The apparatus and method of the zero phase sequence impedance adjustment of zero-phase-sequence current filter
(1) technical field
The present invention relates to zero-phase-sequence current filter to heterogeneous AC power supplies; Specifically, the present invention relates to a kind of zero phase sequence impedance adjustment of zero-phase-sequence current filter.
(2) background technology
In 3 phases, 4 line formula distribution systems,, will there be zero phase-sequence composition electric current to occur the neutral online of distribution system if load is unbalanced.All zero-phase-sequence currents are homophases each other, and do not have phase sequence to exist each other, thereby the amount of neutral online zero-phase-sequence current is 3 times of amount of mutually online zero-phase-sequence current.Yet, tube load balance whether not, 3 mutually the nonlinear-load on the 4 line formula distribution systems all will to cause zero-phase-sequence current to be presented on neutral online.So, use in the general commercial building that uses three-phase and four-line formula distribution system because of nonlinear load is a large amount of, cause sometimes general commercial building neutral line zero phase-sequence composition electric current amount in addition possibly surpass phase current.
Wherein, the zero-phase-sequence current of the neutral line is considered to be unfavorable for System Operation already, and the problem that possibly cause comprises that the neutral line overloads, transformer is overheated, the available system capacity reduces, increases power loss and other known problem.
Many systems are recommended handling 3 neutral line zero-phase-sequence currents of 4 line formula distribution systems mutually, but comparatively complicated and expensive, and need complicated electronic installation, make when using especially trouble relatively.
In 3 phases, 4 line formula distribution systems, use zero phase-sequence FILTER TO CONTROL zero phase-sequence harmonic wave usually with a low zero phase sequence impedance zero phase-sequence.To attract the zero phase-sequence harmonic current, the zero phase-sequence harmonic wave that flows in the distribution system can be reduced by low zero phase sequence impedance effectively.Wherein, the most frequently used zero phase-sequence filter is the reactor or the autotransformer of zig-zag type wiring, because the advantage on price, reliability and the easy mounting, and be usually used in the three-phase and four-line formula distribution system to control the zero-phase-sequence current of the neutral line.And be usually used in the three-phase and four-line formula distribution system to control the zero-phase-sequence current of the neutral line.
Though; One zero phase-sequence filter often is designed to zero-phase-sequence current so that minimum possible impedance to be provided; And be engaged between this zero phase-sequence filter and the power supply and get involved a disabler and can flow into the zero phase-sequence filter through the neutral line mostly, and stop a large amount of zero-phase-sequence currents to flow into distribution systems to force zero-phase-sequence current as far as possible.Yet under some special system demand status, it needs a high impedance; For example in distribution system, particularly in commercial establishment,, and new system requirements are increased because of relatively frequently expanding of equipment.Under this kind situation, in distribution system, the zig-zag type filter that it has existed must be removed, to adapt to this special high impedance; And the demand of this high impedance situation of being directed against, will replace with a zig-zag type filter of customized design.
Fig. 1 is the prior art icon; To show a kind of zero-phase-sequence current filter that to adjust zero phase sequence impedance that has; It comprises first, second and the 3rd pin unshakable in one's determination; Each pin unshakable in one's determination has first and second coil and connects into a zig-zag type reactor; Each first coil 3a1,3b1,3c1 have an input endpoint 13a1,13b1,13c1 to connect so far wherein a phase a, b, the c of three-phase power supply network; The end point of each second coil 3a2,3b2,3c2 is connected to a common end points N, and being connected to a neutral conductor, and the relative ratio that uses the number of active coils that changes first coil on same pin unshakable in one's determination and the number of active coils of second coil is as the means of adjusting zero phase sequence impedance.Its zig-zag type filter by a zero phase-sequence is provided on one of coil on each pin unshakable in one's determination and has one or more tap, or last one or more tap 13a2,13b2,13c2,13a3,13b3,13c3 of having of an ancillary coil 3a3,3b3,3c3 is connected to one of coil on each pin unshakable in one's determination; Optionally,, utilize this tap or ancillary coil, with warp tap or the input endpoint reconstruction power supply of ancillary coil and being connected of filter thus by switching device traditionally.This kind has the zig-zag type reactor of extra tap or ancillary coil; By adjusting the zero phase-sequence magnetic flux so that a kind of zero phase sequence impedance of adjusting zero phase-sequence harmonic current filter to be provided; Can keep under the individual constant situation; When the change demand on distribution network needs, can cooperate changing the zero phase sequence impedance of this filter, and not need other external equipment or substitute new equipment with customized design.
But this kind has the zig-zag type filter of extra tap or ancillary coil; By tap or ancillary coil when changing the zero phase sequence impedance of filter; Also will change the positive sequence and the negative sequence impedance of this filter, thereby the inevitable positive sequence of distribution system and the adverse effect of negative phase-sequence composition fluctuation of also causing.
Therefore, a kind of demand is arranged, need cooperate when changing the zero phase sequence impedance of a zero phase-sequence filter apparatus, do not need other external equipment or substitute new equipment with customized design in system; This zero phase-sequence filter apparatus can need change the zero phase sequence impedance of this device by coupled system, and does not influence the positive sequence impedance and the negative sequence impedance of this device.
(3) summary of the invention
The present invention will solve the above-mentioned shortcoming of prior art; A kind of apparatus and method of zero phase sequence impedance adjustment of zero-phase-sequence current filter are provided; One have the zero phase sequence impedance of the zero phase-sequence filter of common end points as being adjusted between a heterogeneous AC power supplies and the load, and do not influence the positive sequence impedance and the negative sequence impedance of this zero phase-sequence filter.
For realizing the demand; The present invention provide a kind of apparatus and method with as be adjusted between a heterogeneous AC power supplies and the load one have a zero phase-sequence filter of common end points zero phase sequence impedance; Wherein, This device contains: the disabler, an input neutral line and the output neutral line that have two-end-point and one or more tap; Aforesaid input neutral line is connected to aforesaid heterogeneous AC power supplies, and the aforesaid output neutral line is connected to aforesaid load, and the common end points of aforesaid zero phase-sequence filter is connected to the aforesaid input neutral line and the aforesaid output neutral line via aforesaid disabler; And by the means of the tap that changes the aforesaid disabler connected to reach the zero phase sequence impedance that changes with the aforesaid parallelly connected aforesaid zero phase-sequence filter of loading.
Because, in 3 phases, 4 line formula distribution systems, only there is the composition of zero-phase-sequence current to appear on the common end points of zero phase-sequence filter, cause also to venerate on the disabler that is connected with the common end points of zero phase-sequence filter to have the zero-phase-sequence current composition; So can be, reach and change and the zero phase sequence impedance of loading parallelly connected zero phase-sequence filter, and venerate the zero-phase-sequence current composition that influences in the distribution system by the means of the connection of a tap that changes disabler.This kind sees through control switch changes the disabler that connects in 3 phases, 4 line formula distribution systems tap; As far as seeing through the zero phase-sequence filter that disabler is connected with the neutral line; Can reach and venerate the zero phase sequence impedance that changes the zero phase-sequence filter, and not influence the positive sequence impedance and the negative sequence impedance of zero phase-sequence filter.
Further improve, all can be among each embodiment of the present invention at extra disabler of the neutral online connection of the input between heterogeneous AC power supplies and the zero phase-sequence filter; This kind improvement; Can increase the neutral line impedance of power supply; Make zero-phase-sequence current more difficult, get into the zero phase-sequence filter to hinder the zero phase-sequence composition that produces in the system other places, and can prevent because of the adverse effect of misoperation to system's generation via distribution transformer.
In addition, disabler of the present invention can be an inductor, thereby consumed energy hardly is not so have bad influence to the efficient of system.
When the present invention when actual embodiment, the present invention can have other various and not exclusively the same hypostazation measures; It can only repair several details of the present invention, and does not depart from the viewpoint of each item technology item that claim that the present invention narrates puts down in writing, and carries out the present invention.Thereby description that the present invention did and drawing only are to be regarded as explanation in essence at this, but not are the restrictions of actual implementation.
(4) description of drawings
Fig. 1 is the prior art icon, to show a kind of zero-phase-sequence current filter that can adjust zero phase sequence impedance that has.
Fig. 2 is the circuit diagram that first embodiment of apparatus and method of the present invention specializes, and connects zero phase-sequence filter and the typical nonlinear load that typically has common end points with a typical heterogeneous AC power supplies, so that device of the present invention to be described.
Fig. 3 one typically has a circuit diagram icon of the zig-zag type zero phase-sequence filter of common end points.
Fig. 4 one typically has a circuit diagram icon of the wye-delta zero phase-sequence filter of common end points.
Fig. 5 is the circuit diagram that second embodiment of apparatus and method of the present invention specializes, and connects zero phase-sequence filter and the typical nonlinear load that typically has common end points with a typical heterogeneous AC power supplies, so that device of the present invention to be described.
Fig. 6 is the circuit diagram that the 3rd embodiment of apparatus and method of the present invention specializes, and connects zero phase-sequence filter and the typical nonlinear load that typically has common end points with a typical heterogeneous AC power supplies, so that device of the present invention to be described.
Fig. 7 is the circuit diagram that the 4th embodiment of apparatus and method of the present invention specializes, and extra disabler of increase this input between a heterogeneous AC power supplies and a zero phase-sequence filter that is analogous to Fig. 2 circuit diagram is neutral online.
The primary clustering symbol description
The first coil 3a1 of zig-zag type reactor, 3b1,3c1
Input endpoint 13a1,13b1, the 13c1 of first coil of zig-zag type reactor
Wherein a phase a, b, the c of three-phase
The second coil 3a2 of zig-zag type reactor, 3b2,3c2
The ancillary coil 3a3 of zig-zag type reactor, 3b3,3c3
The common end points N of zero phase-sequence filter
The tap 13a2 of the ancillary coil of zig-zag type reactor, 13b2,13c2,13a3,13b3,13c3
Zero phase-sequence filter 30,30a
Heterogeneous AC power supplies 10
Nonlinear-load 20
The disabler 40 that has tap
One of them 42a of the tap of disabler, 42b, 42c, 42d
The two-end-point of disabler one of them 401,402
Control switch 50
Contact 301a, 301b, 301c
Input neutral line 101
The output neutral line 102
The extra disabler 60 of input neutral line
(5) embodiment
The apparatus and method of the zero phase sequence impedance adjustment of zero-phase-sequence current filter of the present invention are applicable to the zero-phase-sequence current of in a heterogeneous AC power supplies distribution system, adjusting the heterogeneous AC power supplies and the neutral line.Apparatus and method of the present invention are adjusted between a heterogeneous AC power supplies and the load one when having the zero phase sequence impedance of zero phase-sequence filter of common end points, and do not influence the positive sequence impedance and the negative sequence impedance of zero phase-sequence filter.
Fig. 2 is the circuit diagram that first embodiment of apparatus and method of the present invention specializes, and connects zero phase-sequence filter and the typical nonlinear load that typically has common end points with a typical heterogeneous AC power supplies, so that device of the present invention to be described.Fig. 3 one typically has a circuit diagram icon of the zig-zag type zero phase-sequence filter 30 of common end points.Fig. 4 one typically has the circuit diagram icon of the wye-delta zero phase-sequence filter 30a of common end points.The zero phase-sequence filter that has common end points in Fig. 2 can be a zig-zag type reactor 30 as shown in Figure 3, or with the zero phase-sequence filter 30 that have common end points of wye-delta zero phase-sequence filter 30a replacement in Fig. 2 shown in Figure 4.In Fig. 2, zero phase-sequence filter 30 is connected to a heterogeneous AC power supplies 10 and a nonlinear-load 20 by contact 301a, 301b, 301c; And the common end points N of zero phase-sequence filter 30 be connected to a disabler 40 two-end-point one of them 401, and be connected to the aforesaid input neutral line 101 and the aforesaid output neutral line 102 by control switch 50 via the tap (42a or 42b or 42c or 42d) of disabler or two-end-point another end points 402 wherein.
In the circuit diagram of Fig. 2, only there is the composition of zero-phase-sequence current to appear on the common end points because of the zero phase-sequence filter, cause also to venerate on the disabler of the common end points that is connected to the zero phase-sequence filter to have zero-phase-sequence current; So; Below state bright as illustration; By the connection of control switch 50 with a tap of change disabler 40; And make the disabler of control switch connection change into tap 42b by tap 42a originally, be connected in parallel to the change of the zero phase-sequence filter equivalence zero phase sequence impedance increase of nonlinear-load with causing with exporting the neutral line, and venerate the zero-phase-sequence current composition that influences in the circuit diagram through disabler 40.This kind running effect can reach the equivalent zero phase sequence impedance that changes the zero phase-sequence filter that is connected in parallel with load, and not influence the positive sequence impedance and the negative sequence impedance of zero phase-sequence filter.
Make under the situation that the special system demand needs, need not be directed against a high impedance situation demand, and with a zig-zag type filter of customized design original device replaced especially.And venerate the viewing system demand that needs, and the tap of the disabler that suitable change control switch connects, the zero phase sequence impedance that can reach modifier is with the coupled system needs.
Fig. 5 is the circuit diagram that second embodiment of apparatus and method of the present invention specializes, and connects zero phase-sequence filter and the typical nonlinear load that typically has common end points with a typical heterogeneous AC power supplies, so that device of the present invention to be described.Among the figure, zero phase-sequence filter 30 is connected between a heterogeneous AC power supplies 10 and the nonlinear-load 20 by contact 301a, 301b, 301c; And an input neutral line 101 and an output neutral line 102 be connected to disabler 40 two-end-point one of them 401, and the common end points N that is connected to zero phase-sequence filter 30 by control switch 50 via a tap (42a or 42b or 42c or 42d) or two-end-point another end points 402 wherein of disabler.
Fig. 6 is the circuit diagram that the 3rd embodiment of apparatus and method of the present invention specializes, and connects zero phase-sequence filter and the typical nonlinear load that typically has common end points with a typical heterogeneous AC power supplies, so that device of the present invention to be described.Among the figure, zero phase-sequence filter 30 is connected between a heterogeneous AC power supplies 10 and the nonlinear-load 20 by contact 301a, 301b, 301c; And the common end points N of zero phase-sequence filter 30 be connected to disabler 40 two-end-point one of them 401; And another end points 402 of disabler two-end-point is connected to an input neutral line 101, and is connected to an output neutral line 102 via a tap (42a or 42b or 42c or 42d) of disabler by control switch 50.
Second embodiment and the 3rd embodiment also can illustrating like first embodiment; By the connection of control switch 50 with a tap of change disabler 40; And make the change of the equivalent zero phase sequence impedance of the zero phase-sequence filter that is connected in parallel through disabler and the output neutral line and nonlinear-load, and venerate the zero-phase-sequence current composition that influences in the circuit diagram.
Fig. 7 is the circuit diagram that the 4th embodiment of apparatus and method of the present invention specializes; The extra disabler 60 of increase that is analogous to Fig. 2 circuit diagram is on the input neutral line 101 between aforesaid heterogeneous AC power supplies 10 and the aforesaid zero phase-sequence filter 30, to be suppressed at the zero phase-sequence composition entering zero phase-sequence filter that the system other places produce.In addition, second embodiment and the 3rd embodiment also can increase the aforesaid input neutral online (not shown) of an extra disabler between aforesaid heterogeneous AC power supplies and aforesaid zero phase-sequence filter like the illustration of the 4th embodiment.
During actual operation, each embodiment can look design demand with the zero phase-sequence filter of each embodiment like the illustrating of first embodiment, and uses zig-zag type zero phase-sequence filter 30 or wye-delta zero phase-sequence filter 30a.
The form of aforesaid various implementation be to illustrate the present invention as an illustration, but the present invention does not receive the restriction of these examples.In this is open, only show and a spot of illustrations more miscellaneous of description the present invention.The present invention can be applied in other combination miscellaneous and the environment, and can in the scope that is no more than the notion of the present invention that is similar to above-mentioned explanation, change or revise.