CN103229400B - In order to protect ESP power supply from the method and apparatus of the transient over-voltage on power network - Google Patents
In order to protect ESP power supply from the method and apparatus of the transient over-voltage on power network Download PDFInfo
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- CN103229400B CN103229400B CN201180058835.7A CN201180058835A CN103229400B CN 103229400 B CN103229400 B CN 103229400B CN 201180058835 A CN201180058835 A CN 201180058835A CN 103229400 B CN103229400 B CN 103229400B
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- 238000000034 method Methods 0.000 title claims abstract description 13
- 230000001052 transient effect Effects 0.000 title claims description 17
- 230000004224 protection Effects 0.000 claims abstract description 52
- 239000012717 electrostatic precipitator Substances 0.000 claims abstract description 48
- 239000000411 inducer Substances 0.000 claims description 46
- 230000000903 blocking effect Effects 0.000 claims description 11
- 230000009466 transformation Effects 0.000 claims 3
- 239000003990 capacitor Substances 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 4
- 210000003141 lower extremity Anatomy 0.000 description 4
- 229910044991 metal oxide Inorganic materials 0.000 description 4
- 150000004706 metal oxides Chemical class 0.000 description 4
- 230000009194 climbing Effects 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 2
- 239000010883 coal ash Substances 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 239000004531 microgranule Substances 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000004064 dysfunction Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
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Abstract
A kind of power supply changeover device unit being particularly used for electrostatic precipitator is disclosed, it is by being rectified into unidirectional current (Udc) by exchange input power supply (1) in commutator (12), this unidirectional current (Udc) is converted into alternating current in the full-bridge inverter (13) in the H-bridge circuit with the switch (48) controlled by control unit (23), the frequency of exchange input power supply (1) is converted into high-frequency ac output (Ua, Ub).According to the present invention, on the input side of commutator (12), and/or in unidirectional current (Udc) section, it is provided that at least one excess voltage protection (34,35,37 39,45).Additionally, the open one of the present invention is used for running this power supply changeover device unit, and the method using this power supply changeover device unit.
Description
Technical field
The present invention relates to such as running the field of the power supply of the device of such as electrostatic precipitator.Additionally, the method that the present invention relates to run such power supply and use such power supply.
Background technology
Along with the consideration of environmental pollution gets more and more, for coal power plant, it is very important problem by using electrostatic precipitator (ESP) to reduce Particulate Emission.ESP is fit closely dust arrester.Their design is the most healthy and the strongest, and they are the most reliable.Additionally, they are the most efficient.Separating degree higher than 99.9% is the rarest.Due to, when comparing with fabric filter, their operating cost is low, and causes damage and the risk stopped work fairly small, so they are natural selection in many cases due to dysfunction.In ESP, dusty gas conducts between the electrode being connected on ESP power supply.Generally, this is high voltage transformer, and it has thyristor control on primary side, and has rectifier bridge on the secondary side.This layout is connected on common AC main line, and thus is powered this layout under 50 Hz or 60 Hz frequencies.Power control is realized by the trigger delay changing IGCT.Delay-angle is the least, i.e. the conduction cycle is the longest, and the electric current being fed to ESP is the most, and the voltage between the electrode of ESP is the highest.Modern ESP is divided into some bus bar sections, to improve collection efficiency.Each power supply (PS) with itself in these bus bar sections, this power supply is controlled individually, and has typical output power scope and the 30-150 of 10-200 kW
The output voltage range of kVDC.
The power supply of modern ESP is often based on resonance converter, in order to utilizes the undesirable property of transformator, and carries out Sofe Switch in wide range of operation.From US
2009/0129124 learns an exemplary power for ESP.
The overvoltage protection of transducer for having line frequency switchmode rectifier is learnt from DE 102007007922.
It addition, learn that from US 2007/0121354 rate of change using voltage is as the input of DC link voltage controller.
Summary of the invention
ESP power supply comprises all devices necessary for supporting to have high-tension single ESP bus bar sections.The primary electron block of ESP power supply is converter unit, high voltage unit and controller unit.Converter unit performs the frequency to ingoing power and changes, and the conversion of this frequency will be typically based on the igbt (IGBT) in so-called H electrical bridge.High voltage unit is the transformator with commutator.According to actual operating state, controller unit makes power flow adapt to bus bar sections.
In the case of power network has transient over-voltage, the DC link in this power supply exists the risk of overvoltage.Accordingly, because the reason of the overvoltage at transistor two ends of the H electrical bridge being in blocked state, IGBT can be occurred to lose efficacy.
The problem being associated with this impact is solved by the apparatus and method claimed according to the present invention's and in appended claims.
Especially, the present invention relates to a kind of power supply changeover device unit being particularly used for electrostatic precipitator, it is by becoming unidirectional current by exchange input power-supply rectifying in commutator, this unidirectional current full-bridge inverter in the H-bridge circuit with the switch controlled by control unit the most again is converted into alternating current, the frequency of exchange input power supply is converted into high-frequency ac output.Especially, according to the present invention, on the input side of commutator, and/or in direct current section, it is provided that at least one excess voltage protection.Term excess voltage protection is not meant to represent the simple electric fuse in incoming line, and refers to relative to ground wire and/or the overvoltage protection of the circuit middle of input.Therefore; according to the first preferred embodiment; excess voltage protection includes at least one voltage limiting circuit, and it will be typically based on the maximum voltage between the individually phase that rheostat (such as metal oxide varistor) limiting AC input respectively is powered or between galvanic level.
According to another preferred embodiment, excess voltage protection includes at least one other voltage limiting circuit, the maximum voltage mutually and between ground wire or between galvanic level and ground wire of its limiting AC input power supply.
Another preferred embodiment is characterised by, excess voltage protection includes exchanging at least one inducer inputted in each phase powered or in galvanic circuit respectively.
Preferentially, the input side of at least one inducer provides at least one voltage limiting circuit, at least one other voltage limiting circuit is provided on the input side of at least one inducer the most combined with itly, and at least one voltage limiting circuit is provided on the outlet side of at least one inducer, at least one other voltage limiting circuit is provided on the outlet side of at least one inducer the most combined with itly.
The voltage limiting circuit provided on the outlet side of at least one inducer may be not enough to during transition changes protect commutator.The input side of at least one inducer in the case of not postponing, it is achieved the rapid rising of input voltage, and also can damage inducer.Therefore, the voltage limiting circuit provided on the input side of at least one inducer is more effectively carried out protection during fast transient.
Owing to voltage limiting circuit is the most undesirable, and in order to control to arrive the maximum rate of change of the voltage/current of the switch of electric bridge safely, this particular combination of two voltage limiting circuits being arranged on the both sides of inducer has proved to be very effective.
Typically, the switch of H electrical bridge is at least four switch element, at least four IGBT element preferably controlled by an identical control unit.
In order to protect switch element from overvoltage all sidedly; according to another preferred embodiment; at least one element or sensor are provided; for detecting the voltage in the circuit of direct current section and/or electric current; and their transient behavior (behaviour) (rate of change); the output valve of described element is used for controlling switch in a control unit, or operatively links with control unit, to control switch.
When reaching the threshold value of voltage and/or electric current and its transient behavior, control unit is suitable to make switch become blocking state.Preferentially, when detected value reaches upper limit threshold or lower threshold, or by reaching the rate of change of value, or the threshold value dynamically calculated by current rate of change based on fixing upper limit threshold/lower threshold and value, control unit starts closes.
In another embodiment, closedown is started by independent protective logic.This allows the dangerous change responding in voltage quickly than the voltage used in voltage controller.Especially, independent relay protective scheme is than Control of Voltage itself faster.Control of Voltage allows to run at higher voltages with the combination of relay protective scheme, thus improves performance, and the range of operation of expansion instrument.
Generally, exchange input power supply is three-phase input, alternatively, three-phase input protecting by the electric fuse in each circuit.
According to specific preferred embodiment; excess voltage protection includes rheostat; preferably metal oxide varistor; wherein; additionally preferably, at least one voltage limiting circuit and/or another voltage limiting circuit are main exclusively based on the rheostat preferentially connecting into corresponding triangle (delta) circuit.
nullEven more particularly，Preferably，Excess voltage protection includes based at least one voltage limiting circuit rheostatic，This at least one voltage limiting circuit limits the maximum voltage between the individually phase of three-phase alternating current input power supply，Wherein，Excess voltage protection farther includes based at least one other voltage limiting circuit rheostatic，This at least one other voltage limiting circuit limits the maximum voltage mutually and between ground wire of three-phase alternating current input power supply，Wherein，Excess voltage protection further includes at least one inducer in each phase of three-phase alternating current input power supply，And wherein，The input side of at least one inducer provides at least one voltage limiting circuit，At least one other voltage limiting circuit is provided on the input side of at least one inducer combined with itly，And at least one voltage limiting circuit is provided on the outlet side of at least one inducer，At least one other voltage limiting circuit is provided on the outlet side of at least one inducer combined with itly.
Additionally, the present invention relates to the method for running power supply changeover device unit described above.According to the method, it is preferable that provide at least one element or sensor, for detecting the voltage in the circuit of direct current section and/or electric current and/or its transient behavior, and the measured value of this element is used for controlling switch in a control unit.
Preferred embodiment according to the method, it is achieved the overvoltage protection of power supply changeover device unit, because when detection/reception records the threshold value of voltage and/or electric current and/or its transient behavior, control unit makes all switches of H electrical bridge become blocking state.
Preferably, by reaching upper limit threshold or lower threshold, or by reaching the maximum rate of change of value, or by the threshold value dynamically calculated based on fixing upper limit threshold/lower threshold and the recording speed change of value, start closedown.In the case of the latter, the target of control is to ensure that magnitude of voltage/current value can never arrive switch, and it can damage this structural detail.Correspondingly, in the case of the rate of change of such as voltage is low, substantially when reaching fixed threshold, closing switch element is safe.But, if rate of change is high, it is necessary for revising threshold value, in order to will not immediately shutdown signal be reacted in view of system, and in view of due to this, the magnitude of voltage that just device has been experienced after signaling switch still can the most jeopardously raise.It is said that in general, the rate of change so to say that detected is the highest, more threshold value will be conservatively set.So, when close to marginal value, rate of change is the highest, it is necessary to the threshold value of selection is the lowest.
Can be by calculating as current voltage (DC link voltage) u (t) in the circuit in direct current section
The control function F (u (t)) of function, provide a feasible control program, wherein function depends on magnitude of voltage u (t) and first derivative u'(t thereof currently recorded).Alternatively, it is possible to by second dervative u, " (t) takes into account.Each derivative can multiplication by constants A and B, thus produce below equation:
。
Preferably, control not only should depend on that the value of F (u (t)) controls, and the value that should also depend on u (t) controls, so depending on that the magnitude of voltage that current DC link records is controlled.Stated differently, since by UmaxRegarding the maximum permissible value of voltage in DC-link as, when at least one in following two condition meets, shutdown switch signal should be started by control unit:
Also corresponding control program can be supplemented further by relevant on the electric current that records in DC link.
Typically, the maximum rate of change of value is in the scope of 0.1-10 kV/ms, preferably at 0.5-2
In the scope of kV/ms, thus the speed of changing value can cause when exceeding the maximum rate of change of this value being automatically switched off all switches.
Typically, upper limit threshold is in the scope of (800 V)-(2000 V), preferably (900
In the scope of V)-(1200 V).Lower threshold is typically in the scope of (0 V)-(700 V), preferably in the scope of (350 V)-(550 V).
In addition the present invention relates to use power supply as described above, it is additionally preferred ground uses the method that operates above to run electrostatic precipitator, wherein, at least two power supply is preferably used, and each of which is at least one bus bar sections of electrostatic precipitator.
Advocate the further embodiment of the present invention in the dependent claims.
Accompanying drawing explanation
Referring to the drawings, being described below the preferred embodiments of the present invention, accompanying drawing is to illustrate presently preferred embodiment of the invention rather than in order to limit them.In the accompanying drawings,
Fig. 1 shows typical ESP device scheme, especially, has by the system of several continuous print bus bar sections of 24 power drives；
Fig. 2 a shows the schematic diagram of single altofrequency ESP power supply, and Fig. 2 b is the schematic diagram of typical single-phase mains frequency ESP power supply, and Fig. 2 c is the block diagram of single altofrequency ESP power supply；
Fig. 3 shows the details of the brachium pontis of full-bridge inverter；
Voltage is shown as the function of time under IGBT switch motion by Fig. 4, and grid lines indicates 10 μ s, so the pulse period is about 40 μ s；
Fig. 5 shows the connectivity of one group of 3 ESP power supply with ESP fan motor as example；
Fig. 6 shows the bridge arm voltage Ua when stopping IGBT switch, and grid lines indicates 200 μ s；
Fig. 7 shows the circuit diagram of the converter unit of the ESP power supply with protection circuit；And
Fig. 8 schematically shows the feasible control program key element function as DC link voltage.
List of parts
1 main line, public feeding
2 low voltage levels or middle voltage level circuit
3 distribution transformers
The 4 gas streams being full of microgranule (such as coal ash)
5 electrostatic precipitator
6 inlet regions
7 mesozones
8 outlet areas
9 chimneys
10 cleanings discharge gas
11 power supplys
12 input rectifiers
13 full-bridge inverters, H electrical bridge
14 resonant tanks and transformator
15 output rectifiers
16 electric currents and/or voltage sensor
17 IGCT blocks
18 DC link. capacitor
The capacitor of 19 series connection
The inducer of 20 series connection
21 transformators
22 drivers
23 control units
24 1
25 2
26 distribution wires
27 communication interfaces
28 extra loads, fan motor
29 as the bridge arm voltage of the function of time
30 stop IGBT switch, and IGBT both closes
31 electric fuses
32 ground wires
33 rheostats for protection relevant with ground wire
Protection circuit on the input side of 34 inducers
Protection circuit on the outlet side of 35 inducers
36 carry out the rheostat protected between three-phase level
37 inducers
The 38 DC inducers on negative level
The 39 DC inducers on positive level
The half-bridge of 40 inverters
41 are used for DC level, the sensor of voltage/current
The slope of 42 DC link voltages
43 DC link upper limit thresholds
44 DC link lower thresholds
45 metal oxide varistors, MOV
46 capacitors
47 diodes
48 switch elements, IGBT
Ua, Ub bridge arm voltage
DC link voltage positive for+Udc
The DC link voltage that-Udc is negative
T time.
Detailed description of the invention
Generally, ESP system is divided into some bus bar sections, to improve particle collection efficiency.In mini-system, only 2 or 3 bus bar sections are connected in series, and in large scale system, some bus bar sections are in parallel and are connected in series.The different power supply with different power ratings usually provides energy to bus bar sections, in order to optimize the collection efficiency of single bus bar sections.
Fig. 1 shows the typical ESP device of the bus bar sections having by some connections of 24 power drives.Electrostatic precipitator 5 includes entrance side, and the gas stream 4 being full of microgranule (such as coal ash) enters ESP by entrance side.ESP has inlet region 6, is mesozone 7 behind, and ESP terminates at outlet area 8, and the outlet of outlet area 8 is connected to chimney 9, and cleaning is discharged gas 10 and left by chimney, arrives environment.So ESP is mechanically divided into the district being connected in series and the unit being connected in parallel, to utilize collection efficiency.Each district/cell position is referred to as bus bar sections.Single bus bar sections is fed by one ESP power supply with high voltage.
Each in district 6-8 has two rows and the duster system (four unit and six districts) of power is provided separately, thus causes 24 bus bar sections, and to this end, provides 24 power supplys (PS) to come to cleaner unit provide energy.To provide energy to power supply by public feeding 1, public feeding 1 is connected on single power supply by low-voltage or middle voltage circuit 2 and distribution transformer 3.In other words, being all connected on public feeder system 1 of power supply, and if these power supplys or at least one part run in pulse mode, then the load on main line may be the most unbalanced.
Illustrating power supply 11 in fig. 2 a, it is for according to an offer power in the single bus bar sections in the device of Fig. 1.On the input side, power supply 11 is connected on main line 1, and first includes input rectifier 12.The outlet side of input rectifier 12 provides unidirectional current (DC), and DC link. capacitor 18 is between level.Then this unidirectional current feeds by having the full-bridge inverter 13 of many transistors triggered accordingly.The operation device driven 22 of full-bridge inverter 13 controls, and the most controlled unit of driver 22 23 controls.Alternating current on the outlet side of full-bridge inverter 13 enters resonant tank and transformer unit 14, and resonance circuit is provided by capacitor 19 and the inducer 20 of the arranged in series before transformator 21.On the output side, unit 14 can be coupled on output rectifier 15, and then the outlet side of output rectifier 15 is coupled on the electrode of electrostatic precipitator 5.
For the pulsing operation of this power supply, full-bridge inverter runs in pulse mode by means of control unit 23 and driver 22.In order to control whole system, it is provided that electric current and voltage sensor 16, the output of this electric current and voltage sensor 16 is used for control unit 23.
The invention is not restricted to that illustrate in fig. 2 a and that schematically show the most further (high frequency) three phase mains, it typically runs with the frequency in 20-200 kHz scope in resonant tank.Mains frequency power processing unit shown in Fig. 2 b is also feasible, and wherein, single-phase main line 1, at unit 17 breaker in middle, is changed by transformator 21, and is rectified, in order to after output rectifier 15, finally uses on ESP.
So in ESP power supply, 3 phases being powered and carries out rectification, and apply DC link voltage (+Udc ,-Udc) at H electrical bridge 13 (Ua, Ub) two ends.This mode of variable frequency square-wave voltage supply to high voltage unit to be controlled the IGBT 48 of electric bridge.
The more detailed description of converter unit IGBT module switch and voltage rating thereof is as follows: Fig. 3 shows the brachium pontis 40 of H electrical bridge.Each door includes the IGBT 48 in parallel with capacitor 46 and diode 47.Brachium pontis 40 runs by this way, that is, one valve (such as top IGBT 24) is in open mode (that is, being in conducted state), and the valve (such as bottom IGBT 25) supplemented is closed (that is, being in blocking state).
The voltage Ua of generation is shown as the function of time by the Fig. 4 pulse period relative to about 40 μ s.The voltage stress of the IGBT being in open mode is the lowest by (-0
V), the IGBT being closed then blocks full DC link voltage.Typically, the IGBT used in this case has 1200
The rated value of V, the most typical rated value can be in the scope of 600 V-6500 V, so in the case of having higher than the transient over-voltage of this value on the net, IGBT will suffer damage.
The possible cause of transient over-voltage can be the connection/disconnection of lightning, Capacitor banks, or has short circuit etc. in the equipment connected.Figure 5 illustrates typical case, it illustrates the most public distribution wire 26 situation to several ESP power source supplies power of the different bus bar sections of electrostatic precipitator.Individually ESP power supply 11 includes control unit 23, and control unit 23 is connected by communication line 27 among each other.In such systems, in ESP power supply, or in the extra different load 28 being attached on identical main line 1 by public distribution wire 26, may there is short trouble.This extra load can be such as the motor 28 for fan, and fan forces gas to flow through ESP shell.When the protectiveness electric fuse of fan 28 disconnects short circuit, the highest voltage transient can be caused, thus severely impact other load being connected on identical distribution wire 26, i.e. severely impact ESP power supply 11.
Stop if the switch of IGBT runs, and the IGBT 24,25 in brachium pontis 40 is both in blocking state, then will share DC link voltage equably between two IGBT 24,25.Therefore, the blocking ability of H electrical bridge 40 doubles the blocking ability of single IGBT.Therefore, under overvoltage situation, IGBT can be protected by shutdown switch action.Fig. 6 shows the bridge arm voltage 29(Ua (indicated) when switch motion stops by arrow 30).As can be seen from FIG., the voltage at IGBT two ends, in 200-400 μ s, settles out at the DC link voltage of 50%.
In addition to the slope on monitoring voltage and DC level thereof and closedown IGBT are so that protecting their this control program, the solution of proposition can comprise protection circuit (this protection circuit can limit the climbing speed causing DC link voltage due to over-voltage transients) and analyze the dynamic of DC link voltage in real time.Produce danger situation when analyzing, the risk (overvoltage) that IGBT lost efficacy at hand time, the switch of IGBT stops.When the situation on DC link returns to normal, switch runs and automatically restarts.
Figure 7 illustrates the corresponding circuit diagram constituted of ESP power supply.
Protection circuit comprises two overvoltage protections 34 and 35 and an inducer 37.Overvoltage protection 34 and 35 is groups of rheostat 45 (metal oxide varistor), and a group 33 protects each circuit level relative to ground wire 32, the voltage difference between another group 36 then protection circuit.Overvoltage protection 34 and 35 is positioned on the both sides of inducer 37.
It practice, the undesirable property of the component due to overvoltage protection, therefore can not get rid of a single overvoltage protection will be inadequate.In other words, the first overvoltage protection 34 can be got rid of in short time range, and high-voltage value will arrive inducer 37.In order to this high-voltage value will be restrained further, it is provided that extra protection device 35.The climbing speed limiting DC link voltage is combined with element 34,35 and 37.Inducer 37 1 (it is connected with extra electric fuse 31) of powering with 3 phases is connected in series.In this type of example realized shown in fig. 2, combine inducer 37 and DC inducer 38 (negative DC level) and 39 (positive DC level) the most in the design.The both sides of inducer 37 are added overvoltage protection 34 and 35.This protection circuit 34 and 35 limits the voltage at inducer 37 and DC inducer 38/39 two ends, and thus limits the slope of the inrush current of the DC link leading to converter unit.When abnormal DC link voltage being detected, limited slope ratio is just, and help makes power electronic component not lost efficacy.
Controller 23 performs the dynamic analysis to the DC link voltage recorded with sensor 41 constantly, and when the DC link voltage at IGBT lower limb two ends has infringement IGBT dangerous, controller 23 determines the switch motion of stopping IGBT module rapidly.
The example that DC link voltage is analyzed dynamically is following (seeing Fig. 8):
1. the DC link voltage at IGBT lower limb two ends reaches the level of the limit 43 higher than " DC link voltage is high "；If meeting this condition, then controller 23 cuts out all IGBT.
2. the DC link voltage at IGBT lower limb two ends reaches the level of the limit 44 less than " DC link electrical forces down "；If meeting this condition, then controller 23 cuts out all IGBT.
3. the slope of the DC link voltage at IGBT lower limb two ends increases/reduces and to obtain too fast (volt/second)；If meeting this condition, then controller 23 cuts out all IGBT.Typically, the change in voltage in the scope of every millisecond of kilovolt is considered as the fastest.
Level 43 and 44 can be arranged to not dynamic value.But, advantageously, it is achieved merging slope and maximum taken into account controls.In other words, maximum level 43 and minimum levels 44 can be dynamically determined the function into slope.If such as DC link voltage promptly increases/reduces, then should select relatively low maximum level 43 and higher minimum levels 44, take into account so that system will not be reacted immediately.So, depend on the speed close to level value, it is necessary to amendment the latter, in order to confirm that the rated value of IGBT will not be exceeded due to response time effect.Controller 23 is continually performed to be analyzed dynamically to DC link voltage.Add the protection circuit 34,35,37 of design to and limit the slope of inrush current leading to transducer, and thus in the case of having over-voltage transients on power network, limit the climbing speed of DC link voltage.This can make ESP power supply have higher reliability, and allows to restart automatically after over-voltage transients.
Also can be in conjunction with inducer 37 in the converter unit with different configurations designs.
The example of different configurations:
The most only on the AC side of input rectifier (only element 37, as shown in Figure 7)；
The most only on the DC side of input rectifier (only element 38/39, as shown in Figure 7)；
3. on the both sides of input rectifier (as shown in Figure 7).Part and parcel is the overvoltage protection on the both sides of inducer.
DC link voltage Dynamic Execution is analyzed by available different mode.It is essential that IGBT switch stops in the case of having time enough surplus to danger situation, in order to stop and lost efficacy.
The scheme proposed also can comprise voltage rigidity (stiff) the IGBT electric bridge with the DC link monitored by control system more generally for any Changer Device.
Claims (17)
1. for a power supply changeover device unit for electrostatic precipitator, including:
Commutator (12), it is for being rectified into unidirectional current (Udc) in come to power exchange input (1) that frequency is converted into high-frequency ac output (Ua, Ub)；
Having the full-bridge inverter (13) in the H-bridge circuit of the switch (48) that can be controlled by control unit (23), it is for being converted into alternating current by described unidirectional current (Udc)；
Protection circuit on the input side of described commutator (12); wherein said protection circuit includes two excess voltage protections (34; 35) and inducer (37), said two excess voltage protection (34,35) is positioned on the both sides of described inducer (37)；And
Wherein said excess voltage protection includes at least one voltage limiting circuit limiting the maximum voltage between the single phase of described exchange input power supply, and described excess voltage protection farther includes to limit at least one other voltage limiting circuit of the maximum voltage between single phase and the ground wire of described exchange input power supply.
2. power supply changeover device unit as claimed in claim 1, wherein, described power supply changeover device unit farther includes at least one excess voltage protection being disposed in unidirectional current (Udc) section of described commutator (12).
Power supply changeover device unit the most according to claim 2; wherein; the excess voltage protection being disposed in unidirectional current (Udc) section of described commutator (12) includes at least one voltage limiting circuit limiting the maximum voltage between the level of described unidirectional current (Udc), and the excess voltage protection being disposed in unidirectional current (Udc) section of described commutator (12) farther includes to limit at least one other voltage limiting circuit of the maximum voltage between level and the ground wire of described unidirectional current (Udc).
Power supply changeover device unit the most according to claim 1, wherein, the excess voltage protection on the input side of described commutator (12) is that inducer and wherein said inducer are in each phase of described exchange input power supply (1).
Power supply changeover device unit the most according to claim 2; wherein, the excess voltage protection being disposed in unidirectional current (Udc) section of described commutator (12) is that inducer and wherein said inducer are in the circuit of described unidirectional current (Udc).
Power supply changeover device unit the most according to claim 1 and 2, at least one voltage limiting circuit (36) that voltage limiting circuit (33) other with at least one on the input side of described inducer (37-39) provides in combination, and at least one voltage limiting circuit (36) provided in combination with at least one other voltage limiting circuit (33) on the outlet side of described inducer (37-39) are be provided.
Power supply changeover device unit the most according to claim 1 and 2, wherein, the switch (48) of described H electrical bridge is at least four switch element (48) controlled by an identical control unit (23).
Power supply changeover device unit the most according to claim 1 and 2, farther include at least one element (41), it is for detecting the voltage (Udc) in described galvanic circuit and/or electric current and their transient behavior, to be used for controlling to switch (48) in control unit (23).
Power supply changeover device unit the most according to claim 1 and 2, wherein, when reaching the threshold value of voltage (Udc) and/or electric current or their transient behavior, control unit (23) makes switch (48) become blocking state, wherein, by reaching upper limit threshold or lower threshold or by the rate of change reaching value or the threshold value dynamically calculated by current rate of change based on fixing upper limit threshold/lower threshold and value, carry out the activate switch transformation to described blocking state.
Power supply changeover device unit the most according to claim 1 and 2, wherein, is three-phase input on described exchange input power supply (1), and the input of described three-phase is by the protection of the electric fuse (31) in each circuit.
11. power supply changeover device unit according to claim 1 and 2, wherein, described excess voltage protection includes rheostat (45), and preferentially connects at least one voltage limiting circuit (36) of delta network.
null12. power supply changeover device unit according to claim 1 and 2，Wherein，Described excess voltage protection (34，35，37-39，45) at least one voltage limiting circuit (36) based on rheostat (45) is included，Described at least one voltage limiting circuit (36) limits the maximum voltage between the individually phase of three-phase alternating current input power supply (1)，Wherein，Described excess voltage protection (34，35，37-39，45) at least one other voltage limiting circuit (33) based on rheostat (45) is farther included，At least one other voltage limiting circuit (33) described limits the maximum voltage mutually and between ground wire (32) of three-phase alternating current input power supply (1)，Wherein，Described excess voltage protection (34，35，37-39，45) further include at described three-phase alternating current input power supply (1) mutually in each at least one inducer (37，38，39)，And wherein，The input side of described at least one inducer (37-39) provides at least one voltage limiting circuit (36)，At least one other voltage limiting circuit (33) is provided on the input side of described at least one inducer (37-39) combined with itly，And on the outlet side of described at least one inducer (37-39), provide at least one voltage limiting circuit (36)，At least one other voltage limiting circuit (33) is provided on the outlet side of described at least one inducer (37-39) combined with itly.
13. 1 kinds are used for the method running power supply changeover device unit according to claim 1, including:
Use voltage (Udc) and/or electric current and/or their transient behavior that at least one element (41) detects in described galvanic circuit；And
The measured value using described at least one element (41) in control unit (23) controls to switch (48).
14. methods according to claim 13; wherein; when described control unit (23) reaches record voltage (Udc) and/or electric current and/or the threshold value of their transient behavior and all switches (48) of described H-bridge circuit are become blocking state, it is achieved the overvoltage protection of described power supply changeover device unit.
15. methods according to claim 13; wherein; when described control unit (23) reaches the threshold value recording voltage (Udc) and/or electric current and/or its transient behavior; realize the overvoltage protection of described power supply changeover device unit, and by reaching upper limit threshold or lower threshold or by reaching the maximum rate of change of value or being started all switches (48) transformation to blocking state of described H-bridge circuit by the threshold value dynamically calculated based on fixing upper limit threshold/lower threshold and the rate of change of value that records.
null16. methods according to claim 13，Wherein，When described control unit (23) reaches the threshold value recording voltage (Udc) and/or electric current and/or its transient behavior，Realize the overvoltage protection of described power supply changeover device unit，And by reaching upper limit threshold or lower threshold、Or by reaching the maximum rate of change of value、Or all switches (48) transformation to blocking state of described H-bridge circuit is started by the threshold value dynamically calculated based on fixing upper limit threshold/lower threshold and the rate of change of value that records，And the maximum rate of change of described value is in the scope of 0.1-10 kV/ms or in the scope of 0.5-2 kV/ms，And/or，Wherein，Described upper limit threshold is in the scope of 800 V-2000 V or in the scope of 900 V-1200 V，And/or described lower threshold is in the scope of 0 V-700 V or in the scope of 350 kV-550 kV.
17. use power supply changeover device unit according to claim 1 to run electrostatic precipitator, wherein, use at least two power supply, each at least one bus bar sections for described electrostatic precipitator in described at least two power supply.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP10186733.1 | 2010-10-06 | ||
| EP10186733 | 2010-10-06 | ||
| PCT/EP2011/067061 WO2012045666A2 (en) | 2010-10-06 | 2011-09-30 | Method and device to protect an esp power supply from transient over-voltages on the power grid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103229400A CN103229400A (en) | 2013-07-31 |
| CN103229400B true CN103229400B (en) | 2016-11-30 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5317498A (en) * | 1992-07-09 | 1994-05-31 | Sundstrand Corporation | Electrical power generation system |
| EP1870994A1 (en) * | 2006-06-23 | 2007-12-26 | ALSTOM Technology Ltd | Power supply for electrostatic precipitator |
| DE102007007922A1 (en) * | 2007-02-14 | 2008-08-28 | Sew-Eurodrive Gmbh & Co. Kg | Inverter has rectifier for producing unipolar intermediate circuit voltage from three-phase main voltage, where rectifier is connected upstream of power choke, which is wired with ohmic resistance for performing oscillations |
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5317498A (en) * | 1992-07-09 | 1994-05-31 | Sundstrand Corporation | Electrical power generation system |
| EP1870994A1 (en) * | 2006-06-23 | 2007-12-26 | ALSTOM Technology Ltd | Power supply for electrostatic precipitator |
| DE102007007922A1 (en) * | 2007-02-14 | 2008-08-28 | Sew-Eurodrive Gmbh & Co. Kg | Inverter has rectifier for producing unipolar intermediate circuit voltage from three-phase main voltage, where rectifier is connected upstream of power choke, which is wired with ohmic resistance for performing oscillations |
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