CN213906294U - Prevent busbar voltage parallel circuit malfunction circuit based on microcomputer five prevent - Google Patents

Abstract

The utility model discloses a prevent busbar voltage and parallel return circuit malfunction circuit based on microcomputer five prevent, lock BS including microcomputer five, change over switch QK, segmentation or mother ally oneself with circuit breaker normally open auxiliary contact FDL, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G and generating line PT parallel relay BLJ, first isolator normally closed auxiliary contact 3G, second isolator normally closed auxiliary contact 4G, segmentation or mother ally oneself with circuit breaker normally closed auxiliary contact FDL1, unusual verifier YCJ and unusual verifier YCJ contact. The utility model discloses can effectively independently prevent that the harm that the PT secondary was in the side by side malfunction produced takes place.

Description

Prevent busbar voltage parallel circuit malfunction circuit based on microcomputer five prevent

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 based on microcomputer five prevent.

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 busbar voltage parallel circuit malfunction return circuit based on microcomputer five prevent, can effectively independently prevent that the harm that the PT secondary produced in the malfunction side by side takes place.

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 based on microcomputer five prevent, including microcomputer five prevent lock BS, change over switch QK, segmentation or mother ally oneself with circuit breaker normally open auxiliary contact FDL, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G and bus PT parallel relay BLJ, first isolator normally closed auxiliary contact 3G, second isolator normally closed auxiliary contact 4G, segmentation or mother ally oneself with circuit breaker normally closed auxiliary contact FDL1, unusual verifier YCJ and unusual verifier YCJ contact, wherein:

one end of the microcomputer five-prevention lock BS is connected with a positive power supply, the other end of the microcomputer five-prevention lock BS is electrically connected with one end of a change-over switch QK after being sequentially electrically connected with a first isolating switch normally-open auxiliary contact 1G, a segmented or bus-coupled breaker normally-open auxiliary contact FDL and a second isolating switch normally-open auxiliary contact 2G, the other end of the change-over switch QK is electrically connected with one end of a coil of a bus PT parallel relay BLJ, and the other end of the coil of the bus PT parallel relay BLJ is connected with a negative power supply; one end of the microcomputer five-prevention lock BS 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 sectional or bus-coupled breaker normally-closed auxiliary contact FDL1, 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 a sectional or bus-coupled breaker normally-closed auxiliary contact FDL1 are connected with an abnormality verifier YCJ, and then are connected with a negative power supply, and the contact of the abnormality verifier YCJ is connected between the microcomputer five-prevention lock BS and the first isolating switch normally-open auxiliary contact 1G;

one of the contacts of the bus PT parallel relay BLJ is in short circuit with two ends of the microcomputer five-prevention lock BS.

Preferably, the bus PT parallel relay BLJ is 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.

Preferably, the bus PT parallel relay BLJ is further provided with 2 normally open auxiliary contacts BLJ-9 and BLJ-10, wherein the normally open auxiliary contacts BLJ-10 are in short circuit with two ends of the microcomputer five-prevention coding lock BS, and the normally open auxiliary contacts BLJ-9 are connected and connected into a common measurement and control device to acquire PT secondary parallel middle information.

Preferably, the five-prevention coded lock also comprises a five-prevention handheld key of a microcomputer, wherein the five-prevention handheld key of the microcomputer is used for communicating two ends of the five-prevention coded lock BS of the microcomputer.

According to the scheme, the microcomputer five-prevention locking loop is added in the parallel starting loop for the second time of the bus PT, so that the bus PT parallel relay BLJ can be started only after the bus or the bus at a subsection interval is operated to be closed; the two ends of the microcomputer five-prevention lock BS are communicated by an operator through a microcomputer five-prevention handheld key, so that the aim of putting the bus PT parallel relay BLJ into the microcomputer five-prevention lock BS after artificial confirmation is achieved, the defect of bus PT parallel is effectively overcome, and the requirement of sequence of performing secondary parallel after confirming once correct parallel is met. The circuit can automatically judge the information of bus PT secondary parallel by adding a microcomputer five-prevention system, and lock the tripping operation of the segmented circuit breaker, thereby effectively preventing the bus PT from being mistakenly disconnected into a primary circuit firstly to cause the accident that secondary forced disconnection is carried out and secondary equipment is burnt. The circuit is connected with the two ends of the microcomputer five-prevention lock BS in a short circuit mode by additionally arranging the auxiliary contact BLJ-9 of the bus PT parallel relay BLJ to be connected, the technical problem that the bus PT parallel relay BLJ cannot be kept is solved, and an effective solution is provided for the microcomputer five-prevention circuit to be used in an electric secondary circuit.

Preferably, still include first generating line PT three phase voltage monitor relay DYJ1 and second generating line PT three phase voltage monitor relay DYJ2, first generating line PT three phase voltage monitor relay DYJ1I inserts between first generating line PT secondary circuit breaker 1DK and the first isolator normally open auxiliary contact 1G, acquires first generating line PT secondary voltage, second generating line PT three phase voltage monitor relay DYJ2 inserts between second generating line PT secondary circuit breaker 2DK and the second isolator normally open auxiliary contact 2G, acquires second generating line PT secondary voltage.

Preferably, the bus PT parallel relay BLJ is further provided with a normally open auxiliary contact BLJ-11, the first bus PT three-phase voltage monitoring relay DYJ1 is provided with a normally open contact DYJ1-1 and a normally closed contact DYJ1-2, one end of the normally open auxiliary contact BLJ-11 is electrically connected to one end of the transfer switch QK, the other end of the normally open auxiliary contact BLJ-11 is electrically connected to one end of the normally open contact DYJ1-1, the other end of the normally open contact DYJ1-1 is electrically connected to one end of the normally closed contact DYJ1-2, and the other end of the normally closed contact DYJ1-2 is electrically connected to the other end of the transfer switch QK.

Preferably, the second bus PT three-phase voltage monitoring relay DYJ2 is provided with a normally open contact DYJ2-1 and a normally closed contact DYJ2-2, one end of the normally open contact DYJ2-1 is electrically connected to the other end of the normally open auxiliary contact BLJ-11, the other end of the normally open contact DYJ2-1 is electrically connected to the other end of the normally open contact DYJ1-1 and one end of the normally closed contact DYJ2-2, respectively, and one end of the normally closed contact DYJ2-2 is electrically connected to the other end of the transfer switch QK.

According to the scheme, the three-phase voltage relay is judged by increasing the operation mode of the bus PT, whether three phases are all non-voltage or all voltage is judged, cross combination connection is performed, and the secondary operation state of the bus PT and the parallel state of the bus voltage are effectively reflected. The bus PT secondary parallel circuit can be effectively prevented from being opened by unexpected mistake, the bus PT secondary parallel operation process is effectively prevented from being incorrect, namely, the bus PT secondary parallel operation is carried out only when the electric phases on the two sides of the bus PT parallel relay BLJ contact are ensured to be the same, and the defect that the secondary circuit is burnt out when the load current is cut off by the bus PT parallel relay BLJ contact is effectively prevented. The upgrading and transformation work of the existing bus voltage parallel loop is fully considered, the existing bus PT parallel start is slightly changed, and the upgrading and transformation work can be completed by connecting the contact of the transfer switch QK with the locking loop in parallel in the existing operation.

Preferably, the system further comprises a microcomputer five-prevention host, when the microcomputer five-prevention host obtains the relevant information of the public measurement and control device, the bus connection or the subsection interval measurement and control device according to the transformer substation monitoring network and judges that the secondary parallel condition of the bus PT is met, the microcomputer five-prevention handheld key can obtain an 'allowable bus PT secondary parallel signal' from the microcomputer five-prevention host, and an operator can short-circuit two ends of the microcomputer five-prevention lock BS through the microcomputer five-prevention handheld key.

Preferably, the five-prevention lock system further comprises a microcomputer DL-BS, the five-prevention lock system is connected with an external existing bus tie or segmented circuit breaker operation loop, and the five-prevention lock system DL-BS adds a "bus PT secondary parallel middle" open-circuit blocking prohibition logic, specifically:

when the microcomputer five-prevention handheld key cannot obtain a 'master connection permission or subsection interval circuit breaker opening operation command' from the microcomputer five-prevention handheld key, an operator cannot short-circuit two ends of a microcomputer five-prevention lock DL-BS in a control loop of the bus connection or subsection interval circuit breaker through the microcomputer five-prevention handheld key.

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

the utility model discloses can prevent effectively that the PT secondary from paralleling the in-process, the mistake jumps the segmentation or female antithetical couplet circuit breaker, cause the occurence of failure once earlier than the secondary disconnection, the PT that has avoided consequently arousing is once insurance mistake fusing, secondary switch mistake trip, the phenomenon that secondary component and return circuit burn out takes place, can prevent effectively that the change over switch mistake from dropping into behind "allowwing to be abreast" position, segmentation or female antithetical couplet circuit breaker is closed to the mistake, cause a position to confirm through the inspection that unexpected completion generating line PT secondary parallels, can guarantee to carry out generating line PT secondary disconnection operation simultaneously at generating line PT parallel relay BLJ contact both sides electric phase, effectively prevent generating line PT parallel relay BLJ contact disconnection load current from burning out the shortcoming in secondary circuit.

Drawings

FIG. 1 is a schematic structural diagram of a bus voltage parallel loop malfunction preventing circuit based on microcomputer five-prevention;

FIG. 2 is a schematic diagram of the output contacts and functional description of a PT parallel relay BLJ;

FIG. 3 is a schematic diagram of a microcomputer five-prevention host signal network;

FIG. 4 is a schematic diagram of the connection of the first bus PT three phase voltage monitor relay DYJ1 and the second bus PT three phase voltage monitor relay DYJ 2;

FIG. 5 is a schematic diagram of a five-prevention locking loop of a bus-coupled or segmented interval primary equipment operation microcomputer;

FIG. 6 is a logic diagram of a microcomputer five-prevention bus voltage parallel permission program;

FIG. 7 is a logic diagram of a signal 'forbid opening and locking in a microcomputer five-prevention code lock DL-BS' bus PT secondary parallel;

FIG. 8 is a logic diagram of "forbid closing and locking" of a microcomputer five-prevention code lock DL-BS "bus PT secondary parallel QK diverter switch at an allowable position.

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

As shown in fig. 1-8, the present embodiment provides a bus voltage parallel circuit malfunction preventing circuit based on microcomputer five-prevention, as shown in fig. 1, including microcomputer five-prevention lock BS, transfer switch QK, sectional or bus tie breaker normally open auxiliary contact FDL, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G and bus PT parallel relay BLJ, first isolator normally closed auxiliary contact 3G, second isolator normally closed auxiliary contact 4G, sectional or bus tie breaker normally closed auxiliary contact FDL1, abnormality verifier YCJ and abnormality verifier YCJ contact, wherein:

one end of the microcomputer five-prevention lock BS is connected with a positive power supply, the other end of the microcomputer five-prevention lock BS is electrically connected with one end of a change-over switch QK after being sequentially electrically connected with a first isolating switch normally-open auxiliary contact 1G, a segmented or bus-coupled breaker normally-open auxiliary contact FDL and a second isolating switch normally-open auxiliary contact 2G, the other end of the change-over switch QK is electrically connected with one end of a coil of a bus PT parallel relay BLJ, and the other end of the coil of the bus PT parallel relay BLJ is connected with a negative power supply; one end of the microcomputer five-prevention lock BS 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 sectional or bus-coupled breaker normally-closed auxiliary contact FDL1, 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 a sectional or bus-coupled breaker normally-closed auxiliary contact FDL1 are connected with an abnormality verifier YCJ, and then are connected with a negative power supply, and the contact of the abnormality verifier YCJ is connected between the microcomputer five-prevention lock BS and the first isolating switch normally-open auxiliary contact 1G;

one of the contacts of the bus PT parallel relay BLJ is in short circuit with two ends of the microcomputer five-prevention lock BS.

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 isolating switch, the auxiliary contact of the circuit breaker FDL and the normally open contact 2G of the second isolating switch are all switched on, and the normally closed contacts of the normally closed auxiliary contact 3G of the first isolating switch, the normally closed auxiliary contact FDL1 of the segmented or bus-coupled circuit breaker and the normally closed auxiliary contact 4G of the second isolating 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 of allowing parallel connection, when at least one normally open contact of the first isolating switch normally open auxiliary contact 1G, the breaker FDL auxiliary contact 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 of the abnormal verifier YCJ contact breaks the PT parallel relay BLJ to enable the parallel relay to be incapable of realizing parallel connection, and on the other hand, the normally open contact is connected after the abnormal verifier YCJ contact acts, and the QK change-over switch allows the parallel contact to send out a 'contact abnormal PT secondary incapable of parallel connection alarm signal'.

As shown in fig. 2, the bus PT parallel relay BLJ is provided with 8 normally open contacts BLJ-1 to BLJ-8, which are respectively connected to the secondary windings of different voltages of the bus PT, so as to implement the parallel function of the secondary windings of different voltages of the bus PT.

The bus PT parallel relay BLJ is also provided with 2 normally open auxiliary contacts BLJ-9 and BLJ-10, wherein the normally open auxiliary contact BLJ-10 is in short circuit with two ends of the microcomputer five-prevention coded lock BS, and the normally open auxiliary contact BLJ-9 is connected and connected into a common measurement and control device to acquire PT secondary parallel middle information.

The five-prevention coded lock also comprises a five-prevention handheld key of the microcomputer, and the five-prevention handheld key of the microcomputer is used for communicating two ends of the five-prevention coded lock BS of the microcomputer.

When the segmented or bus-coupled circuit breaker, the normally-open auxiliary contact 1G of the first isolating switch and the normally-open auxiliary contact 2G of the second isolating switch are all in the closed position, the fact that the first bus and the second bus in the primary electrical system are parallel is indicated, and at the moment, the closed auxiliary contact of the segmented or bus-coupled circuit breaker, the normally-open auxiliary contact 1G of the first isolating switch and the closed auxiliary contact 2G of the normally-open auxiliary contact 2G of the second isolating switch are all in the connected state, and bus PT secondary parallel can be conducted;

if the changeover switch QK is switched to the 'parallel allowing' position, when the changeover switch QK is switched to the 'parallel allowing' position, the 1-2 contact and the 5-6 contact of the changeover switch QK are both in the connection state; after the 5-6 contact of the change-over switch QK is connected, the public measurement and control device transmits the information to the microcomputer five-prevention host computer, as shown in figure 3; meanwhile, after the sectional or bus tie breaker normally open auxiliary contact FDL is switched on, the first disconnecting switch normally open auxiliary contact 1G is switched on, and the second disconnecting switch normally open auxiliary contact 2G is switched on, the sectional or bus tie measurement and control device transmits the information to the microcomputer five-prevention host computer, as shown in figure 3; the microcomputer five-prevention host machine receives the information and judges that: the primary system has paralleled the buses, and after artificially confirming that the primary buses are paralleled normally, the change-over switch is switched to the 'parallel allowing' position to allow the buses PT to be paralleled for the second time; when the microcomputer five-prevention host sends the 'bus PT secondary parallel' allowing information to the microcomputer five-prevention handheld key, an operator enables two ends of the microcomputer five-prevention coding lock BS to be communicated by using the microcomputer five-prevention handheld key, then a negative power supply passes through a bus PT parallel relay BLJ coil, a 1-2 contact of a selector switch QK, a 2G on auxiliary contact of a second disconnecting switch normally open auxiliary contact, a FDL on auxiliary contact of a segmented or bus-coupled breaker normally open auxiliary contact, and a 1G on auxiliary contact of a first disconnecting switch normally open auxiliary contact to one end of the microcomputer five-prevention coding lock BS, the other end of the microcomputer five-prevention coding lock BS is connected with the positive power supply, and the bus PT parallel relay BLJ acts;

after the bus PT parallel relay BLJ acts, on one hand, the bus PT parallel relay BLJ is provided with 8 normally open contacts BLJ-1 to BLJ-8 to be switched on, so that the parallel function of secondary windings with different voltages of the bus PT is realized; on the other hand, the bus PT parallel relay BLJ is provided with 2 normally-open auxiliary contacts BLJ-9 which are connected with the BLJ-10 contacts, wherein the auxiliary contacts BLJ-10 are connected to short-circuit two ends of the microcomputer five-prevention coding lock BS, so that a positive power supply is connected to a negative power supply through the auxiliary contacts BLJ-10, the first disconnecting switch normally-open auxiliary contact 1G on auxiliary contacts, the segmented or bus-coupled circuit breaker normally-open auxiliary contact FDL on auxiliary contacts, the second disconnecting switch normally-open auxiliary contact 2G on auxiliary contacts, the 1-2 contacts of the transfer switch QK and a bus PT parallel relay BLJ coil, and the bus PT parallel relay BLJ is kept in an action state; the auxiliary contact BLJ-9 is connected and connected into a public measurement and control device, the public measurement and control device obtains 'bus PT secondary parallel middle' information and sends the information to a microcomputer five-prevention host, after the microcomputer five-prevention host obtains the information, the fact that the bus PT secondary forbids the tripping of the sectional switch in parallel is judged, at the moment, a microcomputer five-prevention handheld key cannot obtain 'section switch tripping allowing signals' at the microcomputer five-prevention host, namely, two ends of a microcomputer five-prevention coded lock DL-BS in a section breaker tripping operation loop cannot be short-circuited through the microcomputer five-prevention handheld key, the section breaker operation loop cannot obtain a positive power supply, and the locking of the section breaker tripping operation is achieved.

Still include first generating line PT three phase voltage monitor relay DYJ1 and second generating line PT three phase voltage monitor relay DYJ2, first generating line PT three phase voltage monitor relay DYJ1I inserts between first generating line PT secondary circuit breaker 1DK and the first isolator normally open auxiliary contact 1G, acquires first generating line PT secondary voltage, second generating line PT three phase voltage monitor relay DYJ2 inserts between second generating line PT secondary circuit breaker 2DK and the second isolator normally open auxiliary contact 2G, acquires second generating line PT secondary voltage.

The bus PT parallel relay BLJ is further provided with a normally open auxiliary contact BLJ-11, the first bus PT three-phase voltage monitoring relay DYJ1 is provided with a normally open contact DYJ1-1 and a normally closed contact DYJ1-2, one end of the normally open auxiliary contact BLJ-11 is electrically connected with one end of a transfer switch QK, the other end of the normally open auxiliary contact BLJ-11 is electrically connected with one end of the normally open contact DYJ1-1, the other end of the normally open contact DYJ1-1 is electrically connected with one end of the normally closed contact DYJ1-2, and the other end of the normally closed contact DYJ1-2 is electrically connected with the other end of the transfer switch QK.

The second bus PT three-phase voltage monitoring relay DYJ2 is provided with a normally open contact DYJ2-1 and a normally closed contact DYJ2-2, one end of the normally open contact DYJ2-1 is electrically connected with the other end of a normally open auxiliary contact BLJ-11, the other end of the normally open contact DYJ2-1 is electrically connected with the other end of the normally open contact DYJ1-1 and one end of the normally closed contact DYJ2-2 respectively, and one end of the normally closed contact DYJ2-2 is electrically connected with the other end of the transfer switch QK.

As shown in fig. 4, DYJ1 is expressed as: the relay is connected with the PT secondary voltage of the first bus between a PT secondary circuit breaker 1DK of the first bus and an auxiliary contact point of a disconnecting switch PT-1G of the first bus PT; the action condition of the first bus PT three-phase voltage monitoring relay DYJ1 is that when the three-phase voltages are all less than the setting value U1, the first bus PT three-phase voltage monitoring relay DYJ1 judges that the bus voltage disappears, and the normally closed contact is on and the normally open contact is off; when one phase voltage of the three-phase voltage is greater than the setting value U2, the first bus PT three-phase voltage monitoring relay DYJ1 judges that the bus has voltage, and a normally open contact of the bus is connected, and a 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 second 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 first bus PT three-phase voltage monitoring relay DYJ1 judges that the first bus PT secondary voltage exists, the normally open contact of the first bus PT three-phase voltage monitoring relay DYJ1 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 second bus PT secondary three phases are normally put into operation, the bus PT parallel relay BLJ acts and the contact is switched on, the first bus PT three-phase voltage monitoring relay DYJ1 judges that the first bus PT secondary voltage is available, the normally open contact of the first bus PT three-phase voltage monitoring relay DYJ1 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 at the moment, if the secondary three-phase circuit breaker 1DK of the first bus PT is in an on position or in a off position, the voltage access position of the first bus PT three-phase voltage monitoring relay DYJ1 has no voltage, the first bus PT three-phase voltage monitoring relay DYJ1 judges that the first bus PT has no voltage for the second time, the normally closed contact of the first bus PT three-phase voltage monitoring relay DYJ1 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, the secondary three-phase circuit breaker 1DK of the first bus PT is in a closed position, when no power supply of the bus is connected for the first time, the voltage connection position of the PT three-phase voltage monitoring relay DYJ1 of the first bus has no voltage, the PT three-phase voltage monitoring relay DYJ1 of the first bus judges that the PT secondary voltage of the first bus is not available, the normally closed contact of the PT three-phase voltage monitoring relay DYJ1 of the first bus is closed, and the normally open contact of the PT three-phase voltage monitoring relay DYJ1 of the first bus is opened;

DYJ2 is expressed as: the relay is connected with a PT secondary voltage of the second bus between a PT secondary circuit breaker 2DK of the second bus and a PT-2G auxiliary contact of a PT disconnecting switch PT-2G of the second bus; the action condition of the second bus PT three-phase voltage monitoring relay DYJ2 is that when the three-phase voltages are all smaller than the setting value U1, the second bus PT three-phase voltage monitoring relay judges that the bus voltage disappears, the normally closed contact is connected, and the normally open contact is disconnected; when one phase of the three-phase voltage is greater than the setting value U2, the second bus PT three-phase voltage monitoring relay DYJ2 judges that the bus has voltage, and a normally open contact of the second bus PT three-phase voltage monitoring relay is connected, and a normally closed contact of the second bus PT three-phase voltage monitoring relay 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-phase is normally put into operation, namely the second bus PT secondary circuit breaker 2DK is in an on-position, the second bus PT three-phase voltage monitoring relay DYJ2 judges that the first bus PT secondary voltage is available, the normally open contact of the second bus PT three-phase voltage monitoring relay DYJ2 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 second bus PT three-phase voltage monitoring relay DYJ2 judges that the second bus PT secondary voltage is available, the normally open contact of the second bus PT three-phase voltage monitoring relay DYJ2 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 at the moment, if the secondary three-phase circuit breaker 2DK of the second bus PT is in an on position or in a off position, and the voltage receiving position of the PT three-phase voltage monitoring relay DYJ2 has no voltage, the PT three-phase voltage monitoring relay DYJ2 of the second bus judges that the PT secondary of the second bus is voltage-free, the normally closed contact of the PT three-phase voltage monitoring relay DYJ2 of the second bus 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, the secondary II bus PT three-phase circuit breaker 2DK is in a closed position, when no power supply is connected to the bus for the first time, the voltage connecting position of the PT three-phase voltage monitoring relay DYJ2 of the second bus has no voltage, the PT three-phase voltage monitoring relay DYJ2 of the second bus judges that no voltage exists in the PT three-phase voltage monitoring relay of the second bus, the normally closed contact of the PT three-phase voltage monitoring relay DYJ2 of the second bus is closed, and the normally open contact is opened;

when the bus PT parallel relay BLJ acts, the normally open auxiliary contact BLJ-11 of the bus PT parallel relay BLJ is switched on, if the first bus PT normally operates, the normally open contact of the first bus PT three-phase voltage monitoring relay DYJ1 is switched on, and the normally closed contact is switched off; if the second bus PT quits operation, the normally closed contact of the second bus PT three-phase voltage monitoring relay DYJ2 is switched on, and the normally open contact is switched off; at the moment, the normally open auxiliary contact BLJ-11 of the bus PT parallel relay BLJ, the normally open contact of the first bus PT three-phase voltage monitoring relay DYJ1 and the normally closed contact of the second bus PT three-phase voltage monitoring relay DYJ2 are used for short-circuiting the contact 1-2 of the transfer switch QK, and at the moment, an operator switches the transfer switch QK to an unallowable parallel position to disconnect the contact 1-2 of the transfer switch QK, so that the bus PT parallel relay BLJ cannot be deenergized and returned, the disconnection and locking of the bus PT are reliably realized, the secondary power supply of one section of the bus PT can be effectively prevented, and the accident of arc breakage and burning of the contact of the deenergized return contact of the bus PT parallel relay BLJ caused by the disconnection of the other section of the bus PT without the power supply occurs;

when the bus PT parallel relay BLJ acts, the normally open auxiliary contact BLJ-11 of the bus PT parallel relay BLJ is switched on, if the first bus PT normally operates, the normally open contact of the first bus PT three-phase voltage monitoring relay DYJ1 is switched on, and the normally closed contact is switched off; if the second bus PT also runs normally, the normally open contact of the second bus PT three-phase voltage monitoring relay DYJ2 is switched on, and the normally closed contact is switched off; at the moment, normally closed contacts of the first bus PT three-phase voltage monitoring relay DYJ1 and the second bus PT three-phase voltage monitoring relay DYJ2 are both disconnected, the transfer switch QK contact 1-2 cannot be short-circuited, and after an operator switches the transfer switch QK to a non-allowable parallel position to disconnect the transfer switch QK contact 1-2, the bus PT parallel relay BLJ loses power and returns, so that secondary disconnection of the bus PT is reliably realized;

when the bus PT parallel relay BLJ acts, the normally open auxiliary contact BLJ-11 of the bus PT parallel relay BLJ is switched on, if the first bus PT exits from running, the normally closed contact of the first bus PT three-phase voltage monitoring relay DYJ1 is switched on, and the normally open contact is switched off; if the second bus PT also quits the operation, the normally closed contact of the second bus PT three-phase voltage monitoring relay DYJ2 is switched on, and the normally open contact is switched off; at the moment, normally open contacts of the first bus PT three-phase voltage monitoring relay DYJ1 and the second bus PT three-phase voltage monitoring relay DYJ2 are disconnected, the transfer switch QK contact 1-2 cannot be short-circuited, and after an operator switches the transfer switch QK to a non-allowable parallel position to disconnect the transfer switch QK contact 1-2, the bus PT parallel relay BLJ loses power and returns, so that secondary disconnection of the bus PT is reliably realized; note: disconnection is allowed when both bus bars PT exit run.

The system is characterized by further comprising a microcomputer five-prevention host, when the microcomputer five-prevention host obtains relevant information of a public measurement and control device, a bus coupler or a segmented interval measurement and control device according to a transformer substation monitoring network and judges that bus PT secondary parallel conditions are met, as shown in fig. 6, the microcomputer five-prevention handheld key can obtain 'bus PT secondary parallel signals' from the microcomputer five-prevention host, and an operator can short-circuit two ends of the microcomputer five-prevention lock BS through the microcomputer five-prevention handheld key.

The five-prevention lock system further comprises a microcomputer DL-BS, the five-prevention lock system is connected with an external existing bus tie or sectional breaker operation loop, and the five-prevention lock system DL-BS adds a 'bus PT secondary parallel middle' tripping and locking forbidding logic, as shown in FIG. 7, specifically:

when the microcomputer five-prevention handheld key cannot obtain a 'master connection permission or subsection interval circuit breaker opening operation command' from the microcomputer five-prevention handheld key, an operator cannot short-circuit two ends of a microcomputer five-prevention lock DL-BS in a control loop of the bus connection or subsection interval circuit breaker through the microcomputer five-prevention handheld key.

The five-prevention-lock DL-BS of the microcomputer adds a closing-forbidding and locking logic of 'bus PT secondary parallel QK change-over switch at an allowed position', as shown in FIG. 8, specifically comprising:

when the microcomputer five-prevention host obtains the related information of the public measurement and control device, the bus coupler or the subsection interval measurement and control device according to the transformer substation monitoring network, the QK change-over switch is judged to be in the allowable parallel position, the bus coupler or the subsection interval circuit breaker FDL is judged to be in the open position at the same time, the requirement that the bus PT secondary parallel circuit change-over switch QK is forbidden to carry out the closing operation of the bus coupler or the subsection interval circuit breaker in the allowable parallel position is met, the microcomputer five-prevention handheld key cannot obtain the closing operation command of the allowable bus coupler or the subsection interval circuit breaker from the microcomputer five-prevention host, and an operator cannot short-circuit two ends of a microcomputer five-prevention lock DL-BS in a control loop of the bus coupler or the subsection interval circuit breaker through the microcomputer five-prevention handheld key.

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 (9)

1. The utility model provides a prevent busbar voltage parallel circuit malfunction circuit based on five preventions of computer, a serial communication port, including five preventions of computer locking BS, change over switch QK, segmentation or mother ally oneself with circuit breaker normally open auxiliary contact FDL, first isolator normally open auxiliary contact 1G, second isolator normally open auxiliary contact 2G, bus PT parallel relay BLJ, first isolator normally closed auxiliary contact 3G, second isolator normally closed auxiliary contact 4G, segmentation or mother ally oneself with circuit breaker normally closed auxiliary contact FDL1, abnormity verifier YCJ and abnormity verifier YCJ contact, wherein:

one end of the microcomputer five-prevention lock BS is connected with a positive power supply, the other end of the microcomputer five-prevention lock BS is electrically connected with one end of a change-over switch QK after being sequentially electrically connected with a first isolating switch normally-open auxiliary contact 1G, a segmented or bus-coupled breaker normally-open auxiliary contact FDL and a second isolating switch normally-open auxiliary contact 2G, the other end of the change-over switch QK is electrically connected with one end of a coil of a bus PT parallel relay BLJ, and the other end of the coil of the bus PT parallel relay BLJ is connected with a negative power supply; one end of the microcomputer five-prevention lock BS 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 sectional or bus-coupled breaker normally-closed auxiliary contact FDL1, 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 a sectional or bus-coupled breaker normally-closed auxiliary contact FDL1 are connected with an abnormality verifier YCJ, and then are connected with a negative power supply, and the contact of the abnormality verifier YCJ is connected between the microcomputer five-prevention lock BS and the first isolating switch normally-open auxiliary contact 1G;

one of the contacts of the bus PT parallel relay BLJ is in short circuit with two ends of the microcomputer five-prevention lock BS.

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

3. The circuit for preventing misoperation of the bus voltage parallel circuit based on the five-prevention microcomputer according to claim 1, wherein the bus PT parallel relay BLJ is further provided with 2 normally open auxiliary contacts BLJ-9 and BLJ-10, wherein the normally open auxiliary contact BLJ-10 is in short circuit with two ends of the five-prevention microcomputer coded lock BS, and the normally open auxiliary contact BLJ-9 is connected and connected into a common measurement and control device to obtain PT secondary parallel middle information.

4. The circuit for preventing misoperation of the bus voltage parallel circuit based on the microcomputer five-prevention as claimed in claim 3, further comprising a microcomputer five-prevention hand-held key for communicating two ends of the microcomputer five-prevention coded lock BS.

5. The circuit for preventing misoperation of the parallel circuit of the bus voltages based on the microcomputer five-prevention of any one of claims 1 to 3, further comprising a first bus PT three-phase voltage monitoring relay DYJ1 and a second bus PT three-phase voltage monitoring relay DYJ2, wherein the first bus PT three-phase voltage monitoring relay DYJ1I is connected between the first bus PT secondary circuit breaker 1DK and the normally open auxiliary contact 1G of the first isolating switch to obtain the first bus PT secondary voltage, and the second bus PT three-phase voltage monitoring relay DYJ2 is connected between the second bus PT secondary circuit breaker 2DK and the normally open auxiliary contact 2G of the second isolating switch to obtain the second bus PT secondary voltage.

6. The microcomputer five-prevention-based misoperation prevention circuit for the bus voltage parallel circuit is characterized in that the bus PT parallel relay BLJ is further provided with a normally open auxiliary contact BLJ-11, the first bus PT three-phase voltage monitoring relay DYJ1 is provided with a normally open contact DYJ1-1 and a normally closed contact DYJ1-2, one end of the normally open auxiliary contact BLJ-11 is electrically connected with one end of a transfer switch QK, the other end of the normally open auxiliary contact BLJ-11 is electrically connected with one end of the normally open contact DYJ1-1, the other end of the normally open contact DYJ1-1 is electrically connected with one end of the normally closed contact DYJ1-2, and the other end of the normally closed contact DYJ1-2 is electrically connected with the other end of the transfer switch QK.

7. The microcomputer five-prevention-based misoperation prevention circuit for the bus voltage parallel circuit as claimed in claim 6, wherein the second bus PT three-phase voltage monitoring relay DYJ2 is provided with a normally open contact DYJ2-1 and a normally closed contact DYJ2-2, one end of the normally open contact DYJ2-1 is electrically connected with the other end of the normally open auxiliary contact BLJ-11, the other end of the normally open contact DYJ2-1 is electrically connected with the other end of the normally open contact DYJ1-1 and one end of the normally closed contact DYJ2-2, and one end of the normally closed contact DYJ2-2 is electrically connected with the other end of the transfer switch QK.

8. The circuit for preventing misoperation of the bus voltage parallel loop based on the microcomputer five-prevention as claimed in claim 6 or 7, further comprising a microcomputer five-prevention host, wherein when the microcomputer five-prevention host obtains relevant information of a public measurement and control device, a bus coupler or a segmented interval measurement and control device according to a transformer substation monitoring network and judges that a bus PT secondary parallel condition is met, the microcomputer five-prevention handheld key can obtain an 'allowable bus PT secondary parallel signal' from the microcomputer five-prevention host, and an operator can short-circuit two ends of the microcomputer five-prevention lock BS through the microcomputer five-prevention handheld key.

9. The circuit for preventing misoperation of the bus voltage parallel circuit based on microcomputer five-prevention as claimed in claim 6, further comprising a microcomputer five-prevention lock DL-BS, wherein the microcomputer five-prevention lock is connected with an external bus-tie or sectional breaker operation circuit.

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