CN111786363B - Rapid protection method and device for switch cabinet bus - Google Patents
Rapid protection method and device for switch cabinet bus Download PDFInfo
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- CN111786363B CN111786363B CN202010773389.9A CN202010773389A CN111786363B CN 111786363 B CN111786363 B CN 111786363B CN 202010773389 A CN202010773389 A CN 202010773389A CN 111786363 B CN111786363 B CN 111786363B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/22—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
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Abstract
The application provides a method and a device for quickly protecting a switch cabinet bus, after a first bus or a second bus has a bus fault and any differential protection is started, if a sampling value of CT at a section switch is greater than a fault current setting value, the section switch is in an on position and a non-fault bus is connected with a power supply end, or the section switch is in an off position and a fault occurs in a dead zone, the section switch is tripped at first 0 time limit, if a fault current flows through a step-down switch of a first main transformer or a second main transformer, the fault occurs on the first bus or the second bus connected with the first main transformer or the second main transformer, and therefore the overcurrent first main transformer or the second main transformer and a small power supply wiring switch of the bus in which the overcurrent first main transformer or the second main transformer exist after a step difference time limit, otherwise the fault dead zone occurs on the bus not connected with the power supply end and the fault is already cut off, and the technical problems that the existing switch cabinet bus protection is easy to reject or malfunction, long in fault isolation time and cannot adapt to different grounding modes and the dead zone exist are solved.
Description
Technical Field
The application relates to the technical field of relay protection, in particular to a method and a device for quickly protecting a switch cabinet bus.
Background
In an electric power system, primary conductive parts on 20kV or 10kV side of a transformer substation of 110kV or more are arranged in the form of an indoor switch cabinet (including a distribution switch station) as shown in figure 1. As shown in fig. 2, the 10kV parts are all arranged in the switch cabinet, and each part is arranged in an independent switch cabinet at intervals, and the electrical interconnection is realized through a 10kV bus.
The interior of the switch cabinet consists of a bus chamber, a circuit breaker handcart chamber, a cable chamber and a relay instrument chamber. Wherein, three-phase copper bars are arranged in the bus chamber in parallel, the distances between the phases and the metal cabinet body are generally only 12.5cm. In case of a fault, due to the action of arc light, the structure in the cabinet can spread and convert the fault very quickly, and if the fault is not removed quickly through protection, the adjacent switch cabinets can be burnt out and even explode at the same time.
There are two types of switchgear bus protection at present: one is simple bus protection, but because the wiring is complex, and when the outside and inside of the area simultaneously fail or the outside failure causes the inside following failure, the simple bus protection has the defect of refusing to operate; the other type is arc light protection, wherein a sensor receives arc light in the cabinet and senses the intensity of the arc light to judge whether a fault occurs. This kind of protection takes place the maloperation easily when external light appears, and complicated cabinet inner structure receives arc light to the sensor and produces the obstacle, and there is the blind spot in the protection in other words, and the sensor inspection installation and maintain inconveniently. Both protections are rarely put into use due to their respective fatal drawbacks. In actual operation, the only protection of cubical switchboard generating line is exactly that the main transformer becomes the reserve protection of step-down, and its fault removal time is 1.2S and above, can not satisfy the needs, consequently in case the trouble (such as lightning breakdown, switch contact failure, typhoon intake, toy crawl in the reason) often just burns the company of camping, probably arouses the explosion when serious.
Therefore, a method and a device for quickly protecting a switch cabinet bus are needed to be provided, so that the technical problems that the existing switch cabinet bus protection is easy to have operation failure or misoperation, long in fault isolation time, incapable of adapting to different grounding mode systems, and even has dead zones are solved.
Disclosure of Invention
The embodiment of the application provides a method and a device for quickly protecting a switch cabinet bus, and solves the technical problems that the existing switch cabinet bus protection is easy to miss or malfunction, and even has dead zones.
In view of the above, a first aspect of the present application provides a method for quickly protecting a bus of a switchgear, where the method includes:
the method comprises the steps that CT sampling values of differential protection access configured on a first bus and a second bus respectively are obtained, wherein the first bus and the second bus are connected through a section switch, a CT is arranged at the section switch, the differential protection access of the first bus is connected to the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the step-down switch of a first main transformer connected with the first bus and the sampling value of the CT at the section switch, and the differential protection access of the second bus is connected to the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the step-down switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch;
when the differential protection of the first bus or the second bus is started, if the sampling value of the CT at the section switch is greater than the fault current setting value, the section switch is tripped off in 0 time limit;
and if the sampling value of the CT at the position of the low-level switch of the first main transformer is greater than the fault current setting value or the sampling value of the CT at the position of the low-level switch of the second main transformer is greater than the fault current setting value, tripping off the low-level switch of the first main transformer and a first small power supply wiring switch connected with the first bus or tripping off the low-level switch of the second main transformer and a second small power supply wiring switch connected with the second bus after a pole difference time limit.
Optionally, when the differential protection of the first bus or the second bus is started, if the sampling value of CT at the section switch is smaller than the fault current setting value, the sampling value of CT at the step-down switch of the first main transformer is larger than the fault current setting value, and when the first bus is open at the return voltage, the step-down switch of the first main transformer and the first small power source wiring switch connected with the first bus are tripped at 0 time limit, or when the sampling value of CT at the step-down switch of the second main transformer is larger than the fault current setting value, and when the second bus is open at the return voltage, the step-down switch of the second main transformer and the second small power source wiring switch connected with the second bus are tripped at 0 time limit.
Optionally, when the sum of the sampling value of the CT at the outgoing line switch of the first bus, the sampling value of the CT at the low-change switch of the first main transformer connected to the first bus, and the sampling value of the CT at the section switch is greater than a preset differential flow setting value, the first bus differential protection is started;
and when the sum of the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the low-change switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value, the differential protection of the second bus is started.
Optionally, each outgoing line switch of the first bus includes: the first small power supply wiring switch and the first feeder switch;
each outlet switch of the second bus comprises: the second small power supply wiring switch and the second feeder switch.
Optionally, before the obtaining CT sampling values respectively configured for differential protection access of the first bus and the second bus, the method further includes:
if the CT configured on the first bus or the second bus is broken, the subsequent operation is not executed, otherwise, three-phase voltage sampling values of PT respectively configured on the first bus or the second bus are obtained, when the three-phase voltage sampling values simultaneously meet the condition that the minimum value of three-phase voltage is smaller than a first setting value, the negative sequence voltage value of three-phase voltage is larger than a second setting value and the zero sequence voltage of three-phase voltage is larger than a third setting value, the first bus or the second bus is opened by complex voltage, and otherwise, the first bus or the second bus is closed by complex voltage.
Optionally, when a first zero-sequence current value of a grounded small resistor connected to the first bus is greater than a first preset settable value, the reaching time duration of the first zero-sequence current value is greater than a second preset settable value, any three-phase current of the first bus is greater than a low-going overcurrent setting value of the first bus, and the first bus complex voltage lock is open, the first bus protection is started;
and when a second zero sequence current value of the grounding small-size resistor connected with the second bus is greater than a third preset settable value, the reaching limit duration of the second zero sequence current value is greater than a fourth preset settable value, any three-phase current of the second bus is greater than a low-down overcurrent setting value of the second bus, and the second bus complex voltage lock is opened, the second bus protection is started.
Optionally, when the first neutral point voltage of the first bus is greater than a voltage setting value of a first preset bus neutral point, the out-of-limit duration of the first neutral point voltage is greater than a fifth preset settable value, any three-phase current of the first bus is greater than a low-going over-current setting value of the first bus, and the first bus complex voltage lock is open, the first bus protection is started;
and when the second neutral point voltage of the second bus is greater than the voltage setting value of the neutral point of a second preset bus, the out-of-limit duration time of the second neutral point voltage is greater than a sixth preset settable value, any three-phase current of the second bus is greater than the low-down over-current setting value of the second bus, and the second bus complex voltage lock is opened, the second bus protection is started.
This application second aspect provides a quick protection device of cubical switchboard generating line, the device includes:
the acquisition unit is used for acquiring CT sampling values accessed by differential protection respectively arranged on a first bus and a second bus, wherein the first bus and the second bus are connected through a section switch, a CT is arranged at the section switch, the differential protection of the first bus is accessed to the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the step-down switch of a first main transformer connected with the first bus and the sampling value of the CT at the section switch, and the differential protection of the second bus is accessed to the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the step-down switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch;
the first processing unit is used for tripping the section switch in 0 time limit if a sampling value of a CT (current transformer) at the section switch is greater than a fault current setting value when differential protection of the first bus or the second bus is started;
and the second processing unit is used for tripping off the low-down switch of the first main transformer and a first small power supply wiring switch connected with the first bus or tripping off the low-down switch of the second main transformer and a second small power supply wiring switch connected with the second bus after a limit time if the sampling value of the CT at the low-down switch of the first main transformer is greater than the fault current setting value or the sampling value of the CT at the low-down switch of the second main transformer is greater than the fault current setting value.
Optionally, the method further includes:
and the third processing unit is used for tripping the low-level switch of the first main transformer and a first small power supply wiring switch connected with the first bus within 0 time limit when the differential protection of the first bus or the second bus is started and if the sampling value of the CT at the section switch is smaller than the fault current setting value and the first bus is in the re-voltage opening state, or tripping the low-level switch of the second main transformer and a second small power supply wiring switch connected with the second bus within 0 time limit when the sampling value of the CT at the low-level switch of the second main transformer is larger than the fault current setting value and the second bus is in the re-voltage opening state.
Optionally, the method further includes:
the fourth processing unit is used for starting the first bus differential protection when the sum of the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the low-change switch of the first main transformer connected with the first bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value;
and the fifth processing unit is used for starting the second bus differential protection when the sum of the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the low-change switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value.
According to the technical scheme, the embodiment of the application has the following advantages:
in the embodiment of the application, a method for quickly protecting a bus of a switch cabinet is provided, after a bus fault occurs on a first bus or a second bus and any differential protection is started, if a sampling value of a CT (current transformer) at a section switch is greater than a fault current setting value, the section switch is in an on-position state and a non-fault bus is connected with a power supply end, or the section switch is in an off-position state and a fault occurs in a dead zone, the section switch is tripped off in 0 time limit, if fault current flows through a low-voltage switch of a first main transformer or a second main transformer, the fault occurs on the first bus or the second bus connected with the first main transformer or the second main transformer, and therefore the overcurrent first main transformer or the overcurrent second main transformer and a small power supply wiring switch of the bus in which the overcurrent first main transformer or the second main transformer exist after a stage time limit, otherwise, the fault dead zone occurs on the bus not connected with the power supply end and the fault is already cut off is finished, and the technical problems that the existing switch cabinet bus protection is easy to fail or malfunction, long in fault isolation time cannot adapt to different grounding modes and the dead zone exists are solved.
Drawings
FIG. 1 is a schematic diagram of a 10kV main wiring;
FIG. 2 is a schematic diagram of a 10kV switchgear arrangement;
fig. 3 is a flowchart illustrating a method for quickly protecting a bus of a switch cabinet according to an embodiment of the present disclosure;
fig. 4 is another flowchart of a method for quickly protecting a bus of a switch cabinet according to an embodiment of the present disclosure;
fig. 5 is a schematic structural diagram of a bus bar quick protection device of a switch cabinet in an embodiment of the present application;
FIG. 6 is a diagram of a primary main wiring of a switching station in the embodiment of the present application;
fig. 7 is a logic diagram of a control principle of the embodiment of the present application.
Detailed Description
In order to make those skilled in the art better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Generally, grid faults fall into three categories: single phase earth faults, phase-to-phase (earth) faults and three phase faults. Through comprehensive analysis of multiple high-voltage cabinet accidents, the 10kV bus fault in the switch cabinet has common characteristics, and the grounding method is described as follows according to different system grounding modes:
1. the neutral point is directly grounded: the 10kV intensively-arranged bus generates a single-phase earth fault or any interphase fault to generate large current to start an arc, and the insulation is broken down instantaneously (about a few milliseconds) to develop into a three-phase fault; 2. neutral point ungrounded or arc suppression coil grounded system: when a single-phase grounding fault occurs on the 10kV densely-arranged bus, the short-circuit current is only capacitive current or smaller capacitive current compensated by the arc suppression coil, and the bus is allowed to continue to operate for 2 hours. The protection should not be active but must be prepared, and when the insulation is gradually broken, the fault will be instantaneously transformed into a three-phase fault, which should be active quickly. When a fault is not a single-phase fault (two-phase fault or three-phase fault), a three-phase ground fault is instantaneously developed.
3. The neutral point is grounded through a small resistor: when a non-single-phase fault (interphase fault or three-phase fault) occurs in a 10kV densely-arranged bus, the non-single-phase fault is instantly converted into a three-phase grounding fault; when a single-phase grounding fault occurs, due to factors of neutral point resistance, short-circuit point excess resistance and main transformer capacity, when the three are all in a low-current state (high resistance and low capacity), the single-phase grounding current of the bus is possibly small, the single-phase grounding current cannot be instantly converted into a three-phase grounding fault, insulation is broken for a certain time, and finally the insulation is broken down and converted into a three-phase fault, and at the moment, a new criterion needs to be introduced to achieve rapid removal.
In conclusion, for a 10kV bus fault, only a three-phase fault needs to be concerned, protection starting is performed and preparation is made for other abnormal conditions which are not the three-phase fault, and when the abnormal conditions are converted into the three-phase fault, the fault is removed through rapid and accurate action.
The application designs a method and a device for quickly protecting a switch cabinet bus, and solves the technical problems that the existing switch cabinet bus protection is easy to miss or malfunction, and even has dead zones.
For convenience of understanding, please refer to fig. 3, fig. 3 is a flowchart of a method for quickly protecting a bus of a switch cabinet in an embodiment of the present application, and as shown in fig. 3, the method specifically includes:
301. acquiring CT sampling values of differential protection access configured on a first bus and a second bus respectively, wherein the first bus is connected with the second bus through a section switch, the section switch is provided with a CT, the differential protection of the first bus is accessed into the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the step-down switch of a first main transformer connected with the first bus and the sampling value of the CT at the section switch, and the differential protection of the second bus is accessed into the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the step-down switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch;
302. when the differential protection of the first bus or the second bus is started, if the sampling value of the CT at the section switch is greater than the fault current setting value, the section switch is tripped off in 0 time limit;
303. and if the sampling value of the CT at the position of the low-change switch of the first main transformer is greater than the fault current setting value or the sampling value of the CT at the position of the low-change switch of the second main transformer is greater than the fault current setting value, tripping off the low-change switch of the first main transformer and a first small power supply wiring switch connected with the first bus or tripping off the low-change switch of the second main transformer and a second small power supply wiring switch connected with the second bus after a range time limit.
In the embodiment of the application, a method for quickly protecting a bus of a switch cabinet is provided, after a bus fault occurs in a first bus or a second bus and differential protection is started, if a sampling value of a CT (current transformer) at a section switch is greater than a fault current setting value, it is indicated that the section switch is in a closed position and a non-fault bus is connected with a power supply end, or the section switch is in a separated position and a fault occurs in a dead zone, namely, between the section switch and the CT at the section switch, the section switch is tripped at 0 time limit first, if a fault current flows through a low-down switch of the first main transformer or the second main transformer, the fault occurs in the first bus or the second bus connected with the first main transformer or the second main transformer, so that the overcurrent first main transformer or the second main transformer and a small power supply connection switch of the bus are tripped after a pole difference time limit, otherwise, the fault occurs in the dead zone and is already cut off, and the technical problem that the existing bus protection of the switch cabinet is prone to fail or malfunction, even has the dead zone exists is solved.
Referring to fig. 4, fig. 4 is another flowchart of a method for quickly protecting a bus of a switch cabinet according to an embodiment of the present disclosure, as shown in fig. 4, specifically:
401. if the CT configured on the first bus or the second bus is broken, the subsequent operation is not executed, otherwise, three-phase voltage sampling values of the PT respectively configured on the first bus or the second bus are obtained, when the three-phase voltage sampling values simultaneously meet the condition that the minimum value of the three-phase voltage is smaller than a first setting value, the three-phase negative sequence voltage value is larger than a second setting value and the three-phase zero sequence voltage is larger than a third setting value, the first bus or the second bus is opened through the repeated voltage, and otherwise, the first bus or the second bus is closed through the repeated voltage;
it should be noted that, as shown in the primary main wiring diagram of the switching station in fig. 6, the first bus bar I bus bar is connected to the #1 main transformer, the #1 small power supply wiring, and the feeder 1 and the feeder 2 through the switches and the CT1, CT3, CT4, and CT5 at the switches, the second bus bar II bus bar is connected to the #2 main transformer, the #2 small power supply wiring, the feeder 3, and the feeder 4 through the switches and the CT2, CT6, CT7, and CT8 at the switches, and the first bus bar I bus bar is connected to the second bus bar II bus bar through the section switch 500 and the CT0 at the section switch 500. The head end of the first bus I bus is also connected with a PT1, and the head end of the second bus II bus is also connected with a PT2.
CT is used for collecting current values of all intervals, and an outflow bus is a positive value, and an inflow bus is a negative value. PT is a voltage value for collecting the bus bar. When any CT of the first bus or the second bus is broken, the subsequent operation of locking is performed, otherwise, the three-phase voltage acquired by the PT is analyzed, when the three-phase voltage acquired by the PT simultaneously meets three conditions, the bus complex voltage corresponding to the PT is open, otherwise, the complex voltage is locked, and the three conditions are as follows:
1. the minimum value of the three-phase voltage is smaller than a first setting value;
2. the three-phase negative sequence voltage value is greater than a second setting value;
3. the three-phase zero-sequence voltage is greater than a third setting value;
the first setting value is generally 40V, the second setting value is generally 6V, and the third setting value is generally 6V.
402. The method comprises the steps that CT sampling values of differential protection access respectively configured on a first bus and a second bus are obtained, wherein the first bus and the second bus are connected through a section switch, and a CT is arranged at the section switch;
it should be noted that, a set of differential protection is distributed and configured on the first bus bar I bus and the second bus bar II bus, and the differential protection of the first bus bar I bus is connected to a sampling value of a CT at an outlet switch of the first bus bar I bus, a sampling value of a CT at a low-change switch of a first main transformer connected to the first bus bar I bus, and a sampling value of a CT at a section switch, that is, the differential protection of the first bus bar I bus is connected to sampling values of CT0, CT1, CT3, CT4, and CT 5; similarly, the differential protection of the second bus bar II is connected to the sampling values of CT0, CT2, CT6, CT7 and CT 8.
403. When the sum of the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the low-voltage switch of the first main transformer connected with the first bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value, starting the differential protection of the first bus;
it should be noted that the differential protection of the first bus bar I bus is connected to sampling values I0, I1, I3, I4, I5 of CT0, CT1, CT3, CT4, CT5, and the differential current Ic1= I0+ I1+ I3+ I4+ I5, and when Ic1> Iz1, that is, the differential current setting value is preset, the differential protection of the first bus bar I bus is started.
When the first bus bar I is free of faults, according to kirchhoff current law, the current flowing into the first bus bar I is equal to the current flowing out of the first bus bar I, namely Ic1=0 and is composed of a plurality of layers of Iz1, and differential protection of the first bus bar I is not started; when the first bus bar I bus bar has a fault, the current values of I0, I1 and I3 which are used as power supply ends are large and all flow into the first bus bar I bus bar, and I4 and I5 which are not used as power supply ends have no current. At this time, when the differential flow Ic1> Iz1, namely the differential flow setting value is preset, the differential protection of the first bus bar I bus is started.
404. When the sum of the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the low-voltage switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value, the differential protection of the second bus is started;
it should be noted that the differential protection of the second bus bar II is connected to the sampling values I0, I2, I6, I7, I8 of CT0, CT2, CT6, CT7, CT8, and the differential current Ic2= I0+ I2+ I6+ I7+ I8, and when Ic2> Iz1, that is, the differential current setting value is preset, the differential protection of the second bus bar II is started.
When the second bus bar II has no fault, according to kirchhoff current law, the current flowing into the second bus bar II is equal to the current flowing out of the second bus bar II, namely Ic2=0 and then is Nz 1, and differential protection of the second bus bar II is not started; when the second bus II bus has a fault, the current values of I0, I2 and I6 which are used as power supply ends are large and all flow into the second bus II bus, and the current of I6 and I7 which are not used as the power supply ends is zero. At this time, when the differential flow Ic2> Iz1, namely the differential flow setting value is preset, the differential protection of the second bus bar II is started.
405. When a first zero-sequence current value of a grounding small-size resistor connected with a first bus is larger than a first preset settable value, the reaching limit duration of the first zero-sequence current value is larger than a second preset settable value, any three-phase current of the first bus is larger than a low-level over-current setting value of the first bus, and a first bus complex voltage lock is opened, the first bus protection is started;
406. when a second zero-sequence current value of the grounding small-size resistor connected with the second bus is larger than a third preset settable value, the reaching limit duration time of the second zero-sequence current value is larger than a fourth preset settable value, any three-phase current of the second bus is larger than a low overcurrent setting value of the second bus, and the second bus complex voltage lock is opened, the second bus protection is started;
it should be noted that this starting mode functions in two ways: 1. make up that differential sensitivity is not enough or wiring abnormity can not start in time and cause the protection to refuse to move. If the single-phase earth fault occurs in the bus range and the current is small, when the setting value is high or the wiring is abnormal and the normal start cannot be realized, when the fault lasts for a period of time and is converted into three-phase moment, the protection can be started without starting to enter a judging execution link! 2. The protection can also rapidly remove faults when the faults (the whole switch cabinet including the bus on the upper part of the cabinet can be burnt out in case of arc striking at the position from the feeder line CT to the cable joint in the switch cabinet) threatening the bus and the feeder line protection rejects. When the feeder line near single-phase fault occurs, the feeder line protection is cut off within setting time, if the zero sequence current generated by grounding is larger than the zero sequence protection fixed value of the feeder line and the duration time is longer than the setting time of the feeder line protection, the feeder line protection still exists, and the feeder line protection is rejected. If the bus bar re-pressing lock is opened, the fault is shown to occur in the near zone. When the phenomenon is converted from a single-phase to a three-phase fault, the section of the bus bar should be cut off quickly at the moment.
407. When the first neutral point voltage of the first bus is greater than the voltage setting value of the first preset bus neutral point, the out-of-limit duration time of the first neutral point voltage is greater than a fifth preset settable value, any three-phase current of the first bus is greater than the low-down overcurrent setting value of the first bus, and the first bus complex voltage lock is opened, the first bus protection is started;
408. when the second neutral point voltage of the second bus is greater than the voltage setting value of the neutral point of the second preset bus, the out-of-limit duration time of the second neutral point voltage is greater than a sixth preset settable value, any three-phase current of the second bus is greater than the low-voltage over-current setting value of the second bus, and the second bus re-voltage lock is opened, the second bus protection is started;
it should be noted that the starting mode is used for being compatible with a system in which a neutral point is not grounded or is grounded through an arc suppression coil, and is complementary and perfect to the former two starting modes.
409. When the differential protection of the first bus or the second bus is started, if the sampling value of the CT at the section switch is greater than the fault current setting value, tripping the section switch in 0 time limit;
when the differential protection of the first bus bar I bus or the second bus bar II bus is started, a fault occurs in a zone representing the first bus bar I bus or the second bus bar II bus. If the sampling value I0 of the CT0 at the sectionalizing switch 500 is greater than the fault current setting value, I0> = Iz2, it indicates that the sectionalizing switch 500 is in the on-position and non-fault bus has the connection power supply end, or the sectionalizing switch 500 is in the off-position and the fault point occurs in the dead zone. At this point, the present protection 0 time limit trips the section switch 500.
410. And if the sampling value of the CT at the position of the low-change switch of the first main transformer is greater than the fault current setting value or the sampling value of the CT at the position of the low-change switch of the second main transformer is greater than the fault current setting value, tripping off the low-change switch of the first main transformer and a first small power supply wiring switch connected with the first bus or tripping off the low-change switch of the second main transformer and a second small power supply wiring switch connected with the second bus after a range time limit.
It should be noted that, after the sectionalizing switch 500 is cut off, if a fault current flows through the CT of the low-level switch of the first main transformer or the CT of the low-level switch of the second main transformer, it indicates that a fault occurs on the bus connected to the low-level switch of the main transformer, and after a very bad time limit, the overcurrent low-level switch and the small power connection switch of the bus where the overcurrent low-level switch is located are tripped. Namely:
(1) If the #1 becomes low and overcurrent (i.e. I1> IZ 2) and the bus voltage of the first bus I is released, the protection trips the #1 low and #1 small power supply wiring switch within 0.3 second;
(2) If #2 goes low and over-current (i.e., I2> IZ 2) and the second bus II busbar is open to return voltage, the protection trips the #2 low and #2 small power connection switch for 0.3 seconds.
411. When the differential protection of a first bus or a second bus is started, if the sampling value of the CT at the section switch is smaller than the fault current setting value, the sampling value of the CT at the low-change switch of the first main transformer is larger than the fault current setting value, and when the first bus is in a re-pressing opening state, the low-change switch of the first main transformer and a first small power supply wiring switch connected with the first bus are tripped at 0 time limit, or the sampling value of the CT at the low-change switch of the second main transformer is larger than the fault current setting value, and when the second bus is in a re-pressing opening state, the low-change switch of the second main transformer and a second small power supply wiring switch connected with the second bus are tripped at 0 time limit;
it should be noted that when the differential protection of the first bus bar I bus or the second bus bar II bus is started, no fault current flows through CT0 at the sectionalizing switch 500, i.e. I0< Iz2, which indicates that the sectionalizing switch 500 is in the open position, or that the sectionalizing switch 500 is in the closed position but the non-fault bus bar is not connected to the power supply terminal. At this time, which low becomes overcurrent and the corresponding bus bar voltage recovery is opened indicates that a fault occurs on the bus bar connected with the low, and the protection 0 time limit trips the low of the overcurrent and the small power switch connected with the bus bar. Namely:
(1) If the #1 becomes low and is over-current (i.e. I1> IZ 2) and the bus I of the first bus is re-pressed and opened, the protection 0 time limit trips the #1 low and #1 small power supply wiring switch;
(2) If #2 goes low and is over-current (i.e. I2> Iz 2), and the second bus bar II bus is open, the protection 0 time limit trips the #2 low and #2 small power connection switch.
Specifically, a control principle logic diagram of the switch cabinet bus rapid protection method provided by the application is shown in fig. 7.
In the embodiment of the application, a method for quickly protecting a bus of a switch cabinet is provided, after a bus fault occurs in a first bus or a second bus and differential protection is started, if a sampling value of a CT (current transformer) at a section switch is greater than a fault current setting value, it is indicated that the section switch is in a closed position and a non-fault bus is connected with a power supply end, or the section switch is in a separated position and a fault occurs in a dead zone, namely, between the section switch and the CT at the section switch, the section switch is tripped at 0 time limit first, if a fault current flows through a low-down switch of the first main transformer or the second main transformer, the fault occurs in the first bus or the second bus connected with the first main transformer or the second main transformer, so that the overcurrent first main transformer or the second main transformer and a small power supply connection switch of the bus are tripped after a pole difference time limit, otherwise, the fault occurs in the dead zone and is already cut off, and the technical problem that the existing bus protection of the switch cabinet is prone to fail or malfunction, even has the dead zone exists is solved.
Referring to fig. 5, fig. 5 is a schematic structural diagram of a bus bar fast protection device of a switch cabinet in an embodiment of the present application, as shown in fig. 5, specifically, the bus bar fast protection device includes:
an obtaining unit 501, configured to obtain CT sampling values of differential protection access respectively configured on a first bus and a second bus, where the first bus and the second bus are connected through a section switch, and the section switch is provided with a CT, the differential protection access of the first bus is connected to a sampling value of a CT at an outlet switch of the first bus, a sampling value of a CT at a change-down switch of a first main transformer connected to the first bus, and a sampling value of a CT at the section switch, and the differential protection access of the second bus is connected to a sampling value of a CT at an outlet switch of the second bus, a sampling value of a CT at a change-down switch of a second main transformer connected to the second bus, and a sampling value of a CT at the section switch;
the first processing unit 502 is configured to, when the differential protection of the first bus or the second bus is started, trip the section switch within 0 time limit if a sampling value of a CT at the section switch is greater than a fault current setting value;
and a second processing unit 503, configured to, after a pole difference time limit, trip off the step-down switch of the first main transformer and the first small power source connection switch connected to the first bus, or trip off the step-down switch of the second main transformer and the second small power source connection switch connected to the second bus, if the sampled value of the CT at the step-down switch of the first main transformer is greater than the fault current setting value, or the sampled value of the CT at the step-down switch of the second main transformer is greater than the fault current setting value.
Further, the method also comprises the following steps:
a third processing unit 504, configured to, when the differential protection of the first bus or the second bus is started, if the sampled value of the CT at the section switch is smaller than the fault current setting value, if the sampled value of the CT at the step-down switch of the first main transformer is greater than the fault current setting value, and when the first bus is open under the recompression, trip off the step-down switch of the first main transformer and the first small power source connection switch connected to the first bus within 0 time limit, or if the sampled value of the CT at the step-down switch of the second main transformer is greater than the fault current setting value, and when the second bus is open under the recompression, trip off the step-down switch of the second main transformer and the second small power source connection switch connected to the second bus within 0 time limit.
Further, the method also comprises the following steps:
a fourth processing unit 505, configured to start the first bus differential protection when a sum of a sampling value of a CT at an outlet switch of the first bus, a sampling value of a CT at a low-level switch of a first main transformer connected to the first bus, and a sampling value of a CT at a section switch is greater than a preset differential flow setting value;
a fifth processing unit 506, configured to start the second bus differential protection when a sum of a sampling value of a CT at the outgoing switch of the second bus, a sampling value of a CT at the low-level switch of the second main transformer connected to the second bus, and a sampling value of a CT at the section switch is greater than a preset differential flow setting value.
Further, the method also comprises the following steps:
a sixth processing unit 507, configured to not perform subsequent operations if the CT configured on the first bus or the second bus is disconnected, otherwise obtain three-phase voltage sampling values of PTs configured on the first bus or the second bus, respectively, and when the three-phase voltage sampling values simultaneously satisfy that the minimum value of the three-phase voltage is smaller than the first setting value, the negative sequence voltage value of the three-phase voltage is greater than the second setting value, and the zero sequence voltage of the three-phase voltage is greater than the third setting value, re-voltage opens the first bus or the second bus, otherwise, re-voltage closes the first bus or the second bus.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
The terms "first," "second," "third," "fourth," and the like (if any) in the description of the present application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
It should be understood that, in this application, "at least one" means one or more, "a plurality" means two or more. "and/or" is used to describe the association relationship of the associated object, indicating that there may be three relationships, for example, "a and/or B" may indicate: only A, only B and both A and B are present, wherein A and B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single item(s) or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in the form of hardware, or may also be implemented in the form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present application.
Claims (8)
1. A method for quickly protecting a bus of a switch cabinet is characterized by comprising the following steps:
the method comprises the steps that CT sampling values of differential protection access configured on a first bus and a second bus respectively are obtained, wherein the first bus and the second bus are connected through a section switch, a CT is arranged at the section switch, the differential protection access of the first bus is connected to the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the step-down switch of a first main transformer connected with the first bus and the sampling value of the CT at the section switch, and the differential protection access of the second bus is connected to the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the step-down switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch;
when the differential protection of the first bus or the second bus is started, if the sampling value of the CT at the section switch is greater than the fault current setting value, the section switch is tripped off in 0 time limit;
if the sampling value of the CT at the position of the low-level switch of the first main transformer is greater than the fault current setting value, or the sampling value of the CT at the position of the low-level switch of the second main transformer is greater than the fault current setting value, tripping off the low-level switch of the first main transformer and a first small power supply wiring switch connected with the first bus, or tripping off the low-level switch of the second main transformer and a second small power supply wiring switch connected with the second bus after a pole difference time limit;
when the sum of the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the low-change switch of the first main transformer connected with the first bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value, starting the first bus differential protection;
and when the sum of the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the low-change switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value, the differential protection of the second bus is started.
2. The method for rapidly protecting the bus bar of the switch cabinet according to claim 1,
when the differential protection of the first bus or the second bus is started, if the sampling value of the CT at the section switch is smaller than the fault current setting value, the sampling value of the CT at the change-down switch of the first main transformer is larger than the fault current setting value, and when the first bus is in a re-pressing opening state, the change-down switch of the first main transformer and a first small power supply wiring switch connected with the first bus are tripped at 0 time limit, or the sampling value of the CT at the change-down switch of the second main transformer is larger than the fault current setting value, and when the second bus is in a re-pressing opening state, the change-down switch of the second main transformer and a second small power supply wiring switch connected with the second bus are tripped at 0 time limit.
3. The method for quickly protecting the bus of the switch cabinet according to claim 1 or 2, wherein each outlet switch of the first bus comprises: the first small power supply wiring switch and the first feeder switch;
each outlet switch of the second bus comprises: the second small power supply wiring switch and the second feeder switch.
4. The method for rapidly protecting the bus of the switch cabinet according to claim 1, wherein before the obtaining the CT sampling values of the differential protection access respectively configured on the first bus and the second bus, the method further comprises:
if the CT configured on the first bus or the second bus is broken, the subsequent operation is not executed, otherwise, three-phase voltage sampling values of PT respectively configured on the first bus or the second bus are obtained, when the three-phase voltage sampling values simultaneously meet the condition that the minimum value of three-phase voltage is smaller than a first setting value, the negative sequence voltage value of three-phase voltage is larger than a second setting value and the zero sequence voltage of three-phase voltage is larger than a third setting value, the first bus or the second bus is opened by complex voltage, and otherwise, the first bus or the second bus is closed by complex voltage.
5. The quick protection method for the bus of the switch cabinet according to claim 1 or 2, characterized in that when a first zero-sequence current value of a grounding small-size resistor connected with the first bus is greater than a first preset setting value, the reaching time duration of the first zero-sequence current value is greater than a second preset setting value, any three-phase current of the first bus is greater than a low-size over-current setting value of the first bus, and the first bus complex voltage lock is opened, the differential protection of the first bus is started;
and when a second zero sequence current value of the grounding small-size resistor connected with the second bus is greater than a third preset setting value, the reaching time duration of the second zero sequence current value is greater than a fourth preset setting value, any three-phase current of the second bus is greater than a low-down over-current setting value of the second bus, and the second bus complex voltage lock is opened, the differential protection of the second bus is started.
6. The method for quickly protecting the bus of the switch cabinet according to claim 1 or 2, wherein when the first neutral point voltage of the first bus is greater than a voltage setting value of a first preset bus neutral point, the out-of-limit duration of the first neutral point voltage is greater than a fifth preset settable value, any three-phase current of the first bus is greater than a low-overcurrent setting value of the first bus, and the first bus complex voltage is locked and unlocked, the differential protection of the first bus is started;
and when the second neutral point voltage of the second bus is greater than the voltage setting value of the neutral point of a second preset bus, the out-of-limit duration time of the second neutral point voltage is greater than a sixth preset settable value, any three-phase current of the second bus is greater than the low-down over-current setting value of the second bus, and the second bus complex voltage lock is opened, the differential protection of the second bus is started.
7. The utility model provides a quick protection device of cubical switchboard generating line which characterized in that includes:
the acquisition unit is used for acquiring CT sampling values of differential protection access configured on a first bus and a second bus respectively, wherein the first bus and the second bus are connected through a section switch, the section switch is provided with a CT, the differential protection of the first bus is accessed into the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the step-down switch of a first main transformer connected with the first bus and the sampling value of the CT at the section switch, and the differential protection of the second bus is accessed into the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the step-down switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch;
the first processing unit is used for tripping the section switch in 0 time limit if a sampling value of a CT (current transformer) at the section switch is greater than a fault current setting value when differential protection of the first bus or the second bus is started;
a second processing unit, configured to, after a very bad time limit, trip off a step-down switch of the first main transformer and a first small power source wiring switch connected to the first bus, or trip off a step-down switch of the second main transformer and a second small power source wiring switch connected to the second bus, if a sampling value of CT at the step-down switch of the first main transformer is greater than the fault current setting value, or a sampling value of CT at the step-down switch of the second main transformer is greater than the fault current setting value;
the fourth processing unit is used for starting the first bus differential protection when the sum of the sampling value of the CT at the outlet switch of the first bus, the sampling value of the CT at the low-change switch of the first main transformer connected with the first bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value;
and the fifth processing unit is used for starting the second bus differential protection when the sum of the sampling value of the CT at the outlet switch of the second bus, the sampling value of the CT at the low-change switch of a second main transformer connected with the second bus and the sampling value of the CT at the section switch is greater than a preset differential flow setting value.
8. The switchgear bus bar quick protection device of claim 7, further comprising:
and the third processing unit is used for jumping off the low-level switch of the first main transformer and a first small power supply wiring switch connected with the first bus within 0 time limit when the differential protection of the first bus or the second bus is started and if the sampling value of the CT at the section switch is smaller than the fault current setting value and the first bus is open in a recompression mode, or jumping off the low-level switch of the second main transformer and a second small power supply wiring switch connected with the second bus within 0 time limit when the sampling value of the CT at the low-level switch of the second main transformer is larger than the fault current setting value and the second bus is open in a recompression mode.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106505529A (en) * | 2016-11-09 | 2017-03-15 | 国网辽宁省电力有限公司鞍山供电公司 | A kind of intelligent substation low-voltage bus bar guard method |
| CN108134376A (en) * | 2018-01-03 | 2018-06-08 | 广东电网有限责任公司揭阳供电局 | High-voltage bus fault rapid protection device and protection method |
| JP2019004661A (en) * | 2017-06-19 | 2019-01-10 | 富士電機株式会社 | Bus protection device |
| CN109713648A (en) * | 2018-09-18 | 2019-05-03 | 国网江苏省电力有限公司镇江供电分公司 | Quickly cut off the relay protecting method of imperfect internal bridge dead-zone fault |
| CN109861180A (en) * | 2019-04-02 | 2019-06-07 | 国网江苏省电力有限公司镇江供电分公司 | Anti- section switch dead-zone fault bus differential protection is latched prepared auto restart guard method |
| JP2019165569A (en) * | 2018-03-20 | 2019-09-26 | 三菱電機株式会社 | Failure determination device and protective relay device |
| CN111092413A (en) * | 2019-11-28 | 2020-05-01 | 国电南瑞科技股份有限公司 | Relay protection method and device for rapidly removing fault of empty charge in dead zone of transformer |
-
2020
- 2020-08-04 CN CN202010773389.9A patent/CN111786363B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106505529A (en) * | 2016-11-09 | 2017-03-15 | 国网辽宁省电力有限公司鞍山供电公司 | A kind of intelligent substation low-voltage bus bar guard method |
| JP2019004661A (en) * | 2017-06-19 | 2019-01-10 | 富士電機株式会社 | Bus protection device |
| CN108134376A (en) * | 2018-01-03 | 2018-06-08 | 广东电网有限责任公司揭阳供电局 | High-voltage bus fault rapid protection device and protection method |
| JP2019165569A (en) * | 2018-03-20 | 2019-09-26 | 三菱電機株式会社 | Failure determination device and protective relay device |
| CN109713648A (en) * | 2018-09-18 | 2019-05-03 | 国网江苏省电力有限公司镇江供电分公司 | Quickly cut off the relay protecting method of imperfect internal bridge dead-zone fault |
| CN109861180A (en) * | 2019-04-02 | 2019-06-07 | 国网江苏省电力有限公司镇江供电分公司 | Anti- section switch dead-zone fault bus differential protection is latched prepared auto restart guard method |
| CN111092413A (en) * | 2019-11-28 | 2020-05-01 | 国电南瑞科技股份有限公司 | Relay protection method and device for rapidly removing fault of empty charge in dead zone of transformer |
Non-Patent Citations (1)
| Title |
|---|
| 一种基于柜式母线故障特性的中低压母线精准保护;黎高程 等;《电力系统保护与控制》;电力系统保护与控制;20190902;第47卷(第17期);第156-162页 * |
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