RU2557809C2 - Method to ensure electrical safety during routine switching at power facilities - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: application: in electrical engineering. According to the method during routine switching at power facilities positions of switching devices are indentified, the above positions are transmitted through a radio channel, the Boolean expression is formed for each switching device and power supply is fed to a block lock of the switching device drive at a true value of the Boolean expression. At that data about the position of the functionally related switching devices are accumulated at locations of their drives at local points, data transfer from the local point is made only with a request of the control room, permit for power supply delivery to the block lock is transmitted from the control room through the radio channel, whereat power supply of the block locks is made from in-built self-contained sources.

EFFECT: increasing the operational reliability of the magnetic lock and reducing costs for installation, start-up and commissioning.

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Description

The invention relates to methods for ensuring electrical safety at power plants and substations during operational switching based on the use of interlocking drives of switching devices.

A known method of electromagnetic blocking (1), which includes an automatic alarm from block contacts, the shaft of which is pivotally connected through mechanical elements to a drive that rotates a rotary element that opens or closes an electrical circuit in a switching device, installs block locks on the drives of switching devices, the use of a power supply connected together with block contacts and block locks to a common electrical circuit with cable lines.

The disadvantages of this method of electromagnetic blocking are:

- the occurrence during operation of the discrepancy between the position of the rotary element of the switching apparatus and the position of the rotary shaft of the block contacts, signaling the locking circuit about the position of the switching apparatus, due to backlash and free moves in the joints of the parts of the drive mechanism and large clearances in the articulated joints of the rods;

- unreliable work due to the large number of movable and fixed block contacts located on the drives of switching devices and connected by cable lines to a common electrical circuit, especially in open switchgears (outdoor switchgear), where the switching devices are located in the open air;

- the difficulty of maintaining the required level of insulation of electrical circuits.

A known method of operational blocking (2), including receiving via cable lines telemetry signals about the position of the switching apparatus, checking, if necessary, switching the switching apparatus, the logic blocking circuit implemented in software, and if, according to the logic, control is enabled, the contact relay closes and the block lock receives voltage - the lock is unlocked. The disadvantages of the method are the difficulty of maintaining the required level of isolation of the electrical circuits of both power and telemetry, as well as the appearance during operation of the mismatch of the position of the rotary element of the switching apparatus with the position of the rotary shaft of the contact blocks informing about the position of the switching apparatus.

Closest to the proposed method is an electromagnetic blocking method (3), including determining the position of the switching devices, transmitting the position of the switching device via a radio channel, forming a logic blocking circuit and connecting power to the switching block of the switching device drive when enabled from the logic circuit and receiving a radio signal from the block -Lock when sticking an electromagnetic key into it.

The disadvantages of the known method of electromagnetic blocking is, firstly, the continuous transmission of radio signals from position sensors (two for each switching device). With a certain number of switching devices, due to the loaded ether in the radio exchange between the sensor and the receiving device, malfunctions can be observed. In addition, to ensure communication, continuous power supply to the transceivers is necessary, which puts forward additional requirements for power sources. Secondly, the known method involves external power block locks, i.e. the presence of extended power lines, which can lead to a power failure due to a violation of the insulation of the power cable, especially with a ring topology of power wiring.

The objective of the invention is to increase the reliability of electromagnetic lockout and reduce the cost of installation and commissioning by eliminating the continuous radio exchange between the sensors of the switching devices and receiving devices, as well as by eliminating the power lines of the locks by using built-in self-contained power sources.

This goal is achieved by the way in which electrical safety is provided during operational switching at power facilities, including determining the position of switching devices, transmitting the position of the switching device via radio channel, generating a logical expression for each switching device and connecting power to the switching block drive of the switching device with a true logical value expressions, data on the position of functionally connected switching devices accumulate in places the location of their drives at local points, data transfer from a local point is carried out only upon request from the control room, permission to connect power to the block lock is transmitted from the control room via a radio channel, while power supply to the locks is carried out from built-in autonomous sources.

The implementation of the collection of data on the position of switching devices directly at the control object allows you to implement a master-slave exchange scheme, where the dispatch level acts as the master, and the local level as the slave. Such a scheme allows minimizing all radio exchanges, thereby significantly reducing the likelihood of a radio failure. In addition, this exchange scheme makes it easy to implement communication channel diagnostics and use the multi-channel exchange principle. Such measures can significantly improve the reliability of the operation of locking systems.

The use of autonomous power supplies with regular monitoring of their charge level eliminates the need for power lines, which significantly reduces not only the cost of installation and commissioning, but also eliminates the possibility of power supply failures due to wire insulation failures and, thus, increases the reliability of the system as a whole .

In FIG. 1 shows a structural diagram for implementing the method. It is indicated: l _1о , l _1в - induction position sensors of the first switching apparatus are “disconnected” and “turned on”, respectively; _2o l, l _2c - _No l, l _NB - similarly for the other switching devices; 2 ₁ , 2 _{2 ...} 2 _N - blocking locks of the drives of the first switching device, second, etc .; 3 - controller switching device; 4 - radio-frequency transceiver (transceiver) of the controller; 5 - autonomous power source; 6 - radio-frequency transceiver control room, 7 - logical locking device; 8 - workstation operational personnel.

The method is implemented as follows. For each switching device, according to the operational scheme of the power facility, a logical expression is compiled to allow on and off operations, which are stored in a database located in the memory of workstation 8 of the operating personnel. The operands of a logical expression are the position of the corresponding switching apparatus. The operating staff creates a switching form at the workstation 8, which at the command of the personnel is transferred to the logical locking device 7. The device 7 sequentially on the switching form extracts from the database of switching devices a logical expression for the switching device, which is to be turned off (on). According to the logical expression (logical circuit), the device 7 requests through the transceivers 4, 6 the controller 3 of the switching devices about the position of the switching devices from the logical circuit, i.e. about the state of their induction sensors 1. If the logical expression is true, then the device 7 gives permission to the controller 3 to connect the power to the lock unit 2. The operating personnel using the electromagnetic key unlock the drive and carry out switching. The next line in the switching form is processed in the same way, but under the condition that the previous switching device has turned off (on). Power to all nodes of the locking system, except for the dispatch level, is made from an autonomous power supply 5. The battery level of the source 5 is controlled by periodically polling the device 7 of the logical blocking of the controller 3, which measures the voltage on the batteries of the source 5.

Information sources

1. Instruction manual for operational safety interlocks in high voltage switchgears. Service of excellence and information. M .: Soyuztekhenergo, 1979, p. 9-38.

2. Operational locks on the basis of KP Iset. Yekaterinburg: NTK Interface, 2010, p. 4-7.

3. Description of the invention to the patent of the Russian Federation No. 2274918, cl. IPC Н01Н 9/28, dated June 22, 2004

Claims (1)

A method of ensuring electrical safety in the production of operational switching at power facilities, including determining the position of switching devices, transmitting by radio channel the position of the switching device, generating a logical expression for each switching device and connecting power to the lock-block drive of the switching device with a true value of the logical expression, characterized in that data on the position of functionally connected switching devices accumulate at their locations drives at local points, data transfer from a local point is carried out only upon request from a control room, permission to connect power to the block lock is transmitted from the control room via a radio channel, while power supply to the locks is carried out from built-in autonomous sources.