CN107611961B - A kind of electric current uniform distribution method for direct supercurrent cable - Google Patents

Abstract

An embodiment of the present invention provides a method for evenly distributing current in a superconducting DC cable. The method mainly includes: constructing a circuit model of the multi-parallel superconducting tapes of the superconducting direct current cable and designing an implementation device, after the superconducting direct current cable is powered on, each parallel branch feeds back the direct current to the control device in real time through the current sensor connected thereto, The control device processes the current signals collected by each branch, calculates the control current required by each branch according to the circuit model, and the control device transmits the calculated control current to the coupling device of each branch through the transmission line, and couples different control currents to Resistance compensation is performed in each corresponding branch to realize uniform distribution of the actual passing current in each branch. The invention supports the real-time feedback adjustment of the current of each branch, realizes the uniform distribution of the current of the superconducting DC cable, and the adjustment mechanism of each parallel superconducting branch in the invention is outside the low temperature environment, which is easy to implement and easy to operate.

Description

A Method for Evenly Distributing Current in Superconducting DC Cables

technical field

The invention relates to the technical field of superconducting power cables, in particular to a method for uniform current distribution for superconducting DC cables.

Background technique

High-temperature superconducting DC cables have many advantages such as low line loss, large transmission capacity, small corridor footprint, and environmental friendliness, providing an efficient, compact, reliable, and green power transmission method for the grid. After more than ten years of development, superconducting DC cables have made great progress in basic research, and a number of superconducting DC cable transmission demonstration projects have been put into operation at home and abroad. Considering many factors such as the continuous increase in demand for electric energy and the rapid increase in the proportion of new energy sources, superconducting DC transmission technology that can simultaneously achieve high-efficiency, low-loss and large-capacity power transmission will play a greater role in the future, and its application prospects are very broad.

In the prior art, in order to realize a large transmission current in a superconducting cable, a plurality of superconducting tapes are usually connected in parallel. Ideally, superconductors have zero resistance and no uneven distribution of current. However, in practical applications, due to factors such as the non-superconducting welding between superconductors, the non-superconducting connection between superconductors and terminals, the critical current of different branch superconducting strips and the non-uniformity of N values, each parallel connection The characteristics of the superconducting tapes are not exactly the same, and the differences in the connection accessories of each parallel branch will also cause the impedance of each branch to be different. This will cause each branch to have a small resistance with different resistance, the order of magnitude is about 100nΩ～10μΩ. Although the resistance introduced by the above reasons is very small, the slight difference between them will cause different parallel branches. The current distribution between them is uneven, that is, when used in parallel, the current flowing through each parallel superconducting strip is not the same.

In practical applications, if the current carrying capacity of the superconducting cable is much smaller than the critical current, the unbalanced current will cause the current to circulate between the parallel superconducting tapes, which can reduce the current carrying level of the superconducting cable without causing adverse effects. However, once the current is near the critical current, the superconducting band with a small critical current will be the first to quench and enter a resistive state. After a little longer, it will grow into a "hot-pot" and further vicious development will cause superconductivity. Risk of conduction tape blown. In addition, after a single superconducting band enters the resistance state, the current carrying capacity decreases, and the shunting of other superconducting bands will increase; the heating of the quenched superconducting band will also cause the ambient temperature of other surrounding superconducting bands to rise. This triggers a chain reaction in the superconducting tape until the superconducting cable is completely quenched. If it is under fault conditions, that is, under the impact of a short-circuit fault current much higher than the critical current, the consequences caused by the imbalance of the parallel superconducting strips will be more serious.

A method for changing the current-carrying characteristics of a superconducting DC cable in the prior art is as follows: existing studies have shown that when a superconducting AC cable passes an alternating current, there is an alternating magnetic field around the superconductor, and a specific magnetic field will change the carrying capacity of the superconducting tape. flow characteristics. By controlling the relative position of the superconducting strips, the pitch and angle of the winding, etc., the differences of the parallel superconducting strips can be reduced to a certain extent, and the current-carrying performance of the parallel superconducting strips can be improved in a large current range. balance.

However, the above method has no obvious effect on the current equalization of the parallel superconducting tapes of the superconducting DC cable.

Contents of the invention

Embodiments of the present invention provide a method for evenly distributing current in a superconducting DC cable, so as to solve the above-mentioned problems in the prior art.

In order to achieve the above object, the present invention adopts the following technical solutions.

The present invention proposes a method for uniform current distribution for superconducting DC cables, which is characterized in that it includes:

Constructing a circuit model of the multi-parallel superconducting strips of the superconducting DC cable, establishing a mathematical equation according to the circuit model, and designing an implementation device for a method of uniform current distribution, the implementation device mainly includes a control device and a coupling device;

After the current bus bar of the superconducting DC cable is energized, each parallel branch circuit feeds back the DC current signal to the control device in real time through the current sensor in the connection point connected to it. The control device is based on the DC current signal and according to the circuit The mathematical equation of the model calculates the required regulation current of each branch;

The control device transmits the calculated control current to the coupling device in the connection point of each branch through the transmission line, and the coupling device couples the control current to the connected branches to perform resistance compensation to realize the resistance of each branch. The medium current is evenly distributed.

Preferably, the circuit model of constructing the multi-parallel superconducting tapes of the superconducting DC cable, and establishing a mathematical equation according to the circuit model includes:

The superconducting DC cable includes a plurality of parallel superconducting tapes, each of which constitutes a parallel branch;

The circuit model includes: a current bus and a plurality of parallel branches, wherein the composition of the parallel branches includes: a conventional resistance R _Ni composed of a non-superconducting part, a non-linear resistance R _HTSi composed of a superconducting part, an alternating The inductance L _i generated by the variable current passing through each parallel branch, and the mutual inductance M _ij existing between different parallel branches. Among them, there is a mapping relationship between R _HTSi and the amplitude and frequency of the passing current;

According to the circuit model, the mathematical model is established as follows:

Preferably, the implementation device for designing uniform distribution of current includes:

The implementation device includes: a current bus, a control device, a connection point, a transmission line and each parallel conductor strip;

The connection points are placed on each parallel conductor strip, including current sensors and coupling means;

The control device is respectively connected to the connection points of each parallel branch through a transmission line;

The transmission line includes two parts: one part is used for the control device to transmit the control current to the connection point, and the other part is used for the current sensor at the connection point to transmit the DC current signal back to the control device.

Preferably, after the current bus bar of the superconducting DC cable is energized, each parallel branch feeds back a DC current signal to the control device in real time through the current sensor in the connection point connected to it, including:

There is a connection point on each of the parallel branches, and the current sensor in the connection point is used to collect the DC current signal flowing from the current bus in each branch, and feed back the collected DC current signal to the The control device.

Preferably, the control device calculates the control current required by each branch according to the mathematical equation of the circuit model based on the direct current signal, including:

The regulating device includes a current regulating mechanism, a frequency regulating mechanism, a feedback control unit and an output terminal, and the feedback control unit calculates based on the mathematical equation of the circuit model based on the current signals collected and fed back by each parallel branch The magnitude and frequency of the regulating current that needs to be coupled in each parallel branch.

Preferably, the control device transmits the calculated control current to the coupling device in each branch connection point through a transmission line, including:

The current adjustment mechanism and the frequency adjustment mechanism in the control device perform control operations to adjust the amplitude and frequency of the regulation current, and after the regulation current is adjusted to be consistent with the calculated regulation current, the The regulating current is applied to the coupling device corresponding to the parallel branch through the output terminal connected to the transmission line;

Different output terminals of the control device are independent of each other, and the control currents output by different output terminals are independent of each other.

Preferably, the coupling device couples the regulated current to the connected branches for resistance compensation to achieve uniform distribution of current in each branch, including:

The control device outputs the control currents that are independent of each other to independently adjust different branches, and the control currents that are independent of each other are connected to each parallel branch through the coupling device at the connection point, and the current bus flows into each parallel branch. The DC current of the branch and the regulating current are coupled by the coupling device to become the actual passing current of each parallel branch, and the actual passing current of different branches is uniformly distributed after being coupled by the regulating current.

Preferably, the transmission line includes two parts: one part is used for the control device to transmit the control current to the connection point, and the other part is used for the current sensor at the connection point to return the DC current signal to the control device, including:

The arrangement method of the two parts of the transmission line: the method of using different core wires of the same cable, or the method of using different cables respectively.

Preferably, the control operation of the current adjustment mechanism and the frequency adjustment mechanism in the regulation device includes:

The current adjustment mechanism and the frequency adjustment mechanism adopt manual control or computer automatic control for control operation.

Preferably, the control device is provided with a display mechanism as required to display the current value of each parallel branch in real time.

From the technical solutions provided by the above-mentioned embodiments of the present invention, it can be seen that the embodiment of the present invention constructs a circuit model of multiple parallel superconducting tapes of a superconducting DC cable. The current sensor connected to it feeds back the DC current signal to the control device in real time. The control device processes the signal fed back by each branch, and calculates the control current required by each branch according to the circuit model. The control device transmits the calculated control current through the transmission line to The coupling device of each branch couples the regulating current to each connected branch to perform resistance compensation to realize uniform distribution of current in each branch. The invention can effectively improve the current-carrying balance level between the parallel superconducting tapes of the superconducting direct current cable, and improve the reliability of the superconducting direct current cable.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description, or may be learned by practice of the invention.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a method flow chart of a method for uniform current distribution of a superconducting DC cable provided by an embodiment of the present invention;

2 is a circuit model diagram of a method for uniform current distribution of superconducting DC cables provided by an embodiment of the present invention;

Fig. 3 is a schematic diagram of an implementation device for a method for uniform current distribution of a superconducting DC cable provided by an embodiment of the present invention;

Fig. 4 is a method schematic diagram of a method for uniform current distribution of a superconducting DC cable provided by an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a control device used in a method for uniform current distribution of a superconducting DC cable provided by an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

Those skilled in the art will understand that unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the word "comprising" used in the description of the present invention refers to the presence of said features, integers, steps, operations, elements and/or components, but does not exclude the presence or addition of one or more other features, Integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Additionally, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in commonly used dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as herein explain.

In order to facilitate the understanding of the embodiments of the present invention, several specific embodiments will be taken as examples for further explanation below in conjunction with the accompanying drawings, and each embodiment does not constitute a limitation to the embodiments of the present invention.

Embodiment one

In order to reduce the difference between the parallel superconducting tapes and effectively improve the current-carrying balance of the parallel superconducting tapes during the transmission process of a superconducting cable with multiple superconducting tapes connected in parallel, the embodiment of the present invention proposes a method based on the feedback current signal, according to The circuit model calculates the regulating current, and the regulating device is used to regulate the regulating current of each branch. The invention supports the real-time feedback regulation of the current of each branch, and realizes the uniform distribution of the current of the superconducting DC cable.

An embodiment of the present invention provides a flow chart of a method for uniform current distribution of a superconducting DC cable, as shown in Figure 1, including the following steps:

Step S110: Construct a circuit model of the multi-parallel superconducting tapes of the superconducting DC cable, establish mathematical equations according to the circuit model, and design an implementation device.

The superconducting DC cable includes multiple parallel superconducting tapes, and each superconducting tape forms a parallel branch.

The circuit model of the constructed multi-parallel superconducting tapes of the superconducting DC cable is shown in Figure 2. The components of the circuit model include: a current bus and multiple parallel branches. The output current in the current bus is _total i, i After _{the total} is distributed to each parallel branch, it is respectively: i ₁ , _{i 2} , ..., in , and each current signal i ₁ , _{i 2} , ..., in is the DC current on each parallel branch.

The parallel branch includes: (1) the conventional resistance R _Ni composed of non-superconducting parts such as contact resistance existing in the branch; (2) the non-linear resistance R _HTSi composed of the superconducting part, and the non-linear resistance R _HTSi is , the resistance value is 0, and as the passing current increases, the resistance value rises in an exponential form that depends on the value of N, and is related to the frequency of the passing current; (3) If there is an alternating current passing through the branch, each There is also inductive reactance L _i in the branch; (4) mutual inductance M _ij between different parallel branches; where, there is a mapping relationship between R _HTSi and the amplitude and frequency of the passing current.

According to the above circuit model, the mathematical equation is established as follows:

Based on the dependence of the equivalent impedance of each branch on the frequency of the passing current pointed out in the above physical-mathematical model, the embodiment of the present invention designs an implementation device for a uniform current distribution method of a superconducting DC cable, as shown in Figure 3 , the implementing device includes: a current busbar, a regulating device, a connection point, a transmission line and each parallel conducting strip.

Wherein, the connection point is placed on each parallel conduction strip, including the current sensor and the coupling device.

The control device is connected with each connection point through a transmission line.

The transmission line includes two parts: one part is used for the control device to transmit the control current to the connection point, and the other part is used for the current sensor at the connection point to transmit the DC current signal back to the control device.

For the setting method of the two parts of the transmission line: the method of using different core wires sharing the same cable, or the method of using different cables for each.

Step S120: After the superconducting DC cable is energized, each parallel branch circuit feeds back a DC current signal to the control device in real time through the current sensor connected thereto.

After the superconducting DC cable is energized, the current busbar transmits the DC current to each parallel branch, and each parallel branch has a connection point, and the current sensor in the connection point is used to collect the DC current signal of the branch, and The collected DC current signal is fed back to the control device through the transmission line.

Step S130: the control device processes the current signals collected by each branch, and calculates the control current required by each branch according to the mathematical equation of the circuit model.

The structural diagram of the regulating device is shown in Figure 5, including a current regulating mechanism, a frequency regulating mechanism, a feedback control unit and an output terminal. The mathematical equation of the model calculates the adjusted impedance value of each direct current, and then calculates the amplitude and frequency of the adjusted current coupled by each parallel branch.

Step S140: the control device transmits the calculated control current to the coupling device of each branch through the transmission line.

The control device is respectively connected to the connection points of each parallel branch through the transmission line. The current adjustment mechanism and the frequency adjustment mechanism in the control device perform control operations. By adjusting the current adjustment mechanism and/or the frequency adjustment mechanism, the regulation current of the output terminal can be changed. amplitude and frequency, and apply the regulated current with adjusted amplitude and frequency to the coupling device of the corresponding parallel branch through the output terminal connection transmission line.

Different output terminals in the regulating device are mutually independent to realize fine and independent regulation of different branches, and different regulating currents output are also mutually independent so as to realize corresponding regulation of different branches.

According to needs, the control operation of the current regulating mechanism and the frequency regulating mechanism can be carried out by manual control, or by computer automatic control. The control device can be provided with a display mechanism to display the DC current value of each parallel branch in real time.

Those skilled in the art should be able to understand that the above-mentioned way of using the current adjustment mechanism and the frequency adjustment mechanism to change the amplitude and frequency of the regulation current is only to better illustrate the technical solutions of the embodiments of the present invention, not to implement the present invention. Example restrictions. Any way of changing the amplitude and frequency of the regulating current is included in the scope of the embodiments of the present invention.

Step S150: Controlling current coupling to each connected branch for resistance compensation to achieve uniform current distribution.

The schematic diagram of the method for _evenly distributing the current in the _branches at each connection point is shown in FIG. Feedback to the control device through the transmission line 45; the coupling device 43 couples the direct current _ik from the current bus with the control current i _mk (t) transmitted from the control device through the transmission line 42, so that the flow into the control device through the current bus The DC current i _k of each superconducting parallel branch becomes the actual passing current i′ _k of each branch after being coupled.

In the circuit model, it can be seen that there are different parallel branches: (1) the conventional resistance R _Ni composed of non-superconducting parts such as contact resistance in the branch; (2) the non-linear resistance R _HTSi composed of superconducting parts, When the non-linear resistor R _HTSi is in the superconducting state, the resistance value is 0, and as the passing current increases, the resistance value rises in an exponential form dependent on the N value; (3) If there is an alternating current passing through the branch, then There is also inductive reactance L _i in each branch; (4) Mutual inductance M _ij between different parallel branches; due to the existence of these resistances and inductances, the DC current distribution of each parallel branch is not uniform.

After the control current calculated according to the circuit model is sent to the coupling device to couple with the DC current in each parallel branch, the mutually independent control current can induce a corresponding compensation resistance for different branches, and for different parallel circuits Corresponding resistance compensation is performed on the branches so that the resistances in different parallel branches are the same. After the corresponding resistance compensation, the actual passing current i′ _k obtained by the final coupling of different parallel branches is evenly distributed. So far, the method realizes the uniform distribution of currents to different parallel branches.

Thereafter, the control device collects the DC current in each parallel branch in real time, and performs real-time regulation of the current output of each branch according to the above steps, so as to achieve the purpose of evenly distributing the current of each parallel branch.

Embodiment two

The embodiment of the present invention provides a method for evenly distributing current in a superconducting DC cable, as shown in FIG. 4 connection, the current bus bar 2 of superconducting material (such as copper) is connected to multiple parallel superconducting strips 3 by welding, and the connection point 4 is close to the welding point of the current bus bar 2 .

As shown in Figure 4, each superconducting strip forms a so-called parallel branch. The regulating current 42 is connected to the superconducting tape via a coupling device 43 . In this way, the current 41 flowing into each superconducting parallel branch through the current bus becomes the actual passing current 44 of each branch after being coupled.

As shown in FIG. 4 , the connection point 4 also includes a current sensor 46 to collect the current 41 flowing out of the current bus from each branch in real time. It is sent back to the control device 1 through the connection line 45. 45 and 42 together constitute the transmission line 5, and they can share different core wires of the same cable, or use different cables respectively.

As shown in FIG. 5 , the regulating device 1 includes a current regulating mechanism 11 , a frequency regulating mechanism 12 and a feedback control unit 13 . The current regulating mechanism 11 and the frequency regulating mechanism 12 can be manually controlled or automatically controlled by a computer. The feedback control unit calculates the amplitude and frequency of the regulating current to be coupled by each branch according to the current signal collected by each branch, and applies it to the coupling device of the corresponding branch through the output terminal. According to needs, the control device can be provided with a display mechanism to display the current value of each parallel branch in real time.

The working principle of the present invention is: after the superconducting DC cable is energized, each parallel branch circuit returns a DC current through the current sensor connected to it, the control device processes the DC current signal collected by each branch circuit, and calculates the DC current required for each DC according to the circuit model. The adjusted impedance value is used to calculate the amplitude and frequency of the regulated current required by each branch. Next, the calculated control current of each branch is sent to the coupling device of each branch through the transmission line, and is coupled to the actual passing current of each branch. Thereafter, the control device collects the DC current of each branch in real time, and performs real-time regulation of the current output of each branch according to the above method, so as to achieve the purpose of uniform distribution of the current of each branch.

In summary, the embodiment of the present invention constructs a circuit model of multiple parallel superconducting tapes of a superconducting DC cable. After the superconducting DC cable is energized, each parallel branch feeds back the DC current signal in real time through the current sensor connected to it. To the control device, after the control device obtains the DC current signal fed back by each branch, it calculates the control current required by each branch according to the circuit model, and the control device transmits the calculated control current to the coupling device of each branch through the transmission line , the coupling device couples the regulating current to each branch connected to perform resistance compensation to realize uniform distribution of current. The control device of the present invention collects the current of each branch in real time, performs real-time feedback output adjustment on each branch, realizes the uniform distribution of the current of the superconducting DC cable, and can effectively improve the current-carrying balance between the parallel superconducting tapes of the superconducting DC cable level, improve the reliability of the superconducting direct current cable, and the present invention places the adjustment mechanism of each parallel superconducting branch outside the low-temperature environment, which is easy to implement and easy to operate.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of an embodiment, and the modules or processes in the accompanying drawing are not necessarily necessary for implementing the present invention.

It can be seen from the above description of the implementation manners that those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products can be stored in storage media, such as ROM/RAM, disk , CD, etc., including several instructions to make a computer device (which may be a personal computer, server, or network device, etc.) execute the methods described in various embodiments or some parts of the embodiments of the present invention.

Each embodiment in this specification is described in a progressive manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for relevant parts, refer to part of the description of the method embodiments. The device and system embodiments described above are only illustrative, and the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, It can be located in one place, or it can be distributed to multiple network elements. Part or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. It can be understood and implemented by those skilled in the art without creative effort.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1. a kind of electric current uniform distribution method for direct supercurrent cable characterized by comprising

The circuit model for constructing the multi-parallel superconductive tape of direct supercurrent cable, establishes math equation according to the circuit model, if The implementing device of electric current uniform distribution method is counted, which mainly includes regulation device and coupling device；

After the current bus bar of direct supercurrent cable is powered, each parallel branch passes through the current sense in the tie point being attached thereto Device Real-time Feedback DC current signal is to regulation device, and the regulation device is based on the DC current signal, according to the electricity Regulation electric current needed for the math equation of road model calculates each branch；

The regulation electric current being calculated is delivered to the coupling in each branch tie point by the regulation device by transmission line The regulation current coupling is carried out resnstance transformer into each branch connected and realizes electricity in each branch by device, the coupling device Stream evenly distributes.

2. the electric current uniform distribution method according to claim 1 for direct supercurrent cable, which is characterized in that described The circuit model for constructing the multi-parallel superconductive tape of direct supercurrent cable, establishes math equation according to the circuit model, comprising:

The direct supercurrent cable includes more superconductive tapes in parallel, and each superconductive tape constitutes the branch in parallel Road；

The circuit model includes: a current bus bar and multiple parallel branches, wherein the composition of the parallel branch includes: non- The conventional resistive R that superconductive part is constituted_Ni, the nonlinear resistance R of superconductive part composition_HTSi, alternating current passes through each parallel branch The induction reactance L of generation_i, existing mutual inductance M between different parallel branches_ij, wherein R_HTSiWith the amplitude and frequency presence by electric current Mapping relations；

According to the circuit model, founding mathematical models are as follows:

3. the electric current uniform distribution method according to claim 1 for direct supercurrent cable, which is characterized in that described The implementing device that design current evenly distributes, comprising:

The implementing device includes: current bus bar, regulation device, tie point, transmission line and each conduction band in parallel；

The tie point is placed on each conduction band in parallel, including current sensor and coupling device；

The regulation device is connected with the tie point of each parallel branch respectively by transmission line；

The transmission line includes two parts: a part is for regulation device conveying regulation electric current to tie point, and a part is for connecting DC current signal is passed back to the regulation device by the current sensor of junction.

4. the electric current uniform distribution method according to claim 1 for direct supercurrent cable, which is characterized in that described After the current bus bar of direct supercurrent cable is powered, each parallel branch passes through the current sense in the tie point being attached thereto Device Real-time Feedback DC current signal is to regulation device, comprising:

There is a tie point in each parallel branch respectively, the current sensor in the tie point is for acquiring in each branch From current bus bar flow out DC current signal, and by DC current signal collected by transmission line passback feed back to described in Regulation device.

5. the electric current uniform distribution method according to claim 1 for direct supercurrent cable, which is characterized in that described Regulation device is based on the DC current signal, needed for calculating each branch according to the math equation of the circuit model Regulate and control electric current, comprising:

The regulation device includes current regulation mechanism, frequency adjustment mechanism, feedback control unit and output end, the feedback control The current signal that unit processed is acquired and fed back according to each parallel branch, based on the math equation of the circuit model Calculate the amplitude and frequency of the regulation electric current coupled needed for each parallel branch.

6. the electric current uniform distribution method according to claim 5 for direct supercurrent cable, which is characterized in that described The regulation electric current being calculated is delivered to the coupling device in each branch tie point by transmission line by regulation device, packet It includes:

The current regulation mechanism and the frequency adjustment mechanism in the regulation device carry out control operation, adjust the tune The amplitude and frequency for controlling electric current, after being consistent with the regulation electric current being calculated for regulation current regulation, by the regulation Electric current connects the coupling device that the transmission line is applied to corresponding parallel branch by output end；

The different output ends of the regulation device are mutually indepedent, and the regulation electric current of different output end outputs is mutually indepedent.

7. the electric current uniform distribution method according to claim 1 for direct supercurrent cable, which is characterized in that described The regulation current coupling is carried out resnstance transformer into each branch connected and realizes that electric current is uniform in each branch by coupling device Distribution, comprising:

It is separately adjustable to different branch progress that the mutually independent regulation electric current is exported in the regulation device, it is mutually independent The regulation coupling device of the electric current through the tie point is connect with each parallel branch, and the current bus bar flows into each parallel branch DC current couple with the regulation electric current through the coupling device after become the reality of each parallel branch by electric current, difference Branch is by actually passing through balanced current distribution after regulating and controlling the coupling of electric current.

8. the electric current uniform distribution method according to claim 3 for direct supercurrent cable, which is characterized in that described Transmission line includes two parts: a part is for regulation device conveying regulation electric current to tie point, and a part is at tie point DC current signal is passed back to the regulation device by the current sensor, comprising:

The two-part setting method of the transmission line: it using the method for the different core wires for sharing the same cable, or uses Respectively use the method for different cables.

9. the electric current uniform distribution method according to claim 6 for direct supercurrent cable, which is characterized in that described The current regulation mechanism and the frequency adjustment mechanism in regulation device carry out control operation, comprising:

The current regulation mechanism and the frequency adjustment mechanism, which are taken, to be manually controlled or computer controlled automatic is controlled Operation.

10. the electric current uniform distribution method according to claim 1 for direct supercurrent cable, which is characterized in that described Regulation device indication mechanism, the current value of each parallel branch of real-time display is set as needed.