CN105790075A - Vacuum lightning protection gap device based on hollow cathode effect - Google Patents
Vacuum lightning protection gap device based on hollow cathode effect Download PDFInfo
- Publication number
- CN105790075A CN105790075A CN201610204146.7A CN201610204146A CN105790075A CN 105790075 A CN105790075 A CN 105790075A CN 201610204146 A CN201610204146 A CN 201610204146A CN 105790075 A CN105790075 A CN 105790075A
- Authority
- CN
- China
- Prior art keywords
- electrode
- cover plate
- vacuum
- pressure side
- side cover
- 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.)
- Granted
Links
- 230000000694 effects Effects 0.000 title claims abstract description 16
- 239000000919 ceramic Substances 0.000 claims description 9
- 238000009413 insulation Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 7
- 230000005540 biological transmission Effects 0.000 claims description 6
- 238000004021 metal welding Methods 0.000 claims description 6
- 230000015556 catabolic process Effects 0.000 claims description 2
- 238000012423 maintenance Methods 0.000 abstract description 4
- 238000005516 engineering process Methods 0.000 abstract description 3
- 239000003990 capacitor Substances 0.000 abstract 1
- 238000009422 external insulation Methods 0.000 abstract 1
- 230000001276 controlling effect Effects 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 238000002679 ablation Methods 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 208000025274 Lightning injury Diseases 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- APTZNLHMIGJTEW-UHFFFAOYSA-N pyraflufen-ethyl Chemical compound C1=C(Cl)C(OCC(=O)OCC)=CC(C=2C(=C(OC(F)F)N(C)N=2)Cl)=C1F APTZNLHMIGJTEW-UHFFFAOYSA-N 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T4/00—Overvoltage arresters using spark gaps
- H01T4/10—Overvoltage arresters using spark gaps having a single gap or a plurality of gaps in parallel
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T4/00—Overvoltage arresters using spark gaps
- H01T4/02—Details
Abstract
The invention discloses a vacuum lightning protection gap device based on a hollow cathode effect, comprising a vacuum gap unit and a voltage division loop unit. The vacuum gap unit is of a three-electrode structure, wherein the anode and the cathode of a main gap are of a cavity structure with a hole in the center, a pre-ionization electrode is of a needle structure, and the pre-ionization electrode is arranged inside the cathode and forms a pre-ionization gap with the cathode. The voltage division loop unit is composed of a resistor and a capacitor which are connected in parallel between the main gap and the pre-ionization electrode. Compared with the existing air jet arcing lightning protection gap technology, the advantages of the device are that power-frequency follow current can be cut off in a timely and reliable manner, the device can be reused and has a long service life, and the device is convenient to produce and low in cost of maintenance. Moreover, the device is externally provided with external insulation protection, and can work safely and reliably.
Description
Technical field
The present invention relates to power system lightning protection device technical field, particularly a kind of novel evacuated lightning protection inter space device based on hollow cathode effect.
Background technology
At present, transmission line of electricity lightning protection is one of important leverage mode of power system stability operation.The overvoltage produced during thunderbolt is likely to cause power equipment flashover, and then produces power frequency continued flow, the stable operation of serious harm power equipment safety and electrical network.Therefore power department is generally adopted and installs lightning protection inter space in parallel additional to realize protected effect at transmission line of electricity or power equipment.Existing spark gap have employed multiple different technology path, although the wherein conventional lightning protection inter space with jet-impingement and leakage conductor are widely used, but there is also many open defects, for instance:
1. the existing lightning protection inter space device with jet-impingement, most structure is complicated, volume is relatively big, use, maintenance cost height, is easily damaged and lost efficacy.Further, service life is short, is limited by arc extinguishing gas ball quantity, is only capable of work several times even once, it is necessary to frequently change.
2., although existing leakage conductor low price, it is suppressed that the ability of overvoltage is strong, but when breaking down, it likely can not automatically disengage, jeopardize the safety of power system, and the spark gap with disconnector, except cost height, its disconnector is also disposable.
Summary of the invention
For solving deficiency of the prior art, the present invention provides a kind of novel evacuated lightning protection inter space device based on hollow cathode effect；
Described device includes vacuum gap unit (1) and pressure divider circuit unit (2)；
Described vacuum gap unit (1) and pressure divider circuit unit (2) are connected in parallel, and after parallel connection, upper end is connected with high voltage transmission line (11), lower end ground connection.
Contrast prior art, present invention have an advantage that
1. long service life, utilizes hollow cathode effect, and vacuum gap unit internal electrode ablation is slight, and reusable, the life-span is limited solely by device materials degree of aging and air-tightness, little with number of lightning strokes relation；
2., under vacuum environment, plasma discharging is bulk diffusion rapidly, power current zero crossing can natural blow-out, in time, be assuredly shut off power frequency continued flow, thus reducing the tripping rate with lightning strike of circuit；
3. simple in construction, maintenance cost is low, only needs periodic cleaning vacuum gap cell surface, with little need for maintenance during indoor use during outdoor application.
Accompanying drawing explanation
Fig. 1 is the structural representation of an embodiment in the present invention；Wherein: 1. vacuum gap unit；2. pressure divider circuit unit；3. high-field electrode；4. ceramic insulation cylinder；5. ground electrode；6. pre-ionization electrode；7. high-pressure side cover plate；8. earth terminal cover plate；9. resistance；10. electric capacity；11. high-pressure side；12. vacuum electrode.
Detailed description of the invention
In conjunction with accompanying drawing 1 and specific embodiment, the present invention is further described, but this embodiment is not limiting as protection scope of the present invention.
In one embodiment, the present invention provides a kind of novel evacuated lightning protection inter space device based on hollow cathode effect；
Described device includes vacuum gap unit (1) and pressure divider circuit unit (2)；
Described vacuum gap unit (1) and pressure divider circuit unit (2) are connected in parallel, and after parallel connection, upper end is connected with high voltage transmission line (11), lower end ground connection.
Apparatus structure described in the present embodiment is simple, and easy for installation, service life is extremely long, and reliability is high, it is possible to reliable arc extinguishing rapidly.Tripping rate with lightning strike and the accident rate of power system, protection circuit and power equipment safety can be reduced, improve operation of power networks stability.
In one embodiment, described vacuum gap unit (1) includes high-field electrode (3), ceramic insulation cylinder (4), ground electrode (5), pre-ionization electrode (6), high-pressure side cover plate (7) and earth terminal cover plate (8)；
Described high-field electrode (3) is connected with high-pressure side cover plate (7)；
Described ground electrode (5) is connected with earth terminal cover plate (8)；
Described high-pressure side cover plate (7) is connected by ceramic insulation cylinder (4) with earth terminal cover plate (8)；
Described pre-ionization electrode (6) is connected with described high-pressure side cover plate (7).
In the present embodiment, described vacuum gap unit (1) inside is the low vacuum environment of 1～100Pa, its flash-over characteristic is positioned at left half of Ba Shen curve, adjusts atmospheric pressure value when producing by vacuum pump, controls the breakdown voltage of vacuum gap unit (1).
In the present embodiment, described vacuum pump is positioned at the outside of described device, for regulating the atmospheric pressure value within vacuum gap unit.
In one embodiment, vacuum gap unit also includes vacuum electrode；
Described pre-ionization electrode (6) is connected with high-pressure side cover plate (7) by vacuum electrode (12).
In the present embodiment, described vacuum electrode is for transmitting the signal of telecommunication between described pre-ionization electrode and high-pressure side cover plate.
In one embodiment, described ceramic insulation cylinder (4) adopts ceramic-metal welding method to be tightly connected with high-pressure side cover plate (7) and earth terminal cover plate (8).
In the present embodiment, described ceramic-metal welding method includes the additive methods such as laser weld, electron beam welding, Solid-phase welding.
In one embodiment, described high-field electrode (3) and with holes centered by ground electrode (5), rear are the cylindrical structure of cavity, and the two is coaxially arranged.
In the present embodiment, described high-field electrode is coaxially arranged with both ground electrodes is because only two when electrode front end is parallel and aperture is coaxial, just can produce hollow cathode effect when electric discharge.
In one embodiment, described pressure divider circuit unit (2) is in series by resistance (9) and electric capacity (10)；
Described resistance (9) is connected in parallel between pre-ionization electrode (6) and high-pressure side cover plate (7), and described electric capacity (10) is connected in parallel between high-pressure side cover plate (7) and earth terminal cover plate (8).
In the present embodiment, under power frequency during normal operation, due to the dividing potential drop effect of described resistance and electric capacity, major part voltage drop drops on described high-pressure side cover plate and earth terminal cover plate, namely between described high-field electrode and ground electrode.The voltage undertaken between described pre-ionization electrode and high-field electrode is only small, will not discharge therebetween, and the main gap between described high-field electrode and ground electrode will not puncture.
When lightning impulse or switching impulse overvoltage arrive, dividing potential drop effect due to described resistance and electric capacity, major part voltage drop drops between described pre-ionization electrode and high-field electrode, therebetween first gap punctures, and then the main gap electric discharge between described high-field electrode and ground electrode, dash current of releasing.After impulse overvoltage disappears, main gap, in the zero crossing nature blow-out of power current, is low vacuum environment owing to described vacuum gap unit is internal, and discharge channel plasma dissipates rapidly, current cut-off.
In one embodiment, described vacuum gap unit (1) inside is the low vacuum environment of Pascal's magnitude, and its flash-over characteristic is positioned at left half of Ba Shen curve, by adjusting atmospheric pressure value, controls the flash-over characteristic of vacuum gap unit (1).
In the present embodiment, the discharge voltage of described vacuum gap unit reduces along with the product of air pressure with clearance distance and increases, so its flash-over characteristic is positioned at left half of Ba Shen curve；By progressively adjusting in test vacuum gap atmospheric pressure value, control the flash-over characteristic of vacuum gap.
In one embodiment, described pre-ionization electrode (6) is arranged on the same axis with high-field electrode (3).
In the present embodiment, being arranged in by pre-ionization electrode on high-field electrode axis is to make pre-ionization electrode (6) that the discharge probability of high-field electrode (3) each point is identical, avoid only discharging in the same point of high-field electrode (3), cause serious ablation, and then affect performance and the life-span of high-field electrode (3).
In one embodiment, ceramic-metal welding method is utilized to meet leak rate < 10 when being tightly connected-8The requirement of Pa L/s.
In the present embodiment, leak rate < 10 is met-8The requirement of Pa L/s, is primarily to guarantee discharging gap apparatus air pressure inside (1～2 year) in life cycle, and air pressure change is small so that its discharge voltage has good stability.
In one embodiment, the distance controlling between described high-field electrode (3) and ground electrode (5) is at 3～5mm.
In the present embodiment, the distance controlling of high-field electrode and ground electrode is because discharge voltage at 3-5mm and is controlled by distance, is arranged on this distance segment and enables to the discharge voltage of vacuum gap device at 30～40kV.
In one embodiment, a kind of novel evacuated lightning protection inter space device based on hollow cathode effect is disclosed, including vacuum gap unit 1 and pressure divider circuit unit 2.Described vacuum gap unit 1, ingredient includes high-field electrode 3, ceramic insulation cylinder 4, ground electrode 5, pre-ionization electrode 6, high-pressure side cover plate 7 and earth terminal cover plate 8.Described ceramic insulation cylinder 4 adopts ceramic-metal welding method to be tightly connected with high-pressure side cover plate 7 and earth terminal cover plate 8, meets leak rate < 10-8The requirement of Pa L/s.Centered by described high-field electrode 3 and ground electrode 5, with holes, rear is the cylindrical structure of cavity, and the two coaxial line is arranged in parallel, and distance controlling is in millimeter magnitude.Described pre-ionization electrode 6 is connected with high-pressure side cover plate 7 by vacuum electrode 12, is arranged on the axis of high-field electrode 3.Described pressure divider circuit unit 2 is in series by resistance 9 and electric capacity 10.Described vacuum gap unit 1 is connected in parallel with pressure divider circuit unit 2, and upper end is connected with high voltage transmission line 11, lower end ground connection.Described pre-ionization electrode 6 is connected with high-pressure side 11, and described resistance 9 is connected in parallel between pre-ionization electrode 6 and high-pressure side cover plate 7, and described electric capacity 10 is connected in parallel between high-pressure side cover plate 7 and earth terminal cover plate 8.Described vacuum gap unit 1 inside is the low vacuum environment of Pascal's magnitude, and its flash-over characteristic is positioned at left half of Ba Shen curve, by adjusting atmospheric pressure value, controls the flash-over characteristic of vacuum gap unit 1.
Under power frequency during normal operation, due to the dividing potential drop effect of described resistance 9 and electric capacity 10, major part voltage drop drops on described high-pressure side cover plate 7 and earth terminal cover plate 8, namely between described high-field electrode 3 and ground electrode 5.The voltage undertaken between described pre-ionization electrode 6 and high-field electrode 3 is only small, will not discharge therebetween, and the main gap between described high-field electrode 3 and ground electrode 5 will not puncture.
When lightning impulse or switching impulse overvoltage arrive, dividing potential drop effect due to described resistance 9 and electric capacity 10, major part voltage drop drops between described pre-ionization electrode 6 and high-field electrode 3, therebetween first gap punctures, and then the main gap electric discharge between described high-field electrode 3 and ground electrode 5, dash current of releasing.After impulse overvoltage disappears, main gap, in the zero crossing nature blow-out of power current, is low vacuum environment owing to described vacuum gap unit 1 is internal, and discharge channel plasma dissipates rapidly, current cut-off.
The merely exemplary explanation principles of the invention of above-described embodiment and effect thereof, it is preferable that embodiment does not have all of details of detailed descriptionthe, is not intended to the detailed description of the invention that this invention is only described yet.For a person skilled in the art, under the spirit and category of the present invention, any based on apparent changes such as the equivalent transformation on technical solution of the present invention basis, simple replacements, belong within scope.
Claims (10)
1. the vacuum lightning protection inter space device based on hollow cathode effect, it is characterised in that: described device includes vacuum gap unit (1) and pressure divider circuit unit (2)；
Described vacuum gap unit (1) and pressure divider circuit unit (2) are connected in parallel, and after parallel connection, one end is connected with high voltage transmission line (11), other end ground connection.
2. device according to claim 1, it is characterised in that:
Preferably, described vacuum gap unit (1) includes high-field electrode (3), ceramic insulation cylinder (4), ground electrode (5), pre-ionization electrode (6), high-pressure side cover plate (7) and earth terminal cover plate (8)；
Described high-field electrode (3) is connected with high-pressure side cover plate (7)；
Described ground electrode (5) is connected with earth terminal cover plate (8)；
Described high-pressure side cover plate (7) is connected by ceramic insulation cylinder (4) with earth terminal cover plate (8)；
Described pre-ionization electrode (6) is connected with described high-pressure side cover plate (7).
3. device according to claim 2, it is characterised in that: described vacuum gap unit also includes vacuum electrode (12)；
Described pre-ionization electrode (6) is connected with high-pressure side cover plate (7) by vacuum electrode (12).
4. device according to claim 2, it is characterised in that: described ceramic insulation cylinder (4) adopts ceramic-metal welding method to be tightly connected with high-pressure side cover plate (7) and earth terminal cover plate (8).
5. device according to claim 2, it is characterised in that:
Centered by described high-field electrode (3) and ground electrode (5), with holes, rear is the cylindrical structure of cavity, and the two is coaxially arranged.
6. device according to claim 2, it is characterised in that: described pressure divider circuit unit (2) is in series by resistance (9) and electric capacity (10)；
Described resistance (9) is connected in parallel between pre-ionization electrode (6) and high-pressure side cover plate (7), and described electric capacity (10) is connected in parallel between high-pressure side cover plate (7) and earth terminal cover plate (8).
7. device according to claim 2, it is characterized in that: described vacuum gap unit (1) inside is the low vacuum environment of 1～100Pa, its flash-over characteristic is positioned at left half of Ba Shen curve, adjust atmospheric pressure value when producing by vacuum pump, control the breakdown voltage of vacuum gap unit (1).
8. device according to claim 3, it is characterised in that: described pre-ionization electrode (6) is arranged on the same axis with high-field electrode (3).
9. device according to claim 4, it is characterised in that: utilize ceramic-metal welding method to meet leak rate < 10 when being tightly connected-8The requirement of Pa L/s.
10. device according to claim 5, it is characterised in that: the distance controlling between described high-field electrode (3) and ground electrode (5) is at 3～5mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610204146.7A CN105790075B (en) | 2016-04-01 | 2016-04-01 | A kind of vacuum lightning protection inter space device based on hollow cathode effect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610204146.7A CN105790075B (en) | 2016-04-01 | 2016-04-01 | A kind of vacuum lightning protection inter space device based on hollow cathode effect |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105790075A true CN105790075A (en) | 2016-07-20 |
| CN105790075B CN105790075B (en) | 2017-10-20 |
Family
ID=56395618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610204146.7A Expired - Fee Related CN105790075B (en) | 2016-04-01 | 2016-04-01 | A kind of vacuum lightning protection inter space device based on hollow cathode effect |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105790075B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111834915A (en) * | 2019-04-16 | 2020-10-27 | 段小嬿 | Method and system for back-flushing extinguishing arc plasma |
| CN112666428A (en) * | 2020-12-02 | 2021-04-16 | 西安交通大学 | Vacuum gap-based lightning arrester operation simulation test system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1697107A (en) * | 2005-04-29 | 2005-11-16 | 西安交通大学 | Controllable discharge switch of high-energy impulse in three electrodes under vacuum environment |
| CN201066763Y (en) * | 2007-06-13 | 2008-05-28 | 肖鹏 | Combined arrester for compound resistance capacitance |
| CN201274375Y (en) * | 2008-06-30 | 2009-07-15 | 西安交通大学 | Surface flashover vacuum CROWBAR switch |
| JP2013131391A (en) * | 2011-12-21 | 2013-07-04 | Hokuriku Electric Power Co Inc:The | Failure determination method and failure determination device of arrestor |
| CN104617491A (en) * | 2015-01-21 | 2015-05-13 | 华中科技大学 | Surface breakdown type two-pair-rod electrode structural triggered vacuum switch |
-
2016
- 2016-04-01 CN CN201610204146.7A patent/CN105790075B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1697107A (en) * | 2005-04-29 | 2005-11-16 | 西安交通大学 | Controllable discharge switch of high-energy impulse in three electrodes under vacuum environment |
| CN201066763Y (en) * | 2007-06-13 | 2008-05-28 | 肖鹏 | Combined arrester for compound resistance capacitance |
| CN201274375Y (en) * | 2008-06-30 | 2009-07-15 | 西安交通大学 | Surface flashover vacuum CROWBAR switch |
| JP2013131391A (en) * | 2011-12-21 | 2013-07-04 | Hokuriku Electric Power Co Inc:The | Failure determination method and failure determination device of arrestor |
| CN104617491A (en) * | 2015-01-21 | 2015-05-13 | 华中科技大学 | Surface breakdown type two-pair-rod electrode structural triggered vacuum switch |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111834915A (en) * | 2019-04-16 | 2020-10-27 | 段小嬿 | Method and system for back-flushing extinguishing arc plasma |
| CN112666428A (en) * | 2020-12-02 | 2021-04-16 | 西安交通大学 | Vacuum gap-based lightning arrester operation simulation test system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105790075B (en) | 2017-10-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| IL267864A (en) | Overvoltage protection for power systems | |
| CN110430655B (en) | Enclosed discharge gap triggered by plasma jet and application thereof | |
| WO2020215650A1 (en) | Lightning arrester having external series gap and lightning protection system | |
| CN109038221A (en) | There is the active overvoltage protection gap of plug function under gaseous environment | |
| CN105790075A (en) | Vacuum lightning protection gap device based on hollow cathode effect | |
| CN102110562A (en) | High voltage discharge tube | |
| CN112310814A (en) | Totally-enclosed controllable transformer neutral point protection discharge gap | |
| CN105427970A (en) | Lightning protection device | |
| CN204144931U (en) | A kind of lightning arrester | |
| CN103812007A (en) | Band gap puffer type medium voltage lightning arrester for overhead distribution line | |
| CN106448960A (en) | 35KV multi-gap anti-thunder insulator | |
| CN108521077A (en) | A kind of Penetrative lightning arrester | |
| CN104953470A (en) | Gas spark gap switch for nanosecond pulse generator | |
| CN100353625C (en) | No-follow curren metal ceramic gas discharge tube | |
| CN108565084A (en) | A kind of novel series gap composite insulating metal oxide lightning arrester | |
| CN208548575U (en) | A kind of variable discharging gap apparatus of automatic arc extinguishing | |
| CA2778712C (en) | Surge arrester and gas-insulated electric apparatus | |
| CN210899784U (en) | Lightning arrester and closed discharge gap triggered by plasma jet | |
| CN103138254B (en) | Adjustable excess voltage protective gap fine lightning protection method of power distribution network | |
| CN201616416U (en) | Ceramic high-voltage discharge tube | |
| CN102486956A (en) | Lightning protection device with combination of multigap driven arc extinguishing and driving arc extinguishing by multipoint strong airflow | |
| CN205911090U (en) | 35kV takes many clearances lightning -proof insulator | |
| CN101950647B (en) | Ball-end electrode lightning arrester of urban rail transit contact system | |
| CN105161979A (en) | Multi-level field distortion gas spark switch | |
| CN110661173A (en) | Multi-cavity lightning flashover limiter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20171020 |