CN110739670B - 110kV line disconnection relay protection method for comparing voltages at two sides of line - Google Patents

110kV line disconnection relay protection method for comparing voltages at two sides of line Download PDF

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Publication number
CN110739670B
CN110739670B CN201911186659.XA CN201911186659A CN110739670B CN 110739670 B CN110739670 B CN 110739670B CN 201911186659 A CN201911186659 A CN 201911186659A CN 110739670 B CN110739670 B CN 110739670B
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line
phase
voltage
bus
power
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CN110739670A (en
Inventor
李静
陈永明
杨茹
胡航
曹斌
汤大海
魏刚
王律
徐溯
张�浩
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State Grid Jiangsu Electric Power Co ltd Zhenjiang Power Supply Branch
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State Grid Jiangsu Electric Power Co ltd Zhenjiang Power Supply Branch
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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
    • H02H7/266—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 involving switching on a spare supply
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/0084—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring voltage only
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
    • H02H3/28—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus
    • 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
    • H02H7/261—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 involving signal transmission between at least two stations
    • H02H7/263—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 involving signal transmission between at least two stations involving transmissions of measured values

Abstract

The invention discloses a 110kV line disconnection relay protection method for comparing voltages on two sides of a line, which fully utilizes the fault characteristics of PT secondary voltages of a power supply end and a load end 110kV bus of a transformer substation when the 110kV line is in single-phase disconnection, compares the voltages of the 110kV line and the 110kV line, identifies the 110kV line single-phase disconnection, and adopts a closed-loop operation to transfer power supply by the load end 110kV transformer substation, thus being simple and easy. The influence of the phase-lacking power supply of the transformer on the power grid and the load power supply can be effectively prevented, and the 110kV neutral point of the 110kV transformer is prevented from being burnt, so that the safe and stable operation of the power grid is facilitated.

Description

110kV line disconnection relay protection method for comparing voltages at two sides of line
Technical Field
The invention relates to a 110kV line disconnection relay protection method for comparing voltages on two sides of a line, and belongs to the technical field of power equipment relay protection.
Background
At present, the phenomenon of 110kV line disconnection occurs in power grids in various places. The 110kV transformer powered by the 110kV line is in phase-loss operation due to line breakage, so that the three-phase voltage of the powered transformer is asymmetric, the load power supply is affected, even the 110kV neutral point of the 110kV transformer is broken down and burnt due to zero-sequence overvoltage, and the transformer is forced to be in power failure for maintenance. At present, no relay protection device specially aiming at 110kV line disconnection exists in the prior art. The invention provides a single-phase line-breaking relay protection method which transmits voltage information of two sides of a line through a 110kV line optical fiber channel at a load end transformer substation, compares the voltages of the two sides of the line to identify line breaking of the 110kV line, and transfers power supply by adopting ring closing and opening operation.
Disclosure of Invention
The invention aims to provide a 110kV line disconnection relay protection method for comparing voltages on two sides of a line, which can be applied to a power transmission and distribution network and is used for transmitting voltage information on two sides of the line through a 110kV line optical fiber channel in a load end 110kV transformer substation, comparing the voltages on two sides of the line, identifying the disconnection of the 110kV line and adopting a single-phase disconnection relay protection method for transferring power supply by ring closing and opening operation.
The purpose of the invention is realized by the following technical scheme:
a110 kV line disconnection relay protection method for comparing voltages on two sides of a line comprises the following steps:
first, the condition of tripping on the incoming line breaker after judging that the 110kV line is broken and the load end of the 110kV substation is closed and the standby breaker is opened
1.1 conditions for judging 2DL or 3DL of 1 # 110kV line disconnection on-load end 110kV substation standby circuit breaker and 1DL of 1 # trip incoming line circuit breaker at 1 kV line disconnection on-load end, and starting 1 # 110kV line disconnection alarm condition
a. Collecting 110kV bus PT secondary A-phase voltage U corresponding to 110kV transformer substation at power supply endaPhase U of B phase voltagebC phase voltage UcOpen delta voltage 3Uo；
(1) PT secondary B phase voltage value U of power supply end corresponding to 110kV busaGreater than the setting value U1;
(2) PT secondary C-phase voltage value U of power supply end corresponding to 110kV busbGreater than the setting value U1;
(3) power end pairPT secondary A-phase voltage value U of 110kV buscGreater than the setting value U1;
(4) secondary voltage value 3U of power supply end corresponding to secondary opening triangle of bus PToIs less than the setting value U2;
(5) a power end 110kV line circuit breaker 4DL of a No. 1 110kV line is at a switching-on position;
when the conditions are all met, the voltage of a 110kV bus corresponding to a power end 110kV transformer substation is normal, and the normal voltage signal is transmitted to 110kV disconnection protection in 110kV line protection of a No. 1 110kV transformer substation under the load of the No. 1 110kV line through an optical fiber channel of No. 1 110kV power line optical fiber differential protection;
b. collection load end 110kV transformer substation I section bus PT secondary A phase voltage UaPhase U of B phase voltagebC phase voltage Uc Open delta voltage 3Uo；
(1) The PT secondary voltage value of the 110kV bus at the No. 1 110kV line open-circuit phase load end is lower than a setting value U3;
(2) the PT secondary voltage value of the 110kV bus at the 1 # 110kV line non-broken line phase 1 load end is greater than a setting value U1;
(3) the PT secondary voltage value of the 110kV bus at the No. 1 110kV line non-broken line phase 2 load end is greater than a setting value U1;
(4) the PT opening triangular secondary voltage value of the No. 1 110kV bus at the load end of the 110kV line is greater than a setting value U4;
(5) a load end 110kV line breaker 1DL of a No. 1 110kV line is at a switching-on position;
when the conditions are met, the abnormal voltage of the I section of the bus of the 110kV transformer substation at the load end is represented;
when the received power end 110kV transformer substation corresponds to a normal 110kV bus and the voltage of a first-section bus of the load end 110kV transformer substation is abnormal, identifying and judging that a No. 1 110kV power line is broken, delaying by t1 to protect the 110kV broken line in the protection of the 110kV line of the load end 110kV transformer substation, and after closing a standby power circuit breaker 2DL or 3DL, tripping off a circuit breaker 1DL on the load side of the No. 1 110kV power line to enable a transformer which loses power to be recovered to the standby power line for power supply; simultaneously starting a No. 1 110kV line disconnection alarm;
1.2 conditions for judging 1DL or 3DL of standby circuit breaker of No. 2 110kV line disconnection on-load end 110kV transformer substation and 2DL of tripping-off No. 2 incoming line circuit breaker, and conditions for starting No. 2 110kV line disconnection alarm
a. Collecting 110kV bus PT secondary A-phase voltage U corresponding to 110kV transformer substation at power supply endaPhase U of B phase voltagebC phase voltage UcOpen delta voltage 3Uo；
(1) The voltage value of the PT secondary B phase of the 110kV bus corresponding to the power supply end is greater than a setting value U1;
(2) the PT secondary C-phase voltage value of the power supply end corresponding to the 110kV bus is greater than a setting value U1;
(3) the voltage value of a PT secondary A phase of a 110kV bus corresponding to a power supply end is greater than a setting value U1;
(4) the secondary voltage value 3UO of the secondary opening triangle of the power supply end corresponding to the bus PT is smaller than the setting value U2;
(5) a power end 110kV line circuit breaker 5DL of a No. 2 110kV line is at a switching-on position;
the conditions are all met, and the condition indicates that the 110kV bus voltage corresponding to the 110kV transformer substation at the power end is normal; the normal voltage signal is transmitted to a 110kV disconnection protection in 110kV line protection of a load 110kV transformer substation of a No. 2 110kV line through an optical fiber channel of the No. 2 110kV power line optical fiber differential protection;
b. collecting PT secondary A-phase voltage U of II-section bus of 110kV transformer substation at load endaPhase U of B phase voltagebC phase voltage UcOpen delta voltage 3Uo；
(1) The secondary voltage value of a No. 2 110kV line open-circuit phase load end 110kV bus PT is lower than a setting value U3;
(2) the PT secondary voltage value of the 110kV bus at the non-broken line phase 1 load end of the No. 2kV line is greater than a setting value U1;
(3) the secondary voltage value 3UO of the 110kV bus PT at the non-broken line phase 2 load end of the No. 2kV line is greater than the setting value U1;
(4) the PT opening triangular secondary voltage value of the No. 2 110kV line load end 110kV bus is greater than a setting value U4;
(5) a 110kV line breaker 1DL at a load end of a No. 2 110kV line is at a switching-on position;
when the conditions are met, the voltage abnormality of the second section of the bus of the 110kV transformer substation at the load end is represented;
when the received power end 220kV transformer substation corresponding to a 110kV bus is normal and the voltage of a second-section bus of the load end 110kV transformer substation is abnormal, identifying and judging that a No. 2 110kV power line is broken, delaying by t1 to protect the 110kV broken line in the protection of the 110kV line of the load end 110kV transformer substation, and after closing a standby power circuit breaker 2DL or 3DL, tripping off a circuit breaker 1DL on the load side of the No. 1 110kV power line to enable a transformer without a power supply to be recovered to the standby power line for power supply; and simultaneously, the No. 2 110kV line disconnection alarm is started.
The object of the invention can be further achieved by the following technical measures:
the 110kV line disconnection relay protection method for comparing voltages at two sides of a line comprises the following steps:
setting value U1 is 0.9Ea, Ea is a phase voltage value, and the corresponding PT secondary voltage is 58V; 0.9 Ea-52.2V; setting value U2 is between 4 and 8V; the setting value U3 is 0.55Ea, namely 31.9V; the setting value U4 is 0.9Eab, which is the PT secondary opening triangle rated voltage value and is 100V.
In the 110kV line disconnection relay protection method for comparing voltages at two sides of the line, the time t1 is set as follows: three-phase different-period time when the switch is closed is avoided: taking 0.1-0.2 seconds.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention fully utilizes the fault characteristics of the PT secondary voltage of the 110kV bus of the power supply end and the load end substation when the 110kV line is in single-phase disconnection, compares the bus voltages at two ends of the 110kV line, identifies the 110kV line single-phase disconnection, and transfers power supply by the load end 110kV substation through ring closing and opening operation, thus being simple and easy.
2. According to the invention, the voltage information at two sides of the line is transmitted through the 110kV line optical fiber channel, the voltage at two sides of the line is compared to identify the line break of the 110kV line, the load end 110kV transformer substation transfers power supply by adopting a loop closing and opening operation, so that the transformer losing the power supply is recovered to the relay protection scheme of the power supply on the standby power supply, the influence of the transformer phase-lacking power supply on the power grid and the load power supply can be effectively prevented, the 110kV transformer 110kV neutral point is prevented from being burnt, and the safe and stable operation of the power grid is facilitated.
3. The method is implemented by adopting the 110kV line protection devices on two sides of the 110kV line, and does not need to increase hardware equipment.
4. The method is not only suitable for the mode of ungrounded 110kV neutral points of the transformer, but also suitable for the mode of grounded 110kV neutral points of the transformer.
Drawings
FIG. 1 is a first schematic diagram of a 110kV disconnection primary system;
FIG. 2 is a vector diagram of 110kV bus voltage at load side of a first vector diagram of 110kV bus voltage at line break of 110kV line;
FIG. 3 is a vector diagram of 110kV bus voltage at the power side of a first vector diagram of 110kV bus voltage at the disconnection of 110kV line;
FIG. 4 is a first schematic diagram of a 110kV disconnection and load side disconnection grounding primary system;
FIG. 5 is a vector diagram of 110kV bus voltage on the load side of a 110kV bus voltage vector diagram II when the 110kV line is disconnected;
FIG. 6 is a vector diagram of 110kV bus voltage at the power side of a 110kV bus voltage vector diagram II when the 110kV line is disconnected;
FIG. 7 is a schematic diagram II of a 110kV disconnection primary system;
FIG. 8 is a vector diagram of 110kV bus voltage on the load side of a third vector diagram of the broken bus voltage of the 110kV line;
FIG. 9 is a vector diagram of 110kV bus voltage at the power side of the third vector diagram of the broken bus voltage of the 110kV line;
FIG. 10 is a schematic diagram II of a 110kV disconnection primary system with a load side disconnected;
FIG. 11 is a schematic diagram of the single-phase disconnection protection of the 110kV line of the present invention;
fig. 12 is a primary main wiring diagram of a single bus segment of a 110kV substation.
Detailed Description
The invention is further described with reference to the following figures and specific examples.
110kV line breakage analysis:
and when the 110kV neutral point of the load side 110kV substation transformer is not grounded, the 110kV line disconnection condition is 1. And when the 110kV neutral point of the 110kV substation transformer on the load side is grounded, the 110kV line disconnection condition is 2.
1.1110 kV line broken line 1
1.1.1110 kV line broken wire
Fig. 1 is a schematic diagram of a 110kV disconnection primary system. The 110kV side of the 220kV transformer substation on the system side is an effective grounding system; 110kV neutral points of 110kV substation transformers on the load side are not grounded and are grounded through gaps.
The electric potentials of the 110kV side power supplies of the 220kV transformer substation on the system side are respectively set as EA、EB、EC. When a certain part of the 110kV line is broken, such as phase A, the voltage of the 110kV bus of the 110kV transformer substation at the load side is obtained through analysis:
Figure BDA0002292565210000041
(1) in the formula of UA、UB、UCThe voltage of A phase, B phase and C phase of 110kV bus of 110kV transformer substation at load side is U phase0Is 110kV neutral point voltage of 110kV transformer substation on load side, 3U0The voltage of a secondary open-delta winding of a 110kV bus voltage transformer (PT for short) of a load side 110kV substation transformer is obtained. The vector diagrams are shown in FIGS. 2 and 3.
When a 110kV line is broken, the voltage of the 110kV bus at the 220kV substation on the system side is E, and the voltage of the A phase, the voltage of the B phase and the voltage of the C phase are respectively EA、EB、EC，3U0Is 0, i.e. the three-phase voltage is maintained under normal conditions.
1.1.2110 kV line disconnection and load side disconnection grounding
Fig. 4 is a schematic diagram of a primary system with 110kV line break and load side line break grounded. The 110kV side of the 220kV transformer substation on the system side is an effective grounding system; 110kV neutral points of 110kV substation transformers on the load side are not grounded and are grounded through gaps.
The electric potentials of the 110kV side power supplies of the 220kV transformer substation on the system side are respectively set as EA、EB、EC. When a certain part of the 110kV line is broken and the broken line of the load side is grounded, such as phase A, the voltage of the 110kV bus of the 110kV transformer substation on the load side is obtained through analysis:
Figure BDA0002292565210000051
(2) in the formula of UA、UB、UCThe voltage of A phase, B phase and C phase of 110kV bus of 110kV transformer substation at load side is U phase0Is 110kV neutral point voltage of 110kV transformer substation on load side, 3U0The voltage of a secondary open-delta winding of a 110kV bus voltage transformer (PT for short) of a load side 110kV substation transformer is obtained. The vector diagrams are shown in fig. 5 and 6.
When a 110kV line is broken, the voltage of the 110kV bus at the 220kV substation on the system side is E, and the voltage of the A phase, the voltage of the B phase and the voltage of the C phase are respectively EA、EB、EC，3U0Is 0, i.e. the three-phase voltage is maintained under normal conditions.
1.1.3110 kV line disconnection and system side disconnection point grounding
When the 110kV line is broken and the broken line of the system side is grounded, for the system side, the fault is mainly reflected in the single-phase grounding short-circuit fault of the 110kV line, so that the 110kV line protection of the 220kV transformer substation can start tripping to remove the fault (the 110kV line breaker trips to remove the fault, the 110kV line breaker is overlapped, then the single-phase grounding short-circuit fault of the 110kV line, the 110kV line protection of the 220kV transformer substation restarts tripping and removes the fault).
Analysis of 110kV neutral click-through of 110kV transformer substation in 1.1.4110 kV line disconnection
Table 1 shows the power frequency discharge voltage at different gaps. By analysing the neutral point to ground voltage U of the transformer0It can be determined whether the gap is likely to break down, in conjunction with table 1.
TABLE 1 Power frequency discharge Voltage for different gaps
Figure BDA0002292565210000052
For the analytical results of 1.1.3, 3U0Has a maximum value of 150V, and a neutral point to ground voltage U0The secondary value is 50V, and the primary value is converted to obtain U0The first value, the calculation result is as follows:
Figure BDA0002292565210000061
as the discharge gap of the neutral point of the transformer is 110mm or 120mm, the power frequency withstand voltage of the neutral point of the transformer shown in Table 1 is 52kV or 53.3kV, and the maximum steady-state voltage of the neutral point of the actual transformer is about 55kV and higher than the power frequency withstand voltage value, the discharge gap can be punctured.
1.2110 kV line broken line 2
1.2.1110 kV line broken wire
Fig. 7 is a schematic diagram of a 110kV primary disconnection system. The 110kV side of the 220kV transformer substation on the system side is an effective grounding system; 110kV neutral points of 110kV substation transformers on the load side are grounded.
The electric potentials of the 110kV side power supplies of the 220kV transformer substation on the system side are respectively set as EA、EB、EC. When a certain part of the 110kV line is broken, such as phase A, the voltage of the 110kV bus of the 110kV transformer substation at the load side is obtained through analysis:
Figure BDA0002292565210000062
(2) in the formula of UA、UB、UCThe voltage of A phase, B phase and C phase of 110kV bus of 110kV transformer substation at load side is U phase0Is 110kV neutral point voltage of 110kV transformer substation on load side, 3U0The voltage of a secondary open-delta winding of a 110kV bus voltage transformer (PT for short) of a load side 110kV substation transformer is obtained. The vector diagrams are shown in FIGS. 8 and 9.
When a 110kV line is broken, the voltage of the 110kV bus at the 220kV substation on the system side is E, and the voltage of the A phase, the voltage of the B phase and the voltage of the C phase are respectively EA、EB、EC，3U0Is 0, i.e. the three-phase voltage is maintained under normal conditions.
1.2.2110 kV line disconnection and load side disconnection grounding
Fig. 7 is a schematic diagram of a 110kV disconnection and load side disconnection grounding primary system. The 110kV side of the 220kV transformer substation on the system side is an effective grounding system; 110kV neutral points of 110kV substation transformers on the load side are grounded.
The electric potentials of the 110kV side power supplies of the 220kV transformer substation on the system side are respectively set as EA、EB、EC. When a certain broken line of the 110kV line is disconnected and the broken line of the load side is grounded, such as phase A, analyzing: eB、ECThe synthetic potential at the low-voltage side of the 110KV transformer substation transformer at the load side is-EaThe potential is added to a low-voltage a-phase winding of a 110kV transformer substation at the load side and is converted into a low-voltage A-phase winding of the 110kV transformer at the winding with the potential of-EAGrounding the broken line of the 110kV line and the broken line of the load side to form an A-phase short circuit and an A-phase short circuit current IAThe current of the low-voltage a-phase winding of the transformer is converted into IaThe a-phase winding current is IaForming a circulating current in a low-voltage side winding of the transformer, wherein the current of the a-phase winding is IbPhase C winding current IcThe current of the high-voltage B-phase winding of the transformer is converted into IBC phase winding current is ICDue to Ia、Ib、IcThe currents are equal and in phase, so that I isA、IB、ICThe currents are equal and in phase.
When the 110kV line is broken and the broken line of the transformer side is grounded, for the system side, the fault is mainly reflected in a short-circuit fault, and the zero-sequence current 3I of the system side0＝(IB+IC)/3)＝2IBAnd 3, therefore, the 110kV line protection of the 220kV transformer substation starts tripping to remove the fault (the 110kV line breaker trips to remove the fault, the 110kV line breaker is overlapped, then the 110kV line single-phase grounding short-circuit fault occurs, and the 110kV line protection of the 220kV transformer substation starts tripping again to remove the fault).
1.2.3110 kV line disconnection and system side disconnection point grounding
When the 110kV line is broken and the broken line of the system side is grounded, for the system side, the fault is mainly reflected in the single-phase grounding short-circuit fault of the 110kV line, so that the 110kV line protection of the 220kV transformer substation can start tripping to remove the fault (the 110kV line breaker trips to remove the fault, the 110kV line breaker is overlapped, then the single-phase grounding short-circuit fault of the 110kV line, the 110kV line protection of the 220kV transformer substation restarts tripping and removes the fault).
Analysis of 2.110kV line breaking result
2.1110 kV line break (or and earthing at break)
For three conditions of 1.1.1, 1.1.2 and 1.2.1, 110kV line disconnection protection can be carried out, and load transfer of 110kV line disconnection can be eliminated by matching with the backup power automatic switch, so that the influence of 110kV line disconnection on power supply load can be prevented.
Short circuit caused by 2.2110 kV line disconnection and grounding at disconnection
For three conditions of 1.1.3, 1.2.2 and 1.2.3, because short-circuit fault is caused by grounding at a broken line, tripping can be started by 110kV line protection of a 220kV transformer substation to remove the fault (110kV line breaker tripping removes the fault, 110kV line breaker is overlapped, then 110kV line single-phase grounding short-circuit fault, 220kV transformer substation 110kV line protection restarts tripping again to remove the fault); because the 110kV bus corresponding to the 110kV transformer substation at the load end loses power, the load transfer of 110kV line disconnection is eliminated by the spare power automatic switching action, and the influence of the 110kV line disconnection on the power supply load is prevented.
Fault feature analysis during disconnection of 3.110kV line
For three 110kV line disconnection conditions of 1.1.1, 1.1.2 and 1.2.1, the fault characteristics are as follows: the three-phase voltage of the 110kV bus A, B, C on the power supply side is symmetrical, the amplitude and the phase are not changed greatly, and the voltage is 3U0Is 0, but for 2 kinds of 110kV line disconnection conditions of 1.1.1 and 1.1.2, the fault characteristics are as follows: the three-phase voltage of the 110kV bus A, B, C of the load side transformer substation is asymmetrical, and the phase voltage of the broken line is-E A2 and about 0, 3U0is-3EA/2 or-EAMeanwhile, the amplitude and the phase of the non-fault phase voltage do not change much;there is a potential for breakdown of the transformer neutral. 1.2.1 the fault signature of a broken 110kV line is similar to the case of 1.1.2, where the phase voltage of the broken line is equal to 0.
An example of the method of the present invention is given below (taking fig. 12 as an example).
The 110kV single-bus subsection primary main wiring structure of the 110kV substation is shown in fig. 12:
the No. 1 power supply incoming line branch equipment and the No. 2 power supply incoming line branch equipment are respectively connected with a 110kV I section bus and a 110kV II section bus; a segmented circuit breaker 3DL is arranged between the first segment bus and the second segment bus of 110kV, and is connected with a segmented current transformer CT in series; the No. 1 power supply inlet line branch circuit spacing equipment is a circuit breaker 1DL and is connected with a current transformer CT1 in series; the No. 2 power supply inlet wire branch circuit spacing device is a circuit breaker 2DL and is connected with a current transformer CT2 in series; the 110kV I-section bus is also connected with a No. 1 transformer branch, a No. 2 transformer branch, a No. 1 110kV outgoing line branch and a 110kV I-section bus voltage transformer PT 1; the 110kV II-section bus is also connected with a No. 3 transformer branch, a No. 2 110kV outgoing line branch and a 110kV II-section bus voltage transformer PT 2. There is circuit breaker 4DL No. 1 power inlet wire circuit power supply side, and there is circuit breaker 5DL No. 2 power inlet wire circuit power supply side. The 110kV bus of the power supply end is respectively connected with 110kV PT1 and 110kV PT 2. A110 kV spare power automatic switching device is arranged on the 110kV side of a 110kV substation at a load end. The 110kV line is provided with an optical fiber channel and line optical fiber differential protection.
Aiming at the 110kV single-bus subsection primary main connection, voltage information on two sides of a line is transmitted through a 110kV line optical fiber channel in a power end 220kV transformer substation, the voltage on the two sides of the line is compared to identify the line breakage of the 110kV line, and the load end 110kV transformer substation adopts a scheme of switching on and off loop operation to transfer load power supply to meet the field operation requirement. The 110kV neutral point operation mode of all main transformers on the first section or the second section of buses of the load end 110kV transformer substation is as follows: a) grounding; b) not grounded, grounded through the gap. The 110kV line is provided with an optical fiber channel and line optical fiber differential protection.
The invention discloses a 110kV line disconnection relay protection method for comparing voltages at two sides of a line, which comprises the following steps as shown in fig. 11:
first, the condition of tripping on the incoming line breaker after judging that the 110kV line is broken and the load end of the 110kV substation is closed and the standby breaker is opened
1.1 conditions for judging 2DL or 3DL of 1 # 110kV line disconnection on-load end 110kV substation standby circuit breaker and 1DL of 1 # trip incoming line circuit breaker at 1 kV line disconnection on-load end, and starting 1 # 110kV line disconnection alarm condition
a. Collecting 110kV bus PT secondary A-phase voltage U corresponding to 110kV transformer substation at power supply endaPhase U of B phase voltagebC phase voltage Uc Open delta voltage 3Uo；
(1) PT secondary B phase voltage value U of power supply end corresponding to 110kV busaGreater than the setting value U1;
(2) PT secondary C-phase voltage value U of power supply end corresponding to 110kV busbGreater than the setting value U1;
(3) PT secondary A-phase voltage value U of 110kV bus corresponding to power supply endcGreater than the setting value U1;
(4) secondary voltage value 3U of power supply end corresponding to secondary opening triangle of bus PToIs less than the setting value U2;
(5) a power end 110kV line circuit breaker 4DL of a No. 1 110kV line is at a switching-on position;
when the conditions are all met, the voltage of a 110kV bus corresponding to a power end 110kV transformer substation is normal, and the normal voltage signal is transmitted to 110kV disconnection protection in 110kV line protection of a No. 1 110kV transformer substation under the load of the No. 1 110kV line through an optical fiber channel of No. 1 110kV power line optical fiber differential protection;
b. collection load end 110kV transformer substation I section bus PT secondary A phase voltage UaPhase U of B phase voltagebC phase voltage Uc Open delta voltage 3Uo；
(1) The PT secondary voltage value of the 110kV bus at the No. 1 110kV line open-circuit phase load end is lower than a setting value U3;
(2) the PT secondary voltage value of the 110kV bus at the 1 # 110kV line non-broken line phase 1 load end is greater than a setting value U1;
(3) the PT secondary voltage value of the 110kV bus at the No. 1 110kV line non-broken line phase 2 load end is greater than a setting value U1;
(4) the PT opening triangular secondary voltage value of the No. 1 110kV bus at the load end of the 110kV line is greater than a setting value U4;
(5) a load end 110kV line breaker 1DL of a No. 1 110kV line is at a switching-on position;
when the conditions are met, the abnormal voltage of the I section of the bus of the 110kV transformer substation at the load end is represented;
when the received power end 110kV transformer substation corresponds to a normal 110kV bus and the voltage of a first-section bus of the load end 110kV transformer substation is abnormal, identifying and judging that a No. 1 110kV power line is broken, delaying by t1 to protect the 110kV broken line in the protection of the 110kV line of the load end 110kV transformer substation, and after closing a standby power circuit breaker 2DL or 3DL, tripping off a circuit breaker 1DL on the load side of the No. 1 110kV power line to enable a transformer which loses power to be recovered to the standby power line for power supply; simultaneously starting a No. 1 110kV line disconnection alarm;
1.2 conditions for judging 1DL or 3DL of standby circuit breaker of No. 2 110kV line disconnection on-load end 110kV transformer substation and 2DL of tripping-off No. 2 incoming line circuit breaker, and conditions for starting No. 2 110kV line disconnection alarm
a. Collecting 110kV bus PT secondary A-phase voltage U corresponding to 110kV transformer substation at power supply endaPhase U of B phase voltagebC phase voltage Uc Open delta voltage 3Uo；
(1) The voltage value of the PT secondary B phase of the 110kV bus corresponding to the power supply end is greater than a setting value U1;
(2) the PT secondary C-phase voltage value of the power supply end corresponding to the 110kV bus is greater than a setting value U1;
(3) the voltage value of a PT secondary A phase of a 110kV bus corresponding to a power supply end is greater than a setting value U1;
(4) the secondary voltage value 3UO of the secondary opening triangle of the power supply end corresponding to the bus PT is smaller than the setting value U2;
(5) a power end 110kV line circuit breaker 5DL of a No. 2 110kV line is at a switching-on position;
the conditions are all met, and the condition indicates that the 110kV bus voltage corresponding to the 110kV transformer substation at the power end is normal; the normal voltage signal is transmitted to a 110kV disconnection protection in 110kV line protection of a load 110kV transformer substation of a No. 2 110kV line through an optical fiber channel of the No. 2 110kV power line optical fiber differential protection;
b. 110kV transformer for acquisition load endSecondary A-phase voltage U of II-section bus PT of power stationaPhase U of B phase voltagebC phase voltage Uc Open delta voltage 3Uo；
(1) The secondary voltage value of a No. 2 110kV line open-circuit phase load end 110kV bus PT is lower than a setting value U3;
(2) the PT secondary voltage value of the 110kV bus at the non-broken line phase 1 load end of the No. 2kV line is greater than a setting value U1;
(3) the secondary voltage value 3UO of the 110kV bus PT at the non-broken line phase 2 load end of the No. 2kV line is greater than the setting value U1;
(4) the PT opening triangular secondary voltage value of the No. 2 110kV line load end 110kV bus is greater than a setting value U4;
(5) a 110kV line breaker 1DL at a load end of a No. 2 110kV line is at a switching-on position;
when the conditions are met, the voltage abnormality of the second section of the bus of the 110kV transformer substation at the load end is represented;
when the received power end 220kV transformer substation corresponding to a 110kV bus is normal and the voltage of a second-section bus of the load end 110kV transformer substation is abnormal, identifying and judging that a No. 2 110kV power line is broken, delaying by t1 to protect the 110kV broken line in the protection of the 110kV line of the load end 110kV transformer substation, and after closing a standby power circuit breaker 2DL or 3DL, tripping off a circuit breaker 1DL on the load side of the No. 1 110kV power line to enable a transformer without a power supply to be recovered to the standby power line for power supply; and simultaneously, the No. 2 110kV line disconnection alarm is started.
1.3 in the above 1.1 and 1.2, the control method of 110kV line disconnection identification for comparing voltages at two sides of a 110kV power line is adopted, and is not only suitable for the 110kV neutral point ungrounded mode of the transformer, but also suitable for the 110kV neutral point grounded mode of the transformer.
The reason that the circuit breakers 1DL or 2DL and 4DL or 5DL on two sides of the incoming line of the 110kV power supply are arranged at the switching-on position is as follows: when a power supply incoming line carries a load end 110kV substation, the bus voltage far away from the power supply incoming line can also sense the line disconnection information, and the action behavior of the device can be interfered; in addition, when a line PT is adopted, the power incoming line may have other load end 110kV substations, and if the power incoming line breaker of the load end 110kV substation trips slowly or refuses tripping, the action behavior of the device can be interfered. The logic can be further optimized by adopting the condition that the circuit breakers on two sides of the incoming line of the 110kV power supply are in the switching-on position.
2. The 110kV neutral point operation mode of the main transformer on the I section or II section of the bus of the load end 110kV transformer substation is as follows: a) grounding; b) not grounded, grounded through the gap; the 110kV side is provided with a 110kV spare power automatic switching device. No. 1 and No. 2 power supply 110kV lines are required to be provided with fiber channels and line fiber differential protection.
3. The method is implemented in a single 110kV line disconnection protection device of a load end 110kV transformer substation or in a 110kV line protection device; the 110kV line protection device implemented in the 110kV transformer substation at the load end has the advantages that: no additional hardware devices are required.
The secondary setting value of the 110kV I section bus or II section bus broken line phase PT of the 4-load end 110kV transformer substation is as follows:
(1) load end 110kV bus PT secondary A phase voltage value UaPhase voltage value U of B phasebC phase voltage value UcThe setting value is as follows: the rated phase voltage value is less than or equal to 0.5 and is 1.1 times, namely 31.9V. Note: no more than 0.5 × 58 × 1.1 ═ 31.9V
(2) The voltage setting value of the PT opening triangle of the 110kV bus is as follows: take 0.9 times the rated line voltage value. Taking 90V, and injecting: 0.9 × 100V ═ 90V;
the secondary PT setting value of the 110kV bus of the power supply end 110kV transformer substation when the 4110 kV line is disconnected is as follows:
(1) PT secondary A-phase voltage value U of power supply end 110kV busaPhase voltage value U of B phasebC phase voltage value UcThe setting value is as follows: the phase rated voltage value is not more than 90 percent, namely not more than 52.2V. (Note) 58V 0.9 ═ 52.2V
(2) The voltage setting value of the PT opening triangle of the 110kV bus is as follows: when the voltage value is larger than the unbalanced voltage value in normal operation, taking 4-8V; for example, it may be 5V.
5, the setting value of the time in the single-phase disconnection relay protection method for transferring power supply by adopting ring closing and opening operation in the load end 110kV transformer substation is as follows:
the t1 time is set as: three-phase different-period time when the switch is closed is avoided: taking for 0.1-0.2 seconds;
6. the inventive solution can be used in the following cases: (1) the 110kV neutral point operation mode of all transformers of a load end 110kV transformer substation is as follows: a) grounding; b) not grounded, grounded through the gap; (2) a spare power automatic switching device is arranged on the 110kV side of the 110kV transformer substation; (3) no. 1 and No. 2 power supply 110kV lines are required to be provided with fiber channels and line fiber differential protection.
And can satisfy the following primary main wiring: (1) a 110kV single-bus subsection primary main wiring of a 110kV transformer substation; (2) a 110kV transformer substation 110kV inner bridge primary main wiring; (3) a 110kV substation 110kV primary main wiring is enlarged; (4)110kV transformer substation 110kV line group primary main wiring; (5) a primary main wiring of a 110kV line transformer bank; (6) other primary main connections.
7. If the 110kV transformer substation adopts primary main wiring of a 110kV line transformer set, a standby circuit breaker on the high-low voltage side of the 110kV transformer is adopted on the low-low voltage side of the load side transformer substation, and a power supply task is recovered.
8. For a 110kV line with branch lines, 110kV line breakage protection of pairwise correspondence between a power end transformer substation and each load end transformer substation needs to be implemented.
9. The scheme of the invention can also be used in the case of the disconnection of a 220kV line powered by a single power supply.
An embodiment of the method of the present invention is given below, taking fig. 12 as an example, and the operation mode of the transformer 110kV neutral point is as follows: not grounded, grounded through the gap;
1 operating mode 1
Under this operational mode, 2DL of No. 2 power circuit breaker, the operation of segmentation circuit breaker 3DL, 1DL of No. 1 power circuit breaker is hot standby, 1DL of No. 1 power circuit breaker branch floodgate position promptly.
No. 1.12 110kV power line single-phase line break fault
For example, if phase A is broken, phase B or phase C is broken similarly. When the A phase single-phase disconnection fault of the No. 2 110kV power line occurs, the method is equivalent to pulling a disconnecting switch with load, an electric arc is generated at the disconnection moment, the electric arc cannot be extinguished, the electric arc is further developed to cause the A phase single-phase grounding of the line, and the protection starting action of the distance I section or the section II of the superior No. 2 power line jumps from a power side circuit breaker 5DL of the superior No. 2kV power line within the protection range of the distance I section or the section II of the superior No. 2 power line; after a first section or a second section of buses of a load end 110kV substation lose power, the fault at the phase A disconnection position of a No. 2 110kV power line disappears, and the upper level No. 2kV power line power side circuit breaker 5DL is delayed to be successfully superposed; however, the voltage inductance of the II section of the bus of the load-side substation runs in a phase-loss mode, the PT secondary voltage of the 110kV bus of the power supply end substation is normal, the condition that the single-phase disconnection of the No. 2 110kV power supply line is met, after the time delay t1, the 110kV line in the load-side line protection is protected, after the No. 1 110kV standby power supply circuit breaker 1DL is started to be switched on, the No. 2 110kV power supply incoming line circuit breaker 2DL of the load-side 110kV substation is switched off, and the No. 1, No. 2 and No. 3 transformers losing power supplies power to the standby No. 1 110kV power supply line.
2 operating mode 2
Under this operational mode, 1DL of power breaker, 3DL operation of section circuit breaker, 2 # power breaker 2DL are hot standby, 2 # power breaker 2DL separating brake position promptly.
No. 2.11 110kV power line single-phase line break fault
For example, if phase A is broken, phase B or phase C is broken similarly. When the A phase single-phase line break fault of the No. 1 110kV power line occurs, the method is equivalent to pulling a disconnecting switch with load, electric arcs are generated at the line break moment, the electric arcs cannot be extinguished, the electric arcs further cause the A phase single-phase grounding of the line, and the protection starting action of the No. 1 power line at the section I or the section II of the distance between the No. 1 power line at the upper level jumps away from a circuit breaker 4DL at the power supply side of the No. 1 power line at the upper level because the distance between the No. 1 power line at the upper level and the section I or the; after the load end 110kV substation loses power, the phase disconnection fault of the No. 1 110kV power line A disappears, and the superposition of the No. 1 110kV power line power side circuit breaker 4DL is successful after the time delay; however, the I section bus voltage of the load end transformer substation is subjected to open-phase operation, the PT secondary voltage of the 110kV bus of the power end transformer substation is normal, the condition that the single-phase disconnection of the No. 1 110kV power supply line is met, after the time delay t1, the 110kV line in the load end line protection is protected, after the 2 # 110kV standby power supply circuit breaker 2DL is started to be switched on, the 1 # 110kV power supply incoming line circuit breaker 1DL of the load end 110kV transformer substation is tripped, and the No. 1, No. 2 and No. 3 transformers losing power supplies are recovered to the No. 2 110kV standby power supply line for power supply.
3 operating mode 3
Under this operational mode, 1DL of No. 1 power circuit breaker, 2DL of No. 2 power circuit breaker operate, and the hot reserve of section circuit breaker 3DL, section circuit breaker 3DL separating brake position promptly.
No. 3.11 110kV power line single-phase line break fault
For example, if phase A is broken, phase B or phase C is broken similarly. When the A phase single-phase disconnection fault of the No. 1 110kV power line occurs, the method is equivalent to pulling the isolating switch with load, electric arcs are generated at the disconnection moment, the electric arcs cannot be extinguished, the electric arcs further cause the A phase single-phase grounding of the line, and the protection starting action of the No. 1 superior 110kV power line is tripped out of a power supply side circuit breaker 4DL of the No. 1 superior power line within the protection range of the No. 1 superior power line from the No. 1 superior power; after a load end substation loses power, the fault of the phase disconnection position of a 110kV power line A disappears, and the superposition of a circuit breaker 4DL on the power side of a No. 1 delayed 110kV power line is successful; however, the I section bus voltage inductance of the load end transformer substation is in open-phase operation, the PT secondary voltage of the 110kV bus of the power end transformer substation is normal, the condition that the 1 # 110kV power line is single-phase broken is met, after the time delay t1, the 110kV line in the load end line protection is protected, after the 110kV standby power circuit breaker 3DL is started to be switched on, the 1 # 110kV power incoming circuit breaker 1DL of the load end transformer substation is tripped, and the 1 # and 2 # transformers losing power supply are recovered to the 2 # 110kV standby power line for power supply.
No. 3.22 110kV power line single-phase line break fault
For example, if phase A is broken, phase B or phase C is broken similarly. When the phase-A single-phase disconnection fault of the No. 2 110kV power line occurs, the method is equivalent to pulling the isolating switch with load, electric arcs are generated at the disconnection moment, the electric arcs cannot be extinguished, the electric arcs further cause the phase-A single-phase grounding of the line, and the protection starting action of the section I or the section II of the distance between the upper level No. 2kV power line and the upper level No. 2 power line jumps away from the circuit breaker 5DL at the power supply side of the upper level No. 2 power line because the distance between the upper level No. 2kV power line and the section I or the; after a 110kV II section bus of a load end 110kV substation loses power, a fault at the phase A disconnection position of a 110kV power line disappears, a circuit breaker 5DL at the line power side of a No. 2 delayed 110kV power side line is successfully superposed, but voltage inductance of a II section bus of the load end 110kV substation is in open-phase operation, PT secondary voltage of the II section bus meets the condition 1 for identifying the 110kV line single-phase disconnection, the No. 2 110kV power line A phase single-phase disconnection fault is sent out by time delay t1, after time delay of t2, a 110kV standby power circuit breaker 3DL is started, the No. 1 kV power incoming circuit breaker 1DL of the load end substation is tripped, and a No. 3 transformer which loses power is recovered to a standby No. 2 110kV power line for power supply.
Single-phase line break fault of No. 2.22 110kV power line
For example, if phase A is broken, phase B or phase C is broken similarly. When the A phase single-phase disconnection fault of the No. 2 110kV power line occurs, the method is equivalent to pulling a disconnecting switch with load, electric arcs are generated at the disconnection moment, the electric arcs cannot be extinguished, the electric arcs further cause the A phase single-phase grounding of the line, and the distance between the first section and the second section of the superior No. 2 power line is within the protection range of the first section or the second section of the superior No. 2 power line, so that the superior No. 2 power line is protected and started or the optical fiber differential protection action jumps away from a load side circuit breaker 5DL of the superior No. 2 power line; after the II-section bus of the load-end substation loses power, the fault at the phase-disconnection position A of the No. 2 110kV power line disappears, and the superposition of the No. 2 110kV power line load-side circuit breaker 5DL is successful after the time delay; however, the voltage inductance of the II-section bus of the load-side substation runs in a phase-loss mode, the PT secondary voltage of the 110kV bus of the power supply end substation is normal, the condition that the single-phase disconnection of the No. 2 110kV power supply line is met, after the time delay t1, the 110kV line in the load-side line protection is protected, after the 110kV standby power supply circuit breaker 3DL is started to be switched on, the No. 2 110kV power supply line load-side circuit breaker 5DL is switched off, and the transformer without the power supply is enabled to be recovered to the standby No. 1 110kV power supply line for power supply.
In addition to the above embodiments, the present invention may have other embodiments, and any technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of the claims of the present invention.

Claims (3)

1. A110 kV line disconnection relay protection method for comparing voltages on two sides of a line is characterized by comprising the following steps:
first, the condition of tripping on the incoming line breaker after judging that the 110kV line is broken and the load end of the 110kV substation is closed and the standby breaker is opened
1.1 conditions for judging incoming line breaker 2DL or sectional breaker 3DL and tripping incoming line breaker 1DL of No. 1 110kV line broken line closing load end 110kV transformer substation and starting No. 1 110kV line broken line alarm condition
a. Collecting 110kV bus PT secondary A-phase voltage U corresponding to 110kV transformer substation at power supply endaPhase U of B phase voltagebC phase voltage UcOpen delta voltage 3Uo；
(1)110kV transformer substation corresponding 110kV bus PT secondary A-phase voltage U at power endaGreater than the setting value U1;
(2)110kV transformer substation corresponding 110kV bus PT secondary B phase voltage U at power endbGreater than the setting value U1;
(3)110kV transformer substation corresponding 110kV bus PT secondary c-phase voltage U at power supply endcGreater than the setting value U1;
(4) secondary voltage value 3U of power supply end corresponding to secondary opening triangle of bus PToIs less than the setting value U2;
(5) a power end 110kV line circuit breaker 4DL of a No. 1 110kV line is at a switching-on position;
when the conditions are all met, the voltage of a 110kV bus corresponding to a power end 110kV transformer substation is normal, and the normal voltage signal is transmitted to 110kV disconnection protection in 110kV line protection of a No. 1 110kV transformer substation under the load of the No. 1 110kV line through an optical fiber channel of No. 1 110kV power line optical fiber differential protection;
b. collection load end 110kV transformer substation I section bus PT secondary A phase voltage UaPhase U of B phase voltagebC phase voltage UcOpen delta voltage 3Uo；
(1) The PT secondary voltage value of the 110kV bus at the No. 1 110kV line open-circuit phase load end is lower than a setting value U3;
(2) the PT secondary voltage value of the 110kV bus at the 1 # 110kV line non-broken line phase 1 load end is greater than a setting value U1;
(3) the PT secondary voltage value of the 110kV bus at the No. 1 110kV line non-broken line phase 2 load end is greater than a setting value U1;
(4) the PT opening triangular secondary voltage value of the No. 1 110kV bus at the load end of the 110kV line is greater than a setting value U4;
(5) an incoming line breaker 1DL of a No. 1 110kV line is in a switching-on position;
when the conditions are met, the abnormal voltage of the I section of the bus of the 110kV transformer substation at the load end is represented;
when the received 110kV transformer substation of the power supply end corresponds to a normal 110kV bus and the voltage of a first-section bus of the 110kV transformer substation of the load end is abnormal, identifying and judging that a No. 1 110kV power line is broken, delaying the 110kV broken line protection action in the No. 1 110kV line protection of the 110kV transformer substation of the load end by t1, starting closing an incoming line breaker 2DL or a sectional breaker 3DL, and tripping the incoming line breaker 1DL to enable a transformer without a power supply to recover to a standby power line for power supply; simultaneously starting a No. 1 110kV line disconnection alarm;
1.2 conditions for judging 1DL of on-line incoming breaker or 3DL of sectional breaker and 2DL of off-line incoming breaker of No. 2 110kV line disconnection, and conditions for starting No. 2 110kV line disconnection alarm
a. Collecting 110kV bus PT secondary A-phase voltage U corresponding to 110kV transformer substation at power supply endaPhase U of B phase voltagebC phase voltage UcOpen delta voltage 3Uo；
(1) The voltage value of the PT secondary B phase of the 110kV bus corresponding to the power supply end is greater than a setting value U1;
(2) the PT secondary C-phase voltage value of the power supply end corresponding to the 110kV bus is greater than a setting value U1;
(3) the voltage value of a PT secondary A phase of a 110kV bus corresponding to a power supply end is greater than a setting value U1;
(4) the secondary voltage value 3UO of the secondary opening triangle of the power supply end corresponding to the bus PT is smaller than the setting value U2;
(5) a power end 110kV line circuit breaker 5DL of a No. 2 110kV line is at a switching-on position;
the conditions are all met, and the condition indicates that the 110kV bus voltage corresponding to the 110kV transformer substation at the power end is normal; the normal voltage signal is transmitted to a 110kV disconnection protection in 110kV line protection of a load 110kV transformer substation of a No. 2 110kV line through an optical fiber channel of the No. 2 110kV power line optical fiber differential protection;
b. collecting PT secondary A-phase voltage U of II-section bus of 110kV transformer substation at load endaPhase U of B phase voltagebC phase voltage UcOpen delta voltage 3Uo；
(1) The secondary voltage value of a No. 2 110kV line open-circuit phase load end 110kV bus PT is lower than a setting value U3;
(2) the PT secondary voltage value of the 110kV bus at the non-broken line phase 1 load end of the No. 2kV line is greater than a setting value U1;
(3) the secondary voltage value 3UO of the 110kV bus PT at the non-broken line phase 2 load end of the No. 2kV line is greater than the setting value U1;
(4) the PT opening triangular secondary voltage value of the No. 2 110kV line load end 110kV bus is greater than a setting value U4;
(5) the incoming line breaker 1DL is at the closing position;
when the conditions are met, the voltage abnormality of the second section of the bus of the 110kV transformer substation at the load end is represented;
when the received power end 220kV transformer substation corresponding to a 110kV bus is normal and the voltage of a second-section bus of the load end 110kV transformer substation is abnormal, identifying and judging that a No. 2 110kV power line is broken, delaying by t1 to perform 110kV broken line protection action in the No. 2 110kV line protection of the load end 110kV transformer substation, starting closing an incoming line breaker 2DL or a segmented breaker 3DL, and tripping an incoming line breaker 1DL to enable a transformer without a power supply to recover to a standby power line for power supply; and simultaneously, the No. 2 110kV line disconnection alarm is started.
2. The 110kV line disconnection relay protection method for comparing voltages at two sides of a line as claimed in claim 1, wherein:
setting value U1 is 0.9Ea, Ea is a phase voltage value, and the corresponding PT secondary voltage is 58V; 0.9 Ea-52.2V; setting value U2 is between 4 and 8V; the setting value U3 is 0.55Ea, namely 31.9V; setting value U4 is 0.9Eab, which is PT secondary opening triangle rated voltage value, and Eab is 100V.
3. The 110kV line disconnection relay protection method for comparing voltages at two sides of a line as claimed in claim 1, wherein: and setting the t1 time to avoid three-phase different-phase time when the switch is closed, and taking 0.1-0.2 second.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106505546A (en) * 2016-11-16 2017-03-15 安徽合凯电气科技股份有限公司 High-speed switch type arc-extinguishing resonance-extinguishing device and its operation method
US10468964B1 (en) * 2019-04-03 2019-11-05 Phasor Ltd Detection and compensation of power phase loss

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109738758B (en) * 2019-01-22 2021-07-27 贵州电网有限责任公司 Distribution network line fault type judgment method based on voltage characteristics
CN110542827B (en) * 2019-01-31 2020-08-07 华北电力大学 Method and system for judging fault direction of power distribution network containing inverter type power supply
CN110376483B (en) * 2019-07-01 2020-06-16 浙江大学 Direct current island detection method based on bus voltage positive feedback of specific frequency

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106505546A (en) * 2016-11-16 2017-03-15 安徽合凯电气科技股份有限公司 High-speed switch type arc-extinguishing resonance-extinguishing device and its operation method
US10468964B1 (en) * 2019-04-03 2019-11-05 Phasor Ltd Detection and compensation of power phase loss

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
配电线路单相断线故障保护方法;康奇豹;《电力系统保护与控制》;20190416;第47卷(第8期);全文 *

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