CN102013307B - On-load capacity-regulation distributing transformer - Google Patents
On-load capacity-regulation distributing transformer Download PDFInfo
- Publication number
- CN102013307B CN102013307B CN2010101897317A CN201010189731A CN102013307B CN 102013307 B CN102013307 B CN 102013307B CN 2010101897317 A CN2010101897317 A CN 2010101897317A CN 201010189731 A CN201010189731 A CN 201010189731A CN 102013307 B CN102013307 B CN 102013307B
- Authority
- CN
- China
- Prior art keywords
- transformer
- combination switch
- low
- voltage
- capacity
- 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.)
- Expired - Fee Related
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
Landscapes
- Ac-Ac Conversion (AREA)
- Control Of Electrical Variables (AREA)
Abstract
The invention discloses an on-load capacity-regulation distributing transformer, comprising a transformer body, a detection unit, a control unit and a capacity regulation device, wherein the detection unit is connected with the transformer body, a signal output end of the detection unit is connected with a signal input end of the control unit, a signal output end of the control unit is connected with a signal control end of the capacity regulation device, and a signal output end of the capacity regulation device is respectively connected with a high-voltage coil and a low-voltage coil of the transformer body; the capacity regulation device comprises a contactor and a combination switch, wherein the combination switch has 5KW or below 5KW voltage class and is connected in parallel to an electronic switch of a thyristor; and the control unit can be used for eliminating overcurrent on a high-voltage side and overvoltage on a low-voltage side by selecting a control strategy of nonsynchronous actions on the high-voltage side and the low-voltage side. The invention solves the problems on the voltage class, cost, volume and reliability of the on-load capacity-regulation combination switch of the distributing transformer, and provides the on-load capacity-regulation transformer with the advantages of high automation degree, low cost and easiness in implementation, so as to realize the reliable and economic capacity-regulation operation of the distributing transformer.
Description
Technical field
The present invention relates to electric power system distribution field, relate in particular to a kind of loaded capacity-regulated distribution transformer.
Background technology
Traditional loaded capacity-regulated transformer is to transfer appearance with mechanical switch and motor drive mechanism thereof as combination switch; When switching, the combination switch on-load produces bigger electric arc; The ablation contact causes oil pollution easily; Influence the insulation characterisitic and the useful life of transformer, maintenance workload is big, and cost is also high simultaneously.
The existing loaded capacity-regulated transformer that holds switch with combination switch as accent; Quick, the no arc that has solved distribution transformer is transferred appearance; Like record among the Chinese patent Granted publication CN201170985Y " a kind of combination switch of loaded capacity-regulated distribution transformer and distribution transformer thereof "; Wherein owing to structure and controlling schemes such as stable state high voltage that does not have reduction or inhibition high pressure combination switch to bear and transient overvoltage overcurrent thereof; It is withstand voltage that electronic switch need adopt many thyristor series connection to use to realize switch 10KV, reliability of products is obviously reduced, and cost improves; Mechanical switch need adopt the 12KV high-pressure vacuum switch in the high pressure combination switch, and cost significantly improves, even the price of combination switch is higher than transformer body price.
Summary of the invention
The purpose of this invention is to provide a kind of loaded capacity-regulated distribution transformer, reliability service that can intelligentized realization distribution transformer, and reduce cost.
The present invention adopts following technical proposals: a kind of loaded capacity-regulated distribution transformer; Comprise the transformer body; Detecting unit, control unit, apparatus for adjusting capacity, detecting unit is connected with the transformer body, and the signal output part of detecting unit is connected with the signal input part of control unit; The signal output part of control unit is connected with the signal controlling end of apparatus for adjusting capacity, and the signal output part of apparatus for adjusting capacity is connected with low-voltage coil with the high-tension coil of transformer body respectively; Said apparatus for adjusting capacity comprises by contactor and thyristor electronic switch the be in parallel 5KV that forms and the combination switch of following electric pressure thereof; Said high-tension coil and low-voltage coil all adopt four sections, and each section turn ratio meets the same ratio coefficient; Wherein the transformer high-voltage side is every all needs three high pressure combination switches in mutually; The high pressure combination switch constitutes by capacitance-resistance absorber element, two anti-thyristor, contactors also; Two anti-thyristor two ends also are parallel with the capacitance-resistance absorber element respectively, and contactor is connected in parallel on the thyristor two ends; In three high pressure combination switches of the every phase in high-pressure side in the conduction terminal of first combination switch and the high-tension coil second section lower end be connected with the 3rd section upper end; Second section upper end is connected with the 3rd section upper end in the conduction terminal of second combination switch and the high-tension coil, and second section lower end is connected with the 3rd section lower end in the 3rd combination switch conduction terminal and the high-tension coil; Step down side is every all to need three low pressure combination switches in mutually; The low pressure combination switch comprises capacitance-resistance absorber element, bidirectional thyristor, contactor; Capacitance-resistance absorber element and contactor all are connected in parallel on the thyristor two ends, and the annexation of its mesolow combination switch and low-voltage coil is identical with the annexation of high pressure combination switch and high-tension coil.
Utilize loaded capacity-regulated distribution transformer to realize loaded capacity-regulated method; May further comprise the steps: (1), by the winding construction of detecting unit identification transformer and detect the high and low pressure side voltage and current and phase angle (2), detect transformer load factor whether greater than set point; If; Get into step (4),, get into step (3) if not; Whether the load factor that (3) detects transformer is less than set point and certain time, if get into step (4), if do not continue detection; (4), detect the electric current and voltage phase place, increase the capacity of transformer and get into step (5) if high-pressure side phase voltage phase place is zero corresponding combination switch break-make of control; Reduce the capacity of transformer and get into step (5) if low-pressure side phase current phase place is zero corresponding combination switch break-make of control; (5) after the conversion of high-pressure side and low-pressure side finishes, return step (2).
The invention has the beneficial effects as follows:
1. combination switch electric pressure (being lower than 5KV) significantly reduces among the present invention; Adopt low-voltage grade contactor to replace 12KV level high-pressure vacuum switch, select the thyristor of low-voltage grade for use, the quantity of thyristor significantly reduces; Even need not series connection, and the switch cost significantly reduces; And the combination switch volume is little, more compact structure; Control unit adopts the asynchronous switch control strategy of action respectively of high and low pressure side, eliminates high-pressure side overcurrent and low-pressure side overvoltage effectively, has further improved equipment dependability;
2. high-voltage coil and low-voltage coil adopts the Transformer Winding of multi-segment structure among the present invention, and each section of high-low pressure winding turn ratio all adopts the same ratio coefficient, has reduced the fluctuation of capacitance-adjustable transformer voltage, and the quality of voltage of proof load makes transformer stable operation.
The invention solves electric pressure and cost, volume and the integrity problem of the loaded capacity-regulated combination switch of distribution transformer; A kind of automaticity height, low, the easy loaded capacity-regulated transformer of realizing of cost are provided, to realize reliable, the economical operation of accent appearance of distribution transformer.
Description of drawings
Fig. 1 is a theory diagram of the present invention;
Fig. 2 is the sketch map of mesohigh lateral coil of the present invention;
Fig. 3 is the sketch map of mesolow lateral coil of the present invention;
Fig. 4 is the connection layout of transformer coil among the present invention and apparatus for adjusting capacity;
Fig. 5 is the loaded capacity-regulated flow chart of transformer among the present invention;
The connection status figure of transformer high-voltage lateral coil when Fig. 6 is light running;
The connection status figure of transformer high-voltage lateral coil when Fig. 7 is heavy service;
The simulation result of combination switch transient current when Fig. 8 changes series connection for the high-pressure side parallel connection;
The simulation result of combination switch transient current when Fig. 9 changes series connection for the low-pressure side parallel connection;
The simulation result of combination switch transient voltage when Figure 10 changes series connection for the high-pressure side parallel connection;
The simulation result of combination switch transient voltage when Figure 11 changes series connection for the low-pressure side parallel connection;
Figure 12 is the simulation result of high-pressure side series connection combination switch transient current when changing parallel connection;
Figure 13 is the simulation result of low-pressure side series connection combination switch transient current when changing parallel connection;
Figure 14 is the simulation result of high-pressure side series connection combination switch transient voltage when changing parallel connection;
Figure 15 is the simulation result of low-pressure side series connection combination switch transient voltage when changing parallel connection.
Embodiment
The present invention does with detailed description below in conjunction with accompanying drawing and embodiment.
As shown in Figure 1; The loaded capacity-regulated distribution transformer of the present invention comprises transformer body, detecting unit; Control unit and apparatus for adjusting capacity, detecting unit is connected with the transformer body, and the signal output part of detecting unit is connected with the signal input part of control unit; The signal output part of control unit is connected with the signal controlling end of apparatus for adjusting capacity, and the signal output part of apparatus for adjusting capacity is connected with low-voltage coil with the high-tension coil of transformer body respectively.Wherein apparatus for adjusting capacity adopts the low-voltage grade combination switch that contactor and thyristor are in parallel, and contactor and thyristor receive from the signal of control unit output and closure or disconnection in the combination switch; Combination switch adopts the 3000V grade in the present embodiment; Transformer high-voltage coil and low-voltage coil all adopt multi-segment structure; Adopt the four-part form structure in the present embodiment, like Fig. 2, shown in Figure 3, every phase coil all is divided into four sections; With high-pressure side A is the example explanation mutually: coil is divided into AA2 ', A2A2 ', A3A3 ' and four sections of A3 ' O; Voltage is born to appropriate value in the two ends that the present invention adopts the winding connection of multistage can effectively reduce combination switch, and each section turn ratio meets the same ratio coefficient, can confirm the steady state voltage that each combination switch bears by the segmentation scales of winding.
Thyristor is made the snap action control switch in the combination switch among the present invention, and A.C. contactor is made the stable state switch, and is as shown in Figure 4; The high pressure combination switch is the example explanation with combination switch I1: combination switch I1 comprises antiparallel thyristor 31,32; By the electric capacity 1 capacitance-resistance absorber element that 2 series connection constitute with resistance, A.C. contactor 4, thyristor 31,32 two ends all are parallel with the capacitance-resistance absorber element; A.C. contactor 4 is connected in parallel on the two ends of thyristor 31,32; The two ends of thyristor 31,32 are the conduction terminal of high pressure combination switch, are used for being connected with coil, and the control utmost point of the coil of A.C. contactor 4 and thyristor 31,32 is connected with the signal output part of control unit; The low pressure combination switch is example explanation with combination switch II9: capacitance-resistance absorber element and A.C. contactor 41 that combination switch I19 comprises bidirectional thyristor 5, is made up of electric capacity 11 and resistance 21 series connection; Capacitance-resistance absorber element and A.C. contactor 41 all are connected in parallel on the two ends of bidirectional thyristor 5; The two ends of bidirectional thyristor 5 are the conduction terminal of low pressure combination switch; Be used for being connected with coil, the control utmost point of the coil of A.C. contactor 41 and bidirectional thyristor 5 is connected with the signal output part of control unit.The connection of combination switch and coil is the example explanation with high-pressure side A mutually: the lower end A2 ' of the conduction terminal of the first combination switch I1 and second section of high-tension coil is connected with the 3rd section upper end A 3; The upper end A 2 of the conduction terminal of the second combination switch I2 and second section of high-tension coil is connected with the 3rd section upper end A 3, and the conduction terminal of the 3rd combination switch I3 is connected with the 3rd section lower end A3 ' with second section lower end A2 '; High-pressure side B phase, C are every with the equal mode that is connected with high-pressure side A of phase coil ways of connecting is identical separately with low-pressure side mutually.The high and low pressure side is every all to need three high and low pressure combination switches mutually; Three-phase needs nine high pressure combination switches and nine low pressure combination switches altogether; Every (every 1500～2000V) of 6 thyristor of using mutually of present embodiment mesohigh side; Selecting electric pressure for use with its parallelly connected A.C. contactor is 3000V, and three-phase is totally 18 thyristors; Every 3 bidirectional thyristors (every 220V) that use mutually of low-pressure side, three-phase is totally 9 bidirectional thyristors; The A.C. contactor of high-pressure side and low-pressure side can adopt the one pole A.C. contactor; Also can adopt bipolar A.C. contactor, present embodiment mesohigh side and low-pressure side adopt three one pole A.C. contactors and three bipolar A.C. contactors respectively, and hence one can see that; The electric pressure of combination switch adopts below the 3000V in the present embodiment; The combination switch electric pressure is low, and the negligible amounts of the thyristor that needs has greatly reduced the cost of combination switch.
The present invention is through detection transformer low voltage electric current, low-voltage bus bar voltage; Detect high-low pressure three-phase voltage, three-phase current, calculated in real time and the monitoring transformer load by control unit, control unit sends signal and gives combination switch; Change the connection in series-parallel connected mode of transformer high-low pressure winding coil sections through the break-make of combination switch; Reducing has the combination switch of carrying to bear steady state voltage to appropriate value, realizes regulating transformer capacity, thus the loss purpose when reducing the transformer underloading.As shown in Figure 5, concrete steps are following:
(1), discerns the winding construction of transformer and detect high and low pressure side voltage and current and phase angle by detecting unit;
Whether the load factor that (2), detects transformer is greater than set point, if entering step (4) if not, gets into step (3);
Whether the load factor that (3), detects transformer is less than set point and certain time, if get into step (4), if do not continue detection;
(4), detect the electric current and voltage phase place, increase the capacity of transformer and get into step (5) if high-pressure side phase voltage phase place is zero corresponding combination switch break-make of control; Reduce the capacity of transformer and get into step (5) if low-pressure side phase current phase place is zero corresponding combination switch break-make of control;
(5), after the conversion of high-pressure side and low-pressure side finishes, return step (2).
It is the high side switch action moment when wherein selecting high-pressure side phase voltage phase place to be zero, with effective elimination high-pressure side overcurrent; It is the low-side switch action moment when selecting low-pressure side phase current phase place to be zero; With effective elimination low-pressure side overvoltage; This special switch controlling schemes has effectively suppressed the high and low pressure side temporary overvoltage and the overcurrent that produce owing to the combination switch that adopts the low voltage grade; Thereby can improve the reliability of switch, overcome electronic power switch and carry the withstand voltage deficiency with reliability etc. of combination switch as having.
When transformer load is big, must transformer be transferred to big capacity by low capacity, need to change coil into parallelly connected state by series connection, the high-tension coil series connection is as shown in Figure 6, and the low-voltage coil series connection is identical with high-pressure side coil series connection.As shown in Figure 4; Testing circuit detects load; If load is greater than set point and lasting greater than setting-up time; Then need make high pressure combination switch I 1, I 3, I 4, I 6, I 7, I 9 and low pressure combination switch II 1, II 3, II 4, II 6, II 7, II 9 closures, high pressure combination switch I 2, I 5, I 8 and low pressure combination switch II 2, II 5, II 8 are broken off.
Earlier thyristor among high-pressure side every phase combination switch I 2, I 5, I 8 and low pressure combination switch II 2, II 5, the II 8 is taken turns triggering and conducting and reach setting-up time 40ms, make wherein contactor control circuit outage, its contactor is broken off;
Every phase voltage of detection transformer high-voltage side and the every phase current of low-pressure side, the switching condition if the high-pressure side is consistent, then this phase combination switch action of this side, be the example explanation mutually with high-pressure side A: thyristor turn-offs among the A phase combination switch I 2, release; Simultaneously thyristor takes turns triggering and conducting among A phase combination switch I 1, the I 3; ON time reaches setting-up time 40ms, and its contactor control circuit is closed, its contactor conducting; Its thyristor stops to trigger; Then A phase combination switch release, after the high-pressure side three-phase moved in turn, the action of high pressure combination switch was all over.
Detect transformer high-voltage side voltage and low-pressure side electric current, if meet the congenial tangent condition of low-pressure side, then this phase combination switch action of low-pressure side, course of action such as high-pressure side course of action are identical; After the low-pressure side three-phase moved in turn, the action of low pressure combination switch was all over.
When transformer load hour, must transformer be transferred to low capacity by big capacity, need change high-voltage coil and low-voltage coil into series connection by parallelly connected state, high-tension coil parallel connection state is as shown in Figure 7, low-voltage coil parallel connection state is identical with the parallelly connected state of high-tension coil.As shown in Figure 4; Testing circuit detects load; If load is less than set point and lasting greater than setting-up time; Then need high pressure combination switch I 1, I 3, I 4, I 6, I 7, I 9 and low pressure combination switch II 1, II 3, II 4, II 6, II 7, II 9 are broken off high pressure combination switch I 2, I 5, I 8 and low pressure combination switch II 2, II 5, II 8 closures.Earlier thyristor among high pressure combination switch I 1, I 3, I 4, I 6, I 7, I 9 and low pressure combination switch II 1, II 3, II 4, II 6, II 7, the II 9 is taken turns triggering and conducting and reach setting-up time 40ms; With its contactor control circuit outage, its contactor is broken off again;
Detect transformer high-voltage side voltage and low-pressure side electric current, the switching condition if the high-pressure side is consistent, then this phase combination switch action of this side: with high-pressure side A is example explanation: A phase combination switch I 1, I 3, the shutoff of middle thyristor mutually, release; Simultaneously thyristor takes turns triggering and conducting among the A phase combination switch I 2; ON time reaches setting-up time 40ms, and it is closed to control its contactor control circuit, makes its contactor conducting; Its thyristor stops to trigger; Then high-pressure side A phase combination switch release, after the high-pressure side three-phase moved in turn, the action of high pressure combination switch was all over.
Detect transformer high-voltage side voltage and low-pressure side electric current; If meet the congenial tangent condition of low-pressure side, then this phase combination switch action of low-pressure side, course of action such as high-pressure side course of action are identical; After the low-pressure side three-phase moved in turn, the action of low pressure combination switch was all over.Fig. 8 to Figure 15 is respectively the emulating image of high-pressure side and low-voltage side coil transient current and transient voltage when different conditions.
Claims (2)
1. loaded capacity-regulated distribution transformer; Comprise the transformer body; Detecting unit, control unit, apparatus for adjusting capacity, detecting unit is connected with the transformer body, and the signal output part of detecting unit is connected with the signal input part of control unit; The signal output part of control unit is connected with the signal controlling end of apparatus for adjusting capacity, and the signal output part of apparatus for adjusting capacity is connected with low-voltage coil with the high-tension coil of transformer body respectively; Said apparatus for adjusting capacity comprises that it is characterized in that: said high-tension coil and low-voltage coil all adopt four segment structures by contactor and thyristor electronic switch the be in parallel 5KV that forms and the combination switch of following electric pressure thereof, and each section turn ratio meets the same ratio coefficient; Wherein the transformer high-voltage side is every all needs three high pressure combination switches in mutually; The high pressure combination switch constitutes by capacitance-resistance absorber element, two anti-thyristor, contactors also; Two anti-thyristor two ends also are parallel with the capacitance-resistance absorber element respectively, and contactor is connected in parallel on the thyristor two ends; In three high pressure combination switches of the every phase in high-pressure side in the conduction terminal of first combination switch and the high-tension coil second section lower end be connected with the 3rd section upper end; Second section upper end is connected with the 3rd section upper end in the conduction terminal of second combination switch and the high-tension coil, and second section lower end is connected with the 3rd section lower end in the 3rd combination switch conduction terminal and the high-tension coil; Step down side is every all to need three low pressure combination switches in mutually; The low pressure combination switch comprises capacitance-resistance absorber element, bidirectional thyristor, contactor; Capacitance-resistance absorber element and contactor all are connected in parallel on the thyristor two ends, and the annexation of its mesolow combination switch and low-voltage coil is identical with the annexation of high pressure combination switch and high-tension coil.
2. accent appearance method that realizes loaded capacity-regulated distribution transformer as claimed in claim 1; It is characterized in that: may further comprise the steps: (1), by the winding construction of detecting unit identification transformer and detect the high and low pressure side voltage and current and phase angle (2), detect transformer load factor whether greater than set point; If; Get into step (4),, get into step (3) if not; Whether the load factor that (3) detects transformer is less than set point and certain time, if get into step (4), if do not continue detection; (4), detect the electric current and voltage phase place, increase the capacity of transformer and get into step (5) if high-pressure side phase voltage phase place is zero corresponding combination switch break-make of control; Reduce the capacity of transformer and get into step (5) if low-pressure side phase current phase place is zero corresponding combination switch break-make of control; (5) after the conversion of high-pressure side and low-pressure side finishes, return step (2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010101897317A CN102013307B (en) | 2010-06-02 | 2010-06-02 | On-load capacity-regulation distributing transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010101897317A CN102013307B (en) | 2010-06-02 | 2010-06-02 | On-load capacity-regulation distributing transformer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102013307A CN102013307A (en) | 2011-04-13 |
| CN102013307B true CN102013307B (en) | 2012-07-25 |
Family
ID=43843437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010101897317A Expired - Fee Related CN102013307B (en) | 2010-06-02 | 2010-06-02 | On-load capacity-regulation distributing transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102013307B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102651273B (en) * | 2012-04-09 | 2015-04-01 | 中国电力科学研究院 | Arcless on-load volume regulation and voltage regulation distribution transformer |
| CN104299764A (en) * | 2014-09-12 | 2015-01-21 | 合肥金德电力设备制造有限公司 | Novel capacity regulating transformer |
| CN106128725A (en) * | 2016-08-17 | 2016-11-16 | 山东电工电气集团智能电气有限公司 | A kind of it is applicable to the capacitance-adjustable transformer that seasonal or period load variations is clearly demarcated |
| CN108899183B (en) * | 2018-07-06 | 2019-11-08 | 云南电网有限责任公司丽江供电局 | A kind of loading capacitance-regulating distribution transformer and corresponding capacity transfer method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1093206A (en) * | 1993-03-26 | 1994-10-05 | 姚鸿霖 | Automatic voltage adjusting and capacity controlling method for loaded power transformer |
| CN201170985Y (en) * | 2008-01-10 | 2008-12-24 | 北京电研华源电力技术有限公司 | Combination switch for on-load capacity-regulating distributing transformer and distributing transformer thereof |
| CN201742161U (en) * | 2010-06-02 | 2011-02-09 | 李晓慧 | On-load capacitance regulation distribution transformer |
-
2010
- 2010-06-02 CN CN2010101897317A patent/CN102013307B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN102013307A (en) | 2011-04-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103474983A (en) | High voltage and great current direct-current circuit breaker and control method thereof | |
| CN104900444A (en) | Direct current (DC) breaker topology structure and DC breaker control method | |
| CN102013307B (en) | On-load capacity-regulation distributing transformer | |
| CN104362751A (en) | Intelligent switching switch | |
| CN103441489A (en) | Direct-current breaker used for multi-terminal direct current system and control method of direct-current breaker | |
| CN103457257A (en) | Direct-current breaker used for multi-terminal direct-current system and control method thereof | |
| CN201298065Y (en) | An experiment loop for switching super/extra-high voltage circuit breaker capacitive load | |
| CN103457256A (en) | Direct-current breaker used for multi-terminal direct-current system and control method thereof | |
| CN103840470B (en) | A kind of breaker closing phase control method, Apparatus and system | |
| CN107947132A (en) | It is a kind of that there is micro- loss combined machine formula dc circuit breaker of reclosing | |
| CN201388061Y (en) | High-voltage-to-low-voltage reactive power compensation flexible switching device | |
| CN103441490A (en) | Direct-current breaker used for multi-terminal direct current system and control method of direct-current breaker | |
| CN201742161U (en) | On-load capacitance regulation distribution transformer | |
| CN102013815B (en) | High-voltage DC converter transformer and connection method for on-load tap-changer thereof | |
| CN2796210Y (en) | Zero frequency short circuit high resistance earthed transformer type arc extinguishing coil | |
| CN103545836A (en) | Capacitor commutated converter inverter side system | |
| CN103430414A (en) | Switch for a transmission path for high-voltage direct current | |
| CN202522681U (en) | High-low voltage combination power station load testing device | |
| CN103633978A (en) | Economical on-load tap-changer and method thereof | |
| CN103457258A (en) | Direct-current breaker used for multi-terminal direct-current system and control method thereof | |
| CN103618281A (en) | Hybrid type bidirectional full-load direct current cut-off device and cut-off method based on manual zero passage technology | |
| CN205178490U (en) | Novel solid -state fault current limiter of bridge type | |
| CN1705180A (en) | Three-core five-post grounding current automatic tracking and compensation system | |
| CN102420433A (en) | Reactive power compensation system based on magnetic switch | |
| CN101117097A (en) | Gate circuit transistor controlling series transformer type electrified railway dragging net pressure-regulating-apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120725 Termination date: 20130602 |