts and the second output of the primary winding of the transformer, two relay switches for bypass disconnectors, closing contacts of the relay for fixing commands for switching on and off controlled switches and an automatic switch for remote control of that bypass switch of the contact network in the area of which there is a short circuit from series-connected for the contact network switch of the first path of the make contact of the latching relay, the first make contact of the repeater relay

Description

The utility model relates to a power supply automation system for electric railways, and in particular to automation devices for searching for a short circuit in a rail contact network.

A device for monitoring a short circuit in the contact network of a two-track section of the contact network of an alternating current of electric railways [1], containing 27.5 kV bus traction substation connected through controlled switches of the contact network of the first and second path and the longitudinal power supply line DPR-27.5 kV moreover, the contact network is in the zone of electromagnetic influence of the longitudinal power supply line DPR-27.5 kV and the mutual influence between the contact network of the first and second paths, relay repeaters are disabled circuit breaker status, voltage transformer with primary and secondary windings, voltage relay with make contact, low-pass filter and signal device, the primary winding of the voltage transformer connected with one terminal to the rail, and the secondary winding connected to the low-pass filter input, the signal device through the make contact of the voltage relay connected to "+110 V" and "-110 V" power supply,

For its implementation, it is necessary to install the considered devices [1] on each feeder of the contact network of the traction substation. Similar requirements are in the analogue of [2]. In particular, for a conventional substation, five sets of devices are required. For traction substation, discussed in the prototype [1] - requires two sets. This is the disadvantage of the prototype [1] and analogue [2].

The purpose of the proposed utility model is to simplify the device by installing only one set for monitoring a short circuit on all contact circuit breakers of one traction substation.

This goal is achieved by the fact that a spare bus is introduced into the indicated device, to which the contact network of the first and second paths are connected via controlled bypass disconnectors with block contacts and the second output of the transformer primary winding, two relay bypass switches, closing contacts of the relay for switching on and shutdown of controlled switches and a button for automatically switching on telecontrol of that bypass disconnector of the contact network in the zone of which there is a short circuit, and the circuit from sequentially connected for the contact network switch of the first path of the NO contact of the latching relay, the first make contact of the repeater relay of the disconnected position of the switch, the relay for switching the bypass disconnector of the contact network of the first path with its NC block contact is connected in parallel to the circuit of the second path of the contact of the contact network in series latching relay, second make contact of repeater relay one disconnector of the contact network of the second path with its opening block contact is connected via the make contact of the automatic start button by remote control to “+110 V” and “-110 V” of the power source, and the filter output is connected through the second parallel connected make contacts of the repeaters of the disconnected position of the switches contact network of the first and second path to the voltage relay coil.

This embodiment of the device allows, at the command of the operator (energy dispatcher), to automatically switch one set of the device to the contact network of the path on which the short circuit occurred.

A short circuit monitoring device in the contact network is shown in the drawings.

In Fig. 1, the contact network of the first 2 and second 3 railways through the switches 4 and 5, respectively, and the longitudinal power supply line DPR-27.5 kV 6 through the switch 7 are connected to the tires 1 of the traction substation.

The contact network of the first and second paths is influenced by the induced voltage due to the electrical influence of the contact network of the first and second paths and the DPR-27.5 kV line due to the distributed capacitance: "contact network 2 ways - contact network 1 ways", "DPR-27 , 5 kV - contact network 1 and 2 ways "," contact network 1 and 2 ways - rails "(the equivalent values of the distributed capacity of 8, 9, 10, 11, 12 are shown in figure 1).

Induced voltage on the contact network of the first and second path due to magnetic influence can be in the presence of a load current in the contact network of an adjacent path. The magnetic effect from the DPR-27.5 kV is insignificant due to its small load.

At the traction substation, a spare bus 13 is mounted, to which the contact network of the first and second paths is connected, respectively, through the controlled first and second bypass disconnectors 15 and 14. (Note that for standard designs, the presence of a spare bus is mandatory)

The voltage transformer 16 is connected to the spare bus 13 and the rail 17. The low-pass filter 18 is connected to the coil of the voltage relay 19 through the closing contacts of the repeaters 20 and 21 of the disconnected position of the circuit breakers of the first and second path. The signal device 22 through the make contact 23 of the voltage relay 19 is connected to the "+110 V" and "-110 V" of the power source. A short circuit (short circuit) in the contact network of the first path is fixed at one of the possible points 24.

Figure 2 shows a diagram of the automatic selection of a bypass disconnector (14 or 15) in the zone of which a short circuit occurred.

The circuit is started by the automatic start button by remote control 25. The relay 26 of the bypass disconnector 15 of the first path and the relay 27 of the bypass disconnector 14 of the second path are connected via the make contacts of the latching relays 28 and 29 and the make contacts 30 and 31 of the relay of the repeaters of the disconnected position of the switches, respectively, of the first and second paths and opening block contacts 32 and 33, respectively, bypass disconnectors of the contact network of the first and second paths.

The control circuit of circuit breakers 4 and 5 of the contact network is based on a typical automation circuit of the feeder of the contact AC network [3, Fig. 4.1].

The device operates as follows.

Consider the case of stable fault at the point of the contact network 24.

In the initial state, all the switches 4, 5, 7 are turned on to power the contact network 2 and 3 and the LPR lines 6, bypass disconnectors 14 and 15 are disconnected.

When short circuit at point 24, the contact network switch of the first path 4 is turned off, then it is turned on by the standard reclosure and shuts down again. After that, in accordance with [4], on the electric rolling stock (EPS), the current collectors are lowered for 2 minutes.

At this time, the energy dispatcher prepares a circuit to search for short circuit. To do this, he presses the button 25 and the relay 26 activates the bypass disconnector 15 in the circuit: closed contact 28 of the latching relay of circuit breaker 4 (since the circuit breaker disconnected from the protection), closed contact 30 of the relay of the repeater of the disconnected position of circuit breaker 4 and block contact 32 is closed when disconnected bypass disconnector 15. The output contact of relay 26 includes a bypass disconnector 15. (the control circuit of the disconnector is shown in [3, Fig. 4.10, b]), after which contact 32 opens and relay 26 is de-energized.

It is important to note that the relay 27 will not work, as the switch 5 remains on. This automatically selects the bypass disconnector that must be turned on to search for damage. This is the main thing in the proposed Utility model.

So, after the above steps, the voltage transformer 16 is connected to the contact network of the first path.

If there is no current along the second path, then there is no magnetic effect on the contact network of the first path, and with a short circuit on the first path, the voltage from the electric influence is zero. Therefore, the relay 19 connected to the filter 18 through the closed contact 20, and the signal device 22 will not work.

In the presence of a traction load current in the second path (non-sinusoidal character with a clear separation of 3, 5 and other higher harmonics), the induced voltage from the magnetic influence will also have a pronounced non-sinusoidal character. The filter 15 filters out the higher harmonics of the voltage, and at zero voltage value from the electric influence (since the short circuit is stable on the first path), the relay 19 will not work and therefore the signal device 22 will not work either.

So, with a stable short circuit, the signal device 22 will not work, and this indicates the prohibition of the repeated switching on of the switch 4 and the need for a subsequent search for a short circuit location, for example, by alternately disconnecting the longitudinal disconnectors located along the contact network. In this case, after disconnecting the next disconnector, you do not need to turn on the switch to test the contact network. The operation of the alarm device after disconnecting the next disconnector will indicate the shutdown of the damage, that is, it will indicate the location of the short circuit.

It is important to point out the following. If there was no filter 18, then from the magnetic influence of the signal device 22 would have worked false. Therefore, the low-pass filter 18 filters out the higher harmonics in the voltage of the contact network, which allows you to block the false response of the device.

The device works similarly with more than two contact network switches.

After eliminating the emergency situation, the circuit is returned to its original state with the bypass disconnectors disconnected.

The technical and economic effect of the utility model is determined by the reduction in capital costs for the introduction of a device for searching for damage (short circuit) on the contact network.

Information sources

1. Utility model No. 77447 of March 26, 2008, “A short-circuit monitoring device in a contact alternating current network”

2. Application for invention No. 20071111014 dated 03/27/2007 “Short-circuit monitoring device on a single-track section”, positive decision 05/07/2007

3. Pochayovets B.C. Automated control systems for railway power supply devices. M.: Route, 2003 .-- 318 p.

4. Instruction on the procedure for locomotive crews and employees of power supply distances in case of damage to current collectors, the contact network and their commission consideration. No. ЦЦ-ЦЭ-860. M .: MPS RF, - 2001. - 32 s

Claims (1)

A short circuit monitoring device in the contact network of a two-track section of the contact network for alternating current of electric railways, containing 27.5 kV buses of the traction substation connected via controlled switches of the first and second track contact networks and a longitudinal power supply line of DPR-27.5 kV, the contact network being located in the zone of electromagnetic influence of the longitudinal power supply line DPR-27.5 kV and mutual influence between the contact network of the first and second paths, relay-repeaters of the disconnected state circuit breakers, a voltage transformer with primary and secondary windings, a voltage relay with a make contact, a low-pass filter and a signal device, the primary winding of a voltage transformer connected with one terminal to a rail, and a secondary winding connected to an input of a low-pass filter, a signal device through a make contact of the voltage relay is connected to “+110 V” and “-110 V” of the power source, characterized in that a spare bus is introduced, to which the contact network of the first and second paths are connected via the control removable bypass disconnectors with block contacts and the second output of the primary winding of the transformer, two relay switches for bypass disconnectors, closing contacts of the relay for fixing commands for switching on and off controlled switches and an automatic switch for remote control of that bypass switch of the contact network in the area of which there is a short circuit from series-connected for the contact network switch of the first path of the make contact of the latching relay, the first make contact of the repeater relay the disconnected position of the switch, the relay for switching the bypass disconnector of the contact network of the first path with its opening block contact is connected in parallel to the circuit from the second path of the closing contact of the latching relay, the second closing contact of the relay of the repeater of the disconnected position of the switch, the relay for switching on the bypass switch of the contact network the second path with its opening block contact is connected via the closing contact of the automatic power button Telecontrol to about "110 B" and "-110 V" power source and the filter output is connected through a second parallel-connected normally open contacts repeaters disconnected position switches catenary first and second paths to the coil voltage relay.