CN111478298A - Single-pole ground fault protection method for four-rail traction power supply system - Google Patents

Single-pole ground fault protection method for four-rail traction power supply system Download PDF

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CN111478298A
CN111478298A CN202010438913.7A CN202010438913A CN111478298A CN 111478298 A CN111478298 A CN 111478298A CN 202010438913 A CN202010438913 A CN 202010438913A CN 111478298 A CN111478298 A CN 111478298A
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current
voltage
fault
set3
pole
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CN111478298B (en
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韩正庆
左光耀
刘淑萍
沈睿
韦晓广
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Southwest Jiaotong University
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Southwest Jiaotong University
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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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors

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  • General Physics & Mathematics (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Abstract

A single-pole earth fault protection method for a four-rail traction power supply system comprises the following steps: detecting the voltage to ground of the anode and the voltage to ground of the cathode of each substation, judging that the system has a fault of the cathode or the anode to ground, and closing the one-way conduction device of the anode or the cathode; calculating a differential current for each segment; and cutting off a section of which the differential current is greater than the current setting value. The method also comprises the steps of judging the disconnection of the current sensor and locking protection, and judging the disconnection of the voltage sensor and locking the one-way conduction device. The invention can reliably judge the positive pole ground fault and the negative pole ground fault, so that the non-fault pole one-way conduction devices of all substations form a fault loop; the circuit breakers at two sides of a fault section can reliably act to remove faults, and a non-fault section can reliably not act; the current sensor disconnection criterion can reliably avoid protection misoperation caused by the current sensor disconnection; the disconnection criterion of the voltage sensor can reliably avoid the malfunction of the one-way conduction device caused by the disconnection of the voltage sensor.

Description

Single-pole ground fault protection method for four-rail traction power supply system
Technical Field
The invention relates to the technical field of subway traction power supply systems, in particular to a single-pole ground fault protection method for a four-rail traction power supply system.
Background
The four-rail traction power supply system adopts the special backflow rail backflow, eliminates stray current from the root and has wide development prospect in the subway field. The four-rail traction power supply system is a symmetrical suspension system, and the single-pole earth fault (including a positive earth fault or a negative earth fault) and the relay protection method thereof must be considered. Otherwise, if the first pole-to-ground fault cannot be found and removed as early as possible, a more serious pole-to-pole fault may be caused, so that the safety and reliability of the power supply of the subway are not good.
The existing relay protection technology of the four-rail traction power supply system realizes single-pole ground fault detection by accessing the one-way conduction device. However, the existing technology has two problems: (1) only positive earth faults can be detected; (2) when the four-rail traction power supply system comprises three or more substations, the currents flowing through the unidirectional conduction devices are close to each other and are difficult to distinguish, so that the plurality of substations are tripped, the protection method is not selective, and the power failure range is expanded.
Disclosure of Invention
The invention discloses a single-pole ground fault protection method for a four-rail traction power supply system, which can distinguish a positive pole ground fault from a negative pole ground fault, realize reliable protection on the single-pole ground fault and accurately distinguish a fault section. The invention also discloses a current sensor disconnection detection method and a voltage sensor disconnection detection method, so that incorrect protection action caused by sensor disconnection is prevented.
The technical scheme for realizing the purpose of the invention is as follows:
a single-pole earth fault protection method for a four-rail traction power supply system comprises
The method comprises the following steps: detecting the voltage U of the anode to the ground of each substation+And negative voltage to ground U-(ii) a If | U+|<Uset1And | U+-U-|>Uset2Then delay the wholeTiming Tset1Then closing the negative one-way conduction device; if | U-|<Uset1And | U+-U-|>Uset2Delay the setting time Tset1Then closing the positive one-way conduction device; wherein, Uset1Is a first voltage setting value, Uset2Setting a second voltage value;
step two: calculating the differential current I of each segmentd，
Id＝|IM+IN|；
Wherein, IMFor fault currents to earth of a single pole on the left side of the section, INA unipolar to ground fault current to the right of the segment;
if the positive direction of the current is that the positive pole points to the circuit from the bus and the negative pole points to the bus from the circuit, then
IM＝IM+-IM-，
IN＝IN+-IN-；
If the positive direction of the current is that the positive pole and the negative pole are both directed to the circuit from the bus, then
IM＝IM++IM-，
IN＝IN++IN-；
In the formula IM+Positive line current on the left side of the segment, IM-Negative line current on the left side of the segment, IN+Is the positive line current on the right side of the segment, IN-Negative line current to the right of the segment;
step three: if a sector Id＞Iset1Delay the setting time Tset2Then cutting off the section; wherein, Iset1Is the first current setting value.
Further, before the first step, the method further comprises a step of determining disconnection of the current sensor and a step of locking protection, specifically:
detecting the voltage U of the anode to the ground of each substation+And negative voltage to ground U-And the current I of the positive feeder u of each feed loop of the substationuAnd the current I of the negative feed line ww；
If any one of the power substations is changed,
|U+|>Uset3、|U-|>Uset3、|Iu|＜|Iwi and Iu|-|Iw||＞Iset2If so, delaying the setting time Tset3Then, judging that the current sensor of the positive feeder u of the substation is broken, and carrying out locking protection;
or any one of the power substations can be used,
|U+|>Uset3、|U-|>Uset3、|Iw|＜|Iui and Iu|-|Iw||＞Iset2If so, delaying the setting time Tset3Then, judging that the current sensor of the negative feeder line w of the substation is broken, and carrying out locking protection;
wherein, Iset2Is a second current setting value, Uset3And the third voltage setting value is obtained.
Further, before the first step, the method further comprises a step of determining disconnection of the voltage sensor and locking the input unidirectional conduction device, specifically: detecting the voltage U of the anode to the ground of each substation+And negative voltage to ground U-；
If any one of the power substations is changed,
|U+|<Uset3and U isset3＜|U-|<Uset4If so, delaying the setting time Tset4Then, judging that the positive voltage sensor of the substation is broken, and locking and putting the unidirectional conduction device;
or any one of the power substations can be used,
|U-|<Uset3and U isset3＜|U+|<Uset4If so, delaying the setting time Tset4Then, judging that the negative voltage sensor of the transformer station is broken, and locking the input one-way conduction device;
wherein, Uset3Is a third voltage setting value, Uset4And the fourth voltage setting value is obtained.
The beneficial effect of the invention is that,
(1) the invention can reliably judge the positive pole ground fault and the negative pole ground fault, so that the non-fault pole one-way conduction devices of all substations form a fault loop;
(2) the protection method can ensure that the circuit breakers at two sides of the fault section reliably act to remove the fault, and the non-fault section reliably does not act;
(3) the current sensor disconnection criterion can reliably avoid protection misoperation caused by current sensor disconnection;
(4) the voltage sensor disconnection criterion can reliably avoid malfunction of the one-way conduction device caused by disconnection of the voltage sensor.
Drawings
Fig. 1 is a schematic diagram of the positive unidirectional conducting device connected to a positive busbar.
Fig. 2 is a schematic diagram of the negative unidirectional conduction device connected to the negative busbar.
FIG. 3 is a functional block diagram of positive ground fault determination.
FIG. 4 is a functional block diagram of a negative earth fault determination.
Fig. 5 is a schematic diagram of a positive-to-ground fault current distribution.
Fig. 6 is a schematic diagram of a negative-to-ground fault current distribution.
Fig. 7 is a schematic block diagram of a single pole-to-ground fault current differential protection.
Fig. 8 is a feed line current diagram for a substation.
FIG. 9 is a schematic block diagram of feeder u-current sensor disconnection determination.
Fig. 10 is a schematic block diagram of a feeder line w current sensor disconnection determination.
Fig. 11 is a functional block diagram of feeder s-current sensor disconnection determination.
Fig. 12 is a schematic block diagram of feeder line v current sensor disconnection determination.
Fig. 13 is a schematic block diagram of the positive electrode voltage sensor disconnection determination.
Fig. 14 is a schematic block diagram of the negative voltage sensor disconnection determination.
Fig. 15 is a schematic of a positive-to-ground fault.
Fig. 16 is a schematic of a negative-to-ground fault.
Fig. 17 is a schematic diagram of a disconnection fault of the current sensor CT 1.
Fig. 18 is a schematic diagram of a disconnection fault of the current sensor CT 2.
Fig. 19 is a schematic diagram of a disconnection fault of the current sensor CT 3.
Fig. 20 is a schematic diagram of a disconnection fault of the current sensor CT 4.
FIG. 21 is a schematic diagram of a disconnection fault of the voltage sensor PT 1.
FIG. 22 is a schematic diagram of a disconnection fault of the voltage sensor PT 2.
Detailed Description
The technical scheme of the invention is further explained by combining the drawings and the specific embodiment.
1. One-way conduction device access scheme
The unidirectional conducting device mainly comprises an adjustable resistor and a diode. The installation opposite direction of the diode built-in of the positive pole unidirectional conduction device and the negative pole unidirectional conduction device is opposite, and in order to prevent the positive pole and the negative pole of the substation from being simultaneously connected into the unidirectional conduction device to cause the unidirectional conduction device to always have current, the unidirectional conduction device adopts the following connection scheme: (1) when the traction power supply system normally operates, the one-way conduction devices of the positive electrode busbar and the negative electrode busbar of each traction substation are not connected; (2) when the system has a negative pole-to-ground fault, each traction station protection device determines a negative pole fault through a fault pole determination method, and controls the positive pole one-way conduction device to be connected into the positive pole busbar, as shown in fig. 1; (3) when the system has a positive-electrode ground fault, each traction station protection device determines the positive-electrode fault through a fault-electrode judgment method, and controls the negative-electrode unidirectional conduction device to be connected into the negative-electrode busbar, as shown in fig. 2.
2. Method for determining fault pole
When the four-rail direct-current power supply system normally operates, the positive electrode and the negative electrode are well insulated from the ground, the whole system is a symmetrical suspension system, and the voltage of the positive electrode to the ground is approximately equal to that of the negative electrode to the ground. When the positive pole-to-ground fault occurs, the voltage of the positive pole of each substation is obviously reduced, the voltage of the negative pole is correspondingly increased, and the voltage between the positive pole and the negative pole is basically unchanged. Therefore, a schematic block diagram of the positive-electrode-to-ground fault determination is proposed as shown in fig. 3. When the negative pole is in fault to the ground, the voltage of the negative pole of the substation is obviously reduced, the voltage of the positive pole is correspondingly increased, and the voltage between the positive pole and the negative pole is basically unchanged. Therefore, a functional block diagram of a negative-pole ground fault determination is presented as shown in fig. 4.
In FIGS. 3 and 4, U+、U-Respectively representing the voltage of a positive electrode to ground and the voltage of a negative electrode to ground; u shapeset1、Uset2Respectively representing voltage setting values; t isset1And the delay setting time for closing the switch of the unidirectional conducting device is shown.
Uset1And Uset2The setting calculation formula is as follows:
Uset1＝krelUm.max(1)
Uset2＝Un.min/krel(2)
in the formula, krelIs a reliability factor; u shapem.maxThe voltage of the maximum monopole earth when the monopole earth fault occurs; u shapen.minAnd the minimum operation voltage is provided for the traction power supply system.
3. Single-pole earth fault protection method
When a single-pole ground fault occurs, a non-fault-pole one-way conduction device is connected to form a fault loop, the current distribution relation of the fault circuit is further analyzed, and a single-pole ground fault protection method is provided for distinguishing a fault section from a non-fault section.
(1) Current distribution of positive to ground fault
The four-rail traction power supply system formed by N +1 substations comprises N power supply sections. When the positive pole ground fault occurs in the section i, the protection devices of the substations determine that the positive pole ground fault occurs in the system according to fig. 3, so that the negative unidirectional conducting device is connected to the negative busbar to form a fault loop, and the current distribution diagram of the power supply system is shown in fig. 5. In FIG. 5, the other sections except for section (I-1), section I, and section (I +1) are not shown, and IMk+、INk+N denotes the positive line current on both sides of the segment k, IMk-、INk-N denotes the negative line current on both sides of the section k, IfIndicating fault current, Rk1、Rk2、Rk3、Rk4、Rk5N denotes the impedance of each segment, RckN denotes a locomotive equivalent impedance, RfTransition resistance, U, indicating a point of failurekAnd (k 1.. N +1) represents an equivalent power supply of each substation.
According to kirchhoff's current law, the current relationship of each segment can be calculated respectively.
The current relationship for fault section i is:
IMi++INi+＝IMi-+INi-+If(3)
finishing to obtain:
(IMi+-IMi-)+(INi+-INi-)＝If(4)
for a non-faulty section k (k 1.., i-1, i + 1.. N), the current relationship is:
IMk++INk+＝IMk-+INk-(5)
finishing to obtain:
(IMk+-IMk-)+(INk+-INk-)＝0 (6)
(2) current distribution of negative pole to ground fault
When the negative pole ground fault occurs in the section i, the protection devices of the substations determine that the system has the negative pole ground fault according to fig. 4, so that the positive unidirectional conducting device is connected to the positive busbar to form a fault loop, and the current distribution diagram of the power supply system is shown in fig. 6. And respectively calculating the current relation of each section according to the kirchhoff current law. For the fault section i, the current relationship is consistent with equation (4). For the non-faulty section k (k 1.., i-1, i + 1.. N), the current relationship is consistent with equation (6).
In summary, whether a positive pole-to-ground fault or a negative pole-to-ground fault occurs, the equations (4) and (6) can be used to distinguish between the faulty section and the non-faulty section. Therefore, by representing M and N on either side of the segment, the unipolar to ground fault current on either side can be represented by:
(1) if the positive direction of the current is that the positive pole points to the circuit from the bus and the negative pole points to the bus from the circuit, the fault current of the single poles at the two sides to the ground is
IM＝IM+-IM-(7)
IN＝IN+-IN-(8)
(2) If the positive direction of the current is that the positive pole and the negative pole point to the circuit from the bus, the fault current of the single poles at the two sides to the ground is
IM＝IM++IM-(9)
IN＝IN++IN-(10)
Differential current I of a segmentdCan be expressed as:
Id＝|IM+IN| (11)
a schematic block diagram of the unipolar-to-ground fault current differential protection is shown in fig. 7, taking into account the effects of unbalanced currents due to current sensor measurement errors. In the figure, Iset1Setting the action current setting value according to the maximum unbalanced current under various conditions; t isset2And representing the protection delay setting time.
4. Current sensor disconnection criterion
When the current sensor is disconnected during normal operation of the system, the problem that the current of the positive feeder line and the current of the negative feeder line are unequal in magnitude also exists. In order to avoid current differential protection misoperation caused by disconnection of the current sensor, disconnection criterion locking protection of the current sensor needs to be provided.
The feeder current diagram for a single substation is shown in figure 8. And respectively naming the four feeders of the substation as a feeder s, a feeder u, a feeder v and a feeder w. The feeder u and the feeder w are positive and negative feeders of the same loop, and the feeder s and the feeder v are the same.
When the current sensor is disconnected, the currents of the positive feeder line and the negative feeder line are not equal, but the positive feeder line and the negative feeder line are symmetrical to the ground voltage. Therefore, the principle of the current sensor disconnection determination is proposed as shown in fig. 9 to 12.
In the figure, Iu、Iw、Is、IvRespectively representing the measured currents of the feeders u, w, s and v; i isset2Indicating a current setting value according to not more than Iset1Setting; u shapeset3Indicating voltage setting value, and taking Uset2Half of (1); t isset3And indicating the disconnection alarm delay of the current sensor.
5. Voltage sensor disconnection self-checking method
When the system normally operates and the voltage sensor has a disconnection fault, the voltage of the disconnection pole also drops. In order to avoid the condition that the unidirectional conduction device on the other pole is closed by mistake, a voltage sensor disconnection criterion is required to be put into the unidirectional conduction device in a locking mode.
When the system has a single-pole ground fault, the voltage of the fault electrode is reduced, meanwhile, the voltage of the non-fault electrode is increased, and the voltage between the positive electrode and the negative electrode is kept stable. And when the voltage sensor of a certain stage has a disconnection fault, the other voltage keeps stable. Therefore, a schematic diagram for determining disconnection of the positive electrode voltage sensor and the negative electrode voltage sensor is proposed as shown in fig. 13 and 14.
In the figure, Uset4And representing a voltage setting value.
Uset4The setting calculation formula is as follows:
Uset4＝krelUn.max/2 (12)
in the formula, krelIs a reliability factor; u shapen.maxThe maximum operation voltage of the traction power supply system is provided.
Voltage setting value Uset1、Uset2、Uset3、Uset4And current setting value Iset1、Iset2And can also be determined according to the specific situation of the four-rail traction power supply system.
The specific embodiment is as follows: taking a DC1500V subway four-rail traction power supply system as an example, four cases of positive pole ground fault, negative pole ground fault, current sensor disconnection and voltage sensor disconnection are respectively explained by combining with a schematic diagram.
1. Positive pole to ground fault
Taking five substations as an example, the power supply sections from the substation a to the substation E are sequentially divided into sections one to four from left to right. At some point in segment two, a positive-to-ground fault occurs. According to the fault pole judgment method provided by the invention, the positive pole-to-ground fault criterion is | U+|＜Uset1，|U+-U-|＞Uset2Satisfy the delay Tset1Then, the protection system determines that the fault type is a positive-electrode-to-ground fault, and each traction-controlled negative unidirectional conduction device is connected to a negative busbar, as shown in fig. 15.
After the negative one-way conduction device of each substation is connected with the negative busbar, according to the current differential protection method provided by the invention, the protection system calculates the differential current I of each sectiondThe differential current I of each sectiondAnd protection of the starting current Iset1Comparing, the second section meets the criterion I of positive pole to earth faultd＞Iset1Satisfy the delay Tset2Then, the second protection determination section has a positive-to-ground fault, and the second protection determination section is cut off.
2. Negative pole to ground fault
And a negative pole-to-ground fault occurs at a certain point in the third section at a certain moment. According to the fault pole judgment method provided by the invention, the negative pole-to-ground fault criterion is | U-|＜Uset1，|U+-U-|＞Uset2Satisfy the delay Tset1Then, the protection system determines that the fault type is a negative-electrode-to-ground fault, and each traction-controlled positive unidirectional conduction device is connected to a positive busbar, as shown in fig. 16.
When the positive one-way conduction device of each substation is connected with the positive busbar, according to the current differential protection method provided by the invention, the protection system calculates the differential current I of each sectiondThe differential current I of each sectiondAnd protection of the starting current Iset1Comparing, the third section meets the criterion I of negative pole-to-ground faultd＞Iset1Satisfy the delay Tset2Then, the third protection determination section has a negative-pole-to-ground fault, and the third protection determination section cuts off the section.
3. Current sensor broken wire
The current sensors of the four feeders of the substation C are named CT1, CT2, CT3 and CT4, respectively. The CT1 and CT3 measure the positive and negative feeder currents of the same loop, and the CT2 and CT4 are similar.
(1) Current sensor CT1 disconnection
Current sensor CT1 disconnection fault indicatorIntended as shown in fig. 17. At some point the current sensor CT1 has a disconnection fault. According to the current sensor disconnection self-checking method provided by the invention, the disconnection criterion of the CT1 is | U+|＞Uset3，|U-|＞Uset3，|I31|＜|I33I and I31-I33|＞Iset2Satisfy the delay Tset3Thereafter, the protection decision CT1 has a disconnection fault, and the system locks the protection and sends out an alarm signal.
(2) Current sensor CT2 disconnection
The schematic diagram of the disconnection fault of the current sensor CT2 is shown in fig. 18. At some point the current sensor CT2 has a disconnection fault. According to the current sensor disconnection self-checking method provided by the invention, the disconnection criterion of the CT2 is | U+|＞Uset3，|U-|＞Uset3，|I32|＜|I34I and I32-I34|＞Iset2Satisfy the delay Tset3Thereafter, the protection decision CT2 has a disconnection fault, and the system locks the protection and sends out an alarm signal.
(3) Current sensor CT3 disconnection
The schematic diagram of the disconnection fault of the current sensor CT3 is shown in fig. 19. At some point the current sensor CT3 has a disconnection fault. According to the current sensor disconnection self-checking method provided by the invention, the disconnection criterion of the CT3 is | U+|＞Uset3，|U-|＞Uset3，|I33|＜|I31I and I31-I33|＞Iset2Satisfy the delay Tset3Thereafter, the protection decision CT3 has a disconnection fault, and the system locks the protection and sends out an alarm signal.
(4) Current sensor CT4 disconnection
The schematic diagram of the disconnection fault of the current sensor CT4 is shown in fig. 20. At some point the current sensor CT4 has a disconnection fault. According to the current sensor disconnection self-checking method provided by the invention, the disconnection criterion of the CT4 is | U+|＞Uset3，|U-|＞Uset3，|I34|＜|I32I and I32-I34|＞Iset2Satisfy the delay Tset3After that, protectAnd the protection judges that the CT4 has a disconnection fault, and the system locks the protection and sends out an alarm signal.
4. Voltage sensor disconnection
The voltage sensors of the positive pole and the negative pole of the substation C are named PT1 and PT2 respectively. Under normal conditions, the voltage of the positive electrode and the voltage of the negative electrode of the traction substation are equal in magnitude, and when a voltage sensor at a certain stage breaks down, the voltage of the other electrode is kept stable.
(1) Voltage sensor PT1 disconnection
The schematic diagram of the disconnection fault of the voltage sensor PT1 is shown in fig. 21. At some point, the voltage sensor PT1 has a disconnection fault. According to the self-checking method for the disconnection of the voltage sensor, provided by the invention, the PT1 disconnection criterion is | U+|＜Uset3，Uset3＜|U-|＜Uset4Satisfy the delay Tset4And then, the protection judges that the PT1 has a disconnection fault, and the system locks and puts into a one-way conduction device and sends out an alarm signal.
(2) Voltage sensor PT2 disconnection
The schematic diagram of the disconnection fault of the voltage sensor PT2 is shown in fig. 22. At some point, the voltage sensor PT2 has a disconnection fault. According to the self-checking method for the disconnection of the voltage sensor, provided by the invention, the PT2 disconnection criterion is | U-|＜Uset3，Uset3＜|U+|＜Uset4Satisfy the delay Tset4And then, the protection judges that the PT2 has a disconnection fault, and the system locks and puts into a one-way conduction device and sends out an alarm signal.

Claims (3)

1. A single-pole earth fault protection method for a four-rail traction power supply system is characterized by comprising the following steps
The method comprises the following steps: detecting the voltage U of the anode to the ground of each substation+And negative voltage to ground U-(ii) a If | U+|<Uset1And | U+-U-|>Uset2Delay the setting time Tset1Then closing the negative one-way conduction device; if | U-|<Uset1And | U+-U-|>Uset2Delay the setting time Tset1After that, the air conditioner is started to work,closing the anode one-way conduction device; wherein, Uset1Is a first voltage setting value, Uset2Setting a second voltage value;
step two: calculating the differential current I of each segmentd，
Id＝|IM+IN|；
Wherein, IMFor fault currents to earth of a single pole on the left side of the section, INA unipolar to ground fault current to the right of the segment;
if the positive direction of the current is that the positive pole points to the circuit from the bus and the negative pole points to the bus from the circuit, then
IM＝IM+-IM-，
IN＝IN+-IN-；
If the positive direction of the current is that the positive pole and the negative pole are both directed to the circuit from the bus, then
IM＝IM++IM-，
IN＝IN++IN-；
In the formula IM+Positive line current on the left side of the segment, IM-Negative line current on the left side of the segment, IN+Is the positive line current on the right side of the segment, IN-Negative line current to the right of the segment;
step three: if a sector Id＞Iset1Delay the setting time Tset2Then cutting off the section; wherein, Iset1Is the first current setting value.
2. The single-pole ground fault protection method of the four-rail traction power supply system according to claim 1, wherein before the first step, the method further comprises a step of current sensor disconnection determination and lockout protection, and specifically comprises the steps of:
detecting the voltage U of the anode to the ground of each substation+And negative voltage to ground U-And the current I of the positive feeder u of each feed loop of the substationuAnd the current I of the negative feed line ww；
If any one of the power substations is changed,
|U+|>Uset3、|U-|>Uset3、|Iu|＜|Iwi and Iu|-|Iw||＞Iset2If so, delaying the setting time Tset3Then, judging that the current sensor of the positive feeder u of the substation is broken, and carrying out locking protection;
or any one of the power substations can be used,
|U+|>Uset3、|U-|>Uset3、|Iw|＜|Iui and Iu|-|Iw||＞Iset2If so, delaying the setting time Tset3Then, judging that the current sensor of the negative feeder line w of the substation is broken, and carrying out locking protection;
wherein, Iset2Is a second current setting value, Uset3And the third voltage setting value is obtained.
3. The single-pole ground fault protection method of the four-rail traction power supply system according to claim 1, wherein before the first step, the method further comprises a step of determining disconnection of the voltage sensor and locking the one-way conduction device, specifically:
detecting the voltage U of the anode to the ground of each substation+And negative voltage to ground U-；
If any one of the power substations is changed,
|U+|<Uset3and U isset3＜|U-|<Uset4If so, delaying the setting time Tset4Then, judging that the positive voltage sensor of the substation is broken, and locking and putting the unidirectional conduction device;
or any one of the power substations can be used,
|U-|<Uset3and U isset3＜|U+|<Uset4If so, delaying the setting time Tset4Then, judging that the negative voltage sensor of the transformer station is broken, and locking the input one-way conduction device;
wherein, Uset3Is a third voltage setting value, Uset4Is a fourth voltage setting value。
CN202010438913.7A 2020-05-22 2020-05-22 Single-pole ground fault protection method for four-rail traction power supply system Active CN111478298B (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116073341A (en) * 2023-01-13 2023-05-05 天津保富电气有限公司 Method for judging positive pole ground short circuit fault interval of subway special rail reflux power supply system
CN116073341B (en) * 2023-01-13 2024-06-04 天津保富电气有限公司 Method for judging positive pole ground short circuit fault interval of subway special rail reflux power supply system

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4725914A (en) * 1986-12-16 1988-02-16 Westinghouse Electric Corp. Protective relay system for performing selective-pole trip determination
CN103901315A (en) * 2014-04-21 2014-07-02 阳光电源股份有限公司 Monopole grounding system and device and method for grounding protection and fault monitoring
CN105375451A (en) * 2015-12-21 2016-03-02 上海交通大学 MMC-HVDC DC line single-pole grounding fault protection method based on current waveform recognition
CN107064734A (en) * 2017-03-17 2017-08-18 北京交通大学 A kind of flexible direct current Fault Location for Distribution Network method of utilization fault transient process
CN108196162A (en) * 2017-10-17 2018-06-22 西安科技大学 The DC distribution net monopolar grounding fault wireline inspection method of model and parameters identification
CN109142942A (en) * 2017-07-06 2019-01-04 天津中铁电气化设计研究院有限公司 A kind of power supply system Traction networks that positive and negative anodes insulate leakage monitoring system over the ground

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4725914A (en) * 1986-12-16 1988-02-16 Westinghouse Electric Corp. Protective relay system for performing selective-pole trip determination
CN103901315A (en) * 2014-04-21 2014-07-02 阳光电源股份有限公司 Monopole grounding system and device and method for grounding protection and fault monitoring
CN105375451A (en) * 2015-12-21 2016-03-02 上海交通大学 MMC-HVDC DC line single-pole grounding fault protection method based on current waveform recognition
CN107064734A (en) * 2017-03-17 2017-08-18 北京交通大学 A kind of flexible direct current Fault Location for Distribution Network method of utilization fault transient process
CN109142942A (en) * 2017-07-06 2019-01-04 天津中铁电气化设计研究院有限公司 A kind of power supply system Traction networks that positive and negative anodes insulate leakage monitoring system over the ground
CN108196162A (en) * 2017-10-17 2018-06-22 西安科技大学 The DC distribution net monopolar grounding fault wireline inspection method of model and parameters identification

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
韩正庆等: "一种电压互感器断线新判据", 《中国铁道科学》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116073341A (en) * 2023-01-13 2023-05-05 天津保富电气有限公司 Method for judging positive pole ground short circuit fault interval of subway special rail reflux power supply system
CN116073341B (en) * 2023-01-13 2024-06-04 天津保富电气有限公司 Method for judging positive pole ground short circuit fault interval of subway special rail reflux power supply system

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