CN111624507B - Accurate positioning device and method for storage battery ground fault of direct-current power supply system - Google Patents
Accurate positioning device and method for storage battery ground fault of direct-current power supply system Download PDFInfo
- Publication number
- CN111624507B CN111624507B CN202010695447.0A CN202010695447A CN111624507B CN 111624507 B CN111624507 B CN 111624507B CN 202010695447 A CN202010695447 A CN 202010695447A CN 111624507 B CN111624507 B CN 111624507B
- Authority
- CN
- China
- Prior art keywords
- ground
- storage battery
- grounding
- bus
- power supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 17
- 238000009413 insulation Methods 0.000 claims abstract description 47
- 238000012806 monitoring device Methods 0.000 claims abstract description 17
- 238000012544 monitoring process Methods 0.000 claims abstract description 12
- 238000004364 calculation method Methods 0.000 claims description 10
- 238000012360 testing method Methods 0.000 claims description 8
- 238000005259 measurement Methods 0.000 claims description 5
- 230000001105 regulatory effect Effects 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000004088 simulation Methods 0.000 description 5
- 238000012423 maintenance Methods 0.000 description 4
- 230000007547 defect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Classifications
-
- 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
- G01R31/40—Testing power supplies
-
- 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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
-
- 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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The invention relates to a device and a method for accurately positioning a storage battery ground fault of a direct current power supply system, which belong to the technical field of insulation monitoring of the direct current power supply system and solve the problems that: the device and the method for accurately positioning the grounding fault of the storage battery of the station direct-current power supply system are provided; the technical scheme adopted is as follows: accurate positioner of direct current power supply system battery ground fault includes: insulation monitoring device and branch line selection CT; the insulation monitoring device includes: a balancing bridge and a switching bridge; the balance bridge consists of two resistors R 1 and R 4 with equal resistance values; the resistor R 1 is connected between the positive bus of the direct-current power supply system and the ground potential, and the resistor R 4 is connected between the negative bus of the direct-current power supply system and the ground potential; the switching bridge consists of a potentiometer R 2, a potentiometer R 3, a switching switch K 1 and a switching switch K 2.
Description
Technical Field
The invention relates to a device and a method for accurately positioning a grounding fault of a storage battery of a direct-current power supply system, belonging to the technical field of insulation monitoring of the direct-current power supply system.
Background
The station direct current power supply system provides uninterrupted power for important equipment and facilities such as protection equipment, communication equipment, breaker operating mechanism and the like of the transformer substation, and is an important component for guaranteeing safe and stable operation of the transformer substation and the power system. However, monitoring of battery ground faults, particularly two-point ground faults, has been a difficult problem for operators and equipment manufacturers. The two-point grounding of the storage battery can cause internal short circuit of the battery, the protection electric appliance of the direct current power supply system can not work, and serious accidents such as fire disaster and the like are likely to be caused, but the monitoring for the two-point grounding faults of the storage battery is still a dead zone for insulating monitoring of the direct current power supply system. In recent years, a plurality of accidents such as fire of a storage battery, power loss of a direct current bus and the like caused by insulation faults of the storage battery occur in a transformer substation, and great loss is brought to a power grid enterprise.
The existing monitoring device and method can judge that the whole storage battery has the grounding faults, but cannot realize the accurate positioning of the two-point grounding faults of the storage battery and the accurate measurement of the grounding resistance. The existing monitoring method is mainly used for positioning the grounding fault of the storage battery and calculating the grounding resistance through the voltage offset of the balance bridge of the insulation monitoring device, but the method is only suitable for one-point grounding fault of the storage battery, and when the second-point grounding fault occurs to the storage battery, the method cannot be used for positioning and calculating the two-point grounding positions and the grounding resistance respectively. If the storage battery ground fault, particularly the two-point ground fault, cannot be accurately positioned and the ground resistance cannot be accurately calculated, a plurality of difficulties are brought to the operation and maintenance of the direct current power supply system, and the small fault can not be processed in time and can be developed into a large fault, so that the safe and stable operation of the transformer substation and the power system is affected. Therefore, research and application of the related technology for accurately positioning the grounding fault of the storage battery are carried out, the early insulation fault of the storage battery can be found and accurately judged, timely elimination of defects by operation and maintenance staff is facilitated, and the power supply reliability of a transformer substation and a power system is improved.
Disclosure of Invention
The invention overcomes the defects existing in the prior art, and aims to solve the technical problems that: the device and the method for accurately positioning the grounding fault of the storage battery of the station direct-current power supply system are provided.
To solve the technical problems: the technical scheme adopted by the invention is as follows: the accurate positioning device and method for the grounding fault of the storage battery of the direct-current power supply system comprise the following steps: insulation monitoring device and branch line selection CT; the insulation monitoring device includes: a balancing bridge and a switching bridge;
The balance bridge consists of two resistors R 1 and R 4 with equal resistance values; the resistor R 1 is connected between the positive bus of the direct-current power supply system and the ground potential, and the resistor R 4 is connected between the negative bus of the direct-current power supply system and the ground potential;
The switching bridge consists of a potentiometer R 2, a potentiometer R 3, a switching switch K 1 and a switching switch K 2, wherein the potentiometer R 2 is connected in series with the switching switch K 1 and then is connected between a positive bus of the direct-current power supply system and the ground potential, and the potentiometer R 3 is connected in series with the switching switch K 2 and then is connected between a negative bus of the direct-current power supply system and the ground potential;
A voltmeter V 1 is connected in series between the positive bus of the direct-current power supply system and the ground potential, and a voltmeter V 2 is connected in series between the negative bus of the direct-current power supply system and the ground potential;
The branch line selection CT is equal to the number of the branches of the direct current power supply system and is electrically connected with the insulation monitoring device, and the incoming line and outgoing line of the branches of the direct current power supply system pass through the branch line selection CT at the same time.
The insulation monitoring device also comprises a main controller; the potentiometer, the change-over switch and the voltmeter are all electrically connected with the main controller.
The accurate positioning method for the grounding fault of the direct current power supply system comprises the following steps:
Step one, calculating the ground resistance: setting the potentiometer R 2 and the potentiometer R 3 to be the same in resistance, closing the change-over switch K 1, opening the change-over switch K 2, and measuring the voltages of the positive bus and the negative bus to the ground to be U +1 and U -1 respectively to obtain an equation (1);
Wherein "//" represents the resistance value after the resistors are connected in parallel, R + is the positive bus-bar ground insulation resistance, and R - is the negative bus-bar ground insulation resistance; since the resistance values of the resistor R 1 and the resistor R 4 are equal, the resistor R 1 and the resistor R 4 are calculated according to the value of R 1 during calculation;
Then, switching on a switch K 1 and switching off a switch K 2 to measure the voltages of the positive bus and the negative bus to the ground as U +2 and U -2 respectively, so as to obtain an equation (2);
After the measurement is finished, switching off a switch K 1 and a switch K 2, obtaining a positive bus ground insulation resistance R + and a negative bus ground insulation resistance R - according to equations (1) and (2), and then entering a second step;
and a second step of: grounding and line selection of the storage battery: if the positive and negative bus ground insulation measured in the first step is lower than the alarm value, starting a grounding line selection program: closing a change-over switch K 1, regulating a potentiometer R 2 to enable the potentiometer R 2 to output a resistance value which is in sinusoidal change, and monitoring the change of a branch line selection CT;
if the test current of the selected line CT of a certain branch is larger than the alarm value, judging that the branch has a grounding fault, and finishing positioning;
If the test current of all the branch line selection CT is lower than the alarm value, judging that the storage battery or the bus has a ground fault, and then entering a third step;
And a third step of: grounding and positioning: assuming that U 1 and U 2 are the voltage value from the positive bus to the ground point and the voltage value from the ground point to the negative bus, respectively, and U d is the voltage value of the positive bus and the negative bus, then U 1+U2＝Ud;
Assuming that R is a grounding resistance value, neglecting the internal resistance of the storage battery; equation (3) and equation (4) can be obtained;
Then the positive bus-to-ground voltage U 1, the ground-to-negative bus voltage U 2, and the ground resistance R can be found according to equations (3) and (4);
At this time, assuming that the number of battery segments is N, the number from the positive electrode to the negative electrode of the battery is: namely 1 to N, equation (5) is obtained
According to equation (5), the number n (rounded to an integer) of the battery with the ground fault can be obtained, and the system records the number n of the faulty battery; when n=0 or n=n, determining that a bus ground fault occurs; then, entering a fourth step;
fourth step: repeating the first step, and if the measured insulation resistance of the positive bus and the negative bus to the ground is the same as that in the first step, indicating that the storage battery is grounded at one point;
If the measured insulation resistance of the positive and negative bus to the ground is different from that in the first step, repeating the second and third steps, and recording the positive and negative bus voltage U +3、U-3 when the switch K 1 is closed and the switch K 2 is opened and the positive and negative bus voltage U +4、U-4 when the switch K 1 is opened and the switch K 2 is closed respectively;
If the calculation result shows that the position of the fault storage battery is consistent with the position of the first grounding fault, judging that one point of the storage battery is grounded and the grounding resistance is changed;
If the calculation result shows that the position of the fault storage battery is inconsistent with the position of the first grounding fault, judging that the storage battery is likely to generate two-point grounding faults, and entering a fifth step;
Fifth step: two-point grounding positioning of a storage battery: if the fourth step judges that the two-point grounding fault occurs in the storage battery or the bus, starting a two-point grounding positioning program of the storage battery;
And respectively solving the voltage U4 of the second point grounding fault battery to the negative bus, the grounding resistance R 'and the fault battery number n' according to the equation (6), the equation (7) and the equation (8), thereby determining the other fault battery number.
Compared with the prior art, the invention has the following beneficial effects: the invention not only can accurately position one point of the grounding fault of the storage battery and calculate one point of the grounding resistance value, but also can accurately position two points of the grounding fault of the storage battery and respectively calculate the two points of the grounding resistance values, solves the problem that the two points of the grounding fault of the storage battery cannot be positioned and calculated as an insulation monitoring blind area, and greatly improves the operation and maintenance convenience and safety of a direct current power supply system.
Drawings
The invention is described in further detail below with reference to the accompanying drawings:
FIG. 1 is a schematic circuit diagram of the present invention;
FIG. 2 is a schematic circuit diagram of an insulation monitoring device according to the present invention;
FIG. 3 is a schematic diagram of an equivalent circuit of a battery pack with one point ground in the present invention;
Fig. 4 is a two-point grounding equivalent circuit diagram of the battery pack in the invention.
Detailed Description
As shown in fig. 1 and 2, the accurate positioning device for the ground fault of the storage battery of the direct current power supply system of the invention comprises: insulation monitoring device and branch line selection CT; the insulation monitoring device includes: a balancing bridge and a switching bridge;
The balance bridge consists of two resistors R 1 and R 4 with equal resistance values; the resistor R 1 is connected between the positive bus of the direct-current power supply system and the ground potential, and the resistor R 4 is connected between the negative bus of the direct-current power supply system and the ground potential;
The switching bridge consists of a potentiometer R 2, a potentiometer R 3, a switching switch K 1 and a switching switch K 2, wherein the potentiometer R 2 is connected in series with the switching switch K 1 and then is connected between a positive bus of the direct-current power supply system and the ground potential, and the potentiometer R 3 is connected in series with the switching switch K 2 and then is connected between a negative bus of the direct-current power supply system and the ground potential;
A voltmeter V 1 is connected in series between the positive bus of the direct-current power supply system and the ground potential, and a voltmeter V 2 is connected in series between the negative bus of the direct-current power supply system and the ground potential;
The branch line selection CT is equal to the number of the branches of the direct current power supply system and is electrically connected with the insulation monitoring device, and the incoming line and outgoing line of the branches of the direct current power supply system pass through the branch line selection CT at the same time.
The insulation monitoring device also comprises a main controller; the potentiometer, the change-over switch and the voltmeter are all electrically connected with the main controller.
In the specific embodiment, a simulation model is established: assuming that the internal resistance of the storage battery is 0.7mΩ, the number of storage battery sections is 104, the voltage difference between positive and negative buses is U d =233v, the resistance to ground is 100gΩ under the condition that the insulation of the positive and negative buses is good, and the resistance with the resistance value of 20kΩ is connected to the ground at the 10 th section of storage battery negative electrode; the resistor R 1 and the resistor R 4 are resistors with the resistance value of 24kΩ; the potentiometer R 2 and the potentiometer R 3 adopt potentiometers with the adjustment range of 50k omega-150 k omega so as to position the fault storage battery and the grounding resistor.
The accurate positioning method for the grounding fault of the storage battery of the direct-current power supply system comprises the following steps:
Step one, calculating the ground resistance: setting the potentiometer R 2 and the potentiometer R 3 to be the same in resistance, closing the change-over switch K 1, opening the change-over switch K 2, and measuring the voltages of the positive bus and the negative bus to the ground to be U +1 and U -1 respectively to obtain an equation (1);
wherein "//" represents the resistance value after the resistors are connected in parallel, R + is the positive bus-bar ground insulation resistance, and R - is the negative bus-bar ground insulation resistance;
Then, switching on a switch K 1 and switching off a switch K 2 to measure the voltages of the positive bus and the negative bus to the ground as U +2 and U -2 respectively, so as to obtain an equation (2);
After the measurement is finished, switching off a switch K 1 and a switch K 2, and obtaining a positive bus ground insulation resistance R + and a negative bus ground insulation resistance R - according to equations (1) and (2);
In the simulation experiment: under the normal operation state, the measured voltage to ground of the positive electrode bus is U + (81.9V), the voltage to ground of the negative electrode bus is U - (153.1V), the voltage difference value delta U= |U +-U- |= |81.9V-153.1 V|= 71.2V, the potentiometer R 2 and the potentiometer R 3 are regulated to be the same resistance value 120kΩ, and the voltage between the positive bus and the negative bus is U d =235V;
Closing a change-over switch K 1 and opening a change-over switch K 2 to measure the voltages of the positive bus and the negative bus to the ground as U +1 (77.1V) and U -1 (157.9V) respectively, so as to obtain an equation (1); switching on a switch K 1 and switching off a switch K 2 to measure the voltages of the positive bus and the negative bus to the ground as U +2 (90.9V) and U -2 (144.1V) respectively, so as to obtain an equation (2); after the measurement is finished, both K 1 and K 2 are in a disconnected state; obtaining positive and negative bus insulation R + (22050.6 omega) and R - (204444.4 omega) according to equations (1) and (2), wherein the grounding resistance R + is less than 25k omega (alarm value); then entering a second step;
and a second step of: grounding and line selection of the storage battery: if the positive and negative bus ground insulation measured in the first step is lower than the alarm value, starting a grounding line selection program: closing a change-over switch K 1, regulating a potentiometer R 2 to enable the potentiometer R 2 to output a resistance value which is in sinusoidal change, and monitoring the change of a branch line selection CT;
if the test current of the selected line CT of a certain branch is larger than the alarm value, judging that the branch has a grounding fault, and finishing positioning;
if the test current of all the branch line selection CT is lower than the alarm value, judging that the storage battery or the bus has a grounding fault;
In the simulation experiment: the positive and negative bus-to-ground insulation measured in the first step is lower than an alarm value, a grounding line selection program is started, a change-over switch K 1 is closed, and a potentiometer R 2 (50 kΩ -150kΩ) is regulated to output a sine-variable resistance value [100+50sin (pi t) ] kΩ; monitoring the change of the branch line selection CT, and judging that the branch has a ground fault if the test current of the branch line selection CT is larger than an alarm value; if the test current of all the branch line selection CT is lower than the alarm value, judging that the storage battery or the bus has a ground fault, and then entering a third step;
And a third step of: grounding and positioning: assuming that U 1 and U 2 are the voltage value from the positive bus to the ground point and the voltage value from the ground point to the negative bus, respectively, and U d is the voltage value of the positive bus and the negative bus, then U 1+U2＝Ud;
as shown in fig. 3, assuming that R is a ground resistance value, the internal resistance of the battery is ignored; equations (3) and (4) can be reached;
Then the positive bus-to-ground voltage U 1, the ground-to-negative bus voltage U 2, and the ground resistance R can be found according to equations (3) and (4);
At this time, assuming that the number of battery segments is N, the number from the positive electrode to the negative electrode of the battery is: namely 1 to N, equation (5) is obtained
According to equation (5), the number n (rounded to an integer) of the battery with the ground fault can be obtained, and the system records the number n of the faulty battery; when n=0 or n=n, determining that a bus ground fault occurs; then, entering a fourth step;
In the simulation experiment: a one-point grounding equivalent circuit diagram of the storage battery is shown in fig. 2, wherein U1 and U2 are respectively the voltage values from a positive bus to a grounding point and from the grounding point to a negative bus, U 1+U2＝Ud,Ud is the voltage value of the positive bus and the negative bus, R is the grounding resistance value, and the internal resistance of the storage battery is ignored; then U 1＝22.9V、U2 = 212.1V and R = 19.9kΩ can be found from equations (3) and (4);
Assuming that the number of battery segments is N, and the number from the positive electrode to the negative electrode of the battery, that is, 1 to N, the number of the battery having the ground fault n=10 can be obtained from equation (5). The system records the faulty battery number n=10, U 1 =22.9v, and r=19.9kΩ.
Fourth step: repeating the first step, and if the measured insulation resistance of the positive bus and the negative bus to the ground is the same as that in the first step, indicating that the storage battery is grounded at one point;
If the measured insulation resistance of the positive and negative bus to the ground is different from that in the first step, repeating the second and third steps, and recording the positive and negative bus voltage U +3、U-3 when the switch K 1 is closed and the switch K 2 is opened and the positive and negative bus voltage U +4、U-4 when the switch K 1 is opened and the switch K 2 is closed respectively;
If the calculation result shows that the position of the fault storage battery is consistent with the position of the first grounding fault, judging that one point of the storage battery is grounded and the grounding resistance is changed;
If the calculation result shows that the position of the fault storage battery is inconsistent with the position of the first grounding fault, judging that the storage battery is likely to generate two-point grounding faults, and entering a fifth step;
As shown in fig. 4, the fifth step: two-point grounding positioning of a storage battery: if the fourth step judges that the two-point grounding fault occurs in the storage battery or the bus, starting a two-point grounding positioning program of the storage battery;
And respectively solving the voltage U 4 of the second point grounding fault battery to the negative bus, the grounding resistance R 'and the fault battery number n' according to the equation (6), the equation (7) and the equation (8), thereby determining the other fault battery number.
In the simulation experiment: setting the grounding access resistance value of the 20 th section to be 50kΩ, simulating the grounding of the second point of the storage battery, and calculating the grounding resistance value and the position of the grounding of the second point of the storage battery by the following method;
According to the third step, the corresponding fault storage battery node numbers n=10, U 1 =22.9v and the grounding resistance value r=19.9kΩ are calculated; the operation process of the first step is repeated, new changes of the insulation resistance of the positive and negative buses to the ground are found, positive and negative bus voltages U +3(73.2V)、U-3 (161.8V) when the switch K 1 is closed and the switch K 2 is opened and positive and negative bus voltages U +4(85.3V)、U-4 (149.7V) when the switch K 1 is opened and the switch K 2 is closed are respectively recorded, and a second-step grounding line selection program is started;
After the branch grounding faults are removed, repeating the third step to obtain calculation of the storage battery grounding resistance R=14.15kΩ and the fault storage battery positioning n=30, wherein the calculation result shows that the position of the fault storage battery is inconsistent with the position of the first grounding fault, and then judging that the storage battery is likely to generate two-point or multi-point grounding faults, wherein the occurrence probability of the two-point grounding faults is highest, and calculating and positioning according to the two-point grounding faults;
And fourthly, judging that the storage battery or the bus has two-point ground faults, starting a two-point ground positioning program of the storage battery, and respectively solving the voltage U 4 = 189.6V, the ground resistance R '= 50.2kΩ and the fault battery number n' = 20 of the second-point ground fault battery to the negative bus according to the equation (6), the equation (7) and the equation (8).
The invention not only can accurately position one point of the grounding fault of the storage battery and calculate one point of the grounding resistance value, but also can accurately position two points of the grounding fault of the storage battery and respectively calculate the two points of the grounding resistance values, solves the problem that the two points of the grounding fault of the storage battery cannot be positioned and calculated as an insulation monitoring blind area, and greatly improves the operation and maintenance convenience and safety of a direct current power supply system.
Claims (1)
1. The positioning method of the accurate positioning device for the grounding fault of the storage battery of the direct-current power supply system is characterized by comprising the following steps of: the accurate positioning device for the grounding fault of the storage battery of the specific direct-current power supply system comprises: insulation monitoring device and branch line selection CT; the insulation monitoring device includes: a balancing bridge and a switching bridge;
The balance bridge consists of two resistors R 1 and R 4 with equal resistance values; the resistor R 1 is connected between the positive bus of the direct-current power supply system and the ground potential, and the resistor R 4 is connected between the negative bus of the direct-current power supply system and the ground potential;
The switching bridge consists of a potentiometer R 2, a potentiometer R 3, a switching switch K 1 and a switching switch K 2, wherein the potentiometer R 2 is connected in series with the switching switch K 1 and then is connected between a positive bus of the direct-current power supply system and the ground potential, and the potentiometer R 3 is connected in series with the switching switch K 2 and then is connected between a negative bus of the direct-current power supply system and the ground potential;
A voltmeter V 1 is connected in series between the positive bus of the direct-current power supply system and the ground potential, and a voltmeter V 2 is connected in series between the negative bus of the direct-current power supply system and the ground potential;
The branch line selection CT is equal to the number of the branches of the direct current power supply system and is electrically connected with the insulation monitoring device, and the incoming line and outgoing line of the branches of the direct current power supply system pass through the branch line selection CT at the same time;
The insulation monitoring device also comprises a main controller; the potentiometer, the change-over switch and the voltmeter are electrically connected with the main controller;
The positioning method of the accurate positioning device for the grounding fault of the storage battery of the direct-current power supply system comprises the following steps:
Step one, calculating the ground resistance: setting the potentiometer R 2 and the potentiometer R 3 to be the same in resistance, closing the change-over switch K 1, opening the change-over switch K 2, and measuring the voltages of the positive bus and the negative bus to the ground to be U +1 and U -1 respectively to obtain an equation (1);
Wherein "//" represents the resistance value after the resistors are connected in parallel, R + is the positive bus-bar ground insulation resistance, and R - is the negative bus-bar ground insulation resistance; since the resistance values of the resistor R 1 and the resistor R 4 are equal, the resistor R 1 and the resistor R 4 are calculated according to the value of R 1 during calculation;
Then, switching on a switch K 1 and switching off a switch K 2 to measure the voltages of the positive bus and the negative bus to the ground as U +2 and U -2 respectively, so as to obtain an equation (2);
After the measurement is finished, switching off a switch K 1 and a switch K 2, obtaining a positive bus ground insulation resistance R + and a negative bus ground insulation resistance R - according to equations (1) and (2), and then entering a second step;
and a second step of: grounding and line selection of the storage battery: if the positive and negative bus ground insulation measured in the first step is lower than the alarm value, starting a grounding line selection program: closing a change-over switch K 1, regulating a potentiometer R 2 to enable the potentiometer R 2 to output a resistance value which is in sinusoidal change, and monitoring the change of a branch line selection CT;
if the test current of the selected line CT of a certain branch is larger than the alarm value, judging that the branch has a grounding fault, and finishing positioning;
If the test current of all the branch line selection CT is lower than the alarm value, judging that the storage battery or the bus has a ground fault, and then entering a third step;
And a third step of: grounding and positioning: assuming that U 1 and U 2 are the voltage value from the positive bus to the ground point and the voltage value from the ground point to the negative bus, respectively, and U d is the voltage value of the positive bus and the negative bus, then U 1+U2＝Ud;
Assuming that R is a grounding resistance value, neglecting the internal resistance of the storage battery; equation (3) and equation (4) can be obtained;
Then the positive bus-to-ground voltage U 1, the ground-to-negative bus voltage U 2, and the ground resistance R can be found according to equations (3) and (4);
At this time, assuming that the number of battery segments is N, the number from the positive electrode to the negative electrode of the battery is: namely 1 to N, equation (5) is obtained
According to equation (5), the number n (rounded to an integer) of the battery with the ground fault can be obtained, and the system records the number n of the faulty battery; when n=0 or n=n, determining that a bus ground fault occurs; then, entering a fourth step;
fourth step: repeating the first step, and if the measured insulation resistance of the positive bus and the negative bus to the ground is the same as that in the first step, indicating that the storage battery is grounded at one point;
If the measured insulation resistance of the positive and negative bus to the ground is different from that in the first step, repeating the second and third steps, and recording the positive and negative bus voltage U +3、U-3 when the switch K 1 is closed and the switch K 2 is opened and the positive and negative bus voltage U +4、U-4 when the switch K 1 is opened and the switch K 2 is closed respectively;
If the calculation result shows that the position of the fault storage battery is consistent with the position of the first grounding fault, judging that one point of the storage battery is grounded and the grounding resistance is changed;
If the calculation result shows that the position of the fault storage battery is inconsistent with the position of the first grounding fault, judging that the storage battery is likely to generate two-point grounding faults, and entering a fifth step;
Fifth step: two-point grounding positioning of a storage battery: if the fourth step judges that the two-point grounding fault occurs in the storage battery or the bus, starting a two-point grounding positioning program of the storage battery;
And respectively solving the voltage U 4 of the second point grounding fault battery to the negative bus, the grounding resistance R 'and the fault battery number n' according to the equation (6), the equation (7) and the equation (8), thereby determining the other fault battery number.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010695447.0A CN111624507B (en) | 2020-07-18 | 2020-07-18 | Accurate positioning device and method for storage battery ground fault of direct-current power supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010695447.0A CN111624507B (en) | 2020-07-18 | 2020-07-18 | Accurate positioning device and method for storage battery ground fault of direct-current power supply system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111624507A CN111624507A (en) | 2020-09-04 |
| CN111624507B true CN111624507B (en) | 2024-06-25 |
Family
ID=72258664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010695447.0A Active CN111624507B (en) | 2020-07-18 | 2020-07-18 | Accurate positioning device and method for storage battery ground fault of direct-current power supply system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111624507B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114325228B (en) * | 2021-12-23 | 2023-10-13 | 蜂巢能源科技股份有限公司 | Insulation fault point positioning method, system and storage medium for energy storage system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN212301808U (en) * | 2020-07-18 | 2021-01-05 | 国网山西省电力公司电力科学研究院 | Accurate positioning device for ground fault of storage battery of direct-current power supply system |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102298091B (en) * | 2011-05-16 | 2013-07-17 | 江苏斯达工业科技有限公司 | Detection circuit of direct-current power supply insulation resistance to ground |
| CN105137363B (en) * | 2015-07-16 | 2017-11-24 | 国网上海市电力公司 | A kind of on-Line Monitor Device for transforming plant DC power-supply system |
| CN106383314A (en) * | 2016-08-26 | 2017-02-08 | 科力远混合动力技术有限公司 | Automobile power battery pack insulation detection circuit and detection judgment method |
| CN108318787B (en) * | 2017-12-28 | 2020-04-28 | 国网智能科技股份有限公司 | Direct-current bus multi-section parallel operation switching method and system |
| CN111060791B (en) * | 2019-12-30 | 2022-05-03 | 华人运通(江苏)技术有限公司 | Insulation fault detection method and device, electric vehicle, terminal equipment and medium |
-
2020
- 2020-07-18 CN CN202010695447.0A patent/CN111624507B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN212301808U (en) * | 2020-07-18 | 2021-01-05 | 国网山西省电力公司电力科学研究院 | Accurate positioning device for ground fault of storage battery of direct-current power supply system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111624507A (en) | 2020-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Senger et al. | Automated fault location system for primary distribution networks | |
| US20150073735A1 (en) | Method for adaptive fault location in power system networks | |
| CN104678341A (en) | Detection device and detection method for station-dedicated DC power system insulation monitoring device | |
| CN108614180B (en) | Single-phase earth fault line searching method | |
| CN115792504B (en) | Power distribution network single-phase earth fault positioning method and system based on phase current abrupt change | |
| CN111624507B (en) | Accurate positioning device and method for storage battery ground fault of direct-current power supply system | |
| CN212301808U (en) | Accurate positioning device for ground fault of storage battery of direct-current power supply system | |
| CN204515113U (en) | Stand with the pick-up unit of DC power system insulation monitoring and warning device | |
| CN103412190B (en) | Switch-class device state evaluation method based on parameter on-line identification | |
| CN114428196A (en) | Asymmetric power distribution network ground fault line selection method based on flexible grounding device | |
| CN110568313B (en) | Single-phase earth fault positioning method and system for small current earthing system | |
| CN112462284A (en) | Method for testing internal resistance and short-circuit current of storage battery | |
| CN110794354A (en) | Alternating current-to-direct current function calibrator for insulation monitoring device and application method thereof | |
| Hossain et al. | Distribution high impedance fault location using localized voltage magnitude measurements | |
| CN115575778A (en) | Calibration system and calibration method of direct-current insulation monitoring device | |
| CN113188582B (en) | System and method for testing data acquisition precision of battery management system | |
| CN113552495B (en) | Online detection method and device for leakage of storage battery of power supply system | |
| CN115980608A (en) | Storage battery pack nuclear-capacity discharge centralized control system | |
| CN211718504U (en) | Alternating-current and direct-current function calibrator for insulation monitoring device | |
| CN109164338B (en) | High-power medium-voltage direct-current dry-type load device with online monitoring function | |
| Naidu et al. | An accurate fault location method for radial distribution system using one terminal data | |
| CN113567811B (en) | Distribution line single-phase fault detection method and related device | |
| CN111190079A (en) | Fault indicator collects unit with withstand voltage automatic test system | |
| CN219715661U (en) | Bridge circuit based on direct current insulation monitoring | |
| CN113484659B (en) | 10kV distribution line single-phase line break fault direction detection method and device based on phase voltage change information |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |