The content of the invention
Embodiment of the present utility model provides a kind of bipolar flexible direct current transmission system and its current conversion station, can suppress bipolar soft
The short circuit current that property DC transmission system DC side produces when breaking down.
To reach above-mentioned purpose, embodiment of the present utility model is adopted the following technical scheme that:
On the one hand, there is provided a kind of current conversion station for bipolar flexible direct current transmission system, including positive polarity change of current part and
Negative polarity change of current part;The positive polarity change of current part includes the first transverter;The negative polarity change of current part is changed including second
Stream device;The current conversion station also includes current limliting module;The current limliting module includes reactor, and the reactor is connected on neutral bus
On.
Preferably, the current limliting module also includes an arrester;One end of the arrester connects with the neutral bus
Connect, other end ground connection;Wherein, the arrester is arranged between the low-voltage end of transverter and the reactor.
Preferably, the current limliting module includes two arresters;One end of one of them arrester and described first
The low-pressure end connection of transverter, other end ground connection;The low-pressure end of one end of another arrester and second transverter
Connection, other end ground connection.
Preferably, the reactor includes at least one sub- reactor;Wherein, when the reactor includes many sub- reactance
During device, many sub- reactors are set in series and/or parallel.
Based on above-mentioned preferred, first transverter and second transverter include multiple valve modules;Each valve
Component includes insulated gate bipolar transistor converter valve.
, there is provided a kind of bipolar flexible direct current transmission system, including sending end current conversion station and receiving end current conversion station on the other hand;
The sending end current conversion station and/or the receiving end current conversion station are above-mentioned current conversion station.
It is further preferred that the sending end current conversion station and the receiving end current conversion station are the current conversion station;It is described to send
Electric end current conversion station turns DC converter station for exchange;The receiving end current conversion station delivers stream current conversion station for direct current.
It is further preferred that the exchange end of the first transverter and the second transverter is connected with converter power transformer;The power transmission
First transverter high-pressure side of positive polarity change of current part and positive polarity change of current part in the receiving end current conversion station in the current conversion station of end
The first transverter high-pressure side, the sending end current conversion station in negative polarity change of current part the second transverter high-pressure side and institute
The the second transverter high-pressure side for stating negative polarity change of current part in receiving end current conversion station passes through bipolarity high-voltage dc transmission electric wire
Connection.
The utility model provides a kind of bipolar flexible direct current transmission system and its current conversion station, and reactor is included by setting
Current limliting module, when the DC side of the current conversion station breaks down to be short-circuited, the electric current for flowing through reactor increases suddenly, and root
According to the characteristic of reactor, it can produce reverse current to limit the electric current of unexpected increase, thus can suppress the current conversion station direct current
The short circuit current of side, it is ensured that the security of the relevant device on transverter and circuit in current conversion station.On this basis, only
Reduce the short circuit current of positive polarity change of current part and negative polarity change of current Partial DC side simultaneously by a current limliting module, reduce
The cost of the current conversion station.
Specific embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is carried out
Clearly and completely describe, it is clear that described embodiment is only a part of embodiment of the utility model, rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made
The every other embodiment for being obtained, belongs to the scope of the utility model protection.
The utility model embodiment provides a kind of current conversion station for bipolar flexible direct current transmission system, including positive polarity is changed
Stream part 100 and negative polarity change of current part 200;Positive polarity change of current part 100 includes the first transverter 110;Negative polarity change of current portion
Dividing 200 includes the second transverter 210;The current conversion station also includes current limliting module 300;Current limliting module 300 includes reactor 310,
Reactor 310 is connected on neutral bus 400.
Wherein, current limliting module 300 is used for when positive polarity change of current part 100 or the appearance of the DC side of negative polarity change of current part 200
Failure, when causing the current conversion station dc-side short-circuit, reduces short circuit current.
It should be noted that the first, the first transverter 110 and the second transverter 210 can be used to be converted to alternating current directly
Stream electricity, it can also be used to which direct current is converted into alternating current.
No matter the first transverter 110 and the second transverter 210 are used to for alternating current to be converted to direct current, or by direct current
Alternating current is converted to, the first transverter high-pressure side 112 and the second transverter high-pressure side 212 are all that connection positive high voltage direct current is defeated respectively
Electric wire and negative high voltage DC transmission line.
Second, the specific structure of the first transverter 110 and the inside of the second transverter 210 is not defined, as long as according to
Need, alternating current can be converted to direct current, or direct current is converted into alternating current.
3rd, the specific current conversion station that the design parameter of reactor 310 can be applied according to it is set, as long as ensureing
During generation dc-side short-circuit, the device in current conversion station is not destroyed.
The utility model embodiment provides a kind of current conversion station, and the current limliting module 300 of reactor 310 is included by setting, when
The DC side of the current conversion station breaks down when being short-circuited, and the electric current for flowing through reactor 310 increases suddenly, and according to reactor
310 characteristic, it can produce reverse current to limit the electric current of unexpected increase, thus can suppress the short of the current conversion station DC side
Road electric current, it is ensured that the security of the relevant device on transverter and circuit in current conversion station.On this basis, only by one
Individual current limliting module 300 reduces the short circuit current of positive polarity change of current part 100 and the DC side of negative polarity change of current part 200, drop simultaneously
The low cost of the current conversion station.
In view of when there is short trouble in the DC side of positive polarity change of current part 100, the first transverter high-pressure side 112 with
First transverter low-pressure end 111 is connected, and causes the voltage spikes of the first transverter low-pressure end 111;Or, when negative polarity change of current portion
When dividing 200 DC side short trouble occur, the second transverter high-pressure side 212 is connected with the second transverter low-pressure end 211, is caused
The voltage spikes of the second transverter low-pressure end 211.In the case, in order to avoid the device in the current conversion station is destroyed, need
Want the insulation against ground level of the first transverter of current conversion station low-pressure end 111 and the second transverter low-pressure end 211 higher, so as to lead
Cause the raising of the first transverter 110 and the cost of the second transverter 210.Based on this, it is preferred that as shown in Fig. 2 current limliting module 300
Also include an arrester 320;One end of arrester 320 is connected with neutral bus 400, other end ground connection;Wherein, arrester
320 are arranged between the low-voltage end of transverter and reactor 310.
It should be noted that it will be recognized by those skilled in the art that arrester 320 can reduce the voltage and electricity in circuit
Stream, protects electric equipment from the harm of transient overvoltage high.
In the utility model embodiment, also include arrester 320 by making current limliting module 300, in the straight of the current conversion station
Stream side is short-circuited failure, and when the voltage of the first transverter low-pressure end 111 or the voltage of the second transverter low-pressure end 211 rise to
During the protection voltage level of arrester 320, arrester 320 works, and the portion of electrical current in short-circuit loop is flowed by arrester 320
Enter the earth, so as to reduce the current stress of reactor 310, it is also possible to improve the first transverter low-pressure end 111 and second change of current
The insulation against ground level of device low-pressure end 211, and then can reduce to the first transverter low-pressure end 111 and the second transverter low-pressure end
The requirement of 211 insulation against ground level.
Or, it is preferred that as shown in figure 3, the current limliting module 300 includes two arresters 320;One of arrester
320 one end is connected with the first transverter low-pressure end 111, other end ground connection;One end of another arrester 320 and second change of current
Device low-pressure end 211 is connected, other end ground connection.
The utility model embodiment is respectively in the first transverter low-pressure end 111 and the connection of the second transverter low-pressure end 211 one
Individual arrester 320, can preferably reduce the insulation against ground of the first transverter low-pressure end 111 and the second transverter low-pressure end 211
The current stress of level and reactor 310.
Relative dc circuit breaker and its relevant device using bigger connecting-disconnecting function, due to high-tension electricity, the direct current of Large Copacity
, still in the development stage, in cannot temporarily directly applying to engineering, and its cost of manufacture is high for breaker, thus limit its
Practical application in DC engineering;Or, it is relative to use traditional restrictor apparatus, but traditional restrictor apparatus are occurring
Open-circuit line is needed after failure, trend distribution and the stability of system is influenceed;Or it is relative using fast based on current-carrying isolator
Fast fault current limiter, does not need open-circuit line after breaking down, failure terminates rear electric current can be continued to circulate from by-pass switch,
Trend under not influenceing system normally to run is distributed, but its equipment is complicated, and manufacturing cost is higher.The utility model embodiment by
Reactor 310 and arrester 320 are included up in current limliting module 300 so that the topology of the current conversion station is free of high-power electric
Electronic device, cost relative moderate, small volume realizes simple and excellent performance, thus is easy to practical application popularization.
Because metal oxide arrester (Metal Oxide Arrester, MOA) has, action response is fast, it is multiple to be resistant to
The advantages of lightning surge or switching overvoltage, energy absorption capability are big, resistance to pollution performance is good, it is preferred, therefore, that arrester
320 is metal oxide arrester.
Preferably, reactor 310 includes at least one sub- reactor 311;Wherein, when reactor 310 includes many height electricity
During anti-device 311, how sub- reactor 311 is set in series and/or parallel.
So that reactor 310 includes two sub- reactors 311 as an example, as shown in figure 4, two sub- reactance in reactor 310
Device 311 is connected in series.Or, as shown in figure 5, two sub- reactors 311 in reactor 310 are connected in parallel.
So that reactor 310 includes three sub- reactors 311 as an example, as shown in fig. 6, two of which electricity in reactor 310
Anti- device 311 is connected in parallel, and is connected in series with another sub- reactor 311.
It should be noted that many sub- reactors 311 are set with a variety of feelings by the way of string and/or parallel connection
Condition, Fig. 4-6 is that sets forth a kind of situation in three kinds of set-up modes.
The utility model embodiment using many sub- reactors 311 go here and there and/or parallel combination by the way of limiting short-circuit current,
Every parameter of sub- reactor 311 can be reduced, so that can reduces cost.
It is out in view of insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT)
It is logical, turn off controllable wholly-controled device, control of the IGBT converter valves to transmission system is more flexible, can control reactive power and
Make current conversion station without huge reactive power compensator, and the switching frequency of IGBT converter valves is of a relatively high, makes the defeated of current conversion station
Go out that voltage harmonic amount is smaller, so that the capacity of the filter installed using the current conversion station of IGBT converter valves is greatly reduced.Base
In this, it is preferred that the first transverter 110 and the second transverter 210 include multiple valve modules;Each valve module includes insulation
Grid bipolar transistor converter valve.
The utility model embodiment also provides a kind of bipolar flexible direct current transmission system, as shown in fig. 7, comprises sending end is changed
Stream station 01 and receiving end current conversion station 02;Sending end current conversion station 01 and/or receiving end current conversion station 02 changing for foregoing any embodiment
Stream station.
It should be noted that Fig. 7 is foregoing any embodiment with sending end current conversion station 01 and receiving end current conversion station 02
Current conversion station is illustrated.
The utility model embodiment includes reactor 310 by being set in the current conversion station of bipolar flexible direct current transmission system
Current limliting module 300, when the current conversion station DC side break down be short-circuited when, the electric current for flowing through reactor 310 is unexpected
Increase, and according to the characteristic of reactor 310, it can produce reverse current to limit the electric current of unexpected increase, thus institute can be suppressed
State the short circuit current of current conversion station DC side, it is ensured that the security of the relevant device on transverter and circuit in current conversion station.
On this basis, positive polarity change of current part 100 and negative polarity change of current part 200 are only reduced by a current limliting module 300 simultaneously
The short circuit current of DC side, reduces the cost of the current conversion station.
It is further preferred that as shown in fig. 7, sending end current conversion station 01 and receiving end current conversion station 02 are the utility model reality
Apply the current conversion station of the foregoing any embodiment of example;Sending end current conversion station 01 turns DC converter station for exchange;Receiving end current conversion station 02 is
Direct current delivers stream current conversion station.
Wherein, when the current conversion station is sending end current conversion station 01, the first transverter 110 and the second transverter 210 are used for
Alternating current is changed into the direct current that multi-line power transmission ability is strong, loss is small;When the current conversion station is sending end current conversion station 01, first
The DC conversion that the transverter 210 of transverter 110 and second is used to receiving be can large area transmission of electricity alternating current.
The utility model embodiment makes the sending end current conversion station 01 and receiving end current conversion station of the bipolar flexible transmission system
02 includes current limliting module 300, it is ensured that when the DC side of the bipolar flexible transmission system breaks down to be short-circuited,
Short circuit current in the circuit of sending end current conversion station 01 and receiving end current conversion station 02 is suppressed, so that the first device in protection circuit
Part is not destroyed.
It is further preferred that as shown in fig. 7, the exchange end of the first transverter 110 and the second transverter 210 and change of current transformation
Device 600 is connected;First transverter high-pressure side 112 of positive polarity change of current part 100 and the receiving end change of current in sending end current conversion station 01
Stand in 02 negative polarity change of current part in first transverter high-pressure side 112, the sending end current conversion station 01 of positive polarity change of current part 100
200 the second transverter high-pressure side 212 and the second transverter high-pressure side of negative polarity change of current part 200 in receiving end current conversion station 02
212 are connected by bipolarity high-voltage dc transmission electric wire.
Wherein, the bipolar flexible direct current transmission system also includes commutating reactor 500, converter power transformer 600, Yi Jijiao
Streaming system.
Commutating reactor 500 is connected with the exchange end of the first transverter 110, the second transverter 210, is used to reduce electric power half
To the influence of AC system waveform during conductor device commutation, and limiting AC side short circuit current.
Converter power transformer 600 is connected by commutating reactor 500 with the end that exchanges of the first transverter 110, the second transverter 210
Connect.
It should be noted that the exchange end of the first transverter 110 and the second transverter 210 is connected with converter power transformer 600,
I.e. the exchange end of the first transverter 110 of sending end current conversion station 01 and receiving end current conversion station 02 and the second transverter 210 with change
Convertor transformer 600 is connected.
The utility model embodiment is by by the exchange end of the first transverter 110 and the second transverter 210 and change of current transformation
Device 600 is connected, on the one hand, be capable of achieving the connection between AC network and direct current network;On the other hand, it is possible to achieve the change of voltage
Change, the AC voltage of the DC voltage of sending end current conversion station 01 or receiving end current conversion station 02 is met its rated voltage and is allowed
Variation.On this basis, sending end current conversion station 01 and receiving end current conversion station are connected by bipolarity high-voltage dc transmission electric wire
02, line transmission ability can be improved, reduce the power consumption during line transmission.
The above, specific embodiment only of the present utility model, but protection domain of the present utility model do not limit to
In this, any one skilled in the art can readily occur in change in the technical scope that the utility model is disclosed
Or replace, should all cover within protection domain of the present utility model.Therefore, protection domain of the present utility model should be with the power
The protection domain that profit is required is defined.