CN105119253A - Demarcation switching zero-sequence current protection setting value calculation method - Google Patents
Demarcation switching zero-sequence current protection setting value calculation method Download PDFInfo
- Publication number
- CN105119253A CN105119253A CN201510578459.4A CN201510578459A CN105119253A CN 105119253 A CN105119253 A CN 105119253A CN 201510578459 A CN201510578459 A CN 201510578459A CN 105119253 A CN105119253 A CN 105119253A
- Authority
- CN
- China
- Prior art keywords
- current
- demarcation switch
- circuit
- fault
- capacitance
- 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.)
- Pending
Links
Abstract
The invention discloses a demarcation switching zero-sequence current protection setting value calculation method, and the method comprises the following steps: respectively measuring a capacitive current of a power supply system, then calculating a constant current of a demarcation switch of the power supply system, and then judging that Idz value is greater than the capacitive current of a circuit of the demarcation switch; setting the direction of the capacitive current to point to a grounding point when a grounding fault happens to the system, judging that a zero-sequence current passing through a fault demarcation switch is the capacitive current of the system, and is not related with the capacitive current of the circuit, wherein a zero-sequence current passing through a non-fault circuit demarcation switch is the capacitive current of the circuit, and is not related with the capacitive current of the system. The method is advantageous in that the method prevents air humidity from affecting constant value calculation; the method prevents the unclear quality of a circuit load (the length of a cable circuit is not precise because the cable circuit is buried underground) from affecting the constant value calculation; and the method can prevent a constant value from being modified when the circuit is changed in a small scale, and reduces the workload.
Description
Technical field
The present invention relates to a kind of power system power supply technology, specifically a kind of operating efficiency high, calculate demarcation switch zero-sequence current protection setting value computational methods accurately.
background technology:
Along with expanding economy, the requirement of client to power supply quality is more and more higher, and require as far as possible few power failure, portions of client even proposes the requirement that do not have a power failure.To earth fault be got rid of in the past, and need that power failure examination is carried out to the every bar circuit under same bus and draw, be i.e. line outage one by one, circuit of fixing a breakdown.This not only can cause electric quantity loss, and also can affect production and daily life, power supply reliability suffers customer complaint, and in addition, cable line ground connection naked eyes cannot judge, reason be found to fix a breakdown, can only lean on apparatus measures.But the supply line of 10kV is often very long, if catch up with sleety weather, larger difficulty can be brought to line walking work.During another line-to-ground, Earth Phase voltage drop, earth-free phase voltage raises, and causes rate of qualified voltage to decline.
Demarcation switch is generally arranged on branch line circuit or user place, and when line failure, the timely correct operation of demarcation switch, is conducive to isolated fault rapidly, looking up the fault point, fast quick-recovery power transmission.This not only can be avoided unnecessary electric quantity loss, reduces customer complaint number of times, can also reduce line walking workload.
At present, without in the system of arc suppression coil, the zero-sequence current of 10kV distribution line demarcation switch calculates according to the capacitance current of circuit, and computing formula is Ic=0.27UL(overhead wire) × 0.01+0.1UL(cable),
I
dz=K
k×Ic。(I
dzfor calculating definite value electric current, K
kfor safety factor, Ic is capacitance current).Namely capacitance current is relevant with the medium of circuit, length, the span of fixed value calculation by after this demarcation switch the parameter of band circuit, comprise the length of overhead wire and cable.When after demarcation switch be with circuit shorter time, or when cable line is more, the correctness of cable line length, produces significant impact to whole calculated value.In addition, the calculating of definite value is subject to the character of circuit institute on-load, weather effect larger.Especially, when there is sleety weather, when namely air humidity is larger, the impact that its capacitance current is subject to air humidity can become large, causes the setting value of calculating less than normal, and the impact of weather can not accurately be grasped, and easily causes demarcation switch misoperation.When the length etc. of circuit changes, definite value, just along with change, does not have certain elasticity number interval, and change definite value quite bothers.
Summary of the invention
The object of the invention is to overcome the deficiencies in the prior art, provide a kind of operating efficiency high, calculate accurately, the demarcation switch zero-sequence current protection setting value computational methods of system stable operation needs can be met.
The present invention can be reached by following measure:
A kind of demarcation switch zero-sequence current protection setting value computational methods, is characterized in that step is as follows:
Step 1, record the capacitance current of electric power system respectively, pass through formulae discovery:
Ic=0.27UL(overhead wire) × 0.01+0.1UL(cable), Ic
systemfor the capacitance current of system, UL is length,
The definite value electric current of step 2, calculating electric power system demarcation switch, the capacitance current input formula by recording:
I
dz=Ic
system/ K
lm.I
dzfor calculating definite value electric current, K
lmfor sensitivity, K
lmvalue is 2-3, Ic
systemfor the capacitance current of system,
Step 3, judgement, I
dzvalue be greater than demarcation switch capacitance current with circuit, both can not cause non-faulting switch motion, fault demarcation switch correct operation; When system generation earth fault, earth point is pointed to by system in capacitance current direction, then the zero-sequence current flowing through fault demarcation switch is system capacitive current, is with line capacitance electric current irrelevant with institute itself; And the zero-sequence current flowing through non-fault line demarcation switch to be institute itself be with line capacitance electric current, irrelevant with system capacitive current.
Ic in the present invention
branch line circuit is maximum< I
dz< Ic
system, make the definite value electric current calculated much larger than each line capacitance electric current, both ensure that the action of fault demarcation switch, and can ensure that again fault-free demarcation switch was failure to actuate.
If the present invention's demarcation switch correct operation, then can directly branch line circuit after it be cut off, do not affect All other routes normal power supply, reduce the impact that external factor causes demarcation switch correct operation, realize the raising of demarcation switch action correctness, tool has the following advantages: one is avoid air humidity reason, on the impact that fixed value calculation causes, two is avoid line load character unclear (cable line owing to being embedded in underground, its length inaccuracy), on the impact that fixed value calculation causes.Three is when circuit changes among a small circle, can avoid changing definite value, reduces workload.
Embodiment
The invention will be further described below:
A kind of demarcation switch zero-sequence current protection setting value computational methods, is characterized in that step is as follows:
Step 1, record the capacitance current of electric power system respectively, pass through formulae discovery:
Ic=0.27UL(overhead wire) × 0.01+0.1UL(cable), Ic
systemfor the capacitance current of system, UL is length,
The definite value electric current of step 2, calculating electric power system demarcation switch, the capacitance current input formula by recording:
I
dz=Ic
system/ K
lm.I
dzfor calculating definite value electric current, K
lmfor sensitivity, K
lmvalue is 2-3, Ic
systemfor the capacitance current of system,
Step 3, judgement, I
dzvalue be greater than demarcation switch capacitance current with circuit, both can not cause non-faulting switch motion, fault demarcation switch correct operation; When system generation earth fault, earth point is pointed to by system in capacitance current direction, then the zero-sequence current flowing through fault demarcation switch is system capacitive current, is with line capacitance electric current irrelevant with institute itself; And the zero-sequence current flowing through non-fault line demarcation switch to be institute itself be with line capacitance electric current, irrelevant with system capacitive current.
Ic in the present invention
branch line circuit is maximum< I
dz< Ic
system, make the definite value electric current calculated much larger than each line capacitance electric current, both ensure that the action of fault demarcation switch, and can ensure that again fault-free demarcation switch was failure to actuate.
If the present invention's demarcation switch correct operation, then can directly branch line circuit after it be cut off, do not affect All other routes normal power supply, reduce the impact that external factor causes demarcation switch correct operation, realize the raising of demarcation switch action correctness, tool has the following advantages: one is avoid air humidity reason, on the impact that fixed value calculation causes, two is avoid line load character unclear (cable line owing to being embedded in underground, its length inaccuracy), on the impact that fixed value calculation causes.Three is when circuit changes among a small circle, can avoid changing definite value, reduces workload.
Before employing the method, carry out any circuit among a small circle relating to demarcation switch branch line circuit in system and cut when changing, all will carry out definite value change to demarcation switch.After employing the method, fixed value calculation leaves certain nargin, can not change frequently, decrease workload.
Claims (2)
1. demarcation switch zero-sequence current protection setting value computational methods, is characterized in that step is as follows:
Step 1, record the capacitance current of electric power system respectively, pass through formulae discovery:
Ic=0.27UL(overhead wire) × 0.01+0.1UL(cable), Ic
systemfor the capacitance current of system, UL is length,
The definite value electric current of step 2, calculating electric power system demarcation switch, the capacitance current input formula by recording:
I
dz=Ic
system/ K
lm,
I
dzfor calculating definite value electric current, K
lmfor sensitivity, K
lmvalue is 2-3, Ic
systemfor the capacitance current of system,
Step 3, judgement, I
dzvalue be greater than demarcation switch capacitance current with circuit, both can not cause non-faulting switch motion, fault demarcation switch correct operation; When system generation earth fault, earth point is pointed to by system in capacitance current direction, then the zero-sequence current flowing through fault demarcation switch is system capacitive current, is with line capacitance electric current irrelevant with institute itself; And the zero-sequence current flowing through non-fault line demarcation switch to be institute itself be with line capacitance electric current, irrelevant with system capacitive current.
2. a kind of demarcation switch zero-sequence current protection setting value computational methods according to claim 1, is characterized in that Ic
branch line circuit is maximum< I
dz< Ic
system, make the definite value electric current calculated much larger than each line capacitance electric current, both ensure that the action of fault demarcation switch, and can ensure that again fault-free demarcation switch was failure to actuate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510578459.4A CN105119253A (en) | 2015-09-14 | 2015-09-14 | Demarcation switching zero-sequence current protection setting value calculation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510578459.4A CN105119253A (en) | 2015-09-14 | 2015-09-14 | Demarcation switching zero-sequence current protection setting value calculation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105119253A true CN105119253A (en) | 2015-12-02 |
Family
ID=54667179
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510578459.4A Pending CN105119253A (en) | 2015-09-14 | 2015-09-14 | Demarcation switching zero-sequence current protection setting value calculation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105119253A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106469905A (en) * | 2016-11-11 | 2017-03-01 | 国网山东省电力公司枣庄供电公司 | Distribution network protection method based on distribution " three lines of defence " |
| CN107167701A (en) * | 2017-03-06 | 2017-09-15 | 国网浙江义乌市供电公司 | Automatically method is sentenced in choosing to distribution singlephase earth fault circuit |
| CN110265972A (en) * | 2019-06-14 | 2019-09-20 | 华中科技大学 | A kind of zero-sequence current protection setting method |
| CN110501611A (en) * | 2019-08-26 | 2019-11-26 | 珠海许继电气有限公司 | A kind of power distribution network complete fibre Fault Locating Method and system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101604838A (en) * | 2009-07-22 | 2009-12-16 | 天津市电力公司 | A kind of method of selecting to excise fault point in the step down side double branch circuits |
| CN102998582A (en) * | 2012-11-16 | 2013-03-27 | 宁海县供电局 | Detection method of distributing line phase short circuit fault and single phase grounding fault |
| CN203071571U (en) * | 2013-01-10 | 2013-07-17 | 永康市供电局 | Intelligent monitoring device for distributed boundary switches |
| CN103901322A (en) * | 2014-03-31 | 2014-07-02 | 国家电网公司 | Small current grounding fault defining method based on power frequency zero sequence voltage and power frequency zero sequence current of defining switch |
| CN104020394A (en) * | 2014-04-30 | 2014-09-03 | 河北工程大学 | Network technology based low-current line selection method of power supply system |
| CN104393582A (en) * | 2014-11-07 | 2015-03-04 | 国网浙江慈溪市供电公司 | Intelligent demarcation switch |
-
2015
- 2015-09-14 CN CN201510578459.4A patent/CN105119253A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101604838A (en) * | 2009-07-22 | 2009-12-16 | 天津市电力公司 | A kind of method of selecting to excise fault point in the step down side double branch circuits |
| CN102998582A (en) * | 2012-11-16 | 2013-03-27 | 宁海县供电局 | Detection method of distributing line phase short circuit fault and single phase grounding fault |
| CN203071571U (en) * | 2013-01-10 | 2013-07-17 | 永康市供电局 | Intelligent monitoring device for distributed boundary switches |
| CN103901322A (en) * | 2014-03-31 | 2014-07-02 | 国家电网公司 | Small current grounding fault defining method based on power frequency zero sequence voltage and power frequency zero sequence current of defining switch |
| CN104020394A (en) * | 2014-04-30 | 2014-09-03 | 河北工程大学 | Network technology based low-current line selection method of power supply system |
| CN104393582A (en) * | 2014-11-07 | 2015-03-04 | 国网浙江慈溪市供电公司 | Intelligent demarcation switch |
Non-Patent Citations (1)
| Title |
|---|
| 张志霞: "《小电流接地系统单相接地故障选线理论研究》", 30 April 2014, 辽宁科学技术出版社 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106469905A (en) * | 2016-11-11 | 2017-03-01 | 国网山东省电力公司枣庄供电公司 | Distribution network protection method based on distribution " three lines of defence " |
| CN107167701A (en) * | 2017-03-06 | 2017-09-15 | 国网浙江义乌市供电公司 | Automatically method is sentenced in choosing to distribution singlephase earth fault circuit |
| CN110265972A (en) * | 2019-06-14 | 2019-09-20 | 华中科技大学 | A kind of zero-sequence current protection setting method |
| CN110265972B (en) * | 2019-06-14 | 2020-10-16 | 华中科技大学 | Zero-sequence current protection setting method |
| CN110501611A (en) * | 2019-08-26 | 2019-11-26 | 珠海许继电气有限公司 | A kind of power distribution network complete fibre Fault Locating Method and system |
| CN110501611B (en) * | 2019-08-26 | 2021-07-06 | 珠海许继电气有限公司 | Full-line quick-action fault positioning method and system for power distribution network |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103116107B (en) | A kind of high-voltage DC power supply insulating monitor | |
| CN109031000B (en) | A kind of method and system based on non-faulting disturbance In situ Measurement grid short circuit capacity | |
| Ren et al. | An accurate synchrophasor based fault location method for emerging distribution systems | |
| US8665102B2 (en) | Transceiver interface for power system monitoring | |
| CN102135571B (en) | Anti-interference measurement method for zero sequence impedance of super-high-voltage/ultrahigh-voltage multi-loop power transmission line | |
| CN101957396B (en) | On-line monitoring device and method for voltage quality of electric power system | |
| CN104076243A (en) | Method for detection and indication of single-phase ground faults of small current grounding power distribution network and device | |
| CN103454517A (en) | Method for online monitoring capacitive voltage transformers | |
| CN105119253A (en) | Demarcation switching zero-sequence current protection setting value calculation method | |
| CN105652152B (en) | A kind of Fault Locating Method and system of multiple line direct supply system contact net | |
| CN103633629A (en) | High-voltage direct current power transmission line protection method based on wavelet transformation and energy spectrum analysis | |
| CN104253421A (en) | Relay protection optimal configuration method for double-circuit lines on same pole based on substation area information sharing | |
| CN103050980B (en) | Low-voltage capacitance compensating system and control method | |
| CN113241853B (en) | Intelligent diagnosis and early warning method and system for capacitance current of transformer substation | |
| CN103116116A (en) | Judging method and device of over line stoppage property of same pole double-circuit line with paralleling reactor | |
| CN204067890U (en) | Change low-pressure line-outgoing control cubicle for two yuan | |
| CN103983890A (en) | Search method for fault points generated due to the influence of alternating current crosstalk on relay and test circuit | |
| CN104020393B (en) | A kind of with electrical network one-phase short-circuit current Fault Locating Method | |
| CN103048533A (en) | Switch cabinet online monitor easy in information acquisition | |
| CN102832601B (en) | Coal mine high-voltage electricity leakage protecting method based on phase current time-division specific values | |
| CN202221434U (en) | Measurement auxiliary operating platform with insulation megger | |
| CN104242270A (en) | Passive anti-island protection maloperation preventing method | |
| CN103066691A (en) | Alternating current-direct current double-input single-output power distribution system with interlocking switchover function | |
| Guanghui et al. | Research and application of monitoring method of small current grounding fault in distribution line based on cloud computing | |
| Lakshmi et al. | Significance of wavelet and IOT techniques in micro-grid based power system protection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20151202 |
|
| RJ01 | Rejection of invention patent application after publication |