CN112600291B - Automatic switching system and automatic switching method for secondary voltage loop - Google Patents

Automatic switching system and automatic switching method for secondary voltage loop Download PDF

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Publication number
CN112600291B
CN112600291B CN202011332357.1A CN202011332357A CN112600291B CN 112600291 B CN112600291 B CN 112600291B CN 202011332357 A CN202011332357 A CN 202011332357A CN 112600291 B CN112600291 B CN 112600291B
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voltage
switching
output
input
circuit
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CN112600291A (en
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张刚
杨翔
刘小正
***
贾昌晖
王志英
王向利
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Institute of Science and Technology of China Railway Xian Group Co Ltd
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Institute of Science and Technology of China Railway Xian Group Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/02—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which an auxiliary distribution system and its associated lamps are brought into service
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16576—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing DC or AC voltage with one threshold
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00—Details of emergency protective circuit arrangements
    • H02H1/06—Arrangements for supplying operative power
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J11/00—Circuit arrangements for providing service supply to auxiliaries of stations in which electric power is generated, distributed or converted
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/061—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for DC powered loads
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02B90/20—Smart grids as enabling technology in buildings sector
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/12—Energy storage units, uninterruptible power supply [UPS] systems or standby or emergency generators, e.g. in the last power distribution stages
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/20—End-user application control systems
    • Y04S20/221—General power management systems
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/20—End-user application control systems
    • Y04S20/248—UPS systems or standby or emergency generators

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention belongs to the technical field of automatic control, and particularly relates to an automatic switching system and an automatic switching method for a secondary voltage loop.

Description

Automatic switching system and automatic switching method for secondary voltage loop
Technical Field
The invention belongs to the technical field of automatic control, and particularly relates to an automatic switching system and an automatic switching method for a secondary voltage loop.
Background
The railway traction substation converts electric energy sent by a power plant through a power transmission line into voltage suitable for locomotive vehicles and distributes the voltage to a place of a contact net, wherein a 27.5KV bus is an important component of the traction substation, is connected with electric equipment such as a breaker, a disconnecting switch, a current transformer CT, a voltage transformer PT/YH, a lightning arrester, an insulator and the like of the substation, and the working condition of the railway traction substation directly influences the working condition of the whole substation.
A voltage transformer (YH) is arranged on a 27.5kV bus of an existing traction substation, wherein the voltage transformer (YH) is respectively 3YH, 5YH, 4YH and 6YH, usually 3YH and 5YH are a group, 4YH and 6YH are a group, and when the system operates, one group works, and the other group is reserved; the voltage transformer is used for acquiring the bus voltage at the 27.5kV side and converting the bus voltage into AC100V according to a certain proportion, the working voltage transformer AC100V is used for a relay protection and detection voltage loop, the loop formed by the AC100V providing a voltage signal to the relay protection and measurement device is a secondary voltage loop, and the AC100V secondarily output by the standby voltage transformer is used as a standby;
however, the existing circuit has the following problems: although the existing device can meet the requirement of bus detection, manual switching is needed after an abnormal result is detected, and the problems of slow switching reaction, long switching time, misoperation, high working strength and high personnel investment are caused by manual switching.
Disclosure of Invention
Aiming at the technical problems in the prior art, the invention provides an automatic switching system of a secondary voltage loop, which can monitor the secondary voltage loop in real time, accurately switch a fault circuit to a standby circuit in time and ensure normal use.
Meanwhile, the invention also provides a secondary voltage loop automatic switching method realized by using the secondary voltage loop automatic switching system.
The technical scheme adopted by the invention is as follows:
a secondary voltage loop automatic switching system comprises a voltage transformer, a monitoring module, a switching module and an output circuit;
the input end of the voltage transformer is connected with the secondary voltage loop bus, the output end of the voltage transformer is connected with the input end of the monitoring module, the output end of the monitoring module is connected with the input end of the switching module, and the output end of the switching module is connected with the input end of the output circuit.
Further, the switching module comprises a switching circuit, and the switching circuit comprises a first automatic switch, a double-position relay, a second automatic switch, an intermediate relay and a display circuit;
the input end of the monitoring module is connected with the output end of the voltage transformer, the output end of the monitoring module is connected with the input end of the double-position relay, the input end of the first automatic change-over switch is connected with the output end of the voltage transformer, and the output end of the first automatic change-over switch is connected with the input end of the double-position relay; one end of the second automatic transfer switch is connected with the output end of the voltage transformer, the other end of the second automatic transfer switch is connected to a connecting node of a coil and a contact of the double-position relay, the output end of the double-position relay is connected with the input end of the intermediate relay, and the output end of the intermediate relay is connected with the input end of the output circuit through the display circuit.
Further defined, the switching module further comprises a manual switching circuit, a remote control module and an emergency control circuit;
the manual switching circuit comprises a first manual switch QK2, an input/output switch and a plurality of diodes; the output end of the first manual switch QK2 is connected with the input/push-out switch, a plurality of diodes are connected to the output end of the input/push-out switch in parallel, and the output ends of the diodes are respectively and correspondingly connected with the input ends of the intermediate relay;
the remote control module comprises remote control switches which correspond to the input ends of the double-position relay one by one, the input ends of the remote control switches are connected with the output end of the first automatic change-over switch, and the output ends of the remote control switches are connected with the input ends of the double-position relay, so that the remote control of the double-position relay is realized;
the emergency control circuit comprises emergency control switches which correspond to the input ends of the double-position relay one by one, and the emergency control switches correspond to the remote control switches one by one and are connected in parallel; the input end of the emergency control switch is connected with the output end of the first automatic change-over switch, and the output end of the emergency control switch is connected with the input end of the double-position relay, so that emergency manual control over the double-position relay is achieved.
Further limited, the automatic switching system of the secondary voltage loop further comprises a Programmable Logic Controller (PLC), the output end of the monitoring module is connected with the input end of the PLC, and the output end of the PLC is connected with the input end of the switching module.
Further, the monitoring module is a voltage transmitter, the output end of the voltage transformer is connected with the input end of the voltage transmitter, the output end of the voltage transmitter is connected with the input end of the programmable controller, and the output end of the programmable controller is connected with the input end of the switching circuit.
Further, the monitoring module is a voltage monitor, an output end of the voltage transformer is connected with an input end of the voltage monitor, an output end of the voltage monitor is connected with an input end of the programmable controller, and an output end of the programmable controller is connected with an input end of the switching module;
the voltage monitor comprises a voltage monitor 3YJ, a voltage monitor 4YJ, a voltage monitor 5YJ and a voltage monitor 6YJ which are correspondingly connected with the voltage transformer, and the output ends of the voltage monitor 3YJ, the voltage monitor 4YJ, the voltage monitor 5YJ and the voltage monitor 6YJ are respectively connected with the input end I of the programmable controller a0.6 、I a0.7 、I b0.1 、I b0.2 And (4) connecting.
Further, the monitoring module is a voltage monitor, and the voltage monitor comprises a voltage monitor 3YJ, a voltage monitor 4YJ, a voltage monitor 5YJ and a voltage monitor 6YJ which are correspondingly connected with each voltage transformer and have an interlocking function in pairs; a normally open contact of the voltage monitor 3YJ is connected in series with a normally closed contact of the voltage monitor 4YJ, and a normally open contact of the voltage monitor 4YJ is connected in series with a normally closed contact of the voltage monitor 3YJ to form an interlock circuit; a normally open contact of the voltage monitor 5YJ is connected in series with a normally closed contact of the voltage monitor 6YJ, and a normally open contact of the voltage monitor 6YJ is connected in series with a normally closed contact of the voltage monitor 5YJ to form an interlock circuit; the output ends of the voltage monitor 3YJ and the voltage monitor 4YJ are respectively connected with the input ends of the double-position relays ZJ 3-4; the output ends of the voltage monitor 5YJ and the voltage monitor 6YJ are respectively connected with the input ends of the double-position relays ZJ 5-6.
Further, the automatic switching system of the secondary voltage loop further comprises a bypass circuit, wherein the input end of the bypass circuit is connected with the output end of the voltage transformer, and the output end of the bypass circuit is connected with the input end of the output circuit.
A method for automatically switching a secondary voltage loop by using the automatic switching system of the secondary voltage loop comprises the following steps:
(1) The voltage transformer receives voltage signals of a secondary voltage loop bus, outputs mutual inductance voltage after conversion, then the mutual inductance voltage is input into a voltage monitor for detection, a calibration voltage value is set in the voltage monitor, and when the mutual inductance voltage obtained by the voltage monitor is smaller than the calibration voltage, the voltage monitor is conducted and outputs voltage;
(2) The switching module receives the switching signal, the first automatic transfer switch is switched to an automatic normally open state, the coil of the double-position relay is electrified, the second automatic transfer switch is opened, the contact of the double-position relay is closed, the switching contact corresponding to the intermediate relay is electrified, switching current output is carried out through the output circuit, meanwhile, the LED lamp corresponding to the voltage transformer in the working state in the display circuit is lightened, and switching of a secondary voltage loop is completed.
A method for automatically switching a secondary voltage loop by using the automatic switching system of the secondary voltage loop comprises the following steps:
(1) The voltage transformer receives voltage signals of a secondary voltage loop bus, converts the voltage signals and outputs mutual inductance voltage, and the monitoring module receives the mutual inductance voltage signals, converts the mutual inductance voltage into input current signals and transmits the input current signals to the programmable controller;
(2) The programmable controller compares the received input current signal with a preset calibration current value, and when the input current signal is smaller than the calibration current value, the programmable controller outputs a conversion signal to the switching module through the output circuit;
(3) The switching module receives the switching signal, and first automatic transfer switch switches to the automatic normally open state, and the coil of two position relay gets electric, and second automatic transfer switch opens, and the contact of two position relay is closed, and the switching contact that the auxiliary relay corresponds gets electric, will switch current output and carry out the switching through output circuit, and simultaneously, the LED lamp that the voltage transformer that is in operating condition among the display circuit corresponds lights, accomplishes the switching of secondary voltage return circuit.
Compared with the prior art, the automatic switching system and the automatic switching method for the secondary voltage loop have the beneficial effects that:
1. the system adopts a modular design, comprehensively utilizes electronic components such as a voltage monitor or a voltage transmitter, a double-position relay, an intermediate relay PLC and the like, realizes the function of a 27.5KV bus secondary voltage loop automatic switching device, achieves the real-time monitoring of 4-path voltage, has two automatic/manual switching modes, realizes the function of no main-standby switching, achieves the aim of quick automatic switching, provides technical support for the informationized automation of the operation of substation equipment, has complete functions, is simple and clear in circuit design, convenient and quick to install and maintain, saves the working time and improves the working efficiency;
2. the switching module adopted by the system can be timely and effectively switched to the standby circuit when the secondary voltage loop fails, the switching action is fast, the effectiveness and timeliness are improved, and economic loss caused by faults is avoided;
3. the voltage converter of the system obtains different mutual induction voltages by setting different conversion proportions, the application range is wide, the programmable controller is arranged, the accuracy and timeliness of system control are further improved, meanwhile, the system can be suitable for different circuits by changing the setting program, the application range is further improved, meanwhile, the interlocking of the main circuit and the standby circuit is ensured to prevent misoperation by arranging the double-position relay, and the safety of the system is improved;
4. the system can complete the standby switching function in emergency by arranging the bypass circuit and switching through corresponding multi-path air switch bypasses.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
FIG. 1 is a block diagram of the system of the present invention;
FIG. 2 is an external wiring diagram of the present invention;
FIG. 3 is a switching circuit diagram according to the present invention;
FIG. 4 is a voltage monitor + PLC circuit layout of the present invention;
FIG. 5 is a schematic diagram of a voltage transmitter + PLC circuit design according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration only, not by way of limitation, i.e., the embodiments described are intended as a selection of the best mode contemplated for carrying out the invention, not as a full mode. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
It is noted that relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, or module that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, or module. The term "comprising", without further limitation, means that the element so defined is not excluded from the list of additional identical elements in a process, method, or module that comprises the element.
The features and properties of the present invention are described in further detail below with reference to examples.
Example 1
Referring to fig. 1 to 3, the present embodiment will be described by taking an example of automatic switching of the 27.5KV bus secondary voltage circuit of the railway traction substation.
The 27.5kV bus of the railway traction substation is generally provided with voltage transformers 3YH, 5YH, 4YH and 6YH, wherein 3YH and 5YH are generally a group, and 4YH and 6YH are generally a group. When the device is operated, 3YH and 5YH work, 4YH and 6YH are used as standby, the voltage transformer is used for acquiring the voltage of a bus at the 27.5kV side and converting the voltage into AC100V according to a certain proportion, the working voltage transformer AC100V is used for a voltage loop for relay protection and measurement, and AC100V output by the standby voltage transformer is used as standby.
The automatic switching system for the secondary voltage loop of the embodiment mainly comprises a voltage transformer (YH) connected to a 27.5kV bus, a bypass circuit, a monitoring module, a switching module and an output circuit, wherein the output end of the voltage transformer is connected with the input end of the bypass circuit, and the output end of the bypass circuit is connected with the input end of the output circuit. The monitoring module is a voltage monitor (YJ), wherein: the voltage monitor of the present embodiment includes a voltage monitor 3YJ, a voltage monitor 4YJ, a voltage monitor 5YJ, and a voltage monitor 6YJ which are connected correspondingly to the respective voltage transformers and have an interlock function in pairs; the normally open contact of the voltage monitor 3YJ is connected in series with the normally closed contact of the voltage monitor 4YJ, while the normally open contact of the voltage monitor 4YJ is connected in series with the normally closed contact of the voltage monitor 3YJ to form an interlock circuit, the normally open contact of the voltage monitor 5YJ is connected in series with the normally closed contact of the voltage monitor 6YJ, and the normally open contact of the voltage monitor 6YJ is connected in series with the normally closed contact of the voltage monitor 5YJ to form an interlock circuit.
Further, the switching module of the present embodiment includes a switching circuit, which is a pure relay control circuit, comprises a first automatic change-over switch QK1, a double-position relay, a second automatic change-over switch QK3, an intermediate relay and a display circuit, and realizes the basic function of switching, wherein
The input end of the monitoring module is connected with the output end of the voltage transformer, and the output end of the monitoring module is connected with the input end of the double-position relay, namely the double-position relay comprises 2 groups of ZJ3-4 and ZJ5-6, and the input ends of two coils of 1 group of ZJ3-4 are respectively connected with the output ends of the voltage monitors 3YJ and 4 YJ; the input ends of two coils of the other group of coils ZJ5-6 are respectively connected with the output ends of the voltage monitors 5YJ and 6YJ; the input end of the first automatic change-over switch is connected with the output end of the voltage transformer, the output end of the first automatic change-over switch is simultaneously connected with the coil input ends of the double-position relays ZJ3-4 and ZJ5-6, one end of the second automatic change-over switch is connected with the output end of the voltage transformer, the other end of the second automatic change-over switch is connected on the connection nodes of the coil and the contact of the double-position relays, ZJ3-4 and ZJ5-6, the contact output of the ZJ5-6 is correspondingly connected with 1ZJ, 2ZJ, 3ZJ and 4ZJ coil input ends of the intermediate relays, and 1ZJ, 2ZJ, 3ZJ and 4ZJ contact output ends of the intermediate relays are connected with the input end of the output circuit through the display circuit.
The display circuit of the embodiment comprises display lamps LED1, LED2, LED3 and LED4 which are connected with each contact of the intermediate relay in series, a manual/automatic state display switch QK4, a manual state display lamp LED5 and an automatic state display lamp LED6; wherein, the 1ZJ, 2ZJ, 3ZJ, 4 ZJ's of auxiliary relay contact and display lamp LED1, LED2, LED3, LED4 one-to-one, and series connection, each display lamp LED1, LED2, LED3, LED 4's output and output circuit are connected, manual/automatic state display switch QK4 and second automatic transfer switch QK3 series connection, can accurate demonstration each voltage transformer (YH) corresponding generating line's operating condition.
Further, in order to prevent the automatic switching system from being out of order or being incapable of being normally used due to an emergency, a manual switching circuit may be added to the switching circuit, and the manual switching circuit includes a first manual switch QK2, a first input/output switch ZK1, a second input/output switch ZK2, a diode D1, a diode D2, a diode D3, and a diode D4; the output end of the first manual switch QK2 is connected with a first input/push-out switch ZK1 and a second input/push-out switch ZK2, the input ends of the diode D1 and the diode D2 are connected with the output end of the first input/push-out switch ZK1 in parallel, the output end of the diode D1 is connected with a 1ZJ contact of the intermediate relay, and the output end of the diode D2 is connected with a 2ZJ contact of the intermediate relay; the input ends of the diode D3 and the diode D4 are connected in parallel at the output end of the second input/output switch ZK2, the output end of the diode D3 is connected with the 3ZJ contact of the intermediate relay, and the output end of the diode D4 is connected with the 4ZJ contact of the intermediate relay.
When the buses corresponding to 3YH and/or 5YH have faults, the mutual inductance voltage converted by the voltage transformer is output to the first manual switch QK2, the mutual inductance voltage is transmitted to the communicated ZK1, an operator knows that the buses corresponding to 3YH and/or 5YH have faults through the secondary buses, at the moment, the manual switch-off ZK1 is manually switched off, the intermediate relays corresponding to ZK2,4YH and 6YH are switched on, and the intermediate relays are connected with the output end simultaneously to complete manual circuit switching.
In practical use, when the automatic switching function fault of the secondary voltage loop in emergency is faced, the judgment cannot be reasonably carried out, and at the moment, the judgment and the switching need to be carried out manually, so an emergency control circuit is also arranged in the switching module, and comprises an emergency control switch A3-4, an emergency control switch A4-3, an emergency control switch A5-6 and an emergency control switch A6-5; the input ends of the emergency control switch A3-4, the emergency control switch A4-3, the emergency control switch A5-6 and the emergency control switch A6-5 are connected in parallel with the output end of the first automatic switch QK 1; the output ends of the emergency control switch A3-4 and the emergency control switch A4-3 are connected in parallel to the coil input end of the double-set relay ZJ 3-4; the output ends of the emergency control switches A5-6 and A6-5 are connected in parallel with the coil input end of the double-position relay ZJ 5-6. In an emergency situation, the voltage output by the voltage transformer no longer passes through a voltage monitor, but when the emergency control switch A3-4 is pressed, the corresponding 4-a1 and 4-a2 nodes are connected, the ZJ3-4 set switch of the double-position relay is switched, 14 and 13 of the 2ZJ of the intermediate relay are electrified, the contacts 2-5 and 2-9 are electrified, the LED2 is lightened, the emergency switching operation of 3YH switching 4YH is completed, and other switching operations under the emergency operation are also realized through the corresponding emergency control switches.
The automatic switching method of the secondary voltage loop, which is completed by the automatic switching system of the secondary voltage loop, comprises the following steps:
two 27.5KV buses are used as an input circuit, two voltage transformers are connected to the two buses, a No. 3 voltage transformer (3 YH) and a No. 4 voltage transformer (4 YH) are arranged on one bus, a No. 5 voltage transformer (5 YH) and a No. 6 voltage transformer (6 YH) are arranged on the other bus, when the bus is used, the 3YH and the 5YH form a group, the 4YH and the 6YH form a group, one group works, the other group is used as a standby, the output end is a secondary bus, and an air switch is installed in a bypass circuit; the bypass circuit mainly comprises parallel 1KK,2KK,3KK and 4KK which are respectively and correspondingly connected with IN and OUT of 3YH, 4YH, 5YH and 6YH, and the corresponding way of communication of the bypass circuit can be realized by closing corresponding idle opening so as to manually switch under emergency or special conditions. Taking initial use of 3YH and 5YH as an example, air switches 1KK,2KK,3KK and 4KK on the bypass circuit corresponding to 3YH and 5YH are all in a closed state, and when 3YH and 5YH are in a normal working state, mutual inductance voltage converted by the voltage transformer is directly input into the output circuit; when the first automatic transfer switch QK1 is turned to the automatic position, the corresponding node of QK1 is turned on as shown in fig. 3, the manual/automatic status display switch QK4 is switched to the automatic status, and the automatic position indicator LED6 is turned on for display, which shows that after the operating power supply + KM and-KM is turned on, the nodes 3-11 and 3-14 of 3YJ in the voltage monitor 3YJ-4YJ are turned off, and the nodes 4-21 and 4-22 of 4YJ are turned on.
When the voltage monitor 3YJ monitors that the voltage is smaller than the calibrated voltage 100V, the nodes 3-11 and 3-14 of the 3YJ in the voltage monitor are closed, the nodes 4-21 and 4-22 of the 4YJ are kept closed, then the voltage monitor 4YJ is switched on, the nodes 4-1 and 4-10 of the ZJ3-4 of the double-position relay are electrified, the second automatic change-over switch QK3 is automatically opened, the contacts 15-1 and 4-5 of the ZJ3-4 of the double-position relay are switched on, the 2ZJ of the intermediate relay is electrified, the switching current is output and is switched through an output circuit, the 4YH is switched on, the 4YH switch-in indicator light LED2 is switched on for displaying, and the switching function of automatically switching the 3YH to 4YH is realized.
Similarly, after the corresponding bus bar has a fault when 4YH works, the 4-11 and 4-14 nodes of the voltage monitor 4YJ are closed, the 3-21 and 3-22 nodes of the 3YJ are kept closed, the reset nodes 3-2 and 3-9 of the ZJ3-4 of the double-position relay are switched on, the second automatic change-over switch QK3 is automatically opened, the contacts 15-1 and 3-6 of the ZJ3-4 of the double-position relay are switched on, the 1ZJ of the intermediate relay is electrified to output the switching current and perform switching through an output circuit, and the 3YH input indicator light LED1 are switched on for displaying at the same time, so that the switching function of automatically switching the 3YH by 4YH is realized. Similarly, after the bus corresponding to the 5YH fails, the set nodes 5-1 and 5-10 of the ZJ5-6 of the double-position relay are switched on to complete the switching of the 5YH-6YH, and after the bus corresponding to the 6YH fails, the reset nodes 5-2 and 5-9 of the ZJ5-6 of the double-position relay are switched on to complete the switching of the 6YH-5 YH.
Example 2
Different from the embodiment 1 and the embodiment 2, the automatic switching system of the secondary voltage loop of the invention cancels a bypass circuit, is additionally provided with a Programmable Logic Controller (PLC), takes the model Siemens 1214C as an example for explanation, and realizes the automatic switching of the secondary voltage loop. The method specifically comprises the following steps:
the input terminal of the voltage monitor is connected to the secondary voltage loop, and referring to fig. 4, the voltage monitor of the present embodiment includes a voltage monitor 3YJ, a voltage monitor 4YJ, a voltage monitor 5YJ, and a voltage monitor 6YJ connected to the voltage transformer, and the output terminals of the voltage monitor 3YJ, the voltage monitor 4YJ, the voltage monitor 5YJ, and the voltage monitor 6YJ are respectively connected to the input terminal I of the programmable controller a0.6 、I a0.7 、I b0.1 、I b0.2 Connecting; the output end of the PLC is connected with the input end of the switching module, and the output end of the switching module is connected with the input end of the output circuit.
Simultaneously in order to satisfy the in-service use demand, combine PLC automatic control and remote control function, still added remote control module (YD) in the switching module of this embodiment, with telemechanical control system is supporting, realizes remote switch through interface connection, this telemechanical control system belongs to conventional commercial product, can realize the telemechanical control function of this embodiment can.
The input end of the first automatic change-over switch QK1 is connected with a 24V power supply, the automatic output end of the first automatic change-over switch is connected with the Ia0.0 input end of the PLC, the automatic output end of the first automatic change-over switch is connected with the input end of the remote control circuit, and the output end of the manual change-over switch is connected with the input end of the Ia0.1 of the PLC.
The remote control module of the embodiment comprises remote control switches YD3-4, YD4-3, YD5-6 and YD6-5, the input ends of the YD3-4, YD4-3, YD5-6 and YD6-5 are respectively connected with the set node of ZJ3-4, the reset node of ZJ3-4, the set node of ZJ5-6 and the reset node of ZJ5-6 of the double-position relay correspondingly, and the remote control module can remotely control and complete circuit switching on each node of the ZJ3-4 and ZJ5-6 in an automatic switching state.
The automatic switching method of the secondary voltage loop of the embodiment is realized by the following steps:
24VDC is used as a double power supply, two paths of 24V switching power supplies supply power to a system after passing through a redundant power supply module, mutual inductance voltages output by 4 paths of voltage transformers are input to voltage monitors 3YJ, 4YJ, 5YJ and 6YJ, the output ends of the 4 paths of voltage transformers are respectively connected with the input ends of Ia0.6, ia0.7, ib0.1 and Ib0.2 of a PLC, the output ends of intermediate relays 1ZJ, 2ZJ, 3ZJ and 4ZJ are respectively connected with the input ends of Ia0.2, ia0.3, ia0.4 and Ia0.5 of the PLC, calibration signal values are set in the PLC through a program, Q0.0, Q0.1, Q0.2 and Q0.3 of the output end of the PLC are respectively connected with a circuit for converting 3YH into 4YH, 6YH and 5YH of a switching circuit, and a circuit for preventing backflow is arranged on the output end of the PLC.
In the using process, when the mutual inductance voltage converted by the voltage transformer 3YH is less than 100V, the 3-21 and 3-22 nodes of the voltage monitor 3YJ are connected, the 3YJ sends a signal to the PLC from the ia0.6 end, the PLC analyzes and sends an action signal to Q0.0 according to a set program after receiving the signal, the switching module completes the switching of 3YH to 4YH according to the switching method of the above embodiment 1 after receiving the switching instruction of 3YH to 4YH, namely, ZJ3-4 setting nodes 4-1 and 4-10 of the dual-position relay are powered, the action voltage passes through ZJ3-4 contact 15-1 and 4-5 of the dual-position relay after passing through the second automatic switch, 2ZJ of the intermediate relay is powered, the switching current is output and switched through the output circuit, 4YH is input, and the 4YH input indicator light LED2 is connected for displaying, so as to realize the switching function of automatically switching 4YH by 3YH, and 4YH and 5 operate at this time.
After the 28-27 nodes of the automatic switching input end of the PLC are connected, the PLC does not receive input signals of the voltage monitor according to a set program any more, and the circuit switching is completely controlled by the remote control circuit YD; after the 25-26 nodes of the manual switching input end of the PLC are connected, the PLC does not receive input signals of the voltage monitor YJ any more according to a set program, and the connection and disconnection of each node of the voltage monitor are manually adjusted to enable the PLC to make different output signals for different input signals through the set program, so that the PLC controls the connection and disconnection of each voltage transformer and completes circuit switching.
Example 4
Different from embodiment 3, the monitoring module is a voltage transmitter (YB) of 4 to 20mA, referring to fig. 5, the voltage transmitters are YB1, YB2, YB3 and YB4, respectively, input ends thereof are connected to output ends of voltage transformers 3YH, 4YH, 5YH and 6YH, respectively, and output ends of the voltage transmitters YB1, YB2, YB3 and YB4 are connected to a of the PLC, respectively I0 、A I1 、A I2 And A I3 The input ends are connected.
The automatic switching method of the secondary voltage loop of the embodiment is realized by the following steps:
the 24VDC is used as a double power supply, two paths of 24V switching power supplies supply power to a system after passing through a redundant power supply module, if the voltage output by the 3YH is less than 100V, the current output by the voltage transmitter YB1 according to a set proportion is reduced, the PLC sets a calibration current according to a program, the PLC outputs an action signal to Q0.0 according to the input current analysis at the moment, the 3 YH-to-4 YH circuit completes circuit switching after receiving the signal, the circuit switching process is the same as that of the embodiment 1, and the automatic switching of a secondary voltage loop is completed.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (9)

1. A secondary voltage loop automatic switching system is characterized by comprising a voltage transformer, a monitoring module, a switching module and an output circuit;
the input end of the voltage transformer is connected with the secondary voltage loop bus, the output end of the voltage transformer is connected with the input end of the monitoring module, the output end of the monitoring module is connected with the input end of the switching module, and the output end of the switching module is connected with the input end of the output circuit;
the switching module comprises a switching circuit, and the switching circuit comprises a first automatic switching switch, a double-position relay, a second automatic switching switch, an intermediate relay and a display circuit;
the input end of the monitoring module is connected with the output end of the voltage transformer, the output end of the monitoring module is connected with the input end of the double-position relay, the input end of the first automatic change-over switch is connected with the output end of the voltage transformer, and the output end of the first automatic change-over switch is connected with the input end of the double-position relay; one end of the second automatic transfer switch is connected with the output end of the voltage transformer, the other end of the second automatic transfer switch is connected to a connecting node of a coil and a contact of the double-position relay, the output end of the double-position relay is connected with the input end of the intermediate relay, and the output end of the intermediate relay is connected with the input end of the output circuit through the display circuit.
2. The automatic switching system of secondary voltage loop according to claim 1, wherein said switching module further comprises a manual switching circuit and a remote control module, an emergency control circuit;
the manual switching circuit comprises a first manual switch QK2, an input/output switch and a plurality of diodes; the output end of the first manual switch QK2 is connected with the input/push-out switch, a plurality of diodes are connected to the output end of the input/push-out switch in parallel, and the output ends of the diodes are respectively correspondingly connected with the input ends of the intermediate relay;
the remote control module comprises remote control switches which correspond to a plurality of input ends of the double-position relay one by one, the input ends of the remote control switches are connected with the output end of the first automatic change-over switch, and the output ends of the remote control switches are connected with the input ends of the double-position relay, so that the remote control of the double-position relay is realized;
the emergency control circuit comprises emergency control switches which correspond to the input ends of the double-position relay one by one, and the emergency control switches correspond to the remote control switches one by one and are connected in parallel; the input end of the emergency control switch is connected with the output end of the first automatic change-over switch, and the output end of the emergency control switch is connected with the input end of the double-position relay, so that emergency manual control over the double-position relay is achieved.
3. The automatic switching system of the secondary voltage loop according to claim 1 or 2, further comprising a Programmable Logic Controller (PLC), wherein an output end of the monitoring module is connected with an input end of the PLC, and an output end of the PLC is connected with an input end of the switching module.
4. The automatic switching system of the secondary voltage loop according to claim 3, wherein the monitoring module is a voltage transformer, the output terminal of the voltage transformer is connected to the input terminal of the programmable controller, and the output terminal of the programmable controller is connected to the input terminal of the switching circuit.
5. The automatic switching system for secondary voltage loop according to claim 3, wherein the monitoring module is a voltage monitor, the output terminal of the voltage transformer is connected to the input terminal of the voltage monitor, the output terminal of the voltage monitor is connected to the input terminal of the programmable controller, and the output terminal of the programmable controller is connected to the input terminal of the switching module;
the voltage monitor comprises a voltage monitor 3YJ, a voltage monitor 4YJ, a voltage monitor 5YJ and a voltage monitor 6YJ which are correspondingly connected with the voltage transformer, and the output ends of the voltage monitor 3YJ, the voltage monitor 4YJ, the voltage monitor 5YJ and the voltage monitor 6YJ are respectively connected with the input end I of the programmable controller a0.6 、I a0.7 、I b0.1 、I b0.2 And (4) connecting.
6. The automatic switching system of a secondary voltage loop according to claim 1 or 2, wherein the monitoring module is a voltage monitor, and the voltage monitor comprises a voltage monitor 3YJ, a voltage monitor 4YJ, a voltage monitor 5YJ and a voltage monitor 6YJ which are correspondingly connected with each voltage transformer and have an interlocking function in pairs; the normally open contact of the voltage monitor 3YJ is connected in series with the normally closed contact of the voltage monitor 4YJ, and the normally open contact of the voltage monitor 4YJ is connected in series with the normally closed contact of the voltage monitor 3YJ to form an interlock circuit; a normally open contact of the voltage monitor 5YJ is connected in series with a normally closed contact of the voltage monitor 6YJ, and a normally open contact of the voltage monitor 6YJ is connected in series with a normally closed contact of the voltage monitor 5YJ to form an interlock circuit; the output ends of the voltage monitor 3YJ and the voltage monitor 4YJ are respectively connected with the input ends of the double-position relays ZJ 3-4; the output ends of the voltage monitor 5YJ and the voltage monitor 6YJ are respectively connected with the input ends of the double-position relays ZJ 5-6.
7. The automatic switching system for secondary voltage loop according to claim 1 or 2, characterized by further comprising a bypass circuit, wherein an input terminal of the bypass circuit is connected with an output terminal of the voltage transformer, and an output terminal of the bypass circuit is connected with an input terminal of the output circuit.
8. A secondary voltage loop automatic switching method implemented by using the secondary voltage loop automatic switching system according to claim 1, comprising the steps of:
(1) The voltage transformer receives voltage signals of a secondary voltage loop bus, outputs mutual inductance voltage after conversion, then the mutual inductance voltage is input into a voltage monitor for detection, a calibration voltage value is set in the voltage monitor, and when the mutual inductance voltage obtained by the voltage monitor is smaller than the calibration voltage, the voltage monitor is conducted and outputs voltage;
(2) The switching module receives the switching signal, and first automatic transfer switch switches to the automatic normally open state, and the coil of two position relay gets electric, and second automatic transfer switch opens, and the contact of two position relay is closed, and the switching contact that the auxiliary relay corresponds gets electric, will switch current output and carry out the switching through output circuit, and simultaneously, the LED lamp that the voltage transformer that is in operating condition among the display circuit corresponds lights, accomplishes the switching of secondary voltage return circuit.
9. A secondary voltage circuit automatic switching method implemented by the secondary voltage circuit automatic switching system according to claim 1, comprising the steps of:
(1) The voltage transformer receives a voltage signal of a secondary voltage loop bus, converts the voltage signal and then outputs a mutual inductance voltage, and the monitoring module receives the mutual inductance voltage signal, converts the mutual inductance voltage into an input current signal and transmits the input current signal to the programmable controller;
(2) The programmable controller compares the received input current signal with a preset calibration current value, and when the input current signal is smaller than the calibration current value, the programmable controller outputs a conversion signal to the switching module through the output circuit;
(3) The switching module receives the switching signal, the first automatic transfer switch is switched to an automatic normally open state, the coil of the double-position relay is electrified, the second automatic transfer switch is opened, the contact of the double-position relay is closed, the switching contact corresponding to the intermediate relay is electrified, switching current output is carried out through the output circuit, meanwhile, the LED lamp corresponding to the voltage transformer in the working state in the display circuit is lightened, and switching of a secondary voltage loop is completed.
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