CN213637065U - Circuit for preventing misoperation of bus voltage parallel circuit - Google Patents

Abstract

The utility model discloses a prevent busbar voltage parallel circuit malfunction circuit, including QK change over switch, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G, circuit breaker normally open auxiliary contact FDL1, PT parallel relay BLJ, first isolator normally closed auxiliary contact 3G, second isolator normally closed auxiliary contact 4G, circuit breaker normally closed auxiliary contact FDL, unusual verifier YCJ and unusual verifier YCJ contact. The utility model discloses effectively prevent generating line PT secondary when the position side by side, carry out the shutting to the separating brake operation return circuit of segmentation circuit breaker.

Description

Circuit for preventing misoperation of bus voltage parallel circuit

Technical Field

The utility model relates to an electric power system protection technical field, more specifically relates to a prevent busbar voltage parallel circuit malfunction circuit.

Background

A voltage transformer, PT for short, is a special transformer for measuring high voltage of electric network, and can convert the high voltage into lower voltage according to a defined proportion, and then connect it to the devices of protection, measurement and control, safety device, instrument and meter to make collection or measurement. The primary voltage of a voltage transformer is generally set to 57.7 volts or 100 volts regardless of the voltage of the primary side, and the secondary voltage is generally set to supply the voltage required by a voltage coil of an automatic device such as a related meter and relay protection. The primary actual transformation quantity is reflected by the secondary voltage change of the voltage transformer; the voltage transformer has the voltage isolation function of the high-voltage side and the low-voltage side, and the safety of work on a secondary circuit is guaranteed.

A bus voltage parallel device, called PT parallel device for short, is a device which correspondingly connects the secondary sides of voltage transformers on two sections of buses connected with a bus coupler or a section after the bus coupler or the section is put into normal operation at intervals. The bus voltage parallel device is used for enabling a bus PT of one section of bus to be out of operation when the bus PT is abnormal or in fault or needs to be maintained and repaired, so that a voltage signal of the section of bus is lost, the bus voltage parallel device is used for enabling a bus PT secondary of another section of bus to be in parallel connection with the bus PT secondary of the section of bus, the bus voltage parallel device is used for supplying the voltage of the other section of bus to secondary equipment connected with the bus section, and therefore the equipment using the bus PT secondary voltage can work normally. The parallel bus secondary voltage is an operation state when maintenance or maintenance PT is needed, and the bus PT secondary voltage does not need to be operated in the parallel state during normal operation.

And (3) carrying out a bus PT parallel normal operation procedure:

before the buses PT are parallelly connected for the second time, the primary system is parallelly connected, namely, the disconnecting switch and the breaker of the bus coupler or the sectionalized interval are closed to ensure the reliable connection of the two buses, then the bus coupler or the sectionalized interval protection tripping pressing plate is withdrawn, and then the bus PT secondary parallel handle is switched to the parallel position to realize the bus PT secondary parallel. In the actually designed secondary parallel starting circuit, the isolating switches on two sides of the bus coupler or the sectionalizing switch and the closing auxiliary contact of the circuit breaker need to be connected in series to the secondary PT parallel starting circuit, so that the secondary parallel of the bus PT can be realized only under the condition of primary parallel.

And (3) the bus PT is parallel to remove the normal operation program: there are two cases:

the first method comprises the following steps: firstly, confirming that two sections of buses PT in parallel are all in the input position once, confirming that a system is in a parallel state, namely, a bus-coupled or sectionalized isolating switch and a breaker are closed, ensuring that the two sections of buses are in reliable connection, and then switching a bus PT secondary parallel handle to a disconnection (or non-parallel) position to realize that the buses PT in operation are switched from parallel to disconnection.

And the second method comprises the following steps: firstly, confirming that two sections of buses PT in parallel are in exit positions once, and then switching a bus PT secondary parallel handle to a disconnection (or parallel forbidding) position to realize the disconnection of the PT in the bus stop process from parallel.

CN110336278A discloses a parallel operation method of transformers based on current relays, in which a circuit breaker is connected between several sections of buses, a transformer is connected between a high-voltage power supply bus and each section of bus, and the transformers meet the requirements of equal rated voltage, approximately equal transformation ratio, same connection group label, approximately equal short-circuit impedance per unit value and approximately equal short-circuit impedance angle; the error between the transformation ratios of the transformers is not more than +/-0.5 percent; the error between the short-circuit impedance per unit value and the short-circuit impedance angle of the transformers does not exceed +/-10%. When the current of the first transformer exceeds 5% of the set value, the circuit breaker QF2 is normally opened to normally close the second transformer, the second transformer is electrified to be put into operation, when the current of the first transformer is reduced to the set value, the circuit breaker QF2 is reset, the second transformer is withdrawn from operation, and the following problems exist:

firstly, a bus voltage parallel starting loop has no forced locking measure, a primary bus can be disconnected from parallel at any time without being limited by whether the secondary PT of the bus is in parallel or not, and the method has obvious defects, often has operation conditions which do not accord with the 'parallel PT of the bus or the removal of a normal operation program', and brings hidden danger to the safe and stable power supply of a power system;

and secondly, when the bus voltage secondary circuit is in a parallel state, the tripping circuit of the corresponding bus-tie or sectionalized interval circuit breaker is not forcibly locked, and the tripping pressing plate is manually disconnected only by a management mode, so that the risk that the primary parallel circuit is disconnected firstly when a primary system fault occurs, and then the bus voltage secondary parallel circuit is disconnected, and the secondary equipment and the circuit are burnt by short-circuit current is caused.

And thirdly, when the actions of the first disconnecting switch, the second disconnecting switch and the FDL auxiliary contact of the circuit breaker are abnormal in bus coupling or sectional interval, the secondary circuit of the bus voltage cannot be automatically prevented from being started and paralleled.

SUMMERY OF THE UTILITY MODEL

The utility model provides a prevent that busbar voltage from paralleling return circuit malfunction return circuit, can effectively independently prevent that the harm that the PT secondary was in the side by side malfunction produced takes place.

The utility model discloses aim at solving above-mentioned technical problem to a certain extent at least.

In order to solve the technical problem, the technical scheme of the utility model as follows:

the utility model provides a prevent busbar voltage parallel circuit malfunction circuit, includes that QK change over switch, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G, circuit breaker normally open auxiliary contact FDL1 and PT parallel relay BLJ, wherein:

the first end of the QK change-over switch is connected with a positive power supply, and the second end of the QK change-over switch is connected with a first isolating switch normally-open auxiliary contact 1G, a breaker normally-open auxiliary contact FDL1, a second isolating switch normally-open auxiliary contact 2G and a PT parallel relay BLJ in sequence and then connected with a negative power supply;

the circuit for preventing the misoperation of the bus voltage parallel circuit also comprises a first isolating switch normally closed auxiliary contact 3G, a second isolating switch normally closed auxiliary contact 4G, a circuit breaker FDL2 auxiliary contact, an abnormality verifier YCJ and an abnormality verifier YCJ contact,

the second end of QK change over switch all is connected with first isolator normally closed auxiliary contact 3G's one end, second isolator normally closed auxiliary contact 4G's one end and circuit breaker FDL2 auxiliary contact one end respectively, and first isolator normally closed auxiliary contact 3G's the other end, second isolator normally closed auxiliary contact 4G's the other end and circuit breaker FDL2 auxiliary contact's the other end all are connected with the abnormal verification ware YCJ again and are connected with the negative power supply, abnormal verification ware YCJ contact inserts between QK change over switch's second end and first isolator normally open auxiliary contact 1G.

Preferably, 8 normally open contacts BLJ-1 to BLJ-8 are arranged in the PT parallel relay BLJ and are respectively connected with the secondary windings with different voltages of the bus PT, so that the simultaneous parallel function of the secondary windings with different voltages of the bus PT is realized.

Preferably, 2 normally open auxiliary contacts BLJ-9 and BLJ-10 are further arranged in the PT parallel relay BLJ, and are connected with the normally open auxiliary contacts BLJ-9 and BLJ-10 to be respectively connected with the normally open contact starting locking element 1 and the locking element 2 of the existing opening control loop of the segmented circuit breaker, so that the operation locking of the opening operation 1 loop and the operation locking of the opening operation 2 loop of the segmented circuit breaker are achieved.

Preferably, 2 normally closed contacts BLJ-12 and BLJ-13 are further disposed in the PT parallel relay BLJ, and are respectively connected to the normally closed contact start blocking element 1 and the blocking element 2 of the existing opening control loop of the sectionalizing circuit breaker, so as to implement the operation blocking of the opening operation 1 loop and the operation blocking of the opening operation 2 loop of the sectionalizing circuit breaker.

Preferably, the auxiliary switching device further comprises a blocking and closing relay BSJ and a sectional breaker auxiliary contact FDL2, wherein one end of the blocking and closing relay BSJ is connected with a negative power supply of the parallel relay BLJ, the other end of the blocking and closing relay BSJ is connected with one end of the sectional breaker auxiliary contact FDL2, and the other end of the sectional breaker auxiliary contact FDL2 is connected with the other end of the QK switch.

Preferably, 1 normally open contact BSJ-1 is arranged in the blocking and closing relay BSJ, and is connected with a normally open contact starting and locking element of an existing closing control loop of the sectional circuit breaker, so that the operation locking of a closing operation loop of the sectional circuit breaker is realized.

Preferably, the blocking and closing relay BSJ is further provided with 1 normally-closed open contact BSJ-3, which is connected to a normally-closed contact starting and closing element of an existing closing control loop of the sectionalized circuit breaker, so as to realize the operation and closing of the closing operation loop of the sectionalized circuit breaker.

Preferably, the system further comprises a PT disconnection allowing relay JSJ, a first bus PT three-phase voltage monitoring relay DYJ1, a second bus PT three-phase voltage monitoring relay DYJ2, a first bus PT isolating switch PT-1G auxiliary contact and a second bus PT isolating switch PT-2G auxiliary contact, wherein:

one end of the PT permission disconnection relay JSJ is connected with a negative power supply of the parallel relay BLJ, the other end of the PT permission disconnection relay JSJ is connected with one end of a second bus PT three-phase voltage-equalizing-free monitoring relay DYJ2 and one end of a second bus PT isolating switch PT-2G auxiliary contact respectively, the other end of a second bus PT three-phase voltage-equalizing-free monitoring relay DYJ2 is connected with one end of a first bus PT three-phase voltage-equalizing-free monitoring relay DYJ1, the other end of the second bus PT isolating switch PT-2G auxiliary contact is connected with one end of a first bus PT isolating switch PT-1G auxiliary contact, and the other end of a first bus PT three-phase voltage-equalizing-free monitoring relay DYJ1 and the other end of the first bus PT isolating switch PT-1G auxiliary contact are connected with the other end of the QK change-over switch.

Preferably, the PT permission disconnection relay JSJ is provided with 2 normally open contacts JSJ-1 and JSJ-2, the PT permission disconnection relay JSJ is respectively connected with 2 normally closed contacts BLJ-12 and BLJ-13 which are also arranged in the PT parallel relay BLJ in parallel through the normally open contacts JSJ-1 and JSJ-2, the parallel relay BLJ is respectively released from the operation locking of a circuit 1 of the opening operation of the segmented circuit breaker through the 2 normally closed contacts BLJ-12 and BLJ-13 and the operation locking of a circuit 2 of the opening operation of the segmented circuit breaker, and the opening operation of the segmented circuit breaker is permitted.

Preferably, the PT permission disconnection relay JSJ is further provided with 2 normally closed contacts JSJ-4 and JSJ-5, the PT permission disconnection relay JSJ is connected with 2 normally open auxiliary contacts BLJ-9 and BLJ-10 in the PT parallel relay BLJ in series through the normally closed contacts JSJ-4 and JSJ-5 respectively, the PT permission disconnection relay JSJ is further provided with 2 normally open auxiliary contacts BLJ-9 and BLJ-10, the PT permission relay JSJ is connected with the normally open contacts of the existing opening control loop of the sectional circuit breaker to start the locking element 1 and the locking element 2, the locking operation of the opening operation 1 loop of the sectional circuit breaker and the locking operation of the opening operation 2 loop are released, and the opening operation of the sectional circuit breaker is permitted.

Compared with the prior art, the utility model discloses technical scheme's beneficial effect is:

the utility model effectively prevents the closing operation loop of the sectional breaker from being closed (including the closing operation of manual, remote control and protection and automatic devices) when the bus PT is in the parallel position for the second time; meanwhile, the circuit can be adapted to the existing circuit for realizing tripping of the blocking sectional circuit breaker by switching on the normally open contact, the circuit for realizing tripping of the blocking sectional circuit breaker by switching off the normally closed contact and the circuit for realizing closing of the blocking sectional circuit breaker by switching on the normally open contact, and the adaptability is high.

Simultaneously the utility model discloses it has PT to allow splitting relay JSJ and return circuit still to design, realizes whether automatic judgement satisfies generating line PT secondary splitting condition to realize removing automatically after satisfying generating line PT secondary splitting condition the utility model discloses to the shutting of segmentation circuit breaker tripping circuit, have better practicality.

Drawings

FIG. 1 is a schematic view of a circuit configuration in embodiment 1;

FIG. 2 is a schematic diagram showing the output connection points and functions of the PT parallel relay BLJ in embodiment 1;

FIG. 3 is a schematic view of a circuit configuration in embodiment 2;

fig. 4 is a schematic diagram illustrating output contacts and functions of a BSJ in embodiment 2;

FIG. 5 is a schematic view of a circuit configuration in embodiment 3;

FIG. 6 is a schematic diagram showing the JSJ output contacts and the function of the PT disconnection allowing relay in embodiment 3;

FIG. 7 is a schematic diagram of the connection of BLJ-9 and BLJ-10 contacts of a PT parallel relay BLJ to JSJ-4 and JSJ-5 contacts of a PT trip-enabled relay JSJ;

FIG. 8 is a schematic diagram of the connection of the BLJ-12 contact of the PT parallel relay BLJ to the JSJ-1 and JSJ-2 contacts of the PT disconnection-enabling relay JSJ.

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the patent;

for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product;

it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The technical solution of the present invention will be further explained with reference to the accompanying drawings and examples.

Example 1

This embodiment provides a prevent busbar voltage parallel circuit malfunction circuit, like fig. 1 and 2, including QK change over switch, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G, circuit breaker normally open auxiliary contact FDL1 and PT parallel relay BLJ, wherein:

the first end of the QK change-over switch is connected with a positive power supply, and the second end of the QK change-over switch is connected with a first isolating switch normally-open auxiliary contact 1G, a breaker normally-open auxiliary contact FDL1, a second isolating switch normally-open auxiliary contact 2G and a PT parallel relay BLJ in sequence and then connected with a negative power supply;

prevent busbar voltage parallel circuit malfunction circuit still includes first isolator normally closed auxiliary contact 3G, second isolator normally closed auxiliary contact 4G, circuit breaker FDL2 auxiliary contact, abnormal verification ware YCJ and abnormal verification ware YCJ contact, wherein:

the second end of QK change over switch all is connected with first isolator normally closed auxiliary contact 3G's one end, second isolator normally closed auxiliary contact 4G's one end and circuit breaker FDL2 auxiliary contact one end respectively, and first isolator normally closed auxiliary contact 3G's the other end, second isolator normally closed auxiliary contact 4G's the other end and circuit breaker FDL2 auxiliary contact's the other end all are connected with the abnormal verification ware YCJ again and are connected with the negative power supply, abnormal verification ware YCJ contact inserts between QK change over switch's second end and first isolator normally open auxiliary contact 1G.

The normally open auxiliary contact 1G and the normally closed auxiliary contact 3G of the first isolating switch are auxiliary contacts of the same primary device; the normally-open auxiliary contact 2G and the normally-closed auxiliary contact 4G of the second isolating switch are auxiliary contacts of the same primary device; the breaker normally open auxiliary contact FDL1 and the breaker normally closed auxiliary contact FDL3 are auxiliary contacts of the same primary equipment. When the first isolating switch, the circuit breaker and the second isolating switch are closed, the secondary voltages of the first bus PT and the second bus PT are allowed to be parallel.

If the normally open auxiliary contact 1G of the first isolating switch is in the closed position, the normally open contact is in the closed position, and the normally closed contact is in the open position, so that the normally open contact is in the closed position and the normally closed contact is no longer in the open position, the auxiliary contact is abnormal, and the normally open contact is mistakenly connected or the normally closed contact is mistakenly connected, so that the PT is allowed to be parallel only by the normally open contact, and the wrong parallel accident is possible, and measures must be taken to prevent the accident; that is, when the normally open contacts of the normally open auxiliary contact 1G of the first disconnecting switch, the normally open auxiliary contact FDL1 of the circuit breaker and the normally open auxiliary contact 2G of the second disconnecting switch are all switched on, and the normally closed contacts of the normally closed auxiliary contact 3G of the first disconnecting switch, the normally closed auxiliary contact FDL2 of the sectional circuit breaker and the normally closed auxiliary contact 4G of the second disconnecting switch are all switched off, the secondary parallel operation of the bus PT is allowed.

If the QK change-over switch is switched to the state allowing parallel connection, when at least one normally-open contact of the first isolating switch normally-open auxiliary contact 1G, the breaker normally-open auxiliary contact FDL1 and the second isolating switch normally-open auxiliary contact 2G is in the on position, the abnormal verifier YCJ contact acts, on one hand, the normally-closed contact disconnects the PT parallel relay BLJ to enable the parallel relay to be incapable of realizing parallel connection, and on the other hand, after the abnormal verifier YCJ contact acts, the normally-open contact is connected and the QK change-over switch allows the parallel contact to send out a 'contact abnormal PT secondary incapable of parallel connection alarm signal'.

The PT parallel relay BLJ is internally provided with 8 normally open contacts BLJ-1 to BLJ-8 which are respectively connected with the secondary windings with different voltages of the bus PT, so that the parallel function of the secondary windings with different voltages of the bus PT is realized.

The PT parallel relay BLJ is also provided with 2 normally-open auxiliary contacts BLJ-9 and BLJ-10 which are communicated with the normally-open auxiliary contacts BLJ-9 and BLJ-10 and are respectively connected with a normally-open contact starting locking element 1 and a locking element 2 of the existing opening control loop of the sectional circuit breaker, so that the operation locking of the opening operation 1 loop and the operation locking of the opening operation 2 loop of the sectional circuit breaker are realized.

The PT parallel relay BLJ is also provided with 2 normally closed contacts BLJ-12 and BLJ-13 which are respectively connected with a normally closed contact starting locking element 1 and a locking element 2 of the existing opening control loop of the sectional circuit breaker, so that the operation locking of an opening operation 1 loop and the operation locking of an opening operation 2 loop of the sectional circuit breaker are realized.

In the specific implementation process, when the sectionalized (or bus-coupled) circuit breaker on the primary side, the disconnecting switch of the first bus and the disconnecting switch of the second bus are all in a closed position, it is indicated that the first bus and the second bus in the electrical primary system are parallel, and at the moment, the closed auxiliary contact of the sectionalized (or bus-coupled) circuit breaker, the closed auxiliary contact of the disconnecting switch of the first bus and the closed auxiliary contact of the disconnecting switch of the second bus are all in a connected state, so that bus PT secondary parallel can be carried out;

if the QK change-over switch is switched to the 'parallel permission' position at the moment, as shown in figure 1, the QK change-over switch is switched to a 1-2 contact connection state, then a positive power supply passes through the QK contact, a first isolating switch normally open auxiliary contact 1G closing auxiliary contact, a breaker normally open auxiliary contact FDL1 closing auxiliary contact and a second isolating switch normally open auxiliary contact 2G closing auxiliary contact to a 'PT parallel relay BLJ' coil and then to a negative power supply, and at the moment, the 'PT parallel relay BLJ' acts to realize the secondary parallel of the bus PT;

after the 'PT parallel relay BLJ' acts, on one hand, the PT parallel relay BLJ is provided with 8 normally open contacts BLJ-1 to BLJ-8 which are connected, so that the parallel function of different voltage windings of a bus PT is realized, and the specific structure is shown in figure 2; on the other hand, the PT parallel relay BLJ is provided with 2 normally open auxiliary contacts BLJ-9 which are connected with BLJ-10 contacts, and is connected with a loop which is used for respectively realizing the tripping 1 of the blocking sectional breaker and the tripping 2 of the blocking sectional breaker through the normally open contacts; on the other hand, the 'PT parallel relay BLJ' has 2 normally closed auxiliary contacts BLJ-12 and BLJ-13 which are disconnected, and a circuit for respectively implementing the block section breaker trip 1 and the block section breaker trip 2 by the normally closed contact disconnection is connected.

After the PT parallel relay BLJ acts, the PT parallel relay BLJ is provided with 1 normally open contact BLJ-11 to be switched on, a 'signal that a bus PT secondary voltage parallel middle and subsection or bus-tie breaker opening operation loop is locked' is sent to a local monitoring system, and operating and monitoring personnel can adjust own operation behaviors or judge the reason of the tripping failure of the operation subsection breaker at the moment through the signal.

The circuit can effectively prevent the switching-off operation circuit of the segmented circuit breaker from being locked (including the switching-off operation of manual, remote control and protection and automatic devices) when the bus PT is in the parallel position for the second time;

the circuit can adapt to the existing circuit which realizes the tripping of the blocking sectional breaker by switching on the normally open contact and can also adapt to the existing circuit which realizes the tripping of the blocking sectional breaker by switching off the normally closed contact, and the adaptability is strong.

Example 2

In this embodiment, as shown in fig. 3 to 4, on the basis of embodiment 1, the switching circuit further includes a blocking and closing relay BSJ and a section breaker auxiliary contact FDL2, one end of the blocking and closing relay BSJ is connected to a negative power supply of the parallel relay BLJ, the other end of the blocking and closing relay BSJ is connected to one end of the section breaker auxiliary contact FDL2, and the other end of the section breaker auxiliary contact FDL2 is connected to the other end of the QK switch.

The blocking and closing relay BSJ is internally provided with 1 normally open contact BSJ-1 which is connected with a normally open contact starting and locking element of the existing closing control loop of the sectional breaker, so that the operation locking of the closing operation loop of the sectional breaker is realized.

The blocking and closing relay BSJ is also provided with 1 normally-closed open contact BSJ-3 which is connected with a normally-closed contact starting blocking element of the existing closing control loop of the sectional breaker to realize the operation blocking of the closing operation loop of the sectional breaker.

In a specific embodiment, when the transfer switch QK is switched to the "parallel-allowed" position, if the sectionalized (or buscouple) circuit breaker is in an open state, the "blocking and closing relay BSJ" acts to block the sectionalized (or buscouple) circuit breaker to perform closing operation, so as to prevent the bus PT from being parallel unexpectedly for the second time;

when the 'locking and closing relay BSJ' acts, 1 normally open contact BSJ-1 of the locking and closing relay BSJ is switched on, and a loop for realizing the closing of the locking segmented circuit breaker is switched on through the normally open contact, so that the closing operation locking (including the opening operation of a manual device, a remote control device, a protection device and an automatic device) of the segmented circuit breaker is realized; on the other hand, the 1 normally closed auxiliary contact BSJ-3 is disconnected and is connected to a loop for realizing the closing of the blocking sectional breaker through the disconnection of the normally closed contact, and the closing operation blocking (including the opening operation of a manual device, a remote control device, a protection device and an automatic device) of the sectional breaker is realized.

After the 'blocking and closing relay BSJ' acts, 1 normally open contact BSJ-2 of the blocking and closing relay BSJ is switched on, a 'switching switch in a bus PT secondary voltage parallel loop is in a parallel state allowed, a sectional breaker is in a breaking state, the closing operation of the sectional breaker is forbidden' is sent to a local monitoring system, and operating and monitoring personnel can adjust own operation behaviors through the signal or judge the reason of the failure of the sectional breaker to be operated at the moment.

The circuit can effectively prevent unexpected false start of the bus PT secondary paralleling, effectively prevent the bus PT secondary paralleling operation flow from being incorrect, namely, only ensuring that the bus PT is firstly paralleled and then the bus PT is started for secondary paralleling;

the circuit is adaptable to the existing circuit for realizing the closing of the blocking section breaker by switching on the normally open contact, and also adaptable to the existing circuit for realizing the closing of the blocking section breaker by switching off the normally closed contact, and has strong adaptability.

Example 3

This embodiment is as shown in fig. 5 to 6, and further includes a PT disconnection permitting relay JSJ, a first bus PT three-phase voltage monitoring relay DYJ1, a second bus PT three-phase voltage monitoring relay DYJ2, a first bus PT isolating switch PT-1G auxiliary contact, and a second bus PT isolating switch PT-2G auxiliary contact on the basis of embodiment 2, wherein:

one end of the PT permission disconnection relay JSJ is connected with a negative power supply of the parallel relay BLJ, the other end of the PT permission disconnection relay JSJ is connected with one end of a second bus PT three-phase voltage-equalizing-free monitoring relay DYJ2 and one end of a second bus PT isolating switch PT-2G auxiliary contact respectively, the other end of a second bus PT three-phase voltage-equalizing-free monitoring relay DYJ2 is connected with one end of a first bus PT three-phase voltage-equalizing-free monitoring relay DYJ1, the other end of the second bus PT isolating switch PT-2G auxiliary contact is connected with one end of a first bus PT isolating switch PT-1G auxiliary contact, and the other end of a first bus PT three-phase voltage-equalizing-free monitoring relay DYJ1 and the other end of the first bus PT isolating switch PT-1G auxiliary contact are connected with the other end of the QK change-over switch.

As shown in fig. 7 and 8, the PT allows the decoupling relay JSJ to be provided with 2 normally open contacts JSJ-1 and JSJ-2, and is respectively connected in parallel with 2 normally closed contacts BLJ-12 and BLJ-13 in the PT parallel relay BLJ through the normally open contacts JSJ-1 and JSJ-2, so as to respectively release the operation blocking of the parallel relay BLJ on the circuit 1 of the opening operation of the segmented circuit breaker through the 2 normally closed contacts BLJ-12 and BLJ-13 and the operation blocking of the circuit 2 of the opening operation of the segmented circuit breaker, thereby realizing the opening operation of the segmented circuit breaker.

The PT permission disconnection relay JSJ is further provided with 2 normally closed contacts JSJ-4 and JSJ-5, the normally closed contacts JSJ-4 and JSJ-5 are connected with 2 normally open auxiliary contacts BLJ-9 and BLJ-10 which are further arranged in the PT parallel relay BLJ in series respectively, the PT permission disconnection relay JSJ 2 normally closed contacts JSJ-4 and JSJ-5 are disconnected in an action mode, the PT parallel relay BLJ is respectively released from being further provided with 2 normally open auxiliary contacts BLJ-9 and BLJ-10 which are connected with a normally open contact starting locking element 1 and a locking element 2 of an existing tripping control circuit of the segmented circuit breaker, the operation locking release of a tripping operation 1 circuit of the segmented circuit breaker and the operation locking release of a tripping operation 2 circuit of the segmented circuit breaker are achieved, and the tripping operation of the segmented circuit breaker is permitted.

In a specific embodiment, as shown in fig. 5, DYJ1 is represented as: the relay is connected with a PT secondary voltage of the first bus between a PT secondary circuit breaker 1DK of the first bus and a PT-1G auxiliary contact of a disconnecting switch PT-1G of the first bus; DYJ1 the action condition of the three-phase voltage-all-voltage monitoring relay is that when the three-phase voltage is less than the setting value U1, the DYJ1 relay judges that the bus voltage disappears, the normally closed contact is connected, and the normally open contact is disconnected; when one phase voltage of the three-phase voltage is greater than a setting value U2, the DYJ1 relay judges that the bus has voltage, the normally open contact of the bus is connected, and the normally closed contact of the bus is disconnected;

when the first bus PT is put into operation, the auxiliary contact of the isolating switch PT-1G is switched on, and if the two three phases of the first bus PT are normally put into operation, namely the first bus PT secondary circuit breaker 1DK is in an on position, the three-phase voltage-free monitoring relay DYJ1 judges that the two phases of the first bus PT have voltage, the DYJ1 normally open contact is closed, and the normally closed contact is opened; at the moment, if the first bus PT secondary three phases are not normally put into operation, namely the first bus PT secondary circuit breaker 1DK is in a separated position, but the first bus PT secondary three phases are normally put into operation, the bus PT parallel relay BLJ acts and the contact is switched on, the three-phase voltage-free monitoring relay DYJ1 judges that the first bus PT secondary voltage exists, the DYJ1 normally open contact is closed, and the normally closed contact is opened;

when the first bus PT does not run, the auxiliary contact of the isolating switch PT-1G is disconnected, and if the voltage of the secondary three-phase circuit breaker 1DK of the first bus PT is in the closed position or in the separated position, and the voltage receiving position of the three-phase voltage-free monitoring relay DYJ1 has no voltage, the three-phase voltage-free monitoring relay DYJ1 judges that the first bus PT has no voltage for the second time, the DYJ1 normally closed contact is closed, and the normally open contact is disconnected;

when the first bus PT is put into operation, the auxiliary contact of the isolating switch PT-1G is switched on, and the secondary three-phase circuit breaker 1DK of the first bus PT is in a closed position, when no power supply is connected to the bus for the first time, no voltage exists at the voltage receiving position of the three-phase voltage-equalizing and voltage-free monitoring relay DYJ1, the three-phase voltage-equalizing and voltage-free monitoring relay DYJ1 judges that the first bus PT has no voltage for the second time, the DYJ1 normally-closed contact is closed, and the normally-open contact is opened;

DYJ2 is expressed as: the relay is connected with a second bus PT secondary voltage between a second bus PT secondary circuit breaker 2DK and a second bus PT isolation switch PT-2G auxiliary contact; DYJ2 the action condition of the three-phase voltage-all-voltage monitoring relay is that when the three-phase voltage is less than the setting value U1, the DYJ2 relay judges that the bus voltage disappears, the normally closed contact is connected, and the normally open contact is disconnected; when one phase of three-phase voltage is greater than the setting value U2, the DYJ2 relay judges that the bus has voltage, and the normally open contact of the bus is connected and the normally closed contact of the bus is disconnected.

When the second bus PT is put into operation, the auxiliary contact of the isolating switch PT-2G is switched on, and if the second bus PT secondary three phases are normally put into operation, namely the second bus PT secondary circuit breaker 2DK is in an on position, the three-phase voltage-free monitoring relay DYJ2 judges that the first bus PT secondary voltage is available, the DYJ2 normally open contact is closed, and the normally closed contact is opened; at this time, if the second bus PT secondary three phases are not normally put into operation, namely the second bus PT secondary circuit breaker 2DK is in a separated position, but the first bus PT secondary three phases are normally put into operation, the bus PT parallel relay BLJ acts and the contact is switched on, the three-phase no-voltage-average voltage monitoring relay DYJ2 judges that the second bus PT secondary voltage exists, the DYJ2 normally-open contact is closed, and the normally-closed contact is opened;

when the second bus PT does not run, the auxiliary contact of the isolating switch PT-2G is disconnected, and if the secondary three-phase circuit breaker 2DK of the second bus PT is in the closed position or in the separated position, and no voltage exists at the voltage receiving position of the three-phase voltage-free monitoring relay DYJ2, the three-phase voltage-free monitoring relay DYJ2 judges that the second bus PT has no voltage, the DYJ2 normally-closed contact is closed, and the normally-open contact is disconnected;

when the second bus PT is put into operation, the auxiliary contact of the isolating switch PT-2G is switched on, and the secondary three-phase breaker 2DK of the second bus PT is in a closed position, when no power supply is connected to the bus for the first time, no voltage exists at the voltage receiving position of the three-phase voltage-equalizing-voltage monitoring relay DYJ2, the three-phase voltage-equalizing-voltage monitoring relay DYJ2 judges that no voltage exists at the secondary position of the second bus PT, the DYJ2 normally closed contact is closed, and the normally open contact is opened;

when the QK change-over switch is in an unallowable parallel position, the contact point 1-2 of the change-over switch QK is enabled, if the first bus PT is not put into operation, the normally closed auxiliary contact of the isolating switch PT-1G is switched on; if the first bus PT does not run at the moment, the normally closed auxiliary contact of the isolating switch PT-2G is also switched on; at this time, the bus bar PT allows the disconnection relay JSJ to act. When the buses PT are allowed to be in a parallel state, if the first buses PT and the second buses PT are not in a running state, the buses PT are allowed to be disconnected, so that no bus voltage exists, and accidents of damaging a loop and equipment cannot occur when the buses PT are disconnected for the second time;

after the PT allows the disconnection relay JSJ to act, on one hand, 1 normally open contact JSJ-3 of the relay JSJ is connected, and the output of a bus voltage allows the disconnection relay to act signal is realized; on the other hand, after the 'PT allows the action of the disconnecting relay JSJ', 2 normally open auxiliary contacts JSJ-1 and JSJ-2 which are switched on are respectively connected with 2 normally closed auxiliary contacts BLJ-12 and BLJ-13 of the 'prevent bus PT parallel relay BLJ' in parallel for use, namely the 2 normally closed auxiliary contacts BLJ-12 and BLJ-13 which are switched off of the 'PT parallel relay BLJ' are short-circuited, so that the normally closed auxiliary contacts BLJ-12 and BLJ-13 which are switched in and used for respectively realizing 2 disconnections of the 'PT parallel relay BLJ' of a blocking subsection circuit breaker tripping 1 and a blocking subsection circuit breaker tripping 2 loop through the disconnection of the normally closed contacts are short-circuited, and the tripping of the subsection circuit breaker is allowed; meanwhile, after the PT allows the disconnecting relay JSJ to act, 2 disconnected normally-closed auxiliary contacts JSJ-4 and JSJ-4 are respectively connected with 2 normally-open auxiliary contacts BLJ-9 and BLJ-10 of the PT parallel relay BLJ to be used in series, namely, the circuit of the blocking sectional circuit breaker trip 1 and the blocking sectional circuit breaker trip 2 which are connected with the 2 normally-open auxiliary contacts BLJ-9 and BLJ-10 of the PT parallel relay BLJ is disconnected, and the blocking sectional circuit breaker trip is allowed to trip.

The circuit can effectively solve the problem of convenience of a bus PT secondary parallel test when the bus has no voltage at one time;

the circuit can effectively solve the problem of convenience of bus PT secondary parallel test when the buses PT are not put into operation;

the circuit is adaptable to the existing circuit for realizing the closing of the blocking section breaker by switching on the normally open contact, and also adaptable to the existing circuit for realizing the closing of the blocking section breaker by switching off the normally closed contact, and has strong adaptability.

The same or similar reference numerals correspond to the same or similar parts; the terms describing positional relationships in the drawings are for illustrative purposes only and are not to be construed as limiting the patent; it is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations to the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. 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 claims of the present invention.

Claims (10)

1. The utility model provides a prevent busbar voltage parallel circuit malfunction circuit which characterized in that, includes that QK change over switch, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G, circuit breaker normally open auxiliary contact FDL1 and PT parallel relay BLJ, wherein:

the first end of the QK change-over switch is connected with a positive power supply, and the second end of the QK change-over switch is connected with a first isolating switch normally-open auxiliary contact 1G, a breaker normally-open auxiliary contact FDL1, a second isolating switch normally-open auxiliary contact 2G and a PT parallel relay BLJ in sequence and then connected with a negative power supply;

the circuit for preventing the misoperation of the bus voltage parallel circuit also comprises a first isolating switch normally closed auxiliary contact 3G, a second isolating switch normally closed auxiliary contact 4G, a breaker normally closed auxiliary contact FDL3, an abnormality verifier YCJ and an abnormality verifier YCJ contact, the second end of the QK change-over switch is respectively connected with one end of a first isolating switch normally closed auxiliary contact 3G, one end of a second isolating switch normally closed auxiliary contact 4G and one end of a breaker normally closed auxiliary contact FDL3, the other end of the first isolating switch normally closed auxiliary contact 3G, the other end of the second isolating switch normally closed auxiliary contact 4G and the other end of the breaker normally closed auxiliary contact FDL3 are connected with an abnormity verifier YCJ and then connected with a negative power supply, and the YCJ contact of the abnormity verifier is connected between the second end of the QK change-over switch and the normally-open auxiliary contact 1G of the first isolating switch.

2. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in claim 1, wherein the PT parallel relay BLJ is provided with 8 normally open contacts BLJ-1 to BLJ-8, which are respectively connected with the different voltage secondary windings of the bus PT, so as to realize the simultaneous parallel function of the different voltage secondary windings of the bus PT.

3. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in claim 2, wherein 2 normally open auxiliary contacts BLJ-9 and BLJ-10 are further provided in the PT parallel relay BLJ, and are connected to the normally open contact start blocking element 1 and the blocking element 2 of the existing opening control circuit of the segmented circuit breaker through the normally open auxiliary contacts BLJ-9 and BLJ-10, respectively, so as to implement operation blocking of the opening operation 1 circuit and operation blocking of the opening operation 2 circuit of the segmented circuit breaker.

4. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in claim 3, wherein 2 normally closed contacts BLJ-12 and BLJ-13 are further provided in the PT parallel relay BLJ, and are respectively connected to the normally closed contact start blocking element 1 and the blocking element 2 of the existing opening control circuit of the sectionalizer, so as to realize the operation blocking of the opening operation 1 circuit and the opening operation 2 circuit of the sectionalizer.

5. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in any one of claims 1 to 4, further comprising a block and close relay BSJ and a section breaker auxiliary contact FDL2, wherein one end of the block and close relay BSJ is connected to the negative power supply of the parallel relay BLJ, the other end of the block and close relay BSJ is connected to one end of the section breaker auxiliary contact FDL2, and the other end of the section breaker auxiliary contact FDL2 is connected to the other end of the QK switch.

6. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in claim 5, wherein 1 normally open contact BSJ-1 is provided in the latching and closing relay BSJ, and is connected to a normally open contact start locking element of an existing closing control circuit of the segmented circuit breaker, so as to realize operation locking of a closing operation circuit of the segmented circuit breaker.

7. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in claim 6, wherein the BSJ further comprises 1 normally-closed open contact BSJ-3 connected to a normally-closed contact start locking element of an existing switch-on control circuit of the sectionalized circuit breaker, so as to realize operation locking of the switch-on operation circuit of the sectionalized circuit breaker.

8. The circuit of claim 6 or 7, further comprising a PT permission disconnection relay JSJ, a first bus PT three-phase no-voltage monitoring relay DYJ1, a second bus PT three-phase no-voltage monitoring relay DYJ2, a first bus PT isolation switch PT-1G auxiliary contact and a second bus PT isolation switch PT-2G auxiliary contact, wherein:

one end of the PT permission disconnection relay JSJ is connected with a negative power supply of the parallel relay BLJ, the other end of the PT permission disconnection relay JSJ is connected with one end of a second bus PT three-phase voltage-equalizing-free monitoring relay DYJ2 and one end of a second bus PT isolating switch PT-2G auxiliary contact respectively, the other end of a second bus PT three-phase voltage-equalizing-free monitoring relay DYJ2 is connected with one end of a first bus PT three-phase voltage-equalizing-free monitoring relay DYJ1, the other end of the second bus PT isolating switch PT-2G auxiliary contact is connected with one end of a first bus PT isolating switch PT-1G auxiliary contact, and the other end of a first bus PT three-phase voltage-equalizing-free monitoring relay DYJ1 and the other end of the first bus PT isolating switch PT-1G auxiliary contact are connected with the other end of the QK change-over switch.

9. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in claim 8, wherein the PT allows the disconnecting relay JSJ to have 2 normally open contacts JSJ-1 and JSJ-2, and the normally open contacts JSJ-1 and JSJ-2 are respectively connected in parallel with 2 normally closed contacts BLJ-12 and BLJ-13 in the PT parallel relay BLJ, so as to respectively release the operation blocking of the parallel relay BLJ on the open operation 1 circuit and the operation blocking of the open operation 2 circuit of the segmented circuit breaker through the 2 normally closed contacts BLJ-12 and BLJ-13, thereby allowing the open operation of the segmented circuit breaker.

10. The circuit for preventing misoperation of the bus voltage parallel circuit as claimed in claim 9, wherein the PT disconnecting allowing relay JSJ is further provided with 2 normally closed contacts JSJ-4 and JSJ-5, which are connected in series with 2 normally open auxiliary contacts BLJ-9 and BLJ-10 in the PT parallel relay BLJ through normally closed contacts JSJ-4 and JSJ-5, respectively, and the PT disconnecting allowing relay JSJ is further provided with 2 normally closed contacts JSJ-4 and JSJ-5 for being disconnected, respectively, and the PT parallel relay BLJ is further provided with 2 normally open auxiliary contacts BLJ-9 and BLJ-10 for being connected with the normally open contact start blocking element 1 and the blocking element 2 of the existing opening control circuit of the sectional circuit breaker, respectively, so as to realize the operation blocking release of the opening operation 1 circuit and the operation blocking release of the opening operation 2 circuit of the sectional circuit breaker, the implementation allows the opening operation of the sectional breaker.

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