CN105375436A - Automatic cutoff protection apparatus and method for overtime operation of neutral-point resistor cabinet - Google Patents
Automatic cutoff protection apparatus and method for overtime operation of neutral-point resistor cabinet Download PDFInfo
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- CN105375436A CN105375436A CN201510929959.8A CN201510929959A CN105375436A CN 105375436 A CN105375436 A CN 105375436A CN 201510929959 A CN201510929959 A CN 201510929959A CN 105375436 A CN105375436 A CN 105375436A
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- excises
- time
- neutral point
- grounding
- voltage
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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
-
- 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
- H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
Abstract
The invention provides an automatic cutoff protection apparatus and method for overtime operation of a neutral-point resistor cabinet. The apparatus comprises an acquisition unit used for acquiring voltage and current signals, a switching apparatus used for switching off a grounding resistor loop, and a control unit used for judging whether a system has a single-phase grounding fault or not and controlling the switching apparatus to switch off the grounding resistor loop. According to the automatic cutoff protection apparatus and method, a protective action signal can be emitted when the single-phase grounding fault of the system occurs and a fault line is still not tripped off under the condition that design time of a grounding resistor is exceeded through monitoring judgment by functions of routine monitoring control, information communication and the like of the normal neutral-point resistor cabinet, and the grounding resistor loop is quickly switched off by utilizing the resistor switching apparatus, so that the safety of the grounding resistor, a grounding transformer and a power supply system is protected.
Description
Technical field
The present invention relates to power domain, particularly relate to a kind of neutral point resistor cabinet overrun and automatically excise protective device and method.
Background technology
Neutral grounding mode relates to security reliability, the economy of electrical network; The simultaneously directly selection of the apparatus insulated level of influential system, overvoltage level and the means of relay protection, communication interference etc.In general, the voltage neutral point earthing modes at different levels of transformer in Power Network Neutral i.e. electric substation, neutral non-effective grounding mode mainly can be divided into following three kinds: earth-free, through grounding through arc and resistance grounded, in the electric power system of China's medium voltage network, major part is small current neutral grounding system, i.e. isolated neutral or through arc suppression coil or resistance grounded system
At present, in the AC network of China, particularly adopt grounding through resistance increasingly extensive with the network of cable power supply.Neutral Grounding through Resistance in Electrical is exactly a certain resistor of access of connecting between neutral point of electric network with ground; the resistance of suitable selection institute termination resistor; not only can to release the energy of half-wave after single-phase earthing electric arc; thus reduce the possibility of arc reignition; suppress the spoke value of power network overvoltage; can also improve the sensitivity of protective device to act on tripping operation, thus available protecting system is normally run.When system single-phase earthing, perfect phase voltage do not raise or increasing degree less, lower to apparatus insulated class requirement, its withstand voltage level can be selected by phase voltage.During ground connection, because the electric current flowing through faulty line is comparatively large, zero-sequencedirectional protection has good sensitivity, can than being easier to inspection except ground path.But because the electric current of earth point is comparatively large, when zero-sequenceprotection action not in time or tripping time, by making earth point and neighbouring insulation be subject to larger harm, cause phase-to phase fault to occur.When there is single phase ground fault, no matter being permanent or volatile, all acting on tripping operation, the tripping operation number of times of circuit being increased greatly, has had a strong impact on the normal power supply of user, made the reliability decrease that it is powered.
Neutral point resistor cabinet, as one of conventional neutral grounding mode of China's electric power system, is the equipment as very important fault current available protecting when there is single phase ground fault in electric power system.But the ground protection time of the general resistor box design of the characteristic based on resistance material all presses 10 seconds rated designs; and on-the-spot arrange to protect between improper or power plant construction turn(a)round once relaying protection do not throw; very easily occur to cause resistance to burn because the earth fault line trip time exceedes the resistor designs time and grounding transformer burns, and draw fault and spread and cause more severe failure accident.
Summary of the invention
In view of this, the invention provides a kind of neutral point resistor cabinet overrun and automatically excise protective device, to solve the problem.
Neutral point resistor cabinet overrun provided by the invention excises protective device automatically, comprises
For gather voltage and current signal collecting unit, for disconnect earth resistance loop switching device and for judging whether system single phase ground fault occurs and control described switching device to disconnect the control unit in earth resistance loop,
The output of described collecting unit is connected with the input of control unit, and the input of described switching device is connected with the output of control unit.
Further, described control unit comprise for decision-making system be whether ground state condition judgment module, send the Executive Module of excision earth resistance order for calculating the timing module of earth resistance overrun time and the setting-up time for reaching earth resistance when the ground connection time.
Further, the alarm unit for sending grounding alarm signal when system is in ground state is also comprised.
Further, the signal processing unit for processing the voltage and current signal gathered also is comprised.
Further, also comprise manipulation unit, described manipulation unit comprises display module and the input module for input operation order.
The present invention also provides a kind of neutral point resistor cabinet overrun automatically to excise guard method, comprises
A. the voltage and current signal through earth resistance is gathered,
B. judge whether system single phase ground fault occurs,
C., when surpassing the resistance of setting specified ground connection set of time fault time, earth resistance loop is disconnected.
Further, described step b specifically comprises:
Pre-set electric current and voltage action threshold value, when the voltage and current signal through earth resistance exceedes described action threshold value, decision-making system generation single phase ground fault.
Further, described step c specifically comprises:
When after decision-making system generation single phase ground fault, sending grounding alarm signal, and carry out accumulative timing from time of fault inception, when surpassing the resistance of setting specified ground connection set of time fault time, disconnecting earth resistance loop;
Further, to the signal transacting that the voltage and current signal gathered processes.
Beneficial effect of the present invention: the present invention is judged by monitoring; report to the police when system single-phase earth fault occurs; when the time of system single-phase earth fault exceed grounding resistor design time faulty line not yet tripping time; send protection act signal; utilize resistor switching device quick off resistance device grounded circuit, thus the safety of protective earthing resistor and grounding transformer and electric power system.
Accompanying drawing explanation
Below in conjunction with drawings and Examples, the invention will be further described:
Fig. 1 is principle schematic of the present invention.
Embodiment
Below in conjunction with drawings and Examples, the invention will be further described: Fig. 1 is principle schematic of the present invention.
As shown in Figure 1, neutral point resistor cabinet overrun in the present embodiment excises protective device automatically, comprise the collecting unit for gathering voltage and current signal, for disconnect earth resistance loop switching device and for judging whether system single phase ground fault occurs and control described switching device to disconnect the control unit in earth resistance loop;
The output of described collecting unit is connected with the input of control unit, and the input of described switching device is connected with the output of control unit.
In the present embodiment, control unit comprise for decision-making system be whether ground state condition judgment module, send the Executive Module of excision earth resistance order for calculating the timing module of earth resistance overrun time and the setting-up time for reaching earth resistance when the ground connection time.Preferably, the present embodiment, by signals collecting, accesses current signal by the current transformer of connecting in resistor box major loop, accesses voltage signal by voltage transformer.The set-up function of electric current and voltage action threshold value is had in controller; namely system generation single phase ground fault is judged when collection signal exceedes threshold value; and carry out cumulative calculation by timing module from time of fault inception; when surpassing the resistance of setting specified ground connection set of time fault time; actuating signal is sent by Executive Module; the switching device of control resistor disconnects earth resistance loop, protective resistor and grounding transformer, sends off resistance device signal simultaneously.Protective device in the present embodiment also comprises the record cell with landing operation number of times and fault current writing function.And CT no-load voltage ratio arranges function, on-the-spot can arrange the no-load voltage ratio value of selected instrument transformer flexibly, device is provided with communication interface, adopts standard traffic stipulations, can with the communication of system monitoring automated system.
In the present embodiment; also comprise the alarm unit for sending grounding alarm signal when system is in ground state; when being judged to be ground state, immediately resistance interruption being sent to system after protective device excision earth resistance and reporting to the police, facilitating operation maintenance personnel to the judgement of resistance states.
In the present embodiment, also comprise the signal processing unit for processing the voltage and current signal gathered, by the signal processing unit of device inside, the voltage and current signal through earth resistance is carried out the process such as analog-to-digital conversion, filtering, then its ground state is judged.
In the present embodiment, also comprise manipulation unit, described manipulation unit comprises display module and the input module for input operation order.Adopt TFT full color LCDs in the present embodiment, model: OCMJ4x8C_8 type, core control CPU adopts: MSP430F149 chip.Resistance protection action adopts switching value output signal, and other devices that can realize above-mentioned functions also can be adopted to substitute, and those skilled in the art can be obtained easily by prior art, do not repeat them here.
Accordingly, the present embodiment additionally provides a kind of neutral point resistor cabinet overrun and automatically excises guard method, comprises
A. the voltage and current signal through earth resistance is gathered,
B. judge whether system single phase ground fault occurs,
C., when surpassing the resistance of setting specified ground connection set of time fault time, earth resistance loop is disconnected.
Step b specifically comprises:
Pre-set electric current and voltage action threshold value, when the voltage and current signal through earth resistance exceedes described action threshold value, decision-making system generation single phase ground fault.
Step c specifically comprises:
When after decision-making system generation single phase ground fault, sending grounding alarm signal, and carry out accumulative timing from time of fault inception, when surpassing the resistance of setting specified ground connection set of time fault time, disconnecting earth resistance loop;
In the present embodiment, to the signal transacting that the voltage and current signal gathered processes, by the signal processing unit of device inside, the voltage and current signal through earth resistance is carried out the process such as analog-to-digital conversion, filtering, then its ground state is judged.
In the present embodiment, exceed when system single-phase earth fault occurs grounding resistor design time faulty line not yet tripping time, send protection act signal disconnect grounding resistor loop, the safety of protective earthing resistor and grounding transformer and electric power system.With timer, there is data communication facility; also alarm signal will be sent while the available protecting grounding resistor of disconnection earth resistance loop; except playing overtime resistance protection function, also to have the routine monitoring controlling functions of neutral-point grounding resistance cabinet concurrently, play the effect of resistor box intelligent controller.
The present embodiment, adopt 4U chassis design controller, point function plug-in type circuit board layout structure, can adapt to the neutral-point grounding resistance cabinet system of any one strip resistance switching status monitoring.Device, by signals collecting, accesses current signal by the current transformer of connecting in resistor box major loop, accesses voltage signal by voltage transformer.The set-up function of electric current and voltage action threshold value is had in controller; namely system generation single phase ground fault is judged when collection signal exceedes threshold value; and carry out cumulative calculation by time of fault inception; when surpassing the resistance of setting specified ground connection set of time fault time; actuating signal is sent by the master control borad of device; the switching device of control resistor disconnects earth resistance loop, protective resistor and grounding transformer, sends off resistance device signal simultaneously.
What finally illustrate is, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although with reference to preferred embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that, can modify to technical scheme of the present invention or equivalent replacement, and not departing from aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.
Claims (9)
1. neutral point resistor cabinet overrun excises a protective device automatically, it is characterized in that: comprise
For gather voltage and current signal collecting unit, for disconnect earth resistance loop switching device and for judging whether system single phase ground fault occurs and control described switching device to disconnect the control unit in earth resistance loop,
The output of described collecting unit is connected with the input of control unit, and the input of described switching device is connected with the output of control unit.
2. neutral point resistor cabinet overrun according to claim 1 excises protective device automatically, it is characterized in that: described control unit comprise for decision-making system be whether ground state condition judgment module, send the Executive Module of excision earth resistance order for calculating the timing module of earth resistance overrun time and the setting-up time for reaching earth resistance when the ground connection time.
3. neutral point resistor cabinet overrun according to claim 1 excises protective device automatically, it is characterized in that: also comprise the alarm unit for sending grounding alarm signal when system is in ground state.
4. the neutral point resistor cabinet overrun according to the arbitrary claim of claim 1-3 excises protective device automatically, it is characterized in that: also comprise the signal processing unit for processing the voltage and current signal gathered.
5. neutral point resistor cabinet overrun according to claim 4 excises protective device automatically, it is characterized in that: also comprise manipulation unit, and described manipulation unit comprises display module and the input module for input operation order.
6. neutral point resistor cabinet overrun excises a guard method automatically, it is characterized in that: comprise
A. the voltage and current signal through earth resistance is gathered,
B. judge whether system single phase ground fault occurs,
C., when surpassing the resistance of setting specified ground connection set of time fault time, earth resistance loop is disconnected.
7. neutral point resistor cabinet overrun according to claim 6 excises guard method automatically, it is characterized in that: described step b specifically comprises:
Pre-set electric current and voltage action threshold value, when the voltage and current signal through earth resistance exceedes described action threshold value, decision-making system generation single phase ground fault.
8. neutral point resistor cabinet overrun according to claim 6 excises guard method automatically, it is characterized in that: described step c specifically comprises:
When after decision-making system generation single phase ground fault, sending grounding alarm signal, and carry out accumulative timing from time of fault inception, when surpassing the resistance of setting specified ground connection set of time fault time, disconnecting earth resistance loop.
9. the neutral point resistor cabinet overrun according to the arbitrary claim of claim 6-8 excises guard method automatically, it is characterized in that: the signal transacting processed the voltage and current signal gathered.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510929959.8A CN105375436A (en) | 2015-12-14 | 2015-12-14 | Automatic cutoff protection apparatus and method for overtime operation of neutral-point resistor cabinet |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510929959.8A CN105375436A (en) | 2015-12-14 | 2015-12-14 | Automatic cutoff protection apparatus and method for overtime operation of neutral-point resistor cabinet |
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| CN105375436A true CN105375436A (en) | 2016-03-02 |
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| CN201510929959.8A Pending CN105375436A (en) | 2015-12-14 | 2015-12-14 | Automatic cutoff protection apparatus and method for overtime operation of neutral-point resistor cabinet |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108604494A (en) * | 2017-01-11 | 2018-09-28 | 那恩能源有限公司 | Real-time detection/repair system when power distribution system source line fault and its construction method |
| CN109510094A (en) * | 2018-10-30 | 2019-03-22 | 苏州电力设计研究院有限公司 | Distribution transformer earthing system |
| CN113791282A (en) * | 2021-09-13 | 2021-12-14 | 深圳市欧拓自动化科技有限公司 | Power utilization safety monitoring system and building thereof |
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| CN200941111Y (en) * | 2006-08-11 | 2007-08-29 | 保定天威恒通电气有限公司 | Neutral point resistance information detection recorder |
| CN101055301A (en) * | 2007-06-14 | 2007-10-17 | 深圳市华力特电气有限公司 | Neutral point grounding resistor monitoring device |
| CN101499655A (en) * | 2008-11-06 | 2009-08-05 | 江苏省电力公司 | Neutral point grounding resistor plant for electrical power system |
| US20110090606A1 (en) * | 2009-10-19 | 2011-04-21 | Vanessa Ramirez | Countermeasure for EMP-E3 induced currents |
| CN103441485A (en) * | 2013-07-15 | 2013-12-11 | 嘉兴电力局 | 20kV flexible grounding control device and 20kV flexible grounding control method |
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2015
- 2015-12-14 CN CN201510929959.8A patent/CN105375436A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN200941111Y (en) * | 2006-08-11 | 2007-08-29 | 保定天威恒通电气有限公司 | Neutral point resistance information detection recorder |
| CN101055301A (en) * | 2007-06-14 | 2007-10-17 | 深圳市华力特电气有限公司 | Neutral point grounding resistor monitoring device |
| CN101499655A (en) * | 2008-11-06 | 2009-08-05 | 江苏省电力公司 | Neutral point grounding resistor plant for electrical power system |
| US20110090606A1 (en) * | 2009-10-19 | 2011-04-21 | Vanessa Ramirez | Countermeasure for EMP-E3 induced currents |
| CN103441485A (en) * | 2013-07-15 | 2013-12-11 | 嘉兴电力局 | 20kV flexible grounding control device and 20kV flexible grounding control method |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108604494A (en) * | 2017-01-11 | 2018-09-28 | 那恩能源有限公司 | Real-time detection/repair system when power distribution system source line fault and its construction method |
| CN108604494B (en) * | 2017-01-11 | 2021-04-20 | 那恩能源有限公司 | Real-time detection/repair system for power line fault of power distribution system and construction method thereof |
| CN109510094A (en) * | 2018-10-30 | 2019-03-22 | 苏州电力设计研究院有限公司 | Distribution transformer earthing system |
| CN109510094B (en) * | 2018-10-30 | 2020-12-18 | 苏州电力设计研究院有限公司 | Distribution transformer grounding system |
| CN113791282A (en) * | 2021-09-13 | 2021-12-14 | 深圳市欧拓自动化科技有限公司 | Power utilization safety monitoring system and building thereof |
| CN113791282B (en) * | 2021-09-13 | 2024-03-19 | 深圳市欧拓自动化科技有限公司 | Electricity safety monitoring system and building thereof |
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Application publication date: 20160302 |