CN115986682A

CN115986682A - Protection system and protection method for transformer substation

Info

Publication number: CN115986682A
Application number: CN202310082091.7A
Authority: CN
Inventors: 陈晓彬; 孙玉彤; 孙洋; 谢惠藩; 林浩; 孙旭; 彭向阳; 方文田; 王广政; 万志强; 陈太丽; 李伟明; 李翔; 王停娟; 罗奕飞; 黄珊; 吴少钿; 林继杰; 林峻嵩; 邢文忠
Original assignee: China Southern Power Grid Co Ltd; Guangdong Power Grid Co Ltd; Zhuhai Power Supply Bureau of Guangdong Power Grid Co Ltd; Jieyang Power Supply Bureau of Guangdong Power Grid Co Ltd
Current assignee: China Southern Power Grid Co Ltd; Guangdong Power Grid Co Ltd; Zhuhai Power Supply Bureau of Guangdong Power Grid Co Ltd; Jieyang Power Supply Bureau of Guangdong Power Grid Co Ltd
Priority date: 2023-01-17
Filing date: 2023-01-17
Publication date: 2023-04-18

Abstract

The invention discloses a protection system and a protection method of a transformer substation. The transformer substation comprises three circuit breakers sequentially connected between a first bus and a second bus in series, and a branch circuit is connected between every two adjacent circuit breakers. The protection system of transformer substation includes the protection circuit who corresponds the setting with the branch road, and protection circuit includes: the device comprises a three-phase voltage transformer, a first protection device, a second protection device, a measurement and control device, a first main switch, a second main switch, a first branch switch, a second branch switch and a third branch switch. The measurement and control device is used for judging whether to control the circuit breakers on the two sides of the branch circuit to be switched on according to a first preset condition, and the first preset condition comprises the following steps: whether voltage exists on the secondary side of the three-phase voltage transformer, whether the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are in a closed position, and whether the first protection device and the second protection device send out preset abnormal state signals. The technical scheme of the invention is beneficial to reducing the probability of occurrence of misoperation accidents.

Description

Protection system and protection method for transformer substation

Technical Field

The embodiment of the invention relates to the technical field of power systems, in particular to a protection system and a protection method for a transformer substation.

Background

At present, a 500kV voltage class transformer substation usually adopts a three-half wiring mode. For the protection and measurement and control of a 500kV line and a main transformer, a three-phase voltage transformer on the line side or the transformer side is generally adopted for realization. The protection function of the existing protection device for the 500kV line and the main transformer is misjudged, so that a protection misoperation accident is caused, and the safe operation of a power grid is not facilitated.

Disclosure of Invention

The embodiment of the invention provides a protection system and a protection method of a transformer substation, which are used for reducing the probability of occurrence of misoperation accidents, so that the operation safety of a power grid is improved.

In a first aspect, an embodiment of the present invention provides a protection system for a substation, where the substation includes a first bus, a second bus, and three circuit breakers sequentially connected in series between the first bus and the second bus, and a branch is connected between two adjacent circuit breakers, where the branch includes a line branch or a main transformer branch; the protection system of the transformer substation comprises: and a protection circuit corresponding to each branch, the protection circuit comprising:

the three-phase voltage transformer is connected with the corresponding branch circuit and comprises a first secondary winding and a second secondary winding, and the first secondary winding and the second secondary winding both comprise three-phase windings;

each phase winding of the first secondary winding is connected with one phase input end of the first protection device through the first main switch and the first branch switch in sequence;

each phase winding of the second secondary winding is connected with one phase input end of the second protection device through the second main switch and the second branch switch in sequence;

the phase A input end of the measurement and control device is connected with a first node through a third split switch, the first node is located between the first main switch and the first sub switch corresponding to the phase A winding of the first secondary winding, the phase B input end of the measurement and control device is connected with a second node through the third sub switch, the second node is located between the first main switch and the first sub switch corresponding to the phase B winding of the first secondary winding, the phase C input end of the measurement and control device is connected with a third node through the third split switch, and the third node is located between the first main switch and the first sub switch corresponding to the phase C winding of the first secondary winding;

the measurement and control device is used for judging whether to control switching-on of the circuit breakers on the two sides of the branch according to a first preset condition, wherein the first preset condition comprises: whether the secondary side of the three-phase voltage transformer has voltage, whether the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are in a closed position, and whether the first protection device and the second protection device send out preset abnormal state signals.

Optionally, the protection circuit further comprises:

the electrified display is connected with the corresponding branch circuit and is used for detecting and displaying the three-phase voltage of the branch circuit;

a first voltage monitoring relay connected between the first total switch corresponding to the a-phase winding of the first secondary winding and the first node, between the first total switch corresponding to the B-phase winding of the first secondary winding and the second node, and between the first total switch corresponding to the C-phase winding of the first secondary winding and the third node;

a second voltage monitoring relay connected between the second main switch and the second branch switch corresponding to the a-phase winding of the second secondary winding, between the second main switch and the second branch switch corresponding to the B-phase winding of the second secondary winding, and between the second main switch and the second branch switch corresponding to the C-phase winding of the second secondary winding;

wherein the first preset condition further comprises: whether the electrified display detects that the three phases of the branch are all provided with voltage or not; the measurement and control device is further used for detecting the voltages of the first node, the second node and the third node so as to judge whether the secondary side of the three-phase voltage transformer has voltage or not, or judging whether the secondary side of the three-phase voltage transformer has voltage or not according to signals of the first voltage monitoring relay and the second voltage monitoring relay.

Optionally, the preset abnormal state signal includes: alarm signal, blocking signal, DC power supply voltage loss signal and protection channel abnormal signal.

Optionally, the measurement and control device is configured to determine that the circuit breakers on the two sides of the branch are allowed to be manually or remotely switched on when the first preset condition is met;

the first preset condition specifically includes: the secondary side of the three-phase voltage transformer is provided with voltage, a charged display detects that the three phases of the branch circuits are provided with voltage, the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are all in a closed position, and the first protection device and the second protection device do not send out alarm signals, locking signals, direct-current power supply voltage loss signals and protection channel abnormal signals.

Optionally, the first preset condition specifically includes: the secondary side of the three-phase voltage transformer has no voltage, a charged display detects that three phases of the branch have no voltage, the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are all in a closed position, and the first protection device and the second protection device do not send out an alarm signal, a locking signal, a direct-current power supply voltage loss signal and a protection channel abnormal signal.

Optionally, two ends of each circuit breaker are connected with a disconnecting switch, the disconnecting switches connected with different circuit breakers are different, and the branch circuit is connected between two disconnecting switches connected with two adjacent circuit breakers;

the measurement and control device is also used for judging and allowing when meeting second preset conditions the circuit breaker on one side of the branch is manually or remotely switched on, and the second preset conditions comprise:

the circuit breaker both ends are connected isolator all is in the branch position, circuit breaker both ends are connected isolator's motor power all breaks off circuit breaker both ends are connected isolator's motor power all install five additional prevent isolation lock with the circuit breaker is in the maintenance state.

Optionally, the measurement and control device includes:

the device state acquisition module is used for acquiring corresponding on/off state signals of the circuit breaker and the disconnecting switch, the preset abnormal state signals of the first protection device and the second protection device, voltage signals of the first node, the second node and the third node, on/off state signals of the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch, a motor power supply state signal of the disconnecting switch and maintenance state signals of the first protection device and the second protection device;

the analog quantity acquisition module is used for acquiring the single-phase voltage of the first bus and the bus, the three-phase voltage of the branch circuit, the three-phase current and the zero-sequence current;

the power supply conversion module is used for converting an input power supply and then supplying power to the measurement and control device;

and the control module is connected with the equipment state acquisition module, the analog quantity acquisition module, the power conversion module, the circuit breaker and the isolating switch and used for controlling the circuit breaker and the isolating switch.

Optionally, the protection system of the substation further includes: the system comprises a microcomputer five-prevention system, a monitoring system, an intelligent operation and maintenance system and a scheduling automation system; the measurement and control device is in communication connection with the microcomputer five-prevention system, the monitoring system, the intelligent operation and maintenance system and the dispatching automation system through the control module;

the measurement and control device is further used for receiving a control instruction of the monitoring system, the intelligent operation and maintenance system or the dispatching automation system, and the control instruction is executed when meeting the locking requirement so as to control the corresponding circuit breaker and the isolating switch.

Optionally, at least one of the microcomputer five-prevention system, the monitoring system, the intelligent operation and maintenance system and the dispatching automation system is further used for controlling each of the circuit breakers and the disconnecting switches.

In a second aspect, an embodiment of the present invention provides a protection method for a substation, which is executed by a protection system of the substation;

the transformer substation comprises a first bus, a second bus and three circuit breakers sequentially connected in series between the first bus and the second bus, a branch is connected between every two adjacent circuit breakers, and the branch comprises a line branch or a main transformer branch; the protection system of the transformer substation comprises: and a protection circuit corresponding to each branch, the protection circuit comprising:

each phase winding of the first secondary winding is connected with one phase input end of the first protection device sequentially through the first main switch and the first branch switch;

the phase A input end of the measurement and control device is connected with a first node through a third split switch, the first node is positioned between the first main switch and the first split switch corresponding to the phase A winding of the first secondary winding, the phase B input end of the measurement and control device is connected with a second node through the third split switch, the second node is positioned between the first main switch and the first split switch corresponding to the phase B winding of the first secondary winding, the phase C input end of the measurement and control device is connected with a third node through the third split switch, and the third node is positioned between the first main switch and the first split switch corresponding to the phase C winding of the first secondary winding;

the protection method of the transformer substation comprises the following steps:

through whether control according to first preset condition is judged by the measurement and control device the circuit breaker of branch road both sides is closed a floodgate, first preset condition includes: whether the secondary side of the three-phase voltage transformer has voltage, whether the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are in a closed position, and whether the first protection device and the second protection device send out preset abnormal state signals.

The protection system and the protection method of the transformer substation provided by the embodiment of the invention can be applied to the transformer substation adopting three-to-three connection, the transformer substation comprises a first bus, a second bus and three circuit breakers sequentially connected in series between the first bus and the second bus, a branch is connected between every two adjacent circuit breakers, a protection circuit is respectively arranged corresponding to each branch, the protection circuit specifically comprises a three-phase voltage transformer, a first protection device, a second protection device, a measurement and control device, a first main switch, a second main switch, a first branch switch and a second branch switch, and whether the measurement and control device in each protection circuit controls the closing circuit breakers on two sides of the corresponding branch according to whether the secondary side of the three-phase voltage transformer corresponding to the branch is provided with voltage, whether the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are in a closed position, and whether the first protection device and the second protection device send preset abnormal state signals, so that the error judgment of the protection function of the branch is avoided, the probability of the occurrence of the fault accident occurrence of the branch is reduced, and the operation safety of a power grid is improved.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present invention, nor do they necessarily limit the scope of the invention. Other features of the present invention will become apparent from the following description.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of a three-second connection of a substation according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a protection circuit according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a measurement and control device provided in an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a protection system of a substation according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The embodiment of the invention provides a protection system of a transformer substation. Fig. 1 is a schematic diagram of a three-half connection of a substation according to an embodiment of the present invention. Fig. 2 is a schematic structural diagram of a protection circuit according to an embodiment of the present invention. With reference to fig. 1 and 2, the substation includes a first bus 1M, a second bus 2M, and three circuit breakers sequentially connected in series between the first bus 1M and the second bus 2M, a branch 10 is connected between two adjacent circuit breakers, and the branch 10 includes a line branch or a main transformer branch. The protection system of transformer substation includes: a protection circuit provided corresponding to each branch 10. The protection circuit includes: the system comprises a three-phase voltage transformer PT, a first protection device 210, a second protection device 220, a measurement and control device 30, a first main switch, a second main switch, a first branch switch and a second branch switch.

The three-phase voltage transformer PT is connected with the corresponding branch 10 and comprises a first secondary winding and a second secondary winding, and the first secondary winding and the second secondary winding both comprise three-phase windings. Each phase winding of the first secondary winding is connected to a phase input terminal of the first protection device 210 through a first main switch and a first sub switch in sequence. Each phase winding of the second secondary winding is connected to a phase input end of the second protection device 220 sequentially through a second main switch and a second branch switch.

The phase a input end of the measurement and control device 30 is connected to a first node N1 through a third split-phase, the first node N1 is located between a first main switch and a first sub switch corresponding to the phase a winding of the first secondary winding, the phase B input end of the measurement and control device 30 is connected to a second node N2 through a third split-phase, the second node N2 is located between a first main switch and a first sub switch corresponding to the phase B winding of the first secondary winding, the phase C input end of the measurement and control device 30 is connected to a third node N3 through a third split-phase, and the third node N3 is located between a first main switch and a first sub switch corresponding to the phase C winding of the first secondary winding.

Wherein, the measurement and control device 30 is used for judging whether to control the circuit breakers on both sides of the branch 10 to be switched on according to a first preset condition, and the first preset condition includes: whether the secondary side of the three-phase voltage transformer PT has voltage, whether a first main switch, a second main switch, a first branch switch, a second branch switch and a third branch switch are in a closed position, and whether a first protection device 210 and a second protection device 220 send out preset abnormal state signals.

Specifically, the transformer substation in the embodiment of the present invention may be a transformer substation with a 500kV voltage class, and the connection mode adopted by the transformer substation is three-half connection. For the sake of convenience of distinction, three circuit breakers connected in series between the first bus bar 1M and the second bus bar 2M are denoted as a circuit breaker D1, a circuit breaker D2, and a circuit breaker D3. The branch circuit 10 connected between two adjacent circuit breakers includes a branch circuit 10a and a branch circuit 10b, the branch circuit 10a is connected between the circuit breaker D1 and the circuit breaker D2, and the branch circuit 10b is connected between the circuit breaker D2 and the circuit breaker D3. The branch 10a may be a branch connected to the 500kV line 110, hereinafter referred to as 500kV line branch 10a for short, and the branch 10b may be a branch connected to the 500kV main transformer T, hereinafter referred to as 500kV transformer branch 10b for short. The 500kV line branch 10a and the 500kV transformer branch 10b are respectively provided with corresponding protection circuits, and the protection circuit shown in fig. 2 may be a protection circuit of the 500kV line branch 10a or a protection circuit of the 500kV transformer branch 10b.

For the protection circuit of the 500kV line branch 10a, the characteristics are as follows:

the three-phase voltage transformer PT1 is connected with a 500kV line branch 10a, and a three-phase winding of a first secondary winding of the three-phase voltage transformer PT1 comprises an A-phase winding PT02a, a B-phase winding PT02B and a C-phase winding PT02C. The first protection device 210 may include a three-phase input terminal, the a-phase winding PT02a is connected to the a-phase input terminal of the first protection device 210 through the first total switch 2CBa and the first branch switch ZKK a in sequence, the B-phase winding PT02B is connected to the B-phase input terminal of the first protection device 210 through the first total switch 2CBb and the first branch switch ZKK B in sequence, and the C-phase winding PT02C is connected to the C-phase input terminal of the first protection device 210 through the first total switch 2CBc and the first branch switch ZKK C in sequence. The three-phase windings of the second secondary winding of the three-phase voltage transformer PT1 include an a-phase winding PT03a, a B-phase winding PT03B, and a C-phase winding PT03C. The second protection device 220 may include a three-phase input terminal, the a-phase winding PT03a is connected to the a-phase input terminal of the second protection device 220 sequentially through the second main switch 3CBa and the second branch switch ZKK a, the B-phase winding PT03B is connected to the B-phase input terminal of the second protection device 220 sequentially through the second main switch 3CBb and the second branch switch ZKK B, and the C-phase winding PT03C is connected to the C-phase input terminal of the second protection device 220 sequentially through the second main switch 3CBc and the second branch switch ZKK C. The measurement and control device 30 may include a three-phase input end, the phase a input end of the measurement and control device 30 is connected to the first node N1 through the third partial switch ZKK a, the first node N1 is located between the first main switch 2CBa and the first partial switch ZKK a corresponding to the phase a winding PT02a of the first secondary winding, the phase B input end of the measurement and control device 30 is connected to the second node N2 through the third partial switch ZKK B, the second node N2 is located between the first main switch 2CBb and the first partial switch ZKK B corresponding to the phase B winding PT02B of the first secondary winding, the phase C input end of the measurement and control device 30 is connected to the third node N3 through the third partial switch ZKK C, and the third node N3 is located between the first main switch 2CBbc and the first partial switch 3926 zxft 391C corresponding to the phase C winding PT02C of the first secondary winding. The phase-a winding PT02a, the phase-B winding PT02B, the phase-C winding PT02C, the first main switches 2CBa to 2CBc, the phase-a winding PT03a, the phase-B winding PT03B, the phase-C winding PT03C, and the first main switches 3CBa to 3CBc may be disposed in the same interval 410.

Before the transformer is put into operation, the 500kV line branch 10a may be in an electrified state or an uncharged state, and whether the 500kV line branch 10a has voltage or not can be determined according to whether the secondary side of the three-phase voltage transformer PT1 has voltage or not. When any one of the circuit breakers D1 and D2 on both sides of the 500kV line branch 10a is put into operation, as long as it is determined that all three phases of the 500kV line branch 10a have voltage or none voltage, the first main switches 2CBa to 2CBc, the second main switches 3CBa to 3CBc, the first branch switches ZKK a to ZKK c, the second branch switches ZKK a to ZKK c, and the third branch switches ZKK a to ZKK c corresponding to the 500kV line branch 10a are all in on-position, and neither the first protection device 210 nor the second protection device 220 sends out a preset abnormal state signal, it can be ensured that the first protection device 210 and the second protection device 220 do not malfunction. That is to say, the measurement and control device 30 may determine whether to control the circuit breakers D1 and D2 on both sides of the 500kV line branch 10a to be switched on according to the first preset condition, so as to avoid the corresponding first protection device 210 and the second protection device 220 from causing malfunction.

For the protection circuit of the 500kV transformer branch 10b, the structure is similar to that of the protection circuit of the 500kV line branch 10a, and the difference is only that the three-phase voltage transformer therein is the three-phase voltage transformer PT2 connected with the 500kV transformer branch 10b, and the specific structure is not repeated.

Before the transformer is put into operation, the 500kV transformer branch 10b may be in an electrified state or an uncharged state, and whether the 500kV transformer branch 10b has voltage or not can be determined according to whether the secondary side of the three-phase voltage transformer PT2 has voltage or not. When any one of the circuit breakers D2 and D3 on both sides of the 500kV transformer branch 10b is put into operation, it is only required to determine that all three phases of the 500kV transformer branch 10b have voltage or none voltage, and at the same time, the first main switches 2CBa to 2CBc, the second main switches 3CBa to 3CBc, the first branch switches ZKK a to ZKK c, the second branch switches ZKK a to ZKK c and the third branch switches ZKK a to ZKK c corresponding to the 500kV transformer branch 10b are all in the on-position, and neither the first protection device 210 nor the second protection device 220 sends out a preset abnormal state signal, so that the first protection device 210 nor the second protection device 220 cannot malfunction. That is to say, the measurement and control device 30 may determine whether to control the circuit breakers D2 and D3 on the two sides of the 500kV transformer branch 10b to be switched on according to the first preset condition, so as to avoid the corresponding first protection device 210 and the second protection device 220 from causing malfunction.

To sum up, the technical scheme of the embodiment of the invention can be applied to a substation adopting three-to-two connection, the substation comprises a first bus, a second bus and three circuit breakers sequentially connected in series between the first bus and the second bus, a branch is connected between every two adjacent circuit breakers, a protection circuit is respectively arranged corresponding to each branch, the protection circuit specifically comprises a three-phase voltage transformer, a first protection device, a second protection device, a measurement and control device, a first main switch, a second main switch, a first branch switch and a second branch switch, and whether the measurement and control device in each protection circuit controls the circuit breakers on two sides of the corresponding branch according to whether the secondary side of the three-phase voltage transformer corresponding to the branch has voltage, whether the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are in a closed position, and whether the first protection device and the second protection device send out a preset abnormal state signal, so as to help to avoid the occurrence of false operation of the protection function of the branch, thereby reducing the probability of occurrence of false operation accidents and being beneficial to improving the safety of the switching on operation of a power grid.

With reference to fig. 1 and fig. 2, on the basis of the foregoing embodiment, optionally, the protection circuit further includes: an electrified display M, a first voltage monitor relay YJS2, and a second voltage monitor relay YJS3. The live display M is connected to the corresponding branch 10, and is configured to detect and display the three-phase voltage of the branch 10. The 500kV line branch 10a and the 500kV transformer branch 10b can both be connected with an electrical display M. Accordingly, the first preset condition further includes: the live display M detects that the three phases of the branch 10 are all at voltage. The first voltage monitoring relay YJS2 is connected between the first main switch 2CBa corresponding to the a-phase winding PT02a of the first secondary winding and the first node N1, between the first main switch corresponding to the B-phase winding PT02B of the first secondary winding and the second node N2, and between the first main switch 2CBbc corresponding to the C-phase winding PT02C of the first secondary winding and the third node N3. The second voltage monitoring relay YJS3 is connected between the second main switch 3CBa and the second tap switch ZKK a corresponding to the a-phase winding PT03a of the second secondary winding, between the second main switch 3CBb and the second tap switch ZKK B corresponding to the B-phase winding PT03B of the second secondary winding, and between the second main switch 3CBc and the second tap switch ZKK C corresponding to the C-phase winding PT03C of the second secondary winding. The measurement and control device 30 is further configured to detect voltages of the first node N1, the second node N2, and the third node N3 to determine whether a voltage is present on the secondary side of the three-phase voltage transformer PT, or determine whether a voltage is present on the secondary side of the three-phase voltage transformer PT according to signals of the first voltage monitoring relay YJS2 and the second voltage monitoring relay YJS3. The first voltage monitor relay YJS2 and the second voltage monitor relay YJS3 may be both provided within the interface screen 420.

Optionally, the preset abnormal state signals of the first protection device 210 and the second protection device 220 include: alarm signal, blocking signal, DC power supply voltage loss signal and protection channel abnormal signal. Specifically, the alarm signal is a signal for the protection device (i.e., the first protection device 210 or the second protection device 220, the same applies below) to send an alarm, the latching signal is a signal for latching the protection device, the dc power source voltage loss signal is a signal corresponding to the dc power source voltage loss of the protection device, and the protection channel abnormal signal is a signal for the protection channel of the protection device to have an abnormal state.

In one embodiment, the measurement and control device 30 is configured to determine whether to allow the circuit breakers on both sides of the branch 10 to be manually or remotely switched on when a first preset condition is met. Correspondingly, the first preset condition specifically includes: the secondary side of the three-phase voltage transformer PT has voltage, the three phases detected by the electrified display M by the branch circuit 10 all have voltage, the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are all in closed position, and the first protection device 210 and the second protection device 220 do not send out alarm signals, locking signals, direct-current power supply voltage loss signals and protection channel abnormal signals.

A case where the circuit breakers D1 and D2 on both sides of the 500kV line branch 10a are allowed to be closed is described below by taking the protection circuit of the 500kV line branch 10a as an example:

with reference to fig. 1 and fig. 2, the measurement and control device 30 can monitor the voltage of the secondary side of the three-phase voltage transformer PT1 by detecting the voltages of the first node N1, the second node N2, and the third node N3, or collect signals of the first voltage monitoring relay YJS2 and the second voltage monitoring relay YJS3, thereby determining whether the secondary side of the three-phase voltage transformer PT1 has voltage. The live-line display M can monitor the three-phase voltage of the 500kV line branch 10a, and the live-line display M includes an auxiliary contact indicating that the three phases of the 500kV line branch 10a all have voltage, and the auxiliary contact is connectable with the measurement and control device 30, so that the measurement and control device 30 can determine whether the three phases of the 500kV line branch 10a all have voltage. The first main switches 2CBa to 2CBc, the second main switches 3CBa to 3CBc, the first branch switches ZKK a to ZKK c, the second branch switches ZKK a to ZKK c, and the third branch switches ZKK a to ZKK c may each include an auxiliary contact indicating that each switch is in an on-position state and an off-position state, and each auxiliary contact is connected to the measurement and control device 30, so that the measurement and control device 30 can determine the on/off-position state of the corresponding switch according to each auxiliary contact. The first protection device 210 and the second protection device 220 each include an auxiliary contact indicating whether to send out an alarm signal, a blocking signal, a dc power supply voltage loss signal, and a protection channel abnormal signal, and the auxiliary contact may be connected to the measurement and control device 30, so that the measurement and control device 30 can determine whether the first protection device 210 and the second protection device 220 send out the above signals.

When the measurement and control device 30 detects that the secondary side of the three-phase voltage transformer PT1 has voltage, the live display M detects that the three phases of the 500kV line branch 10a have voltage, the first main switches 2CBa to 2CBc, the second main switches 3CBa to 3CBc, the first branch switches ZKK a to ZKK c, the second branch switches ZKK a to ZKK c, and the third branch switches ZKK a to ZKK c are all in on-position, and the first protection device 210 and the second protection device 220 do not send out the alarm signal, the blocking signal, the dc power supply voltage loss signal, and the protection channel abnormal signal, it is determined that a first preset condition is currently satisfied, and the circuit breakers D1 and D2 on both sides of the 500kV line branch 10a are allowed to be switched on, so as to avoid the first protection device 210 and the second protection device 220 from false operation.

In another embodiment, the first preset condition includes: the secondary side of the three-phase voltage transformer PT has no voltage, the charged display M detects that three phases of the branch 10 have no voltage, the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are all in the closed position, and the first protection device 210 and the second protection device 220 do not send out an alarm signal, a locking signal, a direct-current power supply voltage loss signal and a protection channel abnormal signal.

Still taking the protection circuit of the 500kV line branch 10a as an example, another case of allowing the circuit breakers D1 and D2 at both sides of the 500kV line branch 10a to be switched on is described below:

specifically, when the measurement and control device 30 detects that there is no voltage on the secondary side of the three-phase voltage transformer PT1, the live display M detects that there is no voltage on the three phases of the 500kV line branch 10a, the first main switches 2CBa to 2CBc, the second main switches 3CBa to 3CBc, the first branch switches ZKK a to ZKK c, the second branch switches ZKK a to ZKK c, and the third branch switches ZKK a to ZKK c are all in the on-position, and the first protection device 210 and the second protection device 220 do not send out the alarm signal, the blocking signal, the dc power supply voltage loss signal, and the protection channel abnormality signal, it is determined that the first preset condition is currently satisfied, and the circuit breakers D1 and D2 on both sides of the 500kV line branch 10a are allowed to be switched on, so as to avoid the first protection device 210 and the second protection device 220 from false operation.

It should be noted that, the measurement and control device 30 simultaneously satisfies: there is voltage, electrified display M that the secondary side of three-phase voltage transformer PT detects that branch road 10's three-phase all has voltage, first total switch, second total switch, first branch switch, second branch switch and third branch switch all are in and close the position, first protection device 210 and second protection device 220 all do not send alarm signal, blocking signal, DC power supply voltage loss signal and protection channel abnormal signal, perhaps satisfy simultaneously: when the secondary side of the three-phase voltage transformer PT is free of voltage, the charged display M detects that three phases of the branch circuit 10 are all free of voltage, the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are all in the closed position, and the first protection device 210 and the second protection device 220 do not send out an alarm signal, a locking signal, a direct-current power supply voltage loss signal and a protection channel abnormal signal, it can be determined that the circuit breakers on two sides of the branch circuit 10 are allowed to be manually or remotely switched on.

With reference to fig. 1 and fig. 2, on the basis of the above embodiments, two ends of each breaker are connected to disconnectors, the disconnectors connected to different breakers are different, and the branch 10 is connected between two disconnectors connected to two adjacent breakers. The measurement and control device 30 is further configured to determine that the circuit breaker on the side of the branch 10 is allowed to be manually or remotely switched on when a second preset condition is met, where the second preset condition includes: the disconnecting switches connected with the two ends of the circuit breaker are all positioned separately, the motor power supplies of the disconnecting switches connected with the two ends of the circuit breaker are all disconnected, the motor power supplies of the disconnecting switches connected with the two ends of the circuit breaker are all additionally provided with five-prevention disconnecting locks, and the circuit breaker is in an overhauling state.

Illustratively, two ends of the breaker D1 are respectively connected with the disconnector K11 and the disconnector K12, two ends of the breaker D2 are respectively connected with the disconnector K21 and the disconnector K22, and two ends of the breaker D3 are respectively connected with the disconnector K31 and the disconnector K32. The 500kV line branch 10a is specifically connected between the isolating switch K12 and the isolating switch K21, and the 500kV transformer branch 10b is specifically connected between the isolating switch K22 and the isolating switch K31. The line section in which the breaker D1, the disconnector K11 and the disconnector K12 are located may be referred to as a line L1, the line section in which the breaker D2, the disconnector K21 and the disconnector K22 are located may be referred to as a line L2, and the line section in which the breaker D3, the disconnector K31 and the disconnector K32 are located may be referred to as a line L3. The measurement and control device 30 in the protection circuit of the 500kV line branch 10a may be used to determine that the circuit breaker D1 in the line L1 and/or the circuit breaker D2 in the line L2 is allowed to be switched on when a second preset condition is satisfied. The measurement and control device 30 in the protection circuit of the 500kV transformer branch 10b may be used to determine that the breaker D2 in the line L2 and/or the breaker D3 in the line L3 is allowed to be switched on when a second preset condition is satisfied.

The following description will be given by taking the protection circuit of the 500kV line branch 10a as an example:

for the line L1, the isolation switches K11 and K12 may each include an auxiliary contact indicating that each is in an on-position state and an off-position state, and each auxiliary contact is connected to the measurement and control device 30, so that the measurement and control device 30 can determine the on/off-position state of the corresponding switch according to each auxiliary contact. The line L1 further includes auxiliary contacts of motor power supplies of the disconnecting switch K11 and the disconnecting switch K12 in an on/off state, and each auxiliary contact is connected to the measurement and control device 30, so that the measurement and control device 30 can determine the motor power supply states of the disconnecting switch K11 and the disconnecting switch K12 according to each auxiliary contact. The circuit L1 further comprises auxiliary contacts which are used for judging whether a motor power supply of the isolating switch K11 and the isolating switch K12 is additionally provided with a five-prevention isolating lock or not, and each auxiliary contact is connected with the measurement and control device 30, so that the measurement and control device 30 can determine whether the motor power supply of the isolating switch K11 and the isolating switch K12 is additionally provided with the five-prevention isolating lock or not according to each auxiliary contact. The breaker D1 further comprises an auxiliary contact indicating whether it is in a maintenance state, and the auxiliary contact is connected to the measurement and control device 30, so that the measurement and control device 30 can determine whether the breaker D1 further comprises an auxiliary contact indicating whether it is in a maintenance state. When the measurement and control device 30 detects that the isolating switch K11 and the isolating switch K12 are both in the separating position, the motor power supplies of the isolating switch K11 and the isolating switch K12 are all disconnected, the motor power supplies of the isolating switch K11 and the isolating switch K12 are both additionally provided with a five-prevention isolating lock, and the circuit breaker D1 is in the maintenance state, it is determined that the second preset condition is currently satisfied, it is not necessary to determine whether the first preset condition is currently satisfied, and the circuit breaker D1 is directly allowed to be switched on.

Similarly, for the line L2, the isolating switch K21 and the isolating switch K22 may include auxiliary contacts indicating that they are in the on-position state and the off-position state, and each auxiliary contact is connected to the measurement and control device 30, so that the measurement and control device 30 can determine the on-position/off-position state of the corresponding switch according to each auxiliary contact. The line L2 further includes auxiliary contacts of motor power supplies of the disconnecting switch K21 and the disconnecting switch K22 in an on/off state, and each auxiliary contact is connected to the measurement and control device 30, so that the measurement and control device 30 can determine the motor power supply states of the disconnecting switch K21 and the disconnecting switch K22 according to each auxiliary contact. Line L2 still includes whether isolator K21 and isolator K22's motor power installs five additional protection isolation lock's auxiliary contact, and each auxiliary contact all connects measurement and control device 30 to make measurement and control device 30 can confirm whether isolator K21 and isolator K22's motor power installs five additional protection isolation lock according to each auxiliary contact. The breaker D2 further includes an auxiliary contact indicating whether it is in a maintenance state, and the auxiliary contact is connected to the measurement and control device 30, so that the measurement and control device 30 can determine whether the breaker D2 further includes an auxiliary contact indicating whether it is in a maintenance state. When the measurement and control device 30 detects that the isolating switch K21 and the isolating switch K22 are both in the separated position, the motor power supplies of the isolating switch K21 and the isolating switch K22 are all disconnected, the motor power supplies of the isolating switch K21 and the isolating switch K22 are both additionally provided with five-prevention isolation locks, and the breaker D2 is in the maintenance state, it is determined that the second preset condition is currently satisfied, it is not necessary to determine whether the first preset condition is currently satisfied, and the breaker D2 is directly allowed to be switched on.

The protection circuit of the 500kV transformer branch 10b is similar to the working principle of the protection circuit of the 500kV line branch 10a, and determines whether to allow the specific mode of closing the circuit breakers D2 and D3 on both sides of the 500kV transformer branch 10b according to a first preset condition and determines whether to allow the specific mode of closing the circuit breakers D2 and D3 according to a second preset condition, which can be understood by referring to the above embodiments and is not described again.

Fig. 3 is a schematic structural diagram of a measurement and control device provided in an embodiment of the present invention. With reference to fig. 1 to fig. 3, on the basis of the above embodiments, the measurement and control device 30 includes: the device comprises a device state acquisition module 310, an analog quantity acquisition module 320, a power conversion module 330 and a control module 340. The device state acquiring module 310 is configured to acquire an on/off state signal of a corresponding breaker and a corresponding disconnector, a preset abnormal state signal of the first protection device 210 and the second protection device 220, a voltage signal of a first node N1, a second node N2, and a third node N3, an on/off state signal of a first main switch, a second main switch, a first sub switch, a second sub switch, and a third sub switch, a motor power state signal of the disconnector, and a maintenance state signal of the first protection device 210 and the second protection device 220. The analog quantity acquisition module 320 is used for acquiring a single-phase voltage signal F1 of the first bus 1M and the bus, a three-phase voltage signal F2 of the branch 10, a three-phase current signal F3 and a zero-sequence current signal F4. The power conversion module 330 is configured to convert the input power signal V and supply power to the measurement and control device 30. The control module 340 is connected to the device state obtaining module 310, the analog quantity collecting module 320, the power conversion module 330, and the corresponding circuit breaker and disconnecting switch, and is configured to control the corresponding circuit breaker and disconnecting switch.

Specifically, the device status acquiring module 310 may be connected to the auxiliary contacts described in the above embodiments to acquire the responding device status signals through the auxiliary contacts. For the protection circuit of the 500kV line branch 10a, for example, the device status acquisition module 310, can obtain an on/off state signal E1 of a circuit breaker D1, an on/off state signal E2 of a disconnecting switch K11, an on/off state signal E3 of a disconnecting switch K12, an on/off state signal E4 of the circuit breaker D2, an on/off state signal E5 of a disconnecting switch K21, an on/off state signal E6 of a disconnecting switch K22, a preset abnormal state signal (comprising an alarm signal, a blocking signal, a direct-current power supply voltage loss signal and a protection channel abnormal signal) E7 of a first protection device 210, a line side voltage abnormal signal E8 of the first protection device 210, an on/off state signal E9 of first switches ZKK a-ZKK c, a preset abnormal state signal (comprising an alarm signal, a blocking signal, a direct-current power supply voltage loss signal and a protection channel abnormal signal) E10, a preset abnormal state signal of a second protection device 220, a switching state signal (comprising an alarm signal, a blocking signal, a direct-current power supply voltage loss signal and a protection channel abnormal signal) a line side voltage abnormal signal E11 of the second protection device 220, a dividing/closing state signal E12 of the second branch switches ZKK a to ZKK c, a voltage abnormal signal E13 of the 500kV line branch 10a, a dividing/closing state signal E14 of the first main switches 2CBa to 2CBc, a dividing/closing state signal E15 of the second main switches 3CBa to 3CBc, a voltage signal E16 detected by the live displayer M, a motor power state signal E17 of the isolating switch K11, a motor power state signal E18 of the isolating switch K12, a motor power state signal E19 of the isolating switch K21, a motor power state signal E20 of the isolating switch K22, a maintenance state signal E21 of the first protection device 210, a maintenance state signal E22 of the second protection device 220 and the like. The control module 340 may perform blocking logic judgment according to the state signals of various devices acquired by the device state acquisition module 310 and various analog signals acquired by the analog acquisition module 320, so as to control each disconnecting switch and circuit breaker in the lines L1 and L2 on both sides of the 500kV line branch 10 a.

Further, the protection system of the substation further includes: the system comprises a microcomputer five-prevention system, a monitoring system, an intelligent operation and maintenance system and a dispatching automation system. The measurement and control device 30 further includes a first intra-station interconnect interface 351, a second intra-station interconnect interface 352, a third intra-station interconnect interface 353, a fourth intra-station interconnect interface 354, a fifth intra-station interconnect interface 355, and a synchronous pair time interface 360. The control module 340 may exchange information with a station control layer a network through a first intra-station interconnect interface 351 to transmit information to the monitoring system and the scheduling automation system, with a station control layer B network through a second intra-station interconnect interface 352 to transmit information to the monitoring system and the scheduling automation system, with a station control layer C network through a second intra-station interconnect interface 353 to transmit information to the monitoring system and the scheduling automation system, with a first process layer network through a fourth intra-station interconnect interface 354, with a second process layer network through a fifth intra-station interconnect interface 355, and receive a synchronization signal through a synchronization interface 360.

The control module 340 is further connected to a first latching and closing contact 361, a second latching and closing contact 362, a third latching and closing contact 363, a fourth latching and closing contact 364, a fifth latching and closing contact 365, and a sixth latching and closing contact 366. The first closing contact 361 is a contact of the closing circuit breaker D1, and the contact cannot be closed after being disconnected, and an empty contact can be connected to the closing loop of the circuit breaker D1 in series. The second closing contact 362 is a contact of the closing circuit breaker D2, which is not closed after being opened, and an empty contact can be connected in series to the closing loop of the circuit breaker D2. The third closing and locking contact 363 is a contact of the closing and locking isolating switch K11, which cannot be closed after being disconnected, and an empty contact can be connected in series to a closing loop of the isolating switch K11. The fourth closing and locking contact 364 is a contact of the closing and locking disconnecting switch K12, which cannot be closed after being disconnected, and a vacant contact may be connected in series to the closing loop of the disconnecting switch K12. The fifth closing contact 365 is a contact of the closing isolating switch K21, which cannot be closed after being opened, and an empty contact may be connected in series to the closing loop of the isolating switch K21. The sixth closing and locking contact 366 is a contact of the closing and locking disconnecting switch K22, which cannot be closed after being disconnected, and an empty contact may be connected in series to a closing loop of the disconnecting switch K22.

In the above embodiments, the determination of whether to allow the locking logic judgment of the closing of the circuit breakers on the two sides of the 500kV line branch 10a and the 500kV transformer branch 10b according to the first preset condition and the second preset condition may be simultaneously implemented in the measurement and control device 30, the monitoring system, the intelligent operation and maintenance system and the scheduling automation system, so as to implement operations at multiple positions through the locking logic deployment at different positions, and all can implement the anti-misoperation locking logic of the primary device by the related states of the secondary device through the locking logic judgment of the present invention, so as to fully combine the first and second anti-misoperation.

Optionally, the measurement and control device 30 is configured to receive a control instruction of the monitoring system, the intelligent operation and maintenance system, or the scheduling automation system, and execute the control instruction when the control instruction meets a locking requirement, so as to control the corresponding circuit breaker and the corresponding disconnecting switch. Or at least one of the microcomputer five-prevention system, the monitoring system, the intelligent operation and maintenance system and the dispatching automation system is used for controlling each breaker and the isolating switch.

(1) The locking logic judgment is carried out through the measurement and control device and the corresponding control is carried out

Specifically, the measurement and control device 30 may collect the operation state signals of the primary devices and the operation state signals of the secondary devices in the embodiments, and communicate with the microcomputer five-prevention system in the substation through a network, so as to transmit the operation state signals and the operation state signals of the secondary devices collected by the microcomputer five-prevention system to the microcomputer five-prevention system, and collect the state signals of whether the five-prevention isolation lock is additionally installed on the motor power supplies of the isolation switch K11, the isolation switch K12, the isolation switch K21, and the isolation switch K22.

The measurement and control device 30 may sample through the analog quantity acquisition module 320 to obtain the single-phase voltage signal F1 of the first bus 1M and the bus, the three-phase voltage signal F2 of the branch 10, the three-phase current signal F3, and the zero-sequence current signal F4, and transmit the signals to the microcomputer five-prevention system.

The measurement and control device 30 can communicate with the monitoring system in the substation through a network, transmit various collected signals to the monitoring system, and receive control instructions issued by the monitoring system, including a locking instruction and an opening/closing name, after receiving the control instructions issued by the monitoring system, the measurement and control device 30 performs the locking logic judgment, and executes the signals when meeting the non-locking requirement, so as to prevent the signals from not being executed, and the non-executed control instructions can send corresponding reasons for not being executed to the monitoring system.

The measurement and control device 30 can communicate with the intelligent operation and maintenance system in the transformer substation through a network, transmit various collected signals to the intelligent operation and maintenance system, and receive control instructions issued by the intelligent operation and maintenance system, including a locking instruction and a switch-on/switch-off name, after the measurement and control device 30 receives the control instructions issued by the intelligent operation and maintenance system, the locking logic judgment is performed, the locking is performed when the non-locking requirement is met, the non-execution is prevented, and the non-executed control instructions can send reasons corresponding to the non-execution to the intelligent operation and maintenance system.

The measurement and control device 30 can communicate with a dispatching automation system in a transformer substation through a network, transmit various collected signals to the dispatching automation system, and receive control instructions issued by the dispatching automation system, including a locking instruction and an opening/closing name, after the measurement and control device 30 receives the control instructions issued by the dispatching automation system, the locking logic judgment is carried out, the locking is carried out when the non-locking requirement is met, the locking is prevented from being not carried out, and the non-executed control instructions can send corresponding reasons for non-execution to the dispatching automation system.

Therefore, under the condition that the control instruction of the monitoring system, the intelligent operation and maintenance system or the dispatching automation system is executed through the measurement and control device, the measurement and control device can perform locking logic judgment on the received control instruction again, so that the running reliability of the system is improved.

(2) Carry out locking logic judgment and corresponding control through a microcomputer five-prevention system

Specifically, various signals in the transformer substation can be completely acquired through the measurement and control device 30 and a microcomputer five-prevention system in the transformer substation, and meanwhile, the microcomputer five-prevention system is used for acquiring state signals of a five-prevention isolation lock, whether a motor power supply of the isolation switch K11, the isolation switch K12, the isolation switch K21 and the isolation switch K22 is additionally provided with the five-prevention isolation lock or not, and performing the locking logic judgment and corresponding control through the microcomputer five-prevention system so as to realize the operation and locking of primary equipment. When the microcomputer five-prevention system carries out the latching logic judgment and carries out corresponding control, dual latching can be realized through the cooperation of the latching contact of the measurement and control device 30, and therefore the reliability of system operation is improved.

(3) Locking logic judgment and corresponding control are carried out through a monitoring system

Specifically, the measurement and control device 30 and the monitoring system in the transformer substation can be used for completely acquiring various signals in the transformer substation, and meanwhile, the microcomputer five-prevention system is used for acquiring the state signal of whether the five-prevention isolation lock is additionally arranged on the motor power supplies of the isolating switch K11, the isolating switch K12, the isolating switch K21 and the isolating switch K22, and the monitoring system is used for carrying out the locking logic judgment and carrying out corresponding control so as to realize the operation and locking of primary equipment.

(4) Locking logic judgment and corresponding control are carried out through an intelligent operation and maintenance system

Specifically, the measurement and control device 30 and the intelligent operation and maintenance system in the transformer substation can be used for completely acquiring various signals in the transformer substation, and meanwhile, the microcomputer five-prevention system is used for acquiring the state signal of whether the five-prevention isolation lock is additionally arranged on the motor power supply of the isolating switch K11, the isolating switch K12, the isolating switch K21 and the isolating switch K22, and the intelligent operation and maintenance system is used for carrying out the logic judgment of locking and carrying out corresponding control so as to realize the operation and locking of primary equipment.

(5) Carrying out locking logic judgment and corresponding control through a dispatching automation system

Specifically, the measurement and control device 30 and a dispatching automation system in the transformer substation can be used for completely collecting various signals in the transformer substation, meanwhile, a microcomputer five-prevention system is used for collecting state signals of a five-prevention isolation lock, whether a motor power supply of the isolation switch K11, the isolation switch K12, the isolation switch K21 and the isolation switch K22 is additionally provided with the five-prevention isolation lock or not, the dispatching automation system is used for carrying out locking logic judgment, corresponding control is carried out, and operation and locking of primary equipment are achieved.

The above embodiments only take the protection circuit of the 500kV line branch 10a as an example, and the specific structure of the measurement and control device and the principle of performing locking logic judgment and corresponding control on the protection circuit are explained, and the specific structure of the measurement and control device and the principle of performing locking logic judgment and corresponding control on the protection circuit of the 500kV transformer branch 10b are similar to those of the above embodiments, which can be understood with reference to the above contents specifically, and are not described here again.

Fig. 4 is a schematic structural diagram of a protection system of a substation according to an embodiment of the present invention. With reference to fig. 1 to fig. 4, on the basis of the foregoing embodiments, the protection system of the substation may include a first measurement and control device 510, a second measurement and control device 520, a third measurement and control device 530, a fourth measurement and control device 540, a fifth measurement and control device 550, and a sixth measurement and control device 560. The first measurement and control device 510 may be a measurement and control device of a first bus voltage transformer, for example, a measurement and control device of a voltage transformer PT3 connected to the first bus 1M. The second measurement and control device 520 may be a measurement and control device of a second bus voltage transformer, for example, a measurement and control device of a voltage transformer PT4 connected to the second bus 2M. The third measurement and control device 530 may be the measurement and control device 30 in the protection circuit of the 500kV line branch 10 a. The fourth measurement and control device 540 may be the measurement and control device 30 in the protection circuit of the 500kV transformer branch 10b. The fifth measurement and control device 550 may be a measurement and control device for a relevant bus and segment in a substation, and the sixth measurement and control device 560 may be another measurement and control device for a relevant bus and segment in a substation. The monitoring system host 570, the microcomputer five-prevention system host 580, the intelligent operation and maintenance system host 590, the scheduling intelligent operation and maintenance system host 620 and the scheduling automation system host 630 can communicate with each other through the communication network 610. When the monitoring system host 570, the microcomputer five-prevention system host 580 and the intelligent operation and maintenance system host 590 can be located inside the substation 50, the first measurement and control device 510 to the sixth measurement and control device 560 can communicate with the monitoring system host 570, the microcomputer five-prevention system host 580 and the intelligent operation and maintenance system host 590 through the station control layer network.

The embodiment of the invention also provides a protection method of the transformer substation, which is executed by the protection system of the transformer substation in any embodiment. The protection method of the transformer substation specifically comprises the following steps:

whether the circuit breakers on the two sides of the branch circuit are controlled to be switched on or not is judged according to a first preset condition through the measurement and control device, wherein the first preset condition comprises the following steps: whether voltage exists on the secondary side of the three-phase voltage transformer, whether the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are in a closed position, and whether the first protection device and the second protection device send out preset abnormal state signals.

It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps described in the present invention may be executed in parallel, sequentially, or in different orders, and are not limited herein as long as the desired results of the technical solution of the present invention can be achieved.

The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The protection system of the transformer substation is characterized in that the transformer substation comprises a first bus, a second bus and three circuit breakers sequentially connected in series between the first bus and the second bus, a branch is connected between every two adjacent circuit breakers, and the branch comprises a line branch or a main transformer branch; the protection system of the transformer substation comprises: and a protection circuit corresponding to each branch, the protection circuit comprising:

2. The protection system of a substation according to claim 1, wherein the protection circuit further comprises:

the electrified display is connected with the corresponding branch circuit and used for detecting and displaying the three-phase voltage of the branch circuit;

a second voltage monitor relay connected between the second main switch and the second branch switch corresponding to the a-phase winding of the second secondary winding, between the second main switch and the second branch switch corresponding to the B-phase winding of the second secondary winding, and between the second main switch and the second branch switch corresponding to the C-phase winding of the second secondary winding;

wherein the first preset condition further comprises: whether the electrified display detects that the three phases of the branch circuit have voltage or not; the measurement and control device is further used for detecting the voltages of the first node, the second node and the third node so as to judge whether the secondary side of the three-phase voltage transformer has voltage or not, or judging whether the secondary side of the three-phase voltage transformer has voltage or not according to signals of the first voltage monitoring relay and the second voltage monitoring relay.

3. The protection system of a substation according to claim 1, characterized in that the preset abnormal state signal comprises: alarm signal, blocking signal, DC power supply voltage loss signal and protection channel abnormal signal.

4. The protection system of a substation according to claim 1, wherein the measurement and control device is configured to determine that the circuit breakers on both sides of the branch are allowed to be manually or remotely switched on when the first preset condition is met;

5. The protection system of a substation according to claim 1, wherein the first preset condition specifically comprises: the secondary side of the three-phase voltage transformer is free of voltage, a charged display detects that three phases of the branch circuit are free of voltage, the first main switch, the second main switch, the first branch switch, the second branch switch and the third branch switch are all in a closed position, and the first protection device and the second protection device do not send out alarm signals, locking signals, direct-current power supply voltage loss signals and protection channel abnormal signals.

6. The protection system of a substation according to claim 1, wherein both ends of each circuit breaker are connected with a disconnector, the disconnectors connected with different circuit breakers are different, and the branch is connected between two disconnectors connected with two adjacent circuit breakers;

the circuit breaker both ends are connected isolator all is in the branch position circuit breaker both ends are connected isolator's motor power all breaks off circuit breaker both ends are connected isolator's motor power all install five additional prevent isolation lock with the circuit breaker is in the maintenance state.

7. A protection system for a substation according to any of claims 1-6, characterized in that said measurement and control means comprise:

8. The protection system of a substation according to claim 7, characterized in that the protection system of a substation further comprises: the system comprises a microcomputer five-prevention system, a monitoring system, an intelligent operation and maintenance system and a scheduling automation system; the measurement and control device is in communication connection with the microcomputer five-prevention system, the monitoring system, the intelligent operation and maintenance system and the dispatching automation system through the control module;

9. The protection system of a substation according to claim 8, wherein at least one of the microcomputer five-prevention system, the monitoring system, the intelligent operation and maintenance system and the dispatch automation system is further used for controlling each of the circuit breakers and disconnectors.

10. A protection method of a transformer substation is characterized by being executed by a protection system of the transformer substation;