CN103241138A - Low-frequency traction power supply system - Google Patents
Low-frequency traction power supply system Download PDFInfo
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- CN103241138A CN103241138A CN2013101435307A CN201310143530A CN103241138A CN 103241138 A CN103241138 A CN 103241138A CN 2013101435307 A CN2013101435307 A CN 2013101435307A CN 201310143530 A CN201310143530 A CN 201310143530A CN 103241138 A CN103241138 A CN 103241138A
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Abstract
The invention discloses a low-frequency traction power supply system which is composed of traction substations and traction networks. Each traction substation comprises a traction transformer and a transducer, a primary-side three phase of each traction transformer is connected with a public utility grid, a secondary-side three phase of each traction transformer is connected with the corresponding transducer, traction sides output by the transducers is single-phase, and the traction networks are powered through single-phase traction buss. The power supply frequency f of the traction networks meets the following formula: fault removal time limit TS (ms) of the traction network=relay protection action time TR (ms)+half cycle lambda (ms), namely, f=500/(TS-TR), TS)TR and within 5Hz-16Hz, the traction networks of the traction substations can be connected to implement communicated power supply, and during interruption maintenance or traction-side fault of the traction substation, the transducers are switched off and related breakers are switched on. The low-frequency traction power supply system is widely suitable for power supply of metros with one line at one place, light-rail vehicles, tramcars and trolleybuses with two electric traction lines, and convenient to implement.
Description
Technical field
The present invention relates to traffic and transport field, particularly a kind of low frequency traction power supply technology.
Background technology
Utilize that single-phase tractive power supply system has simple in structure, construction cost is cheap, utilization and advantage such as easy to maintenance, the single phase industrial frequence alternating current standard of high voltage (27.5kV) is generally adopted in the main line electrified railway, and city underground, light rail and public transport such as rail, trackless trolley car generally adopt the direct current (DC) standard of low voltage.
Adopt the direct power taking of electrified railway of single phase industrial frequence alternating current standard in utility network, only use cheap, reliable ground voltage transformer, do not use the higher converter plant of cost, and there is tractive output big, the distinguishing feature that freight volume is big, but producing again has electric phase-splitting (power supply breakpoint) problem etc. of dysgenic power quality problem and self based on negative phase-sequence to utility network, difficulty of governance is big, the cost height, simultaneously, in power frequency (China the is 50Hz) power supply, the electric power system loss of voltage that is caused by reactance is much larger than the loss of voltage that is caused by resistance, obviously, total loss of voltage is much larger than the direct current (DC) standard.
The direct-current traction power supply of low voltage (750V and 1500V) is generally adopted in track traffic such as city underground, light rail, the voltage of rail and trackless trolley car is lower, it has the power supply voltage loss little, traction net between the substation can connect to avoid powering advantages such as breakpoint, but have stray current (the earth fan stream), direct current arc is difficult for intrinsic problems such as cut-out during fault.Stray current all will produce electrochemical corrosion to bar construction in railway roadbed bar construction, the tunnel and metallic facilities such as metal pipe line along the line, thereby influence safety and the service life of these structures and metallic facility, administer and maintenance difficulties is big, cost is high, and can not fundamentally eliminate stray current and long-term corrosion influences; Dc circuit breaker will cut off direct current arc, and technical risk is big, mechanism's complexity, and service life is short, cost height, and China's dependence on import always so far.
The future city public transport is crowded will be more and more severeer with pollution situation, increase transport power, raise the efficiency, reduce to pollute and be only the basic method of dealing with problems.For avoiding big, serious to the city pollution drawback of the disposable energy resource consumption of traditional cities public transport, adopting electric traction is the most real selection.Therefore, proposing a kind of between single phase industrial frequence alternating current standard and direct current (DC) standard, that can maximize favourable factors and minimize unfavourable ones and can to select the low frequency power supply standard of line frequency according to self-demand be very necessary, also is very important.
The low frequency tractive power supply system is widely used in the power supply of city underground, light rail and urban public transports such as rail, trackless.Simultaneously, because volume of transformer is inversely proportional to frequency, low frequency power supply can make volume of transformer increase, become extremely uneconomical, therefore, should make every effort to avoid in the low frequency tractive power supply system, using voltage transformer, in other words, being extensive use of with the current transformer at mass transportation facilities is today of the interchange drive technology of power circuit, directly can be too not high because of factors such as the withstand voltage level of considering current transformer (frequency converter) and economic performances to the voltage of the low frequency tractive power supply system of vehicle power supply, generally reach several kilovolts, but along with the development of traffic transport power growth of requirement and Semiconductor Converting Technology and manufacturing technology, may use more high potential with further increase power supply capacity from now on.
Summary of the invention
Purpose of the present invention just provides a kind of low frequency tractive power supply system, be a kind of between single phase industrial frequence alternating current standard and the direct current (DC) standard, can maximize favourable factors and minimize unfavourable ones to single phase industrial frequence alternating current standard and direct current (DC) standard, and can select the low frequency power supply standard of line frequency according to self-demand; Do not re-use dc circuit breaker; Frequency converter can be used as alternating-current switch and cooperates traction substation maintenance and traction side failure removal; Unlike direct current (DC), produce stray current and electrochemical corrosion, also unlike the single phase industrial frequence alternating current utility network produce based on the power quality problem of negative phase-sequence with self have electric phase-splitting (power supply breakpoint) problem; Can implement the traction net UNICOM of each traction substation to connect power supply, and reduce the loss of voltage of traction net greatly.
The present invention solves its technical matters, and the technical scheme that adopts is: a kind of low frequency tractive power supply system, formed by traction substation SS and traction net OCS; Traction substation comprises traction transformer TT and frequency converter UF; The former limit three of the traction transformer utility network PS that is connected, the inferior limit three frequency converter UF that is connected; The traction side of frequency converter UF output is that low frequency is single-phase and power for traction net OCS and vehicle L by single-phase traction bus BB; Traction net line frequency f is on a certain fixed frequency between 5Hz and the 16Hz; The traction net of each traction substation can UNICOM, implements to connect power supply.
Two feeder lines about described single-phase traction bus BB divides, and establish feeder line circuit breaker KL and KR, realization traction net OCS segmentation and train do not cut off the power supply and pass through, and when traction substation interruption maintenance or traction side fault, turn-off its frequency converter.
Consider the factor of aspects such as cost, reliability, degree of ripeness, can large-scale application based on the three-level converter of the IGBT circuit of 1700V or 3300V, its traction net alternating-current voltage/AC voltage is chosen in about 1200V-2000V is advisable.From now on, the traction net alternating-current voltage/AC voltage of the similar frequency converter output of five level can be brought up to 4000V.
Principle of work of the present invention is: a kind of low frequency tractive power supply system, give traction net power supply through traction transformer and frequency converter with the single-phase low-frequency ac that the three-phase main-frequency alternating current of utility network is transformed to the traction side at traction substation; The traction net of each traction substation can UNICOM, implements to connect power supply; Traction net line frequency f is on a certain fixed frequency between 5Hz and the 16Hz; Traction net line frequency f satisfies following formula: traction net failure removal time limit TS (ms)=relaying TR opening time (ms)+half cycle λ (ms), i.e. f=500/(TS-TR), TS〉TR; When traction substation interruption maintenance or traction side fault, turn-off its frequency converter.
For example, require traction net failure removal time limit TS=60ms, relaying TR=20ms opening time, then half cycle=40ms namely selects traction net line frequency f=500/40=12.5Hz; If require traction net failure removal time limit TS=60ms, relaying TR=10ms opening time, then half cycle=50ms namely selects traction net line frequency f=500/50=10Hz.In other words, half cycle is the Minimum Time Limit l that draws the net failure removal.
Compared with prior art, the invention has the beneficial effects as follows:
Direct current arc was difficult for inherent technology problems such as cut-outs when one, the present invention can overcome that there is stray current (the earth fan stream) in the direct current (DC) standard and metallic facility along the line produced electrochemical corrosion, fault, avoided the great number input of stray current control expense and dc circuit breaker.
Two, the present invention utilizes the former limit three-phase Semiconductor Converting Technology of frequency converter, does not produce negative phase-sequence and surpasses harmonic wave and the reactive component of current that GB requires at utility network; Utilize frequency converter can implement to connect power supply to the traction net UNICOM of each traction substation to the buffer action of utility network and traction side, eliminate electric phase-splitting and power supply breakpoint thereof that the electrified railway of industrial frequency AC exists; Just often, low frequency power supply can reduce the loss of voltage of traction net greatly, and during fault, the reactance of traction net can reduce short circuit current and to the impact of power equipment supply.
Three, frequency converter of the present invention can be used with the circuit breaker of traction side, is used for traction substation maintenance and traction side failure removal; The life-span of frequency converter and its switch (conducting and shutoff) number of times is irrelevant, quick action, and the life-span is long, and maintenance cost is low.
Four, traction net of the present invention is implemented to connect power supply, and the regenerated energy during car brakeing can be pulled the vehicle utilization or return utility network, good energy-conserving effect, environmental protection nearby.
Five, the present invention can be widely used in city underground, light rail and urban public transports such as rail, trackless, and comformability is good.
Six, this systems technology advanced person, reliable, easy to operate, over-the-road expense is low, is convenient to implement.
The invention will be further described below in conjunction with the drawings and specific embodiments.
Description of drawings
Fig. 1 is the low frequency tractive power supply system structural representation of the embodiment of the invention.
Fig. 2 is the three-level converter structural representation of the embodiment of the invention.
Fig. 3 is a single-phase line one ground formula tractive power supply system structural representation of the embodiment of the invention.
Fig. 4 is the single-phase double wire system tractive power supply system structural representation of the embodiment of the invention.
The specific embodiment
Embodiment
Fig. 1 is the low frequency tractive power supply system structural representation of the embodiment of the invention.The technical scheme that adopts comprises traction substation SS and traction net OCS; Traction substation SS obtains power supply from utility network PS, be connected to the former limit of traction transformer TT through three-phase alternating current switch MK, low-voltage three-phase AC switch LK through TT limit of traction transformer is connected to frequency converter UF again, the traction side of frequency converter UF output is that low frequency is single-phase and power for traction net OCS and vehicle L by single-phase traction bus BB, 2 feeder lines about single-phase traction bus BB divides, and establish feeder line circuit breaker KL and KR, realize traction net OCS segmentation, so that maintenance and isolated fault.
Principle of work of the present invention is: give traction net power supply through traction transformer and frequency converter with the single-phase low-frequency ac that the three-phase main-frequency alternating current of utility network is transformed to the traction side at traction substation; Draw net line frequency f on a certain fixed frequency between 5Hz and the 16Hz, and satisfy following formula: traction net failure removal time limit TS (ms)=relaying TR opening time (ms)+half cycle (ms), i.e. f=500/(TS-TR), TS〉TR; For example, require traction net failure removal time limit TS=60ms, relaying TR=20ms opening time, then half cycle=40ms namely selects traction net line frequency f=500/40=12.5Hz; If require traction net failure removal time limit TS=60ms, relaying TR=10ms opening time, then half cycle=50ms namely selects traction net line frequency f=500/50=10Hz.In other words, half cycle is the Minimum Time Limit l that draws the net failure removal.The traction net of each traction substation can UNICOM, implements to connect power supply, sees Fig. 3, Fig. 4.When traction substation SS interruption maintenance or traction net fault, turn-off its frequency converter UF, the more relevant feeder line circuit breaker KL of order or KR separating brake.
Fig. 2 is the three-level converter structural representation of the traction substation of the embodiment of the invention.In traction substation, TT limit of traction transformer is connected with frequency converter UF through three-phase current-limiting reactor (can merge with the leakage reactance of traction transformer), frequency converter UF obtains DC current by the three phase full bridge rectification, obtains 5 to 16Hz low frequency single phase alternating current by inversion again and outputs to the traction net; The traction side of frequency converter UF is connected with the single-phase series reactor.
Demonstration shows, considers the factor of aspects such as cost, reliability, degree of ripeness, can large-scale application based on the three-level converter of the IGBT circuit of 1700V or 3300V, and traction net alternating-current voltage/AC voltage of its traction side is chosen in about 1200V-2000V is advisable.From now on, the traction net alternating-current voltage/AC voltage of the similar frequency converter output of five level can be brought up to 4000V.
Fig. 3 is a single-phase line one ground formula tractive power supply system structural representation of the embodiment of the invention, and this sentences 3 traction substations is that example illustrates.Section post SP is set between the adjacent traction substation, and K12, K23 are respectively section post SP1 and SP2 inner breaker, circuit breaker K12, are in closure state when K23 is flat, with the traction net UNICOM with each traction substation, implement to connect power supply.When the traction net generation earth fault between traction substation SS1 and the section post SP1, turn-off the frequency converter UF1 of traction substation SS1 earlier, make the feeder line circuit breaker KR1 of traction substation SS1 and the circuit breaker K12 separating brake of section post SP1 again, the excision fault, open frequency converter UF1 then, recover the supply regular power in trouble free interval.
A single-phase line one ground formula power supply mode is widely used in the power supply of subway, light rail and tramway train, namely by contact system and backflow rail () form the traction net.Advantage be the traction web frame simple, save investment, be convenient to maintenance, in case shortcoming be the human body contact will with contact system and backflow rail () constitute the loop, potential safety hazard is big, therefore, closed-loop commonly used, unrelated person No Admittance.
Fig. 4 illustrates, and the single-phase double wire system tractive power supply system structural representation of the embodiment of the invention is that example illustrates with 3 traction substations still.Between the adjacent traction substation SS section post SP is set, K11 and K12 are the circuit breaker in the section post SP1, the circuit breaker in K22 and the K23 section post SP2, and K11 and K12, K22 and K23 are in closure state when flat, with the traction net UNICOM with each traction substation, implement to connect power supply.When earth fault takes place in up (or descending) between traction substation SS1 and section post SP1 traction net, turn-off the frequency converter UF1 of traction substation SS1 earlier, make up (or descending) feeder line circuit breaker KR11(or the KR12 of traction substation SS1 again) with up circuit breaker KL21(or the KL22 of section post SP1) separating brake, excise up (or descending) fault, open frequency converter UF1 then, recover the supply regular power in trouble free interval.Single-phase double wire system traction power supply mode is widely used in the power supply of trackless and tramway train, namely forms the traction net by two contact lines (contact system).Advantage is mutually insulated all between two contact lines and between two contact lines and the ground, in case human body touches, Shang Buhui makes human body form the loop between contact line and ground, and safety performance is good; Shortcoming is traction web frame complexity, troublesome maintenance.The exposed to contact urban public transport of the personnel that are applicable to.
Claims (3)
1. low frequency tractive power supply system is characterized in that: the low frequency tractive power supply system is made up of traction substation SS and traction net OCS; Traction substation comprises traction transformer TT and frequency converter UF, the former limit three of the traction transformer utility network PS that is connected, the inferior limit three frequency converter UF that is connected; The traction side of frequency converter UF output is that low frequency is single-phase and power for traction net OCS and vehicle L by single-phase traction bus BB; The traction net of each traction substation can UNICOM, implements to connect power supply; Traction net line frequency f is on a certain fixed frequency between 5Hz and the 16Hz.
2. a kind of low frequency tractive power supply system according to claim 1; it is characterized in that: traction net line frequency f is obtained by following formula: traction net failure removal time limit TS (ms)=relaying TR opening time (ms)+half cycle (ms); be f=500/(TS-TR), TS〉TR.
3. a kind of low frequency tractive power supply system according to claim 1, it is characterized in that: two feeder lines about described single-phase traction bus BB divides, and establish feeder line circuit breaker KL and KR, realization traction net OCS segmentation and train do not cut off the power supply and pass through, when traction substation interruption maintenance or traction side fault, turn-off its frequency converter.
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| CN201310143530.7A CN103241138B (en) | 2013-04-24 | 2013-04-24 | Low-frequency traction power supply system |
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| CN201310143530.7A CN103241138B (en) | 2013-04-24 | 2013-04-24 | Low-frequency traction power supply system |
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Cited By (6)
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| CN104648186A (en) * | 2015-03-13 | 2015-05-27 | 西南交通大学 | Trolley bus system |
| CN104979827A (en) * | 2015-07-06 | 2015-10-14 | 中国铁道科学研究院 | Electrified railway power supply device and system thereof |
| CN105470958A (en) * | 2015-12-31 | 2016-04-06 | 北京交通大学 | Alternating current-direct current-alternating current (AC-DC-AC) tractive power supply system with modularized multi-level structure |
| CN111146823A (en) * | 2019-12-18 | 2020-05-12 | 北京交通大学 | High-voltage direct-current urban rail transit traction power supply system |
| CN111313431A (en) * | 2018-12-11 | 2020-06-19 | 西安许继电力电子技术有限公司 | Subway traction power supply system and reactive compensation control method and device thereof |
| WO2022194292A1 (en) * | 2021-03-18 | 2022-09-22 | 中铁电气化局集团有限公司 | Flexible alternating current traction power supply system for implementing through co-phase and operation method therefor |
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| CN111313431A (en) * | 2018-12-11 | 2020-06-19 | 西安许继电力电子技术有限公司 | Subway traction power supply system and reactive compensation control method and device thereof |
| CN111313431B (en) * | 2018-12-11 | 2023-10-20 | 西安许继电力电子技术有限公司 | Subway traction power supply system and reactive compensation control method and device thereof |
| CN111146823A (en) * | 2019-12-18 | 2020-05-12 | 北京交通大学 | High-voltage direct-current urban rail transit traction power supply system |
| WO2022194292A1 (en) * | 2021-03-18 | 2022-09-22 | 中铁电气化局集团有限公司 | Flexible alternating current traction power supply system for implementing through co-phase and operation method therefor |
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| CN103241138B (en) | 2015-07-08 |
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Effective date of registration: 20160630 Address after: 610031 Chengdu City, Sichuan Province, No. two North Ring Road, Southwest Jiao Tong University, Patentee after: Southwest Jiaotong University Patentee after: Li Qunzhan Address before: 610031 Chengdu City, Sichuan Province, No. two North Ring Road, Southwest Jiao Tong University, Patentee before: Southwest Jiaotong University |