CN102510067B - Method for preventing thyristors from being locked during quick and repeated zero cross switching of three-phase thyristor switched capacitor (TSC) - Google Patents
Method for preventing thyristors from being locked during quick and repeated zero cross switching of three-phase thyristor switched capacitor (TSC) Download PDFInfo
- Publication number
- CN102510067B CN102510067B CN201110340469.6A CN201110340469A CN102510067B CN 102510067 B CN102510067 B CN 102510067B CN 201110340469 A CN201110340469 A CN 201110340469A CN 102510067 B CN102510067 B CN 102510067B
- Authority
- CN
- China
- Prior art keywords
- phase
- solid
- capacitor
- state switch
- thyristor
- 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.)
- Active
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
- Y02E40/10—Flexible AC transmission systems [FACTS]
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
- Control Of Electrical Variables (AREA)
Abstract
The invention discloses a method for preventing thyristors from being locked during quick and repeated zero cross switching of a three-phase thyristor switched capacitor (TSC). A switching circuit of the three-phase TSC comprises a first solid-state switch, a second solid-state switch, and single-phase capacitors C1, C2 and C3 which are connected together in a triangular connection manner; one end of the first solid-state switch is connected between the capacitor C1 and the capacitor C3, and the other end of the first solid-state switch is connected to the phase A of a three-phase power supply; one end of the second solid-state switch is connected between the capacitor C1 and the capacitor C2, and the other end of the second solid-state switch is connected to the phase B of the three-phase power supply; the phase C of the three-phase power supply is connected between the capacitor C2 and the capacitor C3; the solid-state switches control switching of the capacitors; and each solid-state switch structurally comprises a pair of inversely parallel connected thyristors. In an actual device, when a three-phase capacitor set is subjected to the quick and repeated zero cross switching, the phenomenon of locking the thyristors can be avoided according to a certain switching off and switching on sequence. The method is simple and economic; and the influence on the repeated zero cross switching response time is low.
Description
Technical field:
The invention belongs to the reactive power compensation technology field in electrotechnics, when particularly a kind of three-phase TSC repeats operating passing zero fast, prevent the method for thyristor locking.
Background technology:
Thyristor switchable capacitor (TSC---Thyristor Switched Capacitor) is a kind of conventional static passive compensation device (SVC---Static Var Compensator), the reactive power of compensation network fast, improve system power factor, saves energy, the voltage fluctuation ， industrial and mining enterprises and the transformer station that reduce system are widely used.
Modern using electricity system becomes increasingly complex, the extensive use of a large amount of impacts such as electric welding machine, crane, rolling mill and nonlinear load makes the demand of reactive power in electric power system also present impact and fast-changing feature, require TSC device can follow the tracks of fast the sudden change of load reactive power, keep at any time best feed power factor, this just has higher requirement to the response speed of TSC device.The response time of TSC device mainly comprises switching two parts of idle detection and capacitor group, therefore requires TSC device fast detecting to go out the order that System Reactive Power is big or small and send opening-closing capacitor bank; Send switching order Hou， actuator (thyristor) and can carry out rapidly associative operation, drop in time or cut out capacitor group, meet the reactive requirement of system.
Interference to distribution system when dropping into or excising in order to reduce capacitor group, what while preventing capacitor group input, produce shoves, improve the useful life of capacitor, when dropping into or excising capacitor group, all require to realize zero transition procedue, when thyristor both end voltage approaches zero or zero passage, just open thyristor access capacitor group; The characteristic of naturally turn-offing while utilizing thyristor current flows zero passage makes capacitor group excise from electrical network.Therefore, TSC device sends and drops into after instruction, and capacitor group not necessarily drops into immediately, only has when thyristor both end voltage approaches zero or zero passage and could drop into capacitor group; Send after excision instruction, the characteristic of naturally turn-offing owing to will utilize thyristor current flows zero passage time, capacitor group is also not necessarily excised immediately.So capacitor group drops into and excision has a transient process, the length of these processes directly has influence on the response speed of TSC device.
So-called thyristor locking, refer under zero transition procedue is opened condition, in three-phase TSC, after the thyristor conducting in one group of solid-state switch, will make in another group solid-state switch the voltage at thyristor two ends not reach or close to zero, thus the phenomenon that this group thyristor cannot normally be opened.After thyristor generation locking, three-phase circuit becomes a single phase circuit, and the operation conditions of circuit occurs to depart from more greatly with design, and causes three-phase reactive power compensation seriously uneven.In controlling, TSC device should avoid the generation of thyristor latch-up phenomenon.
Three-phase TSC has various topological structures, totally can be divided into two classes: phase splitting compensation circuit and three-phase total compensation circuit.Phase splitting compensation circuit can be regarded three single phase circuits in essence as.Therefore, three-phase circuit discussed herein refers to three-phase total compensation circuit.
Figure 1 shows that two solid-state switches of employing conventional in engineering are the one group three-phase TSC circuit theory diagrams of two anti-parallel thyristors to (VTA and VTB) or solid-state relay (SSR) control.In figure, u
a, u
b, u
cfor three-phase mains voltage, phase sequence is positive phase sequence; Solid-state relay (SSR) consists of a pair of antiparallel thyristor VTA, VTB and control circuit thereof; C1, C2 and C3 are three-phase capacitor or three groups of single-phase electricity containers of one group of delta connection, and three groups of single-phase electricity containers can delta connection, also can star connection.This structure not only can suppress triple-frequency harmonics, and both economical.In order to control conveniently, generally the control command that turns on and off of each group thyristor or solid-state relay is sent simultaneously.
For the three-phase TSC circuit structure shown in Fig. 1, drop into after TSC, if VTB first turn-offs while excising capacitor, treat that VTA also closes and has no progeny, while needing again to drop into TSC fast, VTA and VTB both end voltage have zero crossing, therefore, again just there is different conducting orders during conducting.If the first conducting of VTB while dropping into again, after its conducting, VTA both end voltage is just without zero crossing, and VTA is conducting more fast in time just, and thyristor latch-up phenomenon has just occurred for this.If the first conducting of VTA,, just can there is not thyristor latch-up phenomenon in just energy conducting of the voltage zero-cross at VTB two ends after 3/4ths power cycles.
During practical application, except considering the dielectric loss of power capacitor itself, generally for the reasons such as safety are all attached with discharge resistance.While dropping into again after capacitor group excision, even if there is thyristor latch-up phenomenon, along with its residual DC voltage of electric discharge of capacitor group constantly reduces.Through regular hour (second level), the thyristor both end voltage of locking just there will be zero crossing, also just conducting again accordingly, but the response time greatly increase, the response time that it drops into than uncharged capacitor (being without residual voltage on capacitor) is much longer.
The instruction of TSC excision and input capacitor group is all generally to send at random according to the needs of dynamic passive compensation, and for the purpose of controlling simply, VTA, VTB shares a control signal, and the control command that turns on and off of each group TSC is sent simultaneously.Therefore, if do not controlled while capacitor group being carried out to switching in three-phase TSC, just have certain probability and occur thyristor latch-up phenomenon, cause three-phase TSC device normally not drop into fast.If not special control in addition, the probability that thyristor locking occurs in the TSC of three-phase shown in Fig. 1 is 57.1%, is higher.Meanwhile, at thyristor idle interval, the voltage that the voltage that capacitor group is born bears when being much higher than normal switching, may cause capacitor breakdown to damage.
The generation of thyristor latch-up phenomenon, by having a strong impact on the normal operating passing zero fast of capacitor group in three-phase TSC device, cannot realize quick dynamic passive compensation, and jeopardize equipment safety.Therefore, must manage the thyristor latch-up phenomenon that prevents that three-phase TSC device from occurring while repeating operating passing zero fast.
Summary of the invention:
For above-mentioned three-phase thyristor, repeat fast easily to occur in operating passing zero capacitor group process the phenomenon of locking, the object of the invention is to propose to prevent when a kind of three-phase TSC repeats operating passing zero fast the method for thyristor locking.Specific as follows:
Three-phase thyristor switched capacitor prevents a method for thyristor locking while repeating operating passing zero fast, the switching circuit of three-phase thyristor switched capacitor comprises: single-phase capacitance C1, C2 and C3 that the first solid-state switch and the second solid-state switch, delta connection link together; The A that one end of the first solid-state switch is connected between capacitor C 1 and C3, the other end is connected to three phase mains goes up mutually; The B that one end of the second solid-state switch is connected between capacitor C 1 and C2, the other end is connected to three phase mains goes up mutually; The C of three phase mains is connected between capacitor C 2 and C3; The A of three phase mains, B, C are positive phase sequence; The switching of solid-state switch control capacitor; The structure of solid-state switch comprises a pair of antiparallel thyristor; The switching of three-phase thyristor switched capacitor is sequentially: while again dropping into after excision capacitor, and that first conducting of turn-offing after in two solid-state switches while allowing excision.When dropping into instruction, send when being constantly arranged in two solid-state switches and first turn-offing the moment of that conducting, postpone to send input instruction, until that conducting of turn-offing after in two solid-state switches is sent while constantly arriving again.
Described switching order can be also: during excision capacitor, fixedly allow the first solid-state switch first turn-off.When excision instruction, sending is constantly the moment of the second solid-state switch excision, postpones to send excision instruction, until the first solid-state switch excision constantly arrives and sends.
Described solid-state switch is a pair of antiparallel thyristor and control circuit thereof or encapsulates all-in-one-piece solid-state relay by a pair of antiparallel thyristor and control circuit thereof.The circuit that single-phase capacitance C1, the C2 that described delta connection links together and C3 form, also replaceable is a three-phase capacitor that inside is delta connection.
The invention has the beneficial effects as follows: while three-phase condenser bank being repeated to operating passing zero fast in actual device, according to certain excision and input order, just can avoid occurring thyristor latch-up phenomenon.Method is both simple, economical, also little on repeating the impact of switching response time.
Accompanying drawing explanation:
Fig. 1 is three-phase TSC circuit theory diagrams.
Fig. 2 is three-phase TSC main circuit diagram of the present invention.
The working waveform figure of Fig. 3 TSC.
The excision procedure chart that Fig. 4 VTB first turn-offs.
Fig. 5 (a) is the quick repetition operating passing zero procedure chart that VTA first turn-offs.
Fig. 5 (b) is that VTB first turn-offs, the quick repetition operating passing zero procedure chart of the first conducting of VTB.
Fig. 5 (c) is that VTB first turn-offs, the quick repetition operating passing zero procedure chart of the first conducting of VTA.
Embodiment:
Below in conjunction with accompanying drawing, the present invention is described in detail.
Fig. 2 is three-phase TSC main circuit diagram.
The work wave of TSC device as shown in Figure 3.In figure, be respectively from top to bottom three-phase mains voltage u
s(containing u
a, u
b, u
c, three-phase is positive phase sequence, lower same), capacitance voltage u
c(containing u
c1, u
c2, u
c3), line current i
l(containing i
a, i
b).By Fig. 3, at any one power cycle t
1～t
5interior (power cycle is T), if at t
1～t
2or t
3～t
4between send excision order, thyristor first turn-offs VTA (the first solid-state switch); If at t
2～t
3or t
4～t
5between send excision order, be that thyristor first turn-offs VTB (the second solid-state switch).
The excision process of Fig. 4 for first turn-offing for VTB, is respectively switching control signal u from top to bottom in figure
g, three-phase mains voltage u
s(containing u
a, u
b, u
c), capacitance voltage u
c(containing u
c1, u
c2, u
c3), line current i
l(containing i
a, i
b), thyristor both end voltage u
vT(containing u
vTA, u
vTB).By Fig. 4, at a power cycle t
7～t
10in, at t
7～t
9between apply that to drop into instruction be the first conducting of VTB, will there is thyristor latch-up phenomenon in this.
(1) the two pairs of thyristors necessarily can both conducting when in first shutoff situation of VTA, capacitor group drops into again, there will not be thyristor latch-up phenomenon.Therefore, the principle that three-phase TSC device repeats operating passing zero is fast: during excision capacitor group, fixedly allow VTA first turn-off and while dropping into, there will not be thyristor latch-up phenomenon, i.e. the control principle of " A is first shutoff mutually " again.
Sending of TSC control command is easy to by obtaining supply voltage is phase-locked constantly.During due to stable state, phase voltage lags behind 90 ° of line currents, A phase voltage is carried out phase-locked, just can know the current phase of thyristor by inference, thereby can determine the current phase of thyristor while sending excision order, can control the shutoff order of thyristor.
For example,, if system is by detecting, calculate the t in Fig. 3
2～t
3between to send excision instruction, but first turn-off for fear of VTB, at this moment can not send out excision instruction, need time delay to wait until t
3constantly, at t
3～t
4between send out excision instruction, while dropping into so again, send the moment of dropping into instruction not just to be affected.Similarly, to t
4～t
5between excision instruction also postpone till t
5after send, just there will not be thyristor latch-up phenomenon.Clearly, control like this excision capacitor and will cause certain time-delay, delay time is T/6.
(2) if VTA first turn-offs while excising capacitor group, then input there will not be thyristor latch-up phenomenon; If VTB first turn-offs during excision capacitor group, then allow the first conducting of VTA while dropping into, capacitor group also can normally drop into, and there will not be thyristor latch-up phenomenon.Therefore, in order to prevent that three-phase TSC device from repeating to occur in operating passing zero thyristor latch-up phenomenon fast, the Switching rule of three-phase TSC device is: while again dropping into after excision, allow the pilot thyristor of rear shutoff logical, the two pairs of thyristors can both normally, the control principle of " turn-offing afterwards first conducting ".
For example, as shown in Figure 4, after VTA, turn-off; While again dropping into TSC, allow the first conducting of VTA, control command can only be positioned at t
9～t
10.If system, need to be at t by detecting
7～t
9between apply the instruction that drops into TSC, also to postpone till t
9～t
10send.Otherwise, will there is thyristor latch-up phenomenon.Sending of TSC control command is easy to by obtaining supply voltage is phase-locked constantly.
In general, adopt first method both simple, economical, also little on repeating the impact of switching response time.
The controller design that method of the present invention is the quick TSC device of three-phase provides foundation, and the three-phase TSC device that is not only applicable to mesolow is also applicable to three-phase high-voltage TSC device.
Experimental verification
In order to verify that the correctness of above invention carried out corresponding experimental study, wherein, supply voltage is 380V, and every phase capacitor size is 35 μ F, and experimental result as shown in Figure 5.The switching process that wherein Fig. 5 (a) first turn-offs for VTA, system is quick-switching normally, and 4 curves are respectively switching signal u from top to bottom
g, the both end voltage u of thyristor to VTA
vTA, two-phase line current i
a, i
b; In Fig. 5 (b) and Fig. 5 (c), each figure meaning is identical therewith; Fig. 5 (b) first turn-offs for VTB, the switching process of the first conducting of VTB, and having there is thyristor locking in system, only has the B conducting of being on good terms, and A is normal fast conducting mutually; Fig. 5 (c) first turn-offs for VTB, the switching process of the first conducting of VTA, and system can normal quick-switching.
When repeating operating passing zero fast to three-phase condenser bank in actual device, the results show just can avoid occurring thyristor latch-up phenomenon according to certain excision and input order.
Claims (6)
1. when three-phase thyristor switched capacitor repeats operating passing zero fast, prevent a method for thyristor locking, the switching circuit of three-phase thyristor switched capacitor comprises: single-phase capacitance C1, C2 and C3 that the first solid-state switch and the second solid-state switch, delta connection link together; The A that one end of the first solid-state switch is connected between capacitor C 1 and C3, the other end is connected to three phase mains goes up mutually; The B that one end of the second solid-state switch is connected between capacitor C 1 and C2, the other end is connected to three phase mains goes up mutually; The C of three phase mains is connected between capacitor C 2 and C3; The A phase of three phase mains, B phase, C are positive phase sequence mutually; The switching of solid-state switch control capacitor; The structure of solid-state switch comprises a pair of antiparallel thyristor; It is characterized in that, the switching of three-phase thyristor switched capacitor sequentially: when excision drops into after capacitor again, that first conducting of turn-offing after in two solid-state switches while allowing excision.
2. the method that prevents thyristor locking according to claim 1, it is characterized in that, when dropping into instruction, send the conducting during moment that is arranged in the solid-state switch that two solid-state switches first turn-off constantly, postpone to send input instruction, until the conducting of the solid-state switch turn-offing after in two solid-state switches is sent while constantly arriving again.
3. the method that prevents thyristor locking according to claim 1, is characterized in that, described switching sequentially replaces with: during excision capacitor, fixedly allow the first solid-state switch first turn-off.
4. the method that prevents thyristor locking according to claim 3, is characterized in that, when excision instruction, sending is constantly the moment of the second solid-state switch excision, postpones to send excision instruction, until the first solid-state switch excision constantly arrives and sends.
5. according to the method that prevents thyristor locking described in claim 1 to 4 any one, it is characterized in that, described solid-state switch is a pair of antiparallel thyristor and control circuit thereof or is by a pair of antiparallel thyristor and control circuit encapsulation all-in-one-piece solid-state relay thereof.
6. according to the method that prevents thyristor locking described in claim 1 to 4 any one, it is characterized in that, single-phase capacitance C1, the C2 that described delta connection links together and C3 are encapsulated as a three-phase capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110340469.6A CN102510067B (en) | 2011-11-02 | 2011-11-02 | Method for preventing thyristors from being locked during quick and repeated zero cross switching of three-phase thyristor switched capacitor (TSC) |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110340469.6A CN102510067B (en) | 2011-11-02 | 2011-11-02 | Method for preventing thyristors from being locked during quick and repeated zero cross switching of three-phase thyristor switched capacitor (TSC) |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102510067A CN102510067A (en) | 2012-06-20 |
| CN102510067B true CN102510067B (en) | 2014-03-12 |
Family
ID=46222127
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110340469.6A Active CN102510067B (en) | 2011-11-02 | 2011-11-02 | Method for preventing thyristors from being locked during quick and repeated zero cross switching of three-phase thyristor switched capacitor (TSC) |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102510067B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104466991A (en) * | 2014-12-24 | 2015-03-25 | 安徽天沃电气技术有限公司 | Control method for novel thyristor-fast-switched capacitor banks |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2419726Y (en) * | 2000-04-26 | 2001-02-14 | 北京金自天正智能控制股份有限公司 | Automatic compensator for power factor of network |
| CN2544452Y (en) * | 2002-06-15 | 2003-04-09 | 乐清市旭日无功动态补偿设备厂 | Low-voltage idle dynamic compensator |
| CN101572412A (en) * | 2009-06-12 | 2009-11-04 | 北京思能达电力技术有限公司 | High-capacity packet type switchgear |
| CN101667822A (en) * | 2009-09-29 | 2010-03-10 | 河北省电力研究院 | Solid state compound switch structure |
-
2011
- 2011-11-02 CN CN201110340469.6A patent/CN102510067B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2419726Y (en) * | 2000-04-26 | 2001-02-14 | 北京金自天正智能控制股份有限公司 | Automatic compensator for power factor of network |
| CN2544452Y (en) * | 2002-06-15 | 2003-04-09 | 乐清市旭日无功动态补偿设备厂 | Low-voltage idle dynamic compensator |
| CN101572412A (en) * | 2009-06-12 | 2009-11-04 | 北京思能达电力技术有限公司 | High-capacity packet type switchgear |
| CN101667822A (en) * | 2009-09-29 | 2010-03-10 | 河北省电力研究院 | Solid state compound switch structure |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102510067A (en) | 2012-06-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Mouli et al. | Design of a power-electronic-assisted OLTC for grid voltage regulation | |
| Xiang et al. | Research on fast solid state DC breaker based on a natural current zero-crossing point | |
| CN110086161A (en) | A kind of magnetism-regulating type arc suppression coil earthing system | |
| CN204333943U (en) | A kind of multi-objective short-circuit Fault Current Limiting Device | |
| CN105703370B (en) | Unified power flow controller combining series compensation and current converter | |
| CN203761046U (en) | Controllable series compensation system | |
| CN103545836A (en) | Capacitor commutated converter inverter side system | |
| CN102420431A (en) | Low-voltage phase control switch for mechanically switching capacitor | |
| CN104218593A (en) | Series capacitor compensation device for power distribution network | |
| CN104104143A (en) | Parallel-connected quiescent voltage restorer for isolating transient voltage fault of power system | |
| CN107370130B (en) | A kind of hybrid high voltage DC breaker and its control strategy based on modified half-bridge submodule | |
| CN102510067B (en) | Method for preventing thyristors from being locked during quick and repeated zero cross switching of three-phase thyristor switched capacitor (TSC) | |
| Li et al. | A new method of black start based on VSC-HVDC | |
| Sham et al. | Development of adaptive distance relay for STATCOM connected transmission line | |
| CN204030971U (en) | The power cell with bypass functionality of unit series connection type high voltage frequency convertor | |
| CN106208106B (en) | A kind of paralleling compensating device based on compensation/current-limiting reactor | |
| CN105356434A (en) | Novel bridge type solid-state fault current limiter and using method thereof | |
| CN202353224U (en) | Low-voltage phased switching capacitor switch | |
| Yang et al. | Fault isolation characteristics of the hybrid DC circuit breaker | |
| CN205178490U (en) | Novel solid -state fault current limiter of bridge type | |
| CN107785908A (en) | A kind of dynamic electric voltage recovery device with short circuit current limitation function | |
| WO2012126271A1 (en) | Electrified railway traction substation reactive power compensation apparatus | |
| CN205992735U (en) | A kind of paralleling compensating device based on compensation/current-limiting reactor | |
| CN203086142U (en) | Silicon controlled rectifier circuit of pre-charging TSC device | |
| Dong et al. | Effectiveness analysis of evaluating continuous commutation failure with short circuit ratio |
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 |