CN101707367B

CN101707367B - Superconducting current-limiting energy storage circuit

Info

Publication number: CN101707367B
Application number: CN2009102412363A
Authority: CN
Inventors: 郭文勇; 肖立业; 戴少涛; 张志丰
Original assignee: Institute of Electrical Engineering of CAS
Current assignee: Institute of Electrical Engineering of CAS
Priority date: 2009-11-27
Filing date: 2009-11-27
Publication date: 2011-12-14
Anticipated expiration: 2029-11-27
Also published as: CN101707367A

Abstract

The invention relates to a superconducting current-limiting energy storage circuit which utilizes a superconducting magnet as an energy storage link and provides active power required by a power grid; and when a short circuit fault occurs in the power grid, the superconducting magnet can be further connected into the power grid in series for limiting the current through the simple operation of a switch. The superconducting current-limiting energy storage circuit can simultaneously realize reactive power compensation of the power grid, active filter, load fluctuation active power consumption, load voltage sag compensation, peak regulation of the power grid, fault current limitation and other functions and is characterized by high utilization rate and high reliability.

Description

A kind of superconducting current-limiting energy storage circuit

Technical field

The present invention relates to a kind of superconducting current-limiting energy storage circuit.

Background technology

Along with fast development of national economy, society constantly increases electricity needs, driven the continuous development of electric power system, unit and station capacity, substation capacity, city and central concentrated load constantly increase, just make between the electric power system interconnected, short circuit current level in the electrical networks at different levels improves constantly, and short trouble is also increasing to the destructiveness of electric power system and continuous electric equipment thereof.And in growing to the power requirement amount, people also have higher requirement to the quality of power supply, power supply reliability and fail safe etc.Yet the transient stability problem of big electrical network is more outstanding, and wherein one of most important reason is because the conventional electric power technology lacks effective short trouble current limiting technique.At present, extensively adopt circuit breaker that short circuit current is fully cut-off in the world, because short circuit current level is directly related with the capacity of system, under the certain situation of the specified drop-out current level of circuit breaker, adopt and fully cut-off the growth that short circuit current will limit the electric power system capacity, and the circuit breaker price rises rapidly along with the increase of its specified drop-out current.Along with the expansion of net capacity and scale, it is more serious that this problem will become.

Meanwhile, the conventional electric power technology has seriously hindered China's development of electric power industry owing to lack quick electric energy access technique.At first, along with the continuous development of Chinese national economy, people are growing to the demand of electric energy, transferring electricity from the west to the east and on national network inevitable, and the dynamic stability problem of big electrical network becomes increasingly conspicuous; Secondly, along with information technology and microelectric technique are penetrated into industry and people's various fields in life increasingly extensively, and then the quality of power supply and power supply reliability have been proposed more and more higher requirement, the conventional electric power technology has been difficult to adapt to people's this requirement.

Short-circuit fault current limiter is the effective way that solves the short trouble problem.It seals in impedance and comes fault current limiting by when electrical network is short-circuited in faulty line, with the purpose that reaches the protection power equipment and circuit breaker can reliably be cut-off.And superconductive energy storage system (SMES) has the advantage that reaction speed is fast, power density is high and conversion efficiency is high, can bring into play irreplaceable effect aspect the dynamic stability problem that solves existing electric power system, the raising quality of power supply and the power supply reliability.United States Patent (USP) U.S5,726,848 " fault current limiter and AC circuit breaker ", a kind of short-circuit fault current limiter has been proposed, it adopts a kind of single-phase thyristor rectifier bridge construction, and current-limiting inductance is connected in parallel on the dc terminal of rectifier bridge, and the phase shifting angle by the control thyristor comes fault current limiting.The subject matter of this patent is the harmonic content height, and is bigger to the influence of load; Complicated with period control method, reliability is low.U.S. Pat 2002/0030952 " superconducting magnet charging method and device " has proposed a kind of superconductive energy storage system structure, and it can realize the protection to critical loads, and to improve power supply quality, its major defect is a function singleness, and the equipment rate is low with rate.Chinese patent CN100527560C " a kind of bridge circuit type current limiting energy storage circuit " has proposed a kind of circuit that can realize failure current limit and load terminal voltage protection simultaneously.Its major defect is the function that can only realize failure current limit to a circuit, and an other circuit is realized the function of load terminal voltage protection.Can only be applicable to specific occasions, applicable surface is narrow.Chinese patent CN100527559C " a kind of line-to-line voltage compensation type current limiting energy storage circuit " has proposed a kind of circuit that can realize failure current limit and load terminal voltage protection simultaneously; its major defect is because converter is connected with electrical network by current-limiting inductance and transformer; because the existence of current-limiting inductance; can't stablize the voltage at control transformer two ends; therefore the difficulty that realizes the load terminal voltage protection is big, and reliability is low.

Summary of the invention

In order to overcome the deficiency of prior art, the invention provides a kind of superconducting current-limiting energy storage circuit, its versatility height, control method is simple, can be widely used in the failure current limit of various three phase networks, and improves the quality of power supply of electrical network.

The present invention has following four kinds of versions:

1, superconducting current-limiting energy storage circuit structure of the present invention is as follows: first switch, second switch, the 3rd switch, the 4th switch, the 5th switch and the 6th switch are formed first current source converter; The anode of first switch links to each other with the negative electrode of the 4th switch, constitutes first and exchanges tie point; The anode of second switch links to each other with the negative electrode of the 5th switch, constitutes second and exchanges tie point; The anode of the 3rd switch links to each other with the negative electrode of the 6th switch, constitutes the 3rd and exchanges tie point; The negative electrode of first switch, second switch and the 3rd switch links together, and constitutes the first direct current tie point; The anode of the 4th switch, the 5th switch and the 6th switch links together, and constitutes the second direct current tie point.Minion pass, octavo pass, the 9th switch, the tenth switch, the 11 switch and twelvemo are closed and are formed second current source converter; The anode that twelvemo is closed links to each other with the negative electrode of the 9th switch, constitutes the 4th and exchanges tie point; The anode of the 11 switch links to each other with the negative electrode that octavo is closed, and constitutes the 5th and exchanges tie point; The anode of the tenth switch links to each other with the negative electrode that minion is closed, and constitutes the 6th and exchanges tie point.Minion is closed, octavo is closed and the anode of the 9th switch links together, and constitutes the 3rd direct current tie point; The negative electrode that the tenth switch, the 11 switch and twelvemo are closed links together, and constitutes the 4th direct current tie point.The anode of the 13 switch links to each other with the 4th direct current tie point, and its negative electrode links to each other with the 3rd direct current tie point; The two ends of superconducting magnet link to each other with the 3rd direct current tie point with the first direct current tie point respectively; The second direct current tie point links to each other with the 4th direct current tie point.One end of first filter inductance and an end of first filter capacitor exchange tie point and link to each other with first, the other end of first filter inductance contact that links to each other with first of three-phase transformer time limit is continuous; One end of second filter inductance and an end of second filter capacitor exchange tie point and link to each other with second, the other end of second filter inductance contact that links to each other with second of three-phase transformer time limit is continuous; One end of the 3rd filter inductance exchanges tie point with an end of the 3rd filter capacitor and links to each other with the 3rd, the other end of the 3rd filter inductance links to each other with the third phase tie point on three-phase transformer time limit; The other end of first filter capacitor, second filter capacitor and the 3rd filter capacitor interconnects; The former limit of three-phase transformer links to each other with three phase network.One end on one end of the 4th filtering capacitor and first single-phase transformer time limit exchanges tie point and links to each other with the 4th; One end on one end of the 5th filtering capacitor and second single-phase transformer time limit exchanges tie point and links to each other with the 5th; One end on one end of the 6th filtering capacitor and the 3rd single-phase transformer time limit exchanges tie point and links to each other with the 6th; The other end on first single-phase transformer, second single-phase transformer and the 3rd single-phase transformer time limit interconnects.An end of power supply and an end of first phase load link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer; An end of power supply and an end of second phase load link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer; The two ends on the former limit of the 3rd single-phase transformer link to each other with an end of electrical network third phase power supply and an end of third phase load respectively.Described first switch ... the 13 switch is the inverse-impedance type switch, and the perhaps contrary diode of type switch series connection of leading substitutes described inverse-impedance type switch.

Control method to the superconducting current-limiting energy storage circuit of this version can be carried out at following three kinds of operating states respectively: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of second current source converter this moment: minion is closed ... twelvemo is closed all closed, the 13 switch is closed simultaneously, the voltage on first single-phase transformer, second single-phase transformer and the 3rd single-phase transformer time limit is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially.This moment, first current source converter passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; Simultaneously first current source converter also is absorbed with and discharges merit power from electrical network, and superconducting magnet is discharged and recharged, and the electric current of superconducting magnet is remained near the set-point.2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously, and this moment, the control method of first current source converter was identical with the method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state.The 13 switch is opened at this moment, and second current source converter changes the voltage on fourth, fifth and six filter capacitors by Current Control, the voltage harmonic of electrical network, voltage dip etc. is compensated, and then improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state, this moment the 13 switch opens, all switch closures of second current source converter, the second current source converter equivalence is a not control rectifying circuit of a three-phase, this moment, superconducting magnet was automatically connected into electrical network, thereby had realized the function of failure current limit.Meanwhile, first current source converter is operated in the active inversion state, with the rechargeable energy inversion telegram in reply net of giving superconducting magnet in the current limliting process, not impacted by overcurrent with the protection superconducting magnet.

2, a kind of superconducting current-limiting energy storage circuit of the present invention, can also be following structure: first switch, second switch, the 3rd switch, the 4th switch, the 5th switch and the 6th switch are formed first current source converter; The anode of first switch links to each other with the negative electrode of the 4th switch, constitutes first and exchanges tie point; The anode of second switch links to each other with the negative electrode of the 5th switch, constitutes second and exchanges tie point; The anode of the 3rd switch links to each other with the negative electrode of the 6th switch, constitutes the 3rd and exchanges tie point; The negative electrode of first switch, second switch and the 3rd switch links together, and constitutes the first direct current tie point; The anode of the 4th switch, the 5th switch and the 6th switch links together, and constitutes the second direct current tie point.Minion pass, octavo pass, the 9th switch and the tenth switch are formed second current source converter; The negative electrode of the tenth switch links to each other with the anode that minion is closed, and constitutes the 4th and exchanges tie point; The negative electrode of the 9th switch links to each other with the anode that octavo is closed, and constitutes the 5th and exchanges tie point; Minion is closed the negative electrode that closes with octavo and is linked to each other, and constitutes the 3rd direct current tie point; The 9th switch links to each other with the anode of the tenth switch, constitutes the 4th direct current tie point.The 11 switch, twelvemo pass, the 13 switch and the 14 switch are formed the 3rd current source converter; The negative electrode of the 14 switch links to each other with the anode of the 11 switch, constitutes the 6th and exchanges tie point; The negative electrode of the 13 switch links to each other with the anode that twelvemo is closed, and constitutes the 7th and exchanges tie point; The 11 switch links to each other with the negative electrode that twelvemo is closed, and constitutes the 5th direct current tie point; The anode of the 13 switch and the 14 switch links to each other, and constitutes the 6th direct current tie point.The 15 switch, sixteenmo close, the tenth minion is closed and eighteenmo closes composition the 4th current source converter; The negative electrode that eighteenmo closes links to each other with the anode of the 15 switch, constitutes the 8th and exchanges tie point; The negative electrode that the tenth minion is closed links to each other with the anode that sixteenmo closes, and constitutes the 9th and exchanges tie point; The 15 switch links to each other with the negative electrode that sixteenmo closes, and constitutes the 7th direct current tie point; The tenth minion is closed the anode that closes with eighteenmo and is linked to each other, and constitutes the 8th direct current tie point.The two ends of superconducting magnet link to each other with the 4th direct current tie point with the first direct current tie point respectively; The second direct current tie point links to each other with the 7th direct current tie point; The 3rd direct current tie point links to each other with the 6th direct current tie point, and the 5th direct current tie point links to each other with the 8th direct current tie point; The anode of the 19 switch links to each other with the 3rd direct current tie point, and the negative electrode of the 19 switch links to each other with the 4th direct current tie point; The anode of the 20 switch links to each other with the 5th direct current tie point, and the negative electrode of the 20 switch links to each other with the 6th direct current tie point; The anode of the 21 switch links to each other with the 7th direct current tie point, and the negative electrode of the 21 switch links to each other with the 8th direct current tie point.One end of first filter inductance and an end of first filter capacitor exchange tie point and link to each other with first, the other end of first filter inductance contact that links to each other with first of three-phase transformer time limit is continuous; One end of second filter inductance and an end of second filter capacitor exchange tie point and link to each other with second, the other end of second filter inductance contact that links to each other with second of three-phase transformer time limit is continuous; One end of the 3rd filter inductance exchanges tie point with an end of the 3rd filter capacitor and links to each other with the 3rd, the other end of the 3rd filter inductance links to each other with the third phase tie point on three-phase transformer time limit; The other end of first filter capacitor, second filter capacitor and the 3rd filter capacitor interconnects.The former limit of three-phase transformer links to each other with three phase network; Its two ends exchange tie point respectively and exchange tie point with the 5th and link to each other after the inferior limit parallel connection of the 4th filter capacitor and first single-phase transformer with the 4th, its two ends exchange tie point respectively and exchange tie point with the 7th and link to each other after the inferior limit parallel connection of the 5th filter capacitor and second single-phase transformer with the 6th, and its two ends exchange tie point respectively exchange tie point with the 9th continuous after inferior limit parallel connection of the 6th filter capacitor and the 3rd single-phase transformer with the 8th; An end of power supply and an end of first phase load link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer; An end of power supply and an end of second phase load link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer; The two ends on the former limit of the 3rd single-phase transformer link to each other with an end of electrical network third phase power supply and an end of third phase load respectively.Described first switch ... the 21 switch is the inverse-impedance type switch, perhaps substitutes described inverse-impedance type switch with the contrary diode of type switch series connection of leading.

Control method to the superconducting current-limiting energy storage circuit of this version can be carried out at following three kinds of operating states respectively: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of second current source converter, the 3rd current source converter and the 4th current source converter this moment: minion is closed ... eighteenmo closes all closed, the 19 switch, the 20 switch and the 21 switch are closed simultaneously, the voltage on first single-phase transformer, second single-phase transformer and the 3rd single-phase transformer time limit is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially; This moment, first current source converter passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; First current source converter also absorbs and release active power from electrical network simultaneously, and superconducting magnet is discharged and recharged, and the electric current of superconducting magnet is remained near the set-point.2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously.This moment, the control method of first current source converter was identical with the method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state; The 19 switch, the 20 switch and the 21 switch are opened at this moment, second current source converter, the 3rd current source converter and the 4th current source converter pass through Current Control, change the voltage on fourth, fifth and six filter capacitors, thereby the voltage harmonic of electrical network, voltage dip etc. are compensated, improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state.This moment the 19 switch, the 20 switch and the 21 switch opens, all switch closures of second current source converter, the 3rd current source converter and the 4th current source converter, second current source converter, the 3rd current source converter and the 4th current source converter equivalence are three single-phase not control rectifying circuits that are connected in series, this moment, superconducting magnet was automatically connected into electrical network, had realized the function of failure current limit.Meanwhile, first current source converter is operated in the active inversion state, with the rechargeable energy inversion telegram in reply net of giving superconducting magnet in the current limliting process, not impacted by overcurrent with the protection superconducting magnet.

3, a kind of superconducting current-limiting energy storage circuit of the present invention can have following structure again: first switch, second switch, the 3rd switch, the 4th switch, the 5th switch and the 6th switch are formed first voltage source converter; The emitter of first switch links to each other with the collector electrode of the 4th switch, constitutes first and exchanges tie point; The emitter of second switch links to each other with the collector electrode of the 5th switch, constitutes second and exchanges tie point; The emitter of the 3rd switch links to each other with the collector electrode of the 6th switch, constitutes the 3rd and exchanges tie point; The collector electrode of first switch, second switch and the 3rd switch links together, and constitutes the first direct current tie point; The emitter of the 4th switch, the 5th switch and the 6th switch links together, and constitutes the second direct current tie point.The two ends that direct current connects electric capacity link to each other with the second direct current tie point with the first direct current tie point respectively.Minion pass, octavo pass, first diode and second diode are formed first chopper; The emitter that minion is closed links to each other with the negative electrode of second diode, constitutes the 7th and exchanges tie point, and the collector electrode that minion is closed links to each other with the first direct current tie point, and the anode of second diode links to each other with the second direct current tie point; The anode of first diode links to each other with the collector electrode that octavo is closed, and constitutes the 8th and exchanges tie point, and the emitter that octavo is closed links to each other with the second direct current tie point, and the negative electrode of first diode links to each other with the first direct current tie point.The 9th switch, the tenth switch, the 11 switch, twelvemo pass, the 13 switch and the 14 switch are formed first current source converter; The anode of the 14 switch links to each other with the negative electrode of the 11 switch, constitutes the 4th and exchanges tie point; The anode of the 13 switch links to each other with the negative electrode of the tenth switch, constitutes the 5th and exchanges tie point; The anode that twelvemo is closed links to each other with the negative electrode of the 9th switch, constitutes the 6th and exchanges tie point; The anode of the 9th switch, the tenth switch and the 11 switch links together, and constitutes the 3rd direct current tie point; The negative electrode of twelvemo pass, the 13 switch and the 14 switch links together, and constitutes the 4th direct current tie point.The anode of the 15 switch links to each other with the 4th direct current tie point, and its negative electrode links to each other with the 3rd direct current tie point.The two ends of superconducting magnet exchange tie point respectively and link to each other with the 3rd direct current tie point with the 7th; The 8th exchanges tie point links to each other with the 4th direct current tie point; One end of first filter inductance exchanges tie point and links to each other with first, the other end of first filter inductance contact that links to each other with first of three-phase transformer time limit is continuous; One end of second filter inductance exchanges tie point and links to each other with second, the other end of second filter inductance contact that links to each other with second of three-phase transformer time limit is continuous; One end of the 3rd filter inductance exchanges tie point and links to each other with the 3rd, the other end of the 3rd filter inductance links to each other with the third phase tie point on three-phase transformer time limit; The former limit of three-phase transformer links to each other with three phase network.One end on one end of first filtering capacitor and first single-phase transformer time limit exchanges tie point and links to each other with the 4th; One end on one end of second filtering capacitor and second single-phase transformer time limit exchanges tie point and links to each other with the 5th; One end on one end of the 3rd filtering capacitor and the 3rd single-phase transformer time limit exchanges tie point and links to each other with the 6th; The other end on first single-phase transformer, second single-phase transformer and the 3rd single-phase transformer time limit interconnects.An end of power supply and an end of first phase load link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer; An end of power supply and an end of second phase load link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer; The two ends on the former limit of the 3rd single-phase transformer link to each other with an end of electrical network third phase power supply and an end of third phase load respectively.Described first switch ... octavo is closed and is contrary lead type switch, the 9th switch ... the 15 switch is the inverse-impedance type switch, perhaps substitutes described inverse-impedance type switch with the contrary diode of type switch series connection of leading; Described first voltage source converter and first chopper or adopt the version of many level to replace described two level versions.

Control method to the superconducting current-limiting energy storage circuit of this version can be carried out at following three kinds of operating states respectively: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of first current source converter this moment: the 9th switch ... the 14 switch is all closed, the 15 switch is closed simultaneously, the voltage on the first single-phase transformer Tr1, the second single-phase transformer Tr2 and Tr3 limit of the 3rd single-phase transformer is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially; This moment, first voltage source converter passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; First voltage source converter also absorbs and release active power from electrical network simultaneously, and superconducting magnet is discharged and recharged, and the electric current of superconducting magnet is remained near the set-point; First chopper makes it to maintain near the set-point by control the voltage on the direct current connection electric capacity to direct current connection electric capacity injection current.2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously, this moment, the control method of first voltage source converter and first chopper was identical with the control method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state, the 15 switch is opened at this moment, first current source converter passes through Current Control, change the voltage on first and second and three filter capacitors, thereby the voltage harmonic of electrical network, voltage dip etc. are compensated, and then improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state, this moment the 15 switch opens, all switch closures of first current source converter, the first current source converter equivalence is a not control rectifying circuit of a three-phase, this moment, superconducting magnet was automatically connected into electrical network, had realized the function of failure current limit.Meanwhile, first voltage source converter is operated in the active inversion state, as far as possible with the rechargeable energy inversion telegram in reply net of giving superconducting magnet in the current limliting process, not impacted by overcurrent with the protection superconducting magnet; First chopper is by controlling the voltage on the direct current connection electric capacity to direct current connection electric capacity injection current, the voltage that direct current is connected on the electric capacity maintains near the set-point.

4, a kind of superconducting current-limiting energy storage circuit of the present invention can have following structure again: first switch, second switch, the 3rd switch, the 4th switch, the 5th switch and the 6th switch are formed first voltage source converter; The emitter of first switch links to each other with the collector electrode of the 4th switch, constitutes first and exchanges tie point; The emitter of second switch links to each other with the collector electrode of the 5th switch, constitutes second and exchanges tie point; The emitter of the 3rd switch links to each other with the collector electrode of the 6th switch, constitutes the 3rd and exchanges tie point; The collector electrode of first switch, second switch and the 3rd switch links together, and constitutes the first direct current tie point; The emitter of the 4th switch, the 5th switch and the 6th switch links together, and constitutes the second direct current tie point.The two ends that direct current connects electric capacity link to each other with the second direct current tie point with the first direct current tie point respectively.Minion pass, octavo pass, first diode and second diode are formed first chopper; The emitter that minion is closed links to each other with the negative electrode of second diode, constitutes the 7th and exchanges tie point, and the collector electrode that minion is closed links to each other with the first direct current tie point, and the anode of second diode links to each other with the second direct current tie point; The anode of first diode links to each other with the collector electrode that octavo is closed, and constitutes the 8th and exchanges tie point, and the emitter that octavo is closed links to each other with the second direct current tie point, and the negative electrode of first diode links to each other with the first direct current tie point.The 9th switch, the tenth switch, the 11 switch and twelvemo are closed and are formed first current source converter; The negative electrode that twelvemo is closed links to each other with the anode of the 9th switch, constitutes the 4th and exchanges tie point; The negative electrode of the 11 switch links to each other with the anode of the tenth switch, constitutes the 5th and exchanges tie point; The 9th switch links to each other with the negative electrode of the tenth switch, constitutes the 3rd direct current tie point; The 11 switch links to each other with the anode that twelvemo is closed, and constitutes the 4th direct current tie point.The 13 switch, the 14 switch, the 15 switch and sixteenmo close forms second current source converter; The negative electrode that sixteenmo closes links to each other with the anode of the 13 switch, constitutes the 6th and exchanges tie point; The negative electrode of the 15 switch links to each other with the anode of the 14 switch, constitutes the 9th and exchanges tie point; The negative electrode of the 13 switch and the 14 switch links to each other, and constitutes the 5th direct current tie point; The 15 switch links to each other with the anode that sixteenmo closes, and constitutes the 6th direct current tie point.The tenth minion pass, eighteenmo pass, the 19 switch and the 20 switch are formed the 3rd current source converter; The negative electrode of the 20 switch links to each other with the anode that the tenth minion is closed, and constitutes the tenth and exchanges tie point; The negative electrode of the 19 switch links to each other with the anode that eighteenmo closes, and constitutes the 11 and exchanges tie point; The tenth minion is closed the negative electrode that closes with eighteenmo and is linked to each other, and constitutes the 7th direct current tie point; The anode of the 19 switch and the 20 switch links to each other, and constitutes the 8th direct current tie point.The anode of the 21 switch links to each other with the 3rd direct current tie point, and the negative electrode of the 21 switch links to each other with the 4th direct current tie point; The anode that second twelvemo is closed links to each other with the 5th direct current tie point, and the negative electrode that second twelvemo is closed links to each other with the 6th direct current tie point; The anode of the 23 switch links to each other with the 7th direct current tie point, and the negative electrode of the 23 switch links to each other with the 8th direct current tie point.The two ends of superconducting magnet exchange tie point respectively and link to each other with the 4th direct current tie point with the 7th; The 8th exchanges tie point links to each other with the 7th direct current tie point; The 3rd direct current tie point links to each other with the 6th direct current tie point, and the 5th direct current tie point links to each other with the 8th direct current tie point.One end of first filter inductance exchanges tie point and links to each other with first, the other end of first filter inductance contact that links to each other with first of three-phase transformer time limit is continuous; One end of second filter inductance exchanges tie point and links to each other with second, the other end of second filter inductance contact that links to each other with second of three-phase transformer time limit is continuous; One end of the 3rd filter inductance exchanges tie point and links to each other with the 3rd, the other end of the 3rd filter inductance links to each other with the third phase tie point on three-phase transformer time limit; The former limit of three-phase transformer links to each other with three phase network.Its two ends exchange tie point respectively and exchange tie point with the 5th and link to each other after the inferior limit parallel connection of first filter capacitor and first single-phase transformer with the 4th, its two ends exchange tie point respectively and exchange tie point with the 9th and link to each other after the inferior limit parallel connection of second filter capacitor and second single-phase transformer with the 6th, and its two ends exchange tie point and the 11 respectively to exchange tie point continuous after inferior limit parallel connection of the 3rd filter capacitor and the 3rd single-phase transformer with the tenth.An end of power supply and an end of first phase load link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer; An end of power supply and an end of second phase load link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer; The two ends on the former limit of the 3rd single-phase transformer link to each other with an end of electrical network third phase power supply and an end of third phase load respectively.Above-mentioned first switch ... octavo is closed and is contrary lead type switch, the 9th switch ... the 23 switch is the inverse-impedance type switch, and also available contrary diode of type switch series connection of leading is realized; Described first voltage source converter and first chopper or adopt the version of many level to replace described two level versions.

Control method to the superconducting current-limiting energy storage circuit of this version can be carried out at following three kinds of operating states respectively: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of first current source converter, second current source converter and the 3rd current source converter this moment: the 9th switch ... the 20 switch is all closed, the 21 switch, second twelvemo are closed and the 23 switch while closure, the voltage on first single-phase transformer, second single-phase transformer and the 3rd single-phase transformer time limit is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially.This moment, first voltage source converter passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; First voltage source converter also absorbs and release active power from electrical network simultaneously, and superconducting magnet is discharged and recharged, and the electric current of superconducting magnet is remained near the set-point.First chopper makes it to maintain near the set-point by control the voltage on the direct current connection electric capacity to direct current connection electric capacity injection current.2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously.This moment, first voltage source converter was identical with the control method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state with the first chopper control method; The 21 switch, second twelvemo are closed and the 23 switch is opened at this moment, first current source converter, second current source converter and the 3rd current source converter pass through Current Control, change the voltage on first and second and three filter capacitors, thereby the voltage harmonic of electrical network, voltage dip etc. are compensated, improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state.The 21 switch, second twelvemo are closed and the 23 switch opens at this moment, all switch closures of first current source converter, second current source converter and the 3rd current source converter, first current source converter, second current source converter and the 3rd current source converter equivalence are three single-phase not control rectifying circuits that are connected in series, this moment, superconducting magnet was automatically connected into electrical network, had realized the function of failure current limit.Meanwhile, first voltage source converter is operated in the active inversion state, with the rechargeable energy inversion telegram in reply net of giving superconducting magnet in the current limliting process, not impacted by overcurrent with the protection superconducting magnet.First chopper is by controlling the voltage on the direct current connection electric capacity to direct current connection electric capacity injection current, the voltage that direct current is connected on the electric capacity maintains near the set-point.

Description of drawings

Further specify the present invention below in conjunction with the drawings and specific embodiments.

Fig. 1 is the topology diagram of United States Patent (USP) U.S 5,726,848 " fault current limiter and AC circuit breaker ".

The topology diagram of Fig. 2 U.S. Pat 2002/0030952 " superconducting magnet charging method and device ".

The topology diagram of Fig. 3 Chinese patent CN100527560C " a kind of bridge circuit type current limiting energy storage circuit ".

The topology diagram of Fig. 4 Chinese patent CN100527560C " a kind of bridge circuit type current limiting energy storage circuit ".

Fig. 5-Fig. 8 is the topology diagram of the embodiment of the invention.

Embodiment

Fig. 5 is the topological structure of embodiments of the invention 1.As shown in Figure 5, the structure of the embodiment of the invention 1 is as follows: first switch S 1, second switch S2, the 3rd switch S 3, the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 are formed the first current source converter CSC1; The anode of first switch S 1 links to each other with the negative electrode of the 4th switch S 4, constitutes first and exchanges tie point PA1; The anode of second switch S2 links to each other with the negative electrode of the 5th switch S 5, constitutes second and exchanges tie point PA2; The anode of the 3rd switch S 3 links to each other with the negative electrode of the 6th switch S 6, constitutes the 3rd and exchanges tie point PA3; The negative electrode of first switch S 1, second switch S2 and the 3rd switch S 3 links together, and constitutes the first direct current tie point PD1; The anode of the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 links together, and constitutes the second direct current tie point PD2.Minion pass S7, octavo pass S8, the 9th switch S 9, the tenth switch S the 10, the 11 switch S 11 and twelvemo pass S12 form the second current source converter CSC2; The anode that twelvemo is closed S12 links to each other with the negative electrode of the 9th switch S 9, constitutes the 4th and exchanges tie point PA4; The anode of the 11 switch S 11 links to each other with the negative electrode that octavo is closed S8, constitutes the 5th and exchanges tie point PA5; The anode of the tenth switch S 10 links to each other with the negative electrode that minion is closed S7, constitutes the 6th and exchanges tie point PA6.The anode that minion is closed S7, octavo pass S8 and the 9th switch S 9 links together, and constitutes the 3rd direct current tie point PD3; The negative electrode that the tenth switch S the 10, the 11 switch S 11 and twelvemo are closed S12 links together, and constitutes the 4th direct current tie point PD4.The anode of the 13 switch S 13 links to each other with the 4th direct current tie point PD4, and its negative electrode links to each other with the 3rd direct current tie point PD3; The two ends of superconducting magnet Lsc link to each other with the 3rd direct current tie point PD3 with the first direct current tie point PD1 respectively; The second direct current tie point PD2 links to each other with the 4th direct current tie point PD4.The end of the end of the first filter inductance L1 and the first filter capacitor C1 exchanges tie point PA1 and links to each other with first, first of Trs limit of the other end of the first filter inductance L1 and the three-phase transformer contact that links to each other is continuous; The end of the end of the second filter inductance L2 and the second filter capacitor C2 exchanges tie point PA2 and links to each other with second, second of Trs limit of the other end of the second filter inductance L2 and the three-phase transformer contact that links to each other is continuous; The end of the end of the 3rd filter inductance L3 and the 3rd filter capacitor C3 exchanges tie point PA3 and links to each other with the 3rd, the third phase tie point on Trs limit of the other end of the 3rd filter inductance L3 and three-phase transformer links to each other; The other end of the first filter capacitor C1, the second filter capacitor C2 and the 3rd filter capacitor C3 interconnects.The former limit of three-phase transformer links to each other with three phase network; One end on Tr1 limit of the end of the 4th filtering capacitor C4 and first single-phase transformer exchanges tie point PA4 and links to each other with the 4th; One end on Tr2 limit of the end of the 5th filtering capacitor C5 and second single-phase transformer exchanges tie point PA5 and links to each other with the 5th; One end on Tr3 limit of the end of the 6th filtering capacitor C6 and the 3rd single-phase transformer exchanges tie point PA6 and links to each other with the 6th; The other end on the first single-phase transformer Tr1, the second single-phase transformer Tr2 and Tr3 limit of the 3rd single-phase transformer interconnects.The end of power supply Us1 and the end of the first phase load Z1 link to each other mutually with electrical network first respectively at the two ends on the former limit of the first single-phase transformer Tr1; The end of power supply Us2 and the end of the second phase load Z2 link to each other mutually with electrical network second respectively at the two ends on the former limit of the second single-phase transformer Tr2; The two ends on the former limit of the 3rd single-phase transformer Tr3 link to each other with the end of electrical network third phase power supply Us3 and the end of third phase load Z3 respectively.Described first switch S 1 ... the 13 switch S 13 is the inverse-impedance type switch, and the perhaps contrary diode of type switch series connection of leading substitutes described inverse-impedance type switch.

Control method to embodiment shown in Figure 51 can be carried out at the following three kinds of operating states of described superconducting current-limiting energy storage circuit: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of the second current source converter CSC2 this moment: minion is closed S7 ... twelvemo is closed all closures of S12, the 13 switch S 13 is closed simultaneously, the voltage on the first single-phase transformer Tr1, the second single-phase transformer Tr2 and Tr3 limit of the 3rd single-phase transformer is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially.This moment, the first current source converter CSC1 passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; Simultaneously the first current source converter CSC1 also is absorbed with and discharges merit power from electrical network, and Lsc discharges and recharges to superconducting magnet, and the electric current of superconducting magnet Lsc is remained near the set-point.2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously, and this moment, the control method of the first current source converter CSC1 was identical with the method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state; The 13 switch S 13 is opened this moment, and the second current source converter CSC2 changes the voltage on fourth, fifth and six filter capacitors by Current Control, the voltage harmonic of electrical network, voltage dip etc. is compensated, and then improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state, this moment, the 13 switch S 13 was opened, all switch closures of the second current source converter CSC2, the second current source converter CSC2 equivalence is a not control rectifying circuit of a three-phase, this moment, superconducting magnet Lsc was automatically connected into electrical network, thereby had realized the function of failure current limit; Meanwhile, the first current source converter CSC1 is operated in the active inversion state, and with the rechargeable energy inversion telegram in reply net of giving superconducting magnet Lsc in the current limliting process, Lsc is not impacted by overcurrent with the protection superconducting magnet.

Fig. 6 is the topological structure of embodiments of the invention 2.As shown in Figure 6, structure of the present invention is as follows: first switch S 1, second switch S2, the 3rd switch S 3, the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 are formed the first current source converter CSC1; The anode of first switch S 1 links to each other with the negative electrode of the 4th switch S 4, constitutes first and exchanges tie point PA1; The anode of second switch S2 links to each other with the negative electrode of the 5th switch S 5, constitutes second and exchanges tie point PA2; The anode of the 3rd switch S 3 links to each other with the negative electrode of the 6th switch S 6, constitutes the 3rd and exchanges tie point PA3; The negative electrode of first switch S 1, second switch S2 and the 3rd switch S 3 links together, and constitutes the first direct current tie point PD1; The anode of the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 links together, and constitutes the second direct current tie point PD2.Minion is closed S7, octavo is closed S8, the 9th switch S 9 and the tenth switch S 10 compositions second current source converter CSC2; The negative electrode of the tenth switch S 10 links to each other with the anode that minion is closed S7, constitutes the 4th and exchanges tie point PA4; The negative electrode of the 9th switch S 9 links to each other with the anode that octavo is closed S8, constitutes the 5th and exchanges tie point PA5; Minion is closed S7 and is linked to each other with the negative electrode that octavo is closed S8, constitutes the 3rd direct current tie point PD3; The anode of the 9th switch S 9 and the tenth switch S 10 links to each other, and constitutes the 4th direct current tie point PD4.The 11 switch S 11, twelvemo are closed S12, the 13 switch S 13 and the 14 switch S 14 compositions the 3rd current source converter CSC3; The negative electrode of the 14 switch S 14 links to each other with the anode of the 11 switch S 11, constitutes the 6th and exchanges tie point PA6; The negative electrode of the 13 switch S 13 links to each other with the anode that twelvemo is closed S12, constitutes the 7th and exchanges tie point PA7; The 11 switch S 11 links to each other with the negative electrode that twelvemo is closed S12, constitutes the 5th direct current tie point PD5; The anode of the 13 switch S 13 and the 14 switch S 14 links to each other, and constitutes the 6th direct current tie point PD6.The 15 switch S 15, sixteenmo close S16, the tenth minion closes S17 and eighteenmo pass S18 forms the 4th current source converter CSC4; The negative electrode that eighteenmo closes S18 links to each other with the anode of the 15 switch S 15, constitutes the 8th and exchanges tie point PA8; The negative electrode that the tenth minion is closed S17 links to each other with the anode that sixteenmo closes S16, constitutes the 9th and exchanges tie point PA9; The 15 switch S 15 links to each other with the negative electrode that sixteenmo closes S16, constitutes the 7th direct current tie point PD7; The tenth minion is closed S17 and is linked to each other with the anode that eighteenmo closes S18, constitutes the 8th direct current tie point PD8.The two ends of superconducting magnet Lsc link to each other with the 4th direct current tie point PD4 with the first direct current tie point PD1 respectively; The second direct current tie point PD2 links to each other with the 7th direct current tie point PD7; The 3rd direct current tie point PD3 links to each other with the 6th direct current tie point PD6, and the 5th direct current tie point PD5 links to each other with the 8th direct current tie point PD8; The anode of the 19 switch S 19 links to each other with the 3rd direct current tie point PD3, and the negative electrode of the 19 switch S 19 links to each other with the 4th direct current tie point PD4; The anode of the 20 switch S 20 links to each other with the 5th direct current tie point PD5, and the negative electrode of the 20 switch S 20 links to each other with the 6th direct current tie point PD6; The anode of the 21 switch S 21 links to each other with the 7th direct current tie point PD7, and the negative electrode of the 21 switch S 21 links to each other with the 8th direct current tie point PD8.The end of the end of the first filter inductance L1 and the first filter capacitor C1 exchanges tie point PA1 and links to each other with first, first of Trs limit of the other end of the first filter inductance L1 and the three-phase transformer contact that links to each other is continuous; The end of the end of the second filter inductance L2 and the second filter capacitor C2 exchanges tie point PA2 and links to each other with second, second of Trs limit of the other end of the second filter inductance L2 and the three-phase transformer contact that links to each other is continuous; The end of the end of the 3rd filter inductance L3 and the 3rd filter capacitor C3 exchanges tie point PA3 and links to each other with the 3rd, the third phase tie point on Trs limit of the other end of the 3rd filter inductance L3 and three-phase transformer links to each other; The other end of the first filter capacitor C1, the second filter capacitor C2 and the 3rd filter capacitor C3 interconnects.The former limit of three-phase transformer links to each other with three phase network; Its two ends exchange tie point PA4 respectively and exchange tie point PA5 with the 5th and link to each other after the inferior limit parallel connection of the 4th filter capacitor C4 and the first single-phase transformer Tr1 with the 4th, its two ends exchange tie point PA6 respectively and exchange tie point PA7 with the 7th and link to each other after the inferior limit parallel connection of the 5th filter capacitor C5 and the second single-phase transformer Tr2 with the 6th, and its two ends exchange tie point PA8 respectively exchange tie point PA9 with the 9th continuous after inferior limit parallel connection of the 6th filter capacitor C6 and the 3rd single-phase transformer Tr3 with the 8th.The end of power supply Us1 and the end of the first phase load Z1 link to each other mutually with electrical network first respectively at the two ends on the former limit of the first single-phase transformer Tr1; The end of power supply Us2 and the end of the second phase load Z2 link to each other mutually with electrical network second respectively at the two ends on the former limit of the second single-phase transformer Tr2; The two ends on the former limit of the 3rd single-phase transformer Tr3 link to each other with the end of electrical network third phase power supply Us3 and the end of third phase load Z3 respectively.Described first switch S 1 ... the 21 switch S 21 is the inverse-impedance type switch, perhaps substitutes described inverse-impedance type switch with the contrary diode of type switch series connection of leading.

Control method to the embodiment of the invention shown in Figure 62 is carried out at following three kinds of operating states of described superconducting current-limiting energy storage circuit respectively: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of the second current source converter CSC2, the 3rd current source converter CSC3 and the 4th current source converter CSC4 this moment: minion is closed S7 ... eighteenmo closes all closures of S18, the 19 switch S the 19, the 20 switch S 20 and the 21 switch S 21 are closed simultaneously, the voltage on the first single-phase transformer Tr1, the second single-phase transformer Tr2 and Tr3 limit of the 3rd single-phase transformer is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially.This moment, the first current source converter CSC1 passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; The first current source converter CSC1 also absorbs and release active power from electrical network simultaneously, and Lsc discharges and recharges to superconducting magnet, and the electric current of superconducting magnet Lsc is remained near the set-point.2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously.This moment, the control method of the first current source converter CSC1 was identical with the method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state; The 19 switch S the 19, the 20 switch S 20 and the 21 switch S are opened for 21 this moments, the second current source converter CSC2, the 3rd current source converter CSC3 and the 4th current source converter CSC4 pass through Current Control, change the voltage on fourth, fifth and six filter capacitors, thereby the voltage harmonic of electrical network, voltage dip etc. are compensated, improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state.This moment, the 19 switch S the 19, the 20 switch S 20 and the 21 switch S 21 were opened all switch closures of the second current source converter CSC2, the 3rd current source converter CSC3 and the 4th current source converter CSC4.The second current source converter CSC2, the 3rd current source converter CSC3 and the 4th current source converter CSC4 equivalence are three single-phase not control rectifying circuits that are connected in series, and this moment, superconducting magnet Lsc was automatically connected into electrical network, had realized the function of failure current limit.Meanwhile, the first current source converter CSC1 is operated in the active inversion state, and with the rechargeable energy inversion telegram in reply net of giving superconducting magnet Lsc in the current limliting process, Lsc is not impacted by overcurrent with the protection superconducting magnet.

Fig. 7 is the topological structure of embodiments of the invention 3.As shown in Figure 7, the structure of the embodiment of the invention 3 is as follows: first switch S 1, second switch S2, the 3rd switch S 3, the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 are formed the first voltage source converter VSC1; The emitter of first switch S 1 links to each other with the collector electrode of the 4th switch S 4, constitutes first and exchanges tie point PA1; The emitter of second switch S2 links to each other with the collector electrode of the 5th switch S 5, constitutes second and exchanges tie point PA2; The emitter of the 3rd switch S 3 links to each other with the collector electrode of the 6th switch S 6, constitutes the 3rd and exchanges tie point PA3; The collector electrode of first switch S 1, second switch S2 and the 3rd switch S 3 links together, and constitutes the first direct current tie point PD1; The emitter of the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 links together, and constitutes the second direct current tie point PD2.The two ends that direct current connects capacitor C link to each other with the second direct current tie point PD2 with the first direct current tie point PD1 respectively.Minion is closed S7, octavo closes S8, the first diode D1 and the second diode D2 forms the first chopper CH1; The emitter that minion is closed S7 links to each other with the negative electrode of the second diode D2, constitutes the 7th and exchanges tie point PA7, and the collector electrode that minion is closed S7 links to each other with the first direct current tie point PD1, and the anode of the second diode D2 links to each other with the second direct current tie point PD2; The anode of the first diode D1 links to each other with the collector electrode that octavo is closed S8, constitutes the 8th and exchanges tie point PA8, and the emitter that octavo is closed S8 links to each other with the second direct current tie point PD2, and the negative electrode of the first diode D1 links to each other with the first direct current tie point PD1.The 9th switch S 9, the tenth switch S the 10, the 11 switch S 11, twelvemo are closed S12, the 13 switch S 13 and the 14 switch S 14 compositions first current source converter CSC1; The anode of the 14 switch S 14 links to each other with the negative electrode of the 11 switch S 11, constitutes the 4th and exchanges tie point PA4; The anode of the 13 switch S 13 links to each other with the negative electrode of the tenth switch S 10, constitutes the 5th and exchanges tie point PA5; The anode that twelvemo is closed S12 links to each other with the negative electrode of the 9th switch S 9, constitutes the 6th and exchanges tie point PA6; The anode of the 9th switch S 9, the tenth switch S 10 and the 11 switch S 11 links together, and constitutes the 3rd direct current tie point PD3; The negative electrode that twelvemo is closed S12, the 13 switch S 13 and the 14 switch S 14 links together, and constitutes the 4th direct current tie point PD4.The anode of the 15 switch S 15 links to each other with the 4th direct current tie point PD4, and its negative electrode links to each other with the 3rd direct current tie point PD3.The two ends of superconducting magnet Lsc exchange tie point PA7 respectively and link to each other with the 3rd direct current tie point PD3 with the 7th; The 8th exchanges tie point PA8 links to each other with the 4th direct current tie point PD4.The end of the first filter inductance L1 exchanges tie point PA1 and links to each other with first, first of Trs limit of the other end of the first filter inductance L1 and the three-phase transformer contact that links to each other is continuous; The end of the second filter inductance L2 exchanges tie point PA2 and links to each other with second, second of Trs limit of the other end of the second filter inductance L2 and the three-phase transformer contact that links to each other is continuous; The end of the 3rd filter inductance L3 exchanges tie point PA3 and links to each other with the 3rd, the third phase tie point on Trs limit of the other end of the 3rd filter inductance L3 and three-phase transformer links to each other; The former limit of three-phase transformer Trs links to each other with three phase network.One end on Tr1 limit of the end of the first filtering capacitor C1 and first single-phase transformer exchanges tie point PA4 and links to each other with the 4th; One end on Tr2 limit of the end of the second filtering capacitor C2 and second single-phase transformer exchanges tie point PA5 and links to each other with the 5th; One end on Tr3 limit of the end of the 3rd filtering capacitor C3 and the 3rd single-phase transformer exchanges tie point PA6 and links to each other with the 6th; The other end on the first single-phase transformer Tr1, the second single-phase transformer Tr2 and Tr3 limit of the 3rd single-phase transformer interconnects.The end of power supply Us1 and the end of the first phase load Z1 link to each other mutually with electrical network first respectively at the two ends on the former limit of the first single-phase transformer Tr1; The end of power supply Us2 and the end of the second phase load Z2 link to each other mutually with electrical network second respectively at the two ends on the former limit of the second single-phase transformer Tr2; The two ends on the former limit of the 3rd single-phase transformer Tr3 link to each other with the end of electrical network third phase power supply Us3 and the end of third phase load Z3 respectively.Described first switch S 1 ... octavo is closed S8 and is contrary lead type switch, the 9th switch S 9 ... the 15 switch S 15 is the inverse-impedance type switch, perhaps substitutes described inverse-impedance type switch with the contrary diode of type switch series connection of leading; Described first voltage source converter and first chopper or adopt the version of many level to replace described two level versions.

Control method to the embodiment of the invention shown in Figure 73 is carried out at following three kinds of operating states of described superconducting current-limiting energy storage circuit respectively: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of the first current source converter CSC1 this moment: the 9th switch S 9 ... the 14 switch S 14 is all closed, the 15 switch S 15 is closed simultaneously, the voltage on the first single-phase transformer Tr1, the second single-phase transformer Tr2 and Tr3 limit of the 3rd single-phase transformer is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially.This moment, the first voltage source converter VSC1 passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; The first voltage source converter VSC1 also absorbs and release active power from electrical network simultaneously, and Lsc discharges and recharges to superconducting magnet, and the electric current of superconducting magnet Lsc is remained near the set-point; The first chopper CH1 makes it to maintain near the set-point by control the voltage on the direct current connection capacitor C to direct current connection capacitor C injection current; 2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously, this moment, the control method of the first voltage source converter VSC1 and the first chopper CH1 was identical with the control method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state, the 15 switch S is opened for 15 this moments, the first current source converter CSC1 passes through Current Control, change the voltage on first and second and three filter capacitors, thereby the voltage harmonic of electrical network, voltage dip etc. are compensated, and then improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state, this moment, the 15 switch S 15 was opened, all switch closures of the first current source converter CSC1, the first current source converter CSC1 equivalence is a not control rectifying circuit of a three-phase, this moment, superconducting magnet Lsc was automatically connected into electrical network, had realized the function of failure current limit; Meanwhile, the first voltage source converter VSC1 is operated in the active inversion state, and as far as possible with the rechargeable energy inversion telegram in reply net of giving superconducting magnet Lsc in the current limliting process, Lsc is not impacted by overcurrent with the protection superconducting magnet; The first chopper CH1 is by controlling the voltage on the direct current connection capacitor C to direct current connection capacitor C injection current, the voltage that direct current is connected on the capacitor C maintains near the set-point.

Fig. 8 is the topological structure of embodiments of the invention 4.As shown in Figure 8, the structure of the embodiment of the invention 4 is as follows: first switch S 1, second switch S2, the 3rd switch S 3, the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 are formed the first voltage source converter VSC1; The emitter of first switch S 1 links to each other with the collector electrode of the 4th switch S 4, constitutes first and exchanges tie point PA1; The emitter of second switch S2 links to each other with the collector electrode of the 5th switch S 5, constitutes second and exchanges tie point PA2; The emitter of the 3rd switch S 3 links to each other with the collector electrode of the 6th switch S 6, constitutes the 3rd and exchanges tie point PA3; The collector electrode of first switch S 1, second switch S2 and the 3rd switch S 3 links together, and constitutes the first direct current tie point PD1; The emitter of the 4th switch S 4, the 5th switch S 5 and the 6th switch S 6 links together, and constitutes the second direct current tie point PD2.The two ends that direct current connects capacitor C link to each other with the second direct current tie point PD2 with the first direct current tie point PD1 respectively.Minion is closed S7, octavo closes S8, the first diode D1 and the second diode D2 forms the first chopper CH1; The emitter that minion is closed S7 links to each other with the negative electrode of the second diode D2, constitutes the 7th and exchanges tie point PA7, and the collector electrode that minion is closed S7 links to each other with the first direct current tie point PD1, and the anode of the second diode D2 links to each other with the second direct current tie point PD2; The anode of the first diode D1 links to each other with the collector electrode that octavo is closed S8, constitutes the 8th and exchanges tie point PA8, and the emitter that octavo is closed S8 links to each other with the second direct current tie point PD2, and the negative electrode of the first diode D1 links to each other with the first direct current tie point PD1.The 9th switch S 9, the tenth switch S the 10, the 11 switch S 11 and twelvemo pass S12 form the first current source converter CSC1; The negative electrode that twelvemo is closed S12 links to each other with the anode of the 9th switch S 9, constitutes the 4th and exchanges tie point PA4; The negative electrode of the 11 switch S 11 links to each other with the anode of the tenth switch S 10, constitutes the 5th and exchanges tie point PA5; The negative electrode of the 9th switch S 9 and the tenth switch S 10 links to each other, and constitutes the 3rd direct current tie point PD3; The 11 switch S 11 links to each other with the anode that twelvemo is closed S12, constitutes the 4th direct current tie point PD4.The 13 switch S the 13, the 14 switch S the 14, the 15 switch S 15 and sixteenmo close S16 forms the second current source converter CSC2; The negative electrode that sixteenmo closes S16 links to each other with the anode of the 13 switch S 13, constitutes the 6th and exchanges tie point PA6; The negative electrode of the 15 switch S 15 links to each other with the anode of the 14 switch S 14, constitutes the 9th and exchanges tie point PA9; The negative electrode of the 13 switch S 13 and the 14 switch S 14 links to each other, and constitutes the 5th direct current tie point PD5; The 15 switch S 15 links to each other with the anode that sixteenmo closes S16, constitutes the 6th direct current tie point PD6.The tenth minion is closed S17, eighteenmo closes S18, the 19 switch S 19 and the 20 switch S 20 compositions the 3rd current source converter CSC3; The negative electrode of the 20 switch S 20 links to each other with the anode that the tenth minion is closed S17, constitutes the tenth and exchanges tie point PA10; The negative electrode of the 19 switch S 19 links to each other with the anode that eighteenmo closes S18, constitutes the 11 and exchanges tie point PA11; The tenth minion is closed S17 and is linked to each other with the negative electrode that eighteenmo closes S18, constitutes the 7th direct current tie point PD7; The anode of the 19 switch S 19 and the 20 switch S 20 links to each other, and constitutes the 8th direct current tie point PD8.The anode of the 21 switch S 21 links to each other with the 3rd direct current tie point PD3, and the negative electrode of the 21 switch S 21 links to each other with the 4th direct current tie point PD4; The anode that second twelvemo is closed S22 links to each other with the 5th direct current tie point PD5, and the negative electrode that second twelvemo is closed S22 links to each other with the 6th direct current tie point PD6; The anode of the 23 switch S 23 links to each other with the 7th direct current tie point PD7, and the negative electrode of the 23 switch S 23 links to each other with the 8th direct current tie point PD8.The two ends of superconducting magnet Lsc exchange tie point PA7 respectively and link to each other with the 4th direct current tie point PD4 with the 7th; The 8th exchanges tie point PA8 links to each other with the 7th direct current tie point PD7; The 3rd direct current tie point PD3 links to each other with the 6th direct current tie point PD6, and the 5th direct current tie point PD5 links to each other with the 8th direct current tie point PD8.The end of the first filter inductance L1 exchanges tie point PA1 and links to each other with first, first of Trs limit of the other end of the first filter inductance L1 and the three-phase transformer contact that links to each other is continuous; The end of the second filter inductance L2 exchanges tie point PA2 and links to each other with second, second of Trs limit of the other end of the second filter inductance L2 and the three-phase transformer contact that links to each other is continuous; The end of the 3rd filter inductance L3 exchanges tie point PA3 and links to each other with the 3rd, the third phase tie point on Trs limit of the other end of the 3rd filter inductance L3 and three-phase transformer links to each other; The former limit of three-phase transformer links to each other with three phase network.Its two ends exchange tie point PA4 respectively and exchange tie point PA5 with the 5th and link to each other after the inferior limit parallel connection of the first filter capacitor C1 and the first single-phase transformer Tr1 with the 4th, its two ends exchange tie point PA6 respectively and exchange tie point PA9 with the 9th and link to each other after the inferior limit parallel connection of the second filter capacitor C2 and the second single-phase transformer Tr2 with the 6th, and its two ends exchange tie point PA10 respectively exchange tie point PA11 with the 11 continuous after inferior limit parallel connection of the 3rd filter capacitor C3 and the 3rd single-phase transformer Tr3 with the tenth.The end of power supply Us1 and the end of the first phase load Z1 link to each other mutually with electrical network first respectively at the two ends on the former limit of the first single-phase transformer Tr1; The end of power supply Us2 and the end of the second phase load Z2 link to each other mutually with electrical network second respectively at the two ends on the former limit of the second single-phase transformer Tr2; The two ends on the former limit of the 3rd single-phase transformer Tr3 link to each other with the end of electrical network third phase power supply Us3 and the end of third phase load Z3 respectively.Above-mentioned first switch S 1 ... octavo is closed S8 and is contrary lead type switch, the 9th switch S 9 ... the 23 switch S 23 is the inverse-impedance type switch, and also available contrary diode of type switch series connection of leading is realized; Described first voltage source converter and first chopper or adopt the version of many level to replace described two level versions.

Control method to the embodiment of the invention shown in Figure 84 is carried out at following three kinds of operating states of described superconducting current-limiting energy storage circuit respectively: 1, described superconducting current-limiting energy storage circuit is in pure shunt compensation state.Form all switches of the first current source converter CSC1, the second current source converter CSC2 and the 3rd current source converter CSC3 this moment: the 9th switch S 9 ... the 20 switch S 20 is all closed, the 21 switch S 21, second twelvemo close S22 and the 23 switch S 23 is closed simultaneously, the voltage on the first single-phase transformer Tr1, the second single-phase transformer Tr2 and Tr3 limit of the 3rd single-phase transformer is the tube voltage drop of switch at this moment, and load terminal voltage is not had influence substantially.This moment, the first voltage source converter VSC1 passed through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; The first voltage source converter VSC1 also absorbs active power from electrical network simultaneously, and Lsc discharges and recharges to superconducting magnet, and the electric current of superconducting magnet Lsc is remained near the set-point.The first chopper CH1 makes it to maintain near the set-point by control the voltage on the direct current connection capacitor C to direct current connection capacitor C injection current.2, described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously.This moment, the first voltage source converter VSC1 was identical with the control method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state with the first chopper CH1 control method; The 21 switch S 21, second twelvemo close S22 and the 23 switch S is opened for 23 this moments, the first current source converter CSC1, the second current source converter CSC2 and the 3rd current source converter CSC3 pass through Current Control, change the voltage on first and second and three filter capacitors, thereby the voltage harmonic of electrical network, voltage dip etc. are compensated, improve the supply power voltage quality of load.3, described superconducting current-limiting energy storage circuit is in limited current state.The 21 switch S 21, second twelvemo pass S22 and the 23 switch S 23 are opened at this moment, all switch closures of the first current source converter CSC1, the second current source converter CSC2 and the 3rd current source converter CSC3, the first current source converter CSC1, the second current source converter CSC2 and the 3rd current source converter CSC3 equivalence are three single-phase not control rectifying circuits that are connected in series, this moment, superconducting magnet Lsc was automatically connected into electrical network, had realized the function of failure current limit.Meanwhile, the first voltage source converter VSC1 is operated in the active inversion state, and with the rechargeable energy inversion telegram in reply net of giving superconducting magnet Lsc in the current limliting process, Lsc is not impacted by overcurrent with the protection superconducting magnet.The first chopper CH1 is by controlling the voltage on the direct current connection capacitor C to direct current connection capacitor C injection current, the voltage that direct current is connected on the capacitor C maintains near the set-point.

Claims

1. superconducting current-limiting energy storage circuit, it is characterized in that in described superconducting current-limiting energy storage circuit: first switch (S1), second switch (S2), the 3rd switch (S3), the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) are formed first current source converter (CSC1); The anode of first switch (S1) links to each other with the negative electrode of the 4th switch (S4), constitutes first and exchanges tie point (PA1); The anode of second switch (S2) links to each other with the negative electrode of the 5th switch (S5), constitutes second and exchanges tie point (PA2); The anode of the 3rd switch (S3) links to each other with the negative electrode of the 6th switch (S6), constitutes the 3rd and exchanges tie point (PA3); The negative electrode of first switch (S1), second switch (S2) and the 3rd switch (S3) links together, and constitutes the first direct current tie point (PD1); The anode of the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) links together, and constitutes the second direct current tie point (PD2); Minion is closed (S7), octavo is closed (S8), the 9th switch (S9), the tenth switch (S10), the 11 switch (S11) and twelvemo and closed (S12) composition second current source converter (CSC2); The anode that twelvemo is closed (S12) links to each other with the negative electrode of the 9th switch (S9), constitutes the 4th and exchanges tie point (PA4); The anode of the 11 switch (S11) links to each other with the negative electrode that octavo is closed (S8), constitutes the 5th and exchanges tie point (PA5); The anode of the tenth switch (S10) links to each other with the negative electrode that minion is closed (S7), constitutes the 6th and exchanges tie point (PA6); The anode that minion is closed (S7), octavo pass (S8) and the 9th switch (S9) links together, and constitutes the 3rd direct current tie point (PD3); The negative electrode that the tenth switch (S10), the 11 switch (S11) and twelvemo are closed (S12) links together, and constitutes the 4th direct current tie point (PD4); The anode of the 13 switch (S13) links to each other with the 4th direct current tie point (PD4), and its negative electrode links to each other with the 3rd direct current tie point (PD3); The two ends of superconducting magnet (Lsc) link to each other with the 3rd direct current tie point (PD3) with the first direct current tie point (PD1) respectively; The second direct current tie point (PD2) links to each other with the 4th direct current tie point (PD4); One end of one end of first filter inductance (L1) and first filter capacitor (C1) exchanges tie point (PA1) and links to each other with first, the other end of first filter inductance (L1) contact that links to each other with first of the inferior limit of three-phase transformer (Trs) is continuous; One end of one end of second filter inductance (L2) and second filter capacitor (C2) exchanges tie point (PA2) and links to each other with second, the other end of second filter inductance (L2) contact that links to each other with second of the inferior limit of three-phase transformer (Trs) is continuous; One end of one end of the 3rd filter inductance (L3) and the 3rd filter capacitor (C3) exchanges tie point (PA3) and links to each other with the 3rd, the other end of the 3rd filter inductance (L3) links to each other with the third phase tie point on the inferior limit of three-phase transformer (Trs); The other end of first filter capacitor (C1), second filter capacitor (C2) and the 3rd filter capacitor (C3) interconnects; The former limit of three-phase transformer links to each other with three phase network; One end on one end of the 4th filtering capacitor (C4) and the inferior limit of first single-phase transformer (Tr1) exchanges tie point (PA4) and links to each other with the 4th; One end on one end of the 5th filtering capacitor (C5) and the inferior limit of second single-phase transformer (Tr2) exchanges tie point (PA5) and links to each other with the 5th; One end on one end of the 6th filtering capacitor (C6) and the inferior limit of the 3rd single-phase transformer (Tr3) exchanges tie point (PA6) and links to each other with the 6th; The other end on first single-phase transformer (Tr1), second single-phase transformer (Tr2) and the inferior limit of the 3rd single-phase transformer (Tr3) interconnects; An end of power supply (Us1) and an end of first phase load (Z1) link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer (Tr1); An end of power supply (Us2) and an end of second phase load (Z2) link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer (Tr2); The two ends on the former limit of the 3rd single-phase transformer (Tr3) link to each other with an end of electrical network third phase power supply (Us3) and an end of third phase load (Z3) respectively; Described first switch (S1) ... the 13 switch (S13) is the inverse-impedance type switch, and the perhaps contrary diode of type switch series connection of leading substitutes described inverse-impedance type switch.

2. superconducting current-limiting energy storage circuit according to claim 1, it is characterized in that controlling respectively at three kinds of operating states of described superconducting current-limiting energy storage circuit: (1) described superconducting current-limiting energy storage circuit is in pure shunt compensation state, form all switches of second current source converter (CSC2) this moment: minion is closed (S7) ... twelvemo is closed (S12) all closures, the 13 switch (S13) is closed simultaneously, this moment first single-phase transformer (Tr1), the voltage on second single-phase transformer (Tr2) and the inferior limit of the 3rd single-phase transformer (Tr3) is the tube voltage drop of switch, and load terminal voltage is not had influence substantially; First current source converter this moment (CSC1) passes through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; First current source converter (CSC1) also absorbs and release active power from electrical network simultaneously, and (Lsc) discharges and recharges to superconducting magnet, and the electric current of superconducting magnet (Lsc) is remained near the set-point; (2) described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously, and the control method of first current source converter this moment (CSC1) is identical with the method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state; The 13 switch (S13) is opened this moment, second current source converter (CSC2) passes through Current Control, change the voltage on fourth, fifth and six filter capacitors (C4, C5 and C6), voltage harmonic, the voltage dip of electrical network compensated, and then improve the supply power voltage quality of load; (3) described superconducting current-limiting energy storage circuit is in limited current state, the 13 switch this moment (S13) is opened, all switch closures of second current source converter (CSC2), second current source converter (CSC2) equivalence is a not control rectifying circuit of a three-phase, superconducting magnet this moment (Lsc) is automatically connected into electrical network, thereby has realized the function of failure current limit; Meanwhile, first current source converter (CSC1) is operated in the active inversion state, and the rechargeable energy inversion telegram in reply net of giving superconducting magnet (Lsc) with in the current limliting process is not impacted by overcurrent with protection superconducting magnet (Lsc).

3. a superconducting current-limiting energy storage circuit is characterized in that described superconducting current-limiting energy storage circuit structure is as follows: first switch (S1), second switch (S2), the 3rd switch (S3), the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) composition first current source converter (CSC1); The anode of first switch (S1) links to each other with the negative electrode of the 4th switch (S4), constitutes first and exchanges tie point (PA1); The anode of second switch (S2) links to each other with the negative electrode of the 5th switch (S5), constitutes second and exchanges tie point (PA2); The anode of the 3rd switch (S3) links to each other with the negative electrode of the 6th switch (S6), constitutes the 3rd and exchanges tie point (PA3); The negative electrode of first switch (S1), second switch (S2) and the 3rd switch (S3) links together, and constitutes the first direct current tie point (PD1); The anode of the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) links together, and constitutes the second direct current tie point (PD2); Minion is closed (S7), octavo is closed (S8), the 9th switch (S9) and the tenth switch (S10) composition second current source converter (CSC2); The negative electrode of the tenth switch (S10) links to each other with the anode that minion is closed (S7), constitutes the 4th and exchanges tie point (PA4); The negative electrode of the 9th switch (S9) links to each other with the anode that octavo is closed (S8), constitutes the 5th and exchanges tie point (PA5); Minion is closed (S7) and is linked to each other with the negative electrode that octavo is closed (S8), constitutes the 3rd direct current tie point (PD3); The 9th switch (S9) links to each other with the anode of the tenth switch (S10), constitutes the 4th direct current tie point (PD4); The 11 switch (S11), twelvemo are closed (S12), the 13 switch (S13) and the 14 switch (S14) composition the 3rd current source converter (CSC3); The negative electrode of the 14 switch (S14) links to each other with the anode of the 11 switch (S11), constitutes the 6th and exchanges tie point (PA6); The negative electrode of the 13 switch (S13) links to each other with the anode that twelvemo is closed (S12), constitutes the 7th and exchanges tie point (PA7); The 11 switch (S11) links to each other with the negative electrode that twelvemo is closed (S12), constitutes the 5th direct current tie point (PD5); The anode of the 13 switch (S13) and the 14 switch (S14) links to each other, and constitutes the 6th direct current tie point (PD6); The 15 switch (S15), sixteenmo close (S16), the tenth minion closes (S17) and eighteenmo closes (S18) composition the 4th current source converter (CSC4); The negative electrode that eighteenmo closes (S18) links to each other with the anode of the 15 switch (S15), constitutes the 8th and exchanges tie point (PA8); The negative electrode that the tenth minion is closed (S17) links to each other with the anode that sixteenmo closes (S16), constitutes the 9th and exchanges tie point (PA9); The 15 switch (S15) links to each other with the negative electrode that sixteenmo closes (S16), constitutes the 7th direct current tie point (PD7); The tenth minion is closed (S17) and is linked to each other with the anode that eighteenmo closes (S18), constitutes the 8th direct current tie point (PD8); The two ends of superconducting magnet (Lsc) link to each other with the 4th direct current tie point (PD4) with the first direct current tie point (PD1) respectively; The second direct current tie point (PD2) links to each other with the 7th direct current tie point (PD7); The 3rd direct current tie point (PD3) links to each other with the 6th direct current tie point (PD6), and the 5th direct current tie point (PD5) links to each other with the 8th direct current tie point (PD8); The anode of the 19 switch (S19) links to each other with the 3rd direct current tie point (PD3), and the negative electrode of the 19 switch (S19) links to each other with the 4th direct current tie point (PD4); The anode of the 20 switch (S20) links to each other with the 5th direct current tie point (PD5), and the negative electrode of the 20 switch (S20) links to each other with the 6th direct current tie point (PD6); The anode of the 21 switch (S21) links to each other with the 7th direct current tie point (PD7), and the negative electrode of the 21 switch (S21) links to each other with the 8th direct current tie point (PD8); One end of one end of first filter inductance (L1) and first filter capacitor (C1) exchanges tie point (PA1) and links to each other with first, the other end of first filter inductance (L1) contact that links to each other with first of the inferior limit of three-phase transformer (Trs) is continuous; One end of one end of second filter inductance (L2) and second filter capacitor (C2) exchanges tie point (PA2) and links to each other with second, the other end of second filter inductance (L2) contact that links to each other with second of the inferior limit of three-phase transformer (Trs) is continuous; One end of one end of the 3rd filter inductance (L3) and the 3rd filter capacitor (C3) exchanges tie point (PA3) and links to each other with the 3rd, the other end of the 3rd filter inductance (L3) links to each other with the third phase tie point on the inferior limit of three-phase transformer (Trs); The other end of first filter capacitor (C1), second filter capacitor (C2) and the 3rd filter capacitor (C3) interconnects; The former limit of three-phase transformer links to each other with three phase network; Its two ends exchange tie point (PA4) respectively and exchange tie point (PA5) with the 5th and link to each other after the inferior limit parallel connection of the 4th filter capacitor (C4) and first single-phase transformer (Tr1) with the 4th, its two ends exchange tie point (PA6) respectively and exchange tie point (PA7) with the 7th and link to each other after the inferior limit parallel connection of the 5th filter capacitor (C5) and second single-phase transformer (Tr2) with the 6th, and its two ends exchange tie point (PA8) respectively exchange tie point (PA9) with the 9th continuous after the inferior limit parallel connection of the 6th filter capacitor (C6) and the 3rd single-phase transformer (Tr3) with the 8th; An end of power supply (Us1) and an end of first phase load (Z1) link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer (Tr1); An end of power supply (Us2) and an end of second phase load (Z2) link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer (Tr2); The two ends on the former limit of the 3rd single-phase transformer (Tr3) link to each other with an end of electrical network third phase power supply (Us3) and an end of third phase load (Z3) respectively; Described first switch (S1) ... the 21 switch (S21) is the inverse-impedance type switch, perhaps substitutes described inverse-impedance type switch with the contrary diode of type switch series connection of leading.

4. superconducting current-limiting energy storage circuit according to claim 3, it is characterized in that controlling respectively at three kinds of operating states of described superconducting current-limiting energy storage circuit: (1) described superconducting current-limiting energy storage circuit is in pure shunt compensation state, form second current source converter (CSC2) this moment, all switches of the 3rd current source converter (CSC3) and the 4th current source converter (CSC4): minion is closed (S7) ... eighteenmo closes (S18) all closures, the 19 switch (S19), the 20 switch (S20) and the 21 switch (S21) are closed simultaneously, this moment first single-phase transformer (Tr1), the voltage on second single-phase transformer (Tr2) and the inferior limit of the 3rd single-phase transformer (Tr3) is the tube voltage drop of switch, and load terminal voltage is not had influence substantially; First current source converter this moment (CSC1) passes through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; First current source converter (CSC1) also absorbs and release active power from electrical network simultaneously, and (Lsc) discharges and recharges to superconducting magnet, and the electric current of superconducting magnet (Lsc) is remained near the set-point; (2) described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously, and the control method of first current source converter this moment (CSC1) is identical with the method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state; The 19 switch (S19), the 20 switch (S20) and the 21 switch (S21) are opened this moment, second current source converter (CSC2), the 3rd current source converter (CSC3) and the 4th current source converter (CSC4) pass through Current Control, change the voltage on fourth, fifth and six filter capacitors (C4, C5 and C6), thereby voltage harmonic, voltage dip to electrical network compensate, and improve the supply power voltage quality of load; (3) described superconducting current-limiting energy storage circuit is in limited current state, this moment the 19 switch (S19), the 20 switch (S20) and the 21 switch (S21) are opened, second current source converter (CSC2), all switch closures of the 3rd current source converter (CSC3) and the 4th current source converter (CSC4), second current source converter (CSC2), the 3rd current source converter (CSC3) and the 4th current source converter (CSC4) equivalence are three single-phase not control rectifying circuits that are connected in series, superconducting magnet this moment (Lsc) is automatically connected into electrical network, has realized the function of failure current limit; Meanwhile, first current source converter (CSC1) is operated in the active inversion state, and the rechargeable energy inversion telegram in reply net of giving superconducting magnet (Lsc) with in the current limliting process is not impacted by overcurrent with protection superconducting magnet (Lsc).

5. a superconducting current-limiting energy storage circuit is characterized in that described superconducting current-limiting energy storage circuit structure is as follows: first switch (S1), second switch (S2), the 3rd switch (S3), the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) composition first voltage source converter (VSC1); The emitter of first switch (S1) links to each other with the collector electrode of the 4th switch (S4), constitutes first and exchanges tie point (PA1); The emitter of second switch (S2) links to each other with the collector electrode of the 5th switch (S5), constitutes second and exchanges tie point (PA2); The emitter of the 3rd switch (S3) links to each other with the collector electrode of the 6th switch (S6), constitutes the 3rd and exchanges tie point (PA3); The collector electrode of first switch (S1), second switch (S2) and the 3rd switch (S3) links together, and constitutes the first direct current tie point (PD1); The emitter of the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) links together, and constitutes the second direct current tie point (PD2); The two ends that direct current connects electric capacity (C) link to each other with the second direct current tie point (PD2) with the first direct current tie point (PD1) respectively; Minion is closed (S7), octavo is closed (S8), first diode (D1) and second diode (D2) composition, first chopper (CH1); The emitter that minion is closed (S7) links to each other with the negative electrode of second diode (D2), constitute the 7th and exchange tie point (PA7), the collector electrode that minion is closed (S7) links to each other with the first direct current tie point (PD1), and the anode of second diode (D2) links to each other with the second direct current tie point (PD2); The anode of first diode (D1) links to each other with the collector electrode that octavo is closed (S8), constitute the 8th and exchange tie point (PA8), the emitter that octavo is closed (S8) links to each other with the second direct current tie point (PD2), and the negative electrode of first diode (D1) links to each other with the first direct current tie point (PD1); The 9th switch (S9), the tenth switch (S10), the 11 switch (S11), twelvemo are closed (S12), the 13 switch (S13) and the 14 switch (S14) composition first current source converter (CSC1); The anode of the 14 switch (S14) links to each other with the negative electrode of the 11 switch (S11), constitutes the 4th and exchanges tie point (PA4); The anode of the 13 switch (S13) links to each other with the negative electrode of the tenth switch (S10), constitutes the 5th and exchanges tie point (PA5); The anode that twelvemo is closed (S12) links to each other with the negative electrode of the 9th switch (S9), constitutes the 6th and exchanges tie point (PA6); The anode of the 9th switch (S9), the tenth switch (S10) and the 11 switch (S11) links together, and constitutes the 3rd direct current tie point (PD3); The negative electrode that twelvemo is closed (S12), the 13 switch (S13) and the 14 switch (S14) links together, and constitutes the 4th direct current tie point (PD4); The anode of the 15 switch (S15) links to each other with the 4th direct current tie point (PD4), and its negative electrode links to each other with the 3rd direct current tie point (PD3); The two ends of superconducting magnet (Lsc) exchange tie point (PA7) respectively and link to each other with the 3rd direct current tie point (PD3) with the 7th; The 8th exchanges tie point (PA8) links to each other with the 4th direct current tie point (PD4); One end of first filter inductance (L1) exchanges tie point (PA1) and links to each other with first, the other end of first filter inductance (L1) contact that links to each other with first of the inferior limit of three-phase transformer (Trs) is continuous; One end of second filter inductance (L2) exchanges tie point (PA2) and links to each other with second, the other end of second filter inductance (L2) contact that links to each other with second of the inferior limit of three-phase transformer (Trs) is continuous; One end of the 3rd filter inductance (L3) exchanges tie point (PA3) and links to each other with the 3rd, the other end of the 3rd filter inductance (L3) links to each other with the third phase tie point on the inferior limit of three-phase transformer (Trs); The former limit of three-phase transformer (Trs) links to each other with three phase network; One end on one end of first filtering capacitor (C1) and the inferior limit of first single-phase transformer (Tr1) exchanges tie point (PA4) and links to each other with the 4th; One end on one end of second filtering capacitor (C2) and the inferior limit of second single-phase transformer (Tr2) exchanges tie point (PA5) and links to each other with the 5th; One end on one end of the 3rd filtering capacitor (C3) and the inferior limit of the 3rd single-phase transformer (Tr3) exchanges tie point (PA6) and links to each other with the 6th; The other end on first single-phase transformer (Tr1), second single-phase transformer (Tr2) and the inferior limit of the 3rd single-phase transformer (Tr3) interconnects; An end of power supply (Us1) and an end of first phase load (Z1) link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer (Tr1); An end of power supply (Us2) and an end of second phase load (Z2) link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer (Tr2); The two ends on the former limit of the 3rd single-phase transformer (Tr3) link to each other with an end of electrical network third phase power supply (Us3) and an end of third phase load (Z3) respectively; Described first switch (S1) ... octavo is closed (S8) and is contrary lead type switch, the 9th switch (S9) ... the 15 switch (S15) is the inverse-impedance type switch, perhaps substitutes described inverse-impedance type switch with the contrary diode of type switch series connection of leading; Described first voltage source converter (VSC1) and first chopper (CH1) are two level versions, or adopt the version of many level to replace described two level versions.

6. superconducting current-limiting energy storage circuit according to claim 5, it is characterized in that controlling respectively at three kinds of operating states of described superconducting current-limiting energy storage circuit: (1) described superconducting current-limiting energy storage circuit is in pure shunt compensation state, form all switches of first current source converter (CSC1) this moment: the 9th switch (S9) ... the 14 switch (S14) is all closed, the 15 switch (S15) is closed simultaneously, this moment first single-phase transformer (Tr1), the voltage on second single-phase transformer (Tr2) and the inferior limit of the 3rd single-phase transformer (Tr3) is the tube voltage drop of switch, and load terminal voltage is not had influence substantially; First voltage source converter this moment (VSC1) passes through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; First voltage source converter (VSC1) also absorbs and release active power from electrical network simultaneously, and (Lsc) discharges and recharges to superconducting magnet, and the electric current of superconducting magnet (Lsc) is remained near the set-point; First chopper (CH1) makes it to maintain near the set-point by control the voltage on the direct current connection electric capacity (C) to direct current connection electric capacity (C) injection current; (2) described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously, this moment, the control method of first voltage source converter (VSC1) and first chopper (CH1) was identical with the control method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state, the 15 switch (S15) is opened this moment, first current source converter (CSC1) passes through Current Control, change the voltage on first and second and three filter capacitors (C1, C2 and C3), thereby voltage harmonic, voltage dip to electrical network compensate, and then improve the supply power voltage quality of load; (3) described superconducting current-limiting energy storage circuit is in limited current state, the 15 switch this moment (S15) is opened, all switch closures of first current source converter (CSC1), first current source converter (CSC1) equivalence is a not control rectifying circuit of a three-phase, superconducting magnet this moment (Lsc) is automatically connected into electrical network, has realized the function of failure current limit; Meanwhile, first voltage source converter (VSC1) is operated in the active inversion state, with the rechargeable energy inversion telegram in reply net of giving superconducting magnet (Lsc) in the current limliting process, not impacted by overcurrent with protection superconducting magnet (Lsc) as far as possible; First chopper (CH1) is by controlling the voltage on the direct current connection electric capacity (C) to direct current connection electric capacity (C) injection current, the voltage that direct current is connected on the electric capacity (C) maintains near the set-point.

7. a superconducting current-limiting energy storage circuit is characterized in that described superconducting current-limiting energy storage circuit structure is as follows: first switch (S1), second switch (S2), the 3rd switch (S3), the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) composition first voltage source converter (VSC1); The emitter of first switch (S1) links to each other with the collector electrode of the 4th switch (S4), constitutes first and exchanges tie point (PA1); The emitter of second switch (S2) links to each other with the collector electrode of the 5th switch (S5), constitutes second and exchanges tie point (PA2); The emitter of the 3rd switch (S3) links to each other with the collector electrode of the 6th switch (S6), constitutes the 3rd and exchanges tie point (PA3); The collector electrode of first switch (S1), second switch (S2) and the 3rd switch (S3) links together, and constitutes the first direct current tie point (PD1); The emitter of the 4th switch (S4), the 5th switch (S5) and the 6th switch (S6) links together, and constitutes the second direct current tie point (PD2); The two ends that direct current connects electric capacity (C) link to each other with the second direct current tie point (PD2) with the first direct current tie point (PD1) respectively; Minion is closed (S7), octavo is closed (S8), first diode (D1) and second diode (D2) composition, first chopper (CH1); The emitter that minion is closed (S7) links to each other with the negative electrode of second diode (D2), constitute the 7th and exchange tie point (PA7), the collector electrode that minion is closed (S7) links to each other with the first direct current tie point (PD1), and the anode of second diode (D2) links to each other with the second direct current tie point (PD2); The anode of first diode (D1) links to each other with the collector electrode that octavo is closed (S8), constitute the 8th and exchange tie point (PA8), the emitter that octavo is closed (S8) links to each other with the second direct current tie point (PD2), and the negative electrode of first diode (D1) links to each other with the first direct current tie point (PD1); The 9th switch (S9), the tenth switch (S10), the 11 switch (S11) and twelvemo are closed (S12) composition first current source converter (CSC1); The negative electrode that twelvemo is closed (S12) links to each other with the anode of the 9th switch (S9), constitutes the 4th and exchanges tie point (PA4); The negative electrode of the 11 switch (S11) links to each other with the anode of the tenth switch (S10), constitutes the 5th and exchanges tie point (PA5); The 9th switch (S9) links to each other with the negative electrode of the tenth switch (S10), constitutes the 3rd direct current tie point (PD3); The 11 switch (S11) links to each other with the anode that twelvemo is closed (S12), constitutes the 4th direct current tie point (PD4); The 13 switch (S1S), the 14 switch (S14), the 15 switch (S15) and sixteenmo close (S16) forms second current source converter (CSC2); The negative electrode that sixteenmo closes (S16) links to each other with the anode of the 13 switch (S13), constitutes the 6th and exchanges tie point (PA6); The negative electrode of the 15 switch (S15) links to each other with the anode of the 14 switch (S14), constitutes the 9th and exchanges tie point (PA9); The negative electrode of the 13 switch (S13) and the 14 switch (S14) links to each other, and constitutes the 5th direct current tie point (PD5); The 15 switch (S15) links to each other with the anode that sixteenmo closes (S16), constitutes the 6th direct current tie point (PD6); The tenth minion is closed (S17), eighteenmo closes (S18), the 19 switch (S19) and the 20 switch (S20) composition the 3rd current source converter (CSC3); The negative electrode of the 20 switch (S20) links to each other with the anode that the tenth minion is closed (S17), constitutes the tenth and exchanges tie point (PA10); The negative electrode of the 19 switch (S19) links to each other with the anode that eighteenmo closes (S18), constitutes the 11 and exchanges tie point (PA11); The tenth minion is closed (S17) and is linked to each other with the negative electrode that eighteenmo closes (S18), constitutes the 7th direct current tie point (PD7); The anode of the 19 switch (S19) and the 20 switch (S20) links to each other, and constitutes the 8th direct current tie point (PD8); The anode of the 21 switch (S21) links to each other with the 3rd direct current tie point (PD3), and the negative electrode of the 21 switch (S21) links to each other with the 4th direct current tie point (PD4); The anode that second twelvemo is closed (S22) links to each other with the 5th direct current tie point (PD5), and the negative electrode that second twelvemo is closed (S22) links to each other with the 6th direct current tie point (PD6); The anode of the 23 switch (S23) links to each other with the 7th direct current tie point (PD7), and the negative electrode of the 23 switch (S23) links to each other with the 8th direct current tie point (PD8); The two ends of superconducting magnet (Lsc) exchange tie point (PA7) respectively and link to each other with the 4th direct current tie point (PD4) with the 7th; The 8th exchanges tie point (PA8) links to each other with the 7th direct current tie point (PD7); The 3rd direct current tie point (PD3) links to each other with the 6th direct current tie point (PD6), and the 5th direct current tie point (PD5) links to each other with the 8th direct current tie point (PD8); One end of first filter inductance (L1) exchanges tie point (PA1) and links to each other with first, the other end of first filter inductance (L1) contact that links to each other with first of the inferior limit of three-phase transformer (Trs) is continuous; One end of second filter inductance (L2) exchanges tie point (PA2) and links to each other with second, the other end of second filter inductance (L2) contact that links to each other with second of the inferior limit of three-phase transformer (Trs) is continuous; One end of the 3rd filter inductance (L3) exchanges tie point (PA3) and links to each other with the 3rd, the other end of the 3rd filter inductance (L3) links to each other with the third phase tie point on the inferior limit of three-phase transformer (Trs); The former limit of three-phase transformer links to each other with three phase network; Its two ends exchange tie point (PA4) respectively and exchange tie point (PA5) with the 5th and link to each other after the inferior limit parallel connection of first filter capacitor (C1) and first single-phase transformer (Tr1) with the 4th, its two ends exchange tie point (PA6) respectively and exchange tie point (PA9) with the 9th and link to each other after the inferior limit parallel connection of second filter capacitor (C2) and second single-phase transformer (Tr2) with the 6th, and its two ends exchange tie point (PA10) respectively exchange tie point (PA11) with the 11 continuous after the inferior limit parallel connection of the 3rd filter capacitor (C3) and the 3rd single-phase transformer (Tr3) with the tenth; An end of power supply (Us1) and an end of first phase load (Z1) link to each other mutually with electrical network first respectively at the two ends on the former limit of first single-phase transformer (Tr1); An end of power supply (Us2) and an end of second phase load (Z2) link to each other mutually with electrical network second respectively at the two ends on the former limit of second single-phase transformer (Tr2); The two ends on the former limit of the 3rd single-phase transformer (Tr3) link to each other with an end of electrical network third phase power supply (Us3) and an end of third phase load (Z3) respectively; Above-mentioned first switch (S1) ... octavo is closed (S8) and is contrary lead type switch, the 9th switch (S9) ... the 23 switch (S23) is the inverse-impedance type switch, or realizes with the contrary diode of type switch series connection of leading; Described first voltage source converter (VSC1) and first chopper (CH1), two level versions, or adopt the version of many level to replace described two level versions.

8. superconducting current-limiting energy storage circuit according to claim 7, it is characterized in that controlling respectively at three kinds of operating states of described superconducting current-limiting energy storage circuit: (1) described superconducting current-limiting energy storage circuit is in pure shunt compensation state, form first current source converter (CSC1) this moment, all switches of second current source converter (CSC2) and the 3rd current source converter (CSC3): the 9th switch (S9) ... the 20 switch (S20) is all closed, the 21 switch (S21), second twelvemo closes (S22) and the 23 switch (S23) is closed simultaneously, this moment first single-phase transformer (Tr1), the voltage on second single-phase transformer (Tr2) and the inferior limit of the 3rd single-phase transformer (Tr3) is the tube voltage drop of switch, and load terminal voltage is not had influence substantially; First voltage source converter this moment (VSC1) passes through to inject controlled electric current to electrical network, the wave component of the harmonic wave that compensating load produced, reactive power and load active power, thus alleviate the influence of load to the electrical network quality of power supply; First voltage source converter (VSC1) also absorbs and release active power from electrical network simultaneously, and (Lsc) discharges and recharges to superconducting magnet, and the electric current of superconducting magnet (Lsc) is remained near the set-point; First chopper (CH1) makes it to maintain near the set-point by control the voltage on the direct current connection electric capacity (C) to direct current connection electric capacity (C) injection current; (2) described superconducting current-limiting energy storage circuit is in connection in series-parallel compensating coefficient simultaneously; First voltage source converter this moment (VSC1) is identical with the control method that described superconducting current-limiting energy storage circuit is in pure shunt compensation state with first chopper (CH1) control method; The 21 switch (S21), second twelvemo close (S22) and the 23 switch (S23) is opened this moment, first current source converter (CSC1), second current source converter (CSC2) and the 3rd current source converter (CSC3) pass through Current Control, change the voltage on first and second and three filter capacitors (C1, C2 and C3), thereby voltage harmonic, voltage dip to electrical network compensate, and improve the supply power voltage quality of load; (3) described superconducting current-limiting energy storage circuit is in limited current state, this moment the 21 switch (S21), second twelvemo is closed (S22) and the 23 switch (S23) is opened, first current source converter (CSC1), all switch closures of second current source converter (CSC2) and the 3rd current source converter (CSC3), first current source converter (CSC1), second current source converter (CSC2) and the 3rd current source converter (CSC3) equivalence are three single-phase not control rectifying circuits that are connected in series, superconducting magnet this moment (Lsc) is automatically connected into electrical network, has realized the function of failure current limit; Meanwhile, first voltage source converter (VSC1) is operated in the active inversion state, and the rechargeable energy inversion telegram in reply net of giving superconducting magnet (Lsc) with in the current limliting process is not impacted by overcurrent with protection superconducting magnet (Lsc); First chopper (CH1) is by controlling the voltage on the direct current connection electric capacity (C) to direct current connection electric capacity (C) injection current, the voltage that direct current is connected on the electric capacity (C) maintains near the set-point.