Utility model content
This utility model embodiment technical problem to be solved is that electric power electric transformer of the prior art takes up an area face
Product is big, and cost is high.
For this purpose, this utility model embodiment provides following technical scheme:
This utility model embodiment provides a kind of ac-dc conversion circuit, including least one set AC-DC conversion module,
Per group of AC-DC conversion module includes at least one converting branch, includes per converting branch described in bar:
Multiple change of current subelements, correspond to three-phase alternating current respectively;
Multiple DC/AC converting units, the respectively DC side or the change of current subelement with the change of current subelement
DC side it is in series or in parallel after the total DC side connection that constitutes;
Coupling unit, the instantaneous power coupling of the DC/AC converting units output in every phase is added to eliminate
The fluctuation of the instantaneous power in single-phase;
At least one AC/DC converting units, are connected with one or more outfan of the coupling unit;
And cascade Connection between the adjacent described change of current subelement of same phase in the AC-DC conversion module, exchange interface from
The AC of the change of current subelement in per phase is drawn, and the exchange with corresponding phase is electrically connected.
Ac-dc conversion circuit described in this utility model embodiment, it is single per the AC/DC conversions in converting branch described in bar
Unit outfan it is in series or in parallel, and will be in series or in parallel after the AC/DC converting units outfan as isolation
Conversion DC interface.
Ac-dc conversion circuit described in this utility model embodiment, the coupling unit include at least one transformator,
The former limit side of the transformator includes multiple primary side windings, the output of the corresponding DC/AC converting units of difference
Total outfan connection after end or multiple DC/AC converting units are in series or in parallel, secondary side includes at least one secondary
Winding, the outfan of each vice-side winding or multiple vice-side windings it is in series or in parallel after outfan as institute
The outfan of coupling unit is stated, is connected with the input of the AC/DC converting units.
Ac-dc conversion circuit described in this utility model embodiment, the change of current subelement include that at least one first change
Stream electronic circuit, first change of current electronic circuit include first switch device, second switch device, the first diode and the two or two pole
Pipe;
The first switch device and the second switch devices in series, first diode and second diode
Respectively with the first switch device and the second switch device inverse parallel, the first switch device and the second switch
AC of the anode of the common port of device and second diode as the change of current subelement, first diode
DC side of the anode of negative electrode and second diode as the change of current subelement.
Ac-dc conversion circuit described in this utility model embodiment, the change of current subelement include that at least one second change
Stream electronic circuit, second change of current electronic circuit include that first switch device, second switch device, the 3rd switching device, the 4th open
Close device, the first diode, the second diode, the 3rd diode and the 4th diode;
The series arm of the first switch device and the 3rd switching device and the second switch device and described
The series arm of the 4th switching device is connected in parallel, first diode, second diode, the 3rd diode and
4th diode respectively with the first switch device, the second switch device, the 3rd switching device and described
The common port and the second switch device of the 4th switching device inverse parallel, the first switch device and the 3rd switching device
AC of the common port of part and the 4th switching device as the change of current subelement, described two series arms are in parallel even
DC side of the common port after connecing as the change of current subelement.
Ac-dc conversion circuit described in this utility model embodiment, the change of current subelement include that at least one the 3rd change
Stream electronic circuit, the 3rd change of current electronic circuit include first switch device, second switch device, the 3rd switching device, the one or two
Pole pipe, the second diode, the 3rd diode and the 4th diode;
The first switch device and second switch devices in series connection, first diode and the described 2nd 2
Pole pipe respectively with the first switch device and the second switch device inverse parallel, the 3rd diode and the described 3rd opens
Device inverse parallel is closed, and the anode of the 3rd diode is connected with the anode of second diode simultaneously, the described 3rd 2
The negative electrode of pole pipe is connected with the anode of the 4th diode simultaneously, negative electrode and first diode of the 4th diode
Negative electrode connection, the current collection of the common port and the 3rd switching device of the first switch device and the second switch device
The anode of AC of the pole as the change of current subelement, the negative electrode of first diode and the 3rd diode is used as institute
State the DC side of change of current subelement.
Ac-dc conversion circuit described in this utility model embodiment, the change of current subelement include that at least one the 4th change
Stream electronic circuit, the 4th change of current electronic circuit include that first switch device, second switch device, the 3rd switching device, the 4th open
Close device, the 5th switching device, the first diode, the second diode, the 3rd diode, the 4th diode, the 5th diode, the
Six diodes and the 7th diode;
The first switch device and the 3rd switching device are connected in series, first diode and the described 3rd 2
Pole pipe respectively with the first switch device and the 3rd switching device inverse parallel;The second switch device and the described 4th
Switching device is connected in series, second diode and the 4th diode respectively with the second switch device and described
Four switching device inverse parallels;The emitter stage of the 5th switching device is connected with the anode of the 3rd diode, and the described 5th
The colelctor electrode of switching device is connected with the negative electrode of second diode, and the 5th diode is anti-with the 5th switching device
It is in parallel;The anode of the 6th diode is connected with the negative electrode of the 5th diode, the negative electrode of the 6th diode and institute
The negative electrode connection of the first diode is stated, the anode of the 7th diode is connected with the anode of the 4th diode, described the
The negative electrode of seven diodes is connected with the anode of the 3rd diode, the first switch device and the 3rd switching device
AC of the common port of common port and the second switch device and the 4th switching device as the change of current subelement,
A DC side of the anode of the negative electrode of first diode and the 3rd diode as the change of current subelement, it is described
Another DC side of the anode of the negative electrode of the second diode and the 4th diode as the change of current subelement.
Ac-dc conversion circuit described in this utility model embodiment, the change of current subelement include that at least one combination is changed
Stream electronic circuit;
The combination change of current electronic circuit is changed by first change of current electronic circuit, second change of current electronic circuit, the described 3rd
Any two or multiple combinations in stream electronic circuit and the 4th change of current electronic circuit is constituted.
Ac-dc conversion circuit described in this utility model embodiment, it is also including at least one direct current capacitors, and described
The outfan of AC/DC converting units, or it is in series or in parallel after the AC/DC converting units outfan connection, and will
The outfan of the direct current capacitors is used as isolation conversion DC interface.
Ac-dc conversion circuit described in this utility model embodiment, often the change of current subelement of phase cascade Connection is total
Positive pole is connected together as the positive pole of DC interface, is connected to one per total negative pole of the change of current subelement of phase cascade Connection
Play the negative pole as DC interface.
Ac-dc conversion circuit described in this utility model embodiment, also including the 2nd DC/AC converting units, with it is described every
From conversion DC interface connection, and using the outfan of the 2nd DC/AC converting units as isolation conversion exchange interface.
This utility model embodiment additionally provides a kind of electric power electric transformer, including above-mentioned ac-dc conversion circuit.
This utility model embodiment technical scheme, has the advantage that:
This utility model embodiment provides a kind of ac-dc conversion circuit, by coupling unit by three-phase instantaneous power coupling
Addition, the fundamental frequency being effectively offset on each phase bridge arm and two double-frequency fluctuations are closed, without the need for again for the single-phase fluctuating power of suppression every
Large value capacitor is installed on individual change of current subelement, the volume of ac-dc conversion circuit is substantially reduced, if by the alternating current-direct current
Translation circuit is applied to electric power electric transformer, can equally effectively reduce the volume of electric power electric transformer, reduces its cost.
Embodiment 1
A kind of ac-dc conversion circuit is present embodiments provided, as shown in figure 1, including least one set AC-DC conversion module
1, every group of AC-DC conversion module 1 includes at least one converting branch, and every converting branch includes:
Multiple change of current subelements 11, correspond to three-phase alternating current respectively.Specifically, can be effectively by change of current subelement 11
Enter line translation and control to electric energy, can such as pass through to control the on off state and switch frequency of 11 breaker in middle device of change of current subelement
Rate come alternating current is carried out rectification and AC voltage adjusting etc. process.If the structure of the change of current subelement 11 in every converting branch is complete
Unanimously, then the number of the change of current subelement 11 come into operation during every converting branch is per phase is consistent, so that change of current in per phase
The gross output of unit 11 is consistent;If the structure of the change of current subelement 11 in every converting branch is inconsistent certainly, need
The gross output of the change of current subelement 11 come into operation in guaranteeing every phase is consistent.
Multiple DC/AC converting units 12, respectively with the DC side or change of current subelement 11 of change of current subelement 11
The total DC side connection constituted after DC side is in series or in parallel.Specifically, can determine that a DC/AC turns according to real needs
The annexation of unit 12 and 11 DC side of change of current subelement is changed, such as if necessary to reduce ac-dc conversion circuit breaker in middle device
Number of packages amount, after can connect the DC side of change of current subelement 11 in a DC/AC converting units 12 and the converting branch every phase
The total DC side for constituting is attached to lift the amplitude of the voltage of the output of a DC/AC converting units 12, reduces by a DC/AC
Converting unit quantity, and then reduce switching device quantity;Certainly if necessary to reduce the electric current in switching device, then can be by the
One DC/AC converting units 12 and the converting branch per phase in change of current subelement 11 DC side parallel after total DC side for constituting enter
Row connection.For example when converting branch is per mutually two mutually isostructural change of current subelements 11 are included, in order to reduce switching device quantity,
The DC side of two in every phase change of current subelement 11 can be carried out a series connection, by the total DC side constituted after series connection and the
The usage quantity of the first DC/AC converting units 12 can be reduced half by the input connection of one DC/AC converting units 12, when
If so switching device is pressure not high enough, the quantity of a DC/AC converting units 12 can not be reduced, can be by each change of current
The DC side of unit 11 is connected with the input of a DC/AC converting unit 12, or by a DC/AC converting units 12
It is attached with the total DC side constituted after the DC side parallel of change of current subelement 11 in the every phase of the converting branch, to reduce each
The voltage born by switching device;If each change of current subelement 11 has two direct current side ports, can be by each direct current side
Mouth regards the DC side of the change of current subelement 11 as, is connected with the input of a DC/AC converting unit 12 respectively, also may be used
Using after the direct current side ports series connection by change of current subelement 11 as the change of current subelement 11 DC side, only connection one first
The input of DC/AC converting units 12;First DC/AC converting units 12 can be from any one DC/ in prior art
The unidirectional current that the DC side of each change of current subelement 11 is exported is converted to square-wave voltage by AC change-over circuits, is preferably able to conversion
For the DC/AC change-over circuits of medium-high frequency square-wave voltage.During the DC side of change of current subelement 11 is converted into by DC/AC change-over circuits
Carry out isolation coupling after high frequency square wave voltage again.
Coupling unit 13, the instantaneous power coupling that the DC/AC converting units 12 in every phase are exported are added to eliminate
The fluctuation of the instantaneous power in single-phase.Specifically, coupling unit 13 can include multiple inputs and at least one outfan, often
Individual input can be connected with the outfan of a DC/AC converting unit 12 as needed, or with same phase in it is many
Total outfan connection after an individual DC/AC converting units 12 are in series or in parallel etc..
At least one AC/DC converting units 14, are connected with one or more outfan of coupling unit 13.Specifically,
AC/DC converting units 14 can be from any one AC/DC change-over circuit in prior art by 13 three-phase coupling of coupled unit
Voltage conversion after conjunction is unidirectional current.
And in AC-DC conversion module 1 same phase 11 cascade Connections of adjacent change of current subelement, exchange interface from every phase
In the AC of change of current subelement 11 draw, with the exchange of corresponding phase electrical connection.Specifically, the friendship of certain change of current subelement 11
Stream side is connected in series with the AC of adjacent change of current subelement 11, by that analogy, just constitutes the adjacent change of current of same phase
The cascade Connection of unit a, if ac-dc conversion circuit includes multigroup AC-DC conversion module 1, all of alternating current-direct current
In modular converter 1, the AC of the change of current subelement 11 of same phase is cascaded, and has equally constituted adjacent change of current subelement 11
Between cascade Connection.
Specifically, Fig. 1 gives an ac-dc conversion circuit for including two groups of AC-DC conversion modules 1, exchanges interface
Draw from the common port of two groups of AC-DC conversion modules 1, the exchange with corresponding phase is electrically connected.Under this mode, a, b, c three-phase separate
Not Ju You upper and lower two bridge arms, belong in the AC-DC conversion modules 1 of different groups, can be controlled by one or more
Device is controlled to bridge arm voltage to control the quantity of upper and lower bridge arm input change of current subelement 11.Preferably, each bridge arm bag
Change of current subelement 11 containing equal number, is more beneficial for the control that change of current subelement 11 on bridge arm is put into, cut out.Common tune
Mode processed include nearest level approach, carrier wave stacking, phase-shifting carrier wave etc..By taking a phases as an example, the electric current of bridge arm and upper is flow through in a phases
Bridge arm both end voltage is
In formula, UdcFor DC voltage, IdcFor DC current, UacFor a phase phase voltage peak values, IacFor a cross streams side line electric currents
Peak value.
The instantaneous power for flowing through bridge arm in a phases is calculated by equation below:
Understand in a phases, in the instantaneous power of bridge arm, to include DC component, fundamental frequency wave component and two double-frequency fluctuation components.
The coupled unit of a, b, c three-phase in each converting branch is calculated by equation below high frequency square wave voltage 13 is coupled
Output afterwards:
Because three alternate symmetrical operation of alternating current, between a, b, c phase, 120 ° are differed, it is three-phase is instantaneous by coupling unit 13
When power coupling is added, fundamental frequency and two double-frequency fluctuations are offset, it is ensured that the power of the output of coupling unit 13 is substantially without fluctuation.Need not
Large value capacitor is installed on each change of current subelement 11 to suppress the fluctuation of single-phase instantaneous power again, friendship is substantially reduced
Ac-dc conversion circuit in the present embodiment is applied to the electric power such as electric power electric transformer and is set by the volume of DC transfer circuit
It is standby, the volume of electric power electric transformer can be equally effectively reduced, its cost is reduced.
Preferably, the ac-dc conversion circuit in the present embodiment, the AC/DC converting units 14 in every converting branch it is defeated
Go out and hold in series or in parallel, and will be in series or in parallel after AC/DC converting units 14 outfan as isolation conversion direct current
Interface.Specifically, it is the outfan of the AC/DC converting units 14 in each bar converting branch is in parallel, can further reduce isolation
The fluctuation of the DC voltage of conversion DC interface output, and can turn from one or more AC/DC in parallel as needed
The outfan for changing unit 14 draws isolation conversion DC interface;By the output of the AC/DC converting units 14 in each bar converting branch
End series connection, can increase the amplitude of the voltage of isolation conversion DC interface output.
Preferably, the ac-dc conversion circuit in the present embodiment, coupling unit 13 include at least one transformator, transformator
Former limit side include multiple primary side windings, the outfan of the corresponding DC/AC converting units 12 of difference or multiple the
Total outfan connection after one DC/AC converting units 12 are in series or in parallel, secondary side include at least one vice-side winding, each
Outfan of the outfan after the outfan of vice-side winding or multiple vice-side windings are in series or in parallel as coupling unit 13,
It is connected with the input of AC/DC converting units 14.Specifically, can according to demand, the outfan that multiple vice-side windings are connected
As the outfan of coupling unit 13, the amplitude of 13 output voltage of coupling unit can be increased;Can also be by multiple vice-side windings
Outfan of the outfan after parallel connection as coupling unit 13, can further reduce the voltage wave of 13 outfan of coupling unit
It is dynamic, and the current value in each vice-side winding.As shown in Fig. 2 enter a medium/high frequency transformer for outing for one three, by adjusting
The number of turn of the winding that former and deputy side is come into operation can obtain the low-voltage dc voltage value for needing adjusting the no-load voltage ratio of transformator.Turn
Change the high frequency square wave voltage Jing medium/high frequency transformer isolation coupling of each output of the first DC/AC converting units of phase 12 in branch road, exchange
Two double frequency powers of side in alternate autobalance, the power swing of each phase also can autobalance, without the need for single in each change of current again
Large value capacitor is installed in unit 11, the volume and cost of whole ac-dc conversion circuit is significantly reduced, while reducing bridge
The control difficulty that arm is pressed.
Preferably, as shown in figure 3, change of current subelement 11 includes at least one first change of current electronic circuits, first change of current son electricity
Road includes first switch device T1, second switch device T2, the first diode D1 and the second diode D2.
First switch device T1 and second switch device T2 series connection, the first diode D1 and the second diode D2 is respectively with the
The common port and of one switching element T 1 and second switch device T2 inverse parallels, first switch device T1 and second switch device T2
The sun of AC of the anode of two diode D2 as change of current subelement 11, the negative electrode of the first diode D1 and the second diode D2
DC side of the pole as change of current subelement 11.Specifically, the change of current subelement 11 of said structure, under control of the controller, when
One switching element T 1 is turned on, second switch device T2 turn off when, change of current subelement 11 puts into operation, change of current subelement 11 equivalent to
One DC source;When first switch device T1 is turned off, and second switch device T2 is turned on, change of current subelement 11 is out of service, changes
Stream subelement 11 is externally equivalent to short circuit, equivalent to directly having bypassed the change of current subelement 11 out of service.Therefore pass through
The quantity for controlling the change of current subelement 11 that upper and lower bridge arm puts into operation can just control the voltage of upper and lower bridge arm.
, there is provided the structure of another kind of change of current subelement 11, including at least one second changes of current preferably, as shown in Figure 4
Electronic circuit, the second change of current electronic circuit include that first switch device T1, second switch device T2, the 3rd switching element T the 3, the 4th are opened
Close device T4, the first diode D1, the second diode D2, the 3rd diode D3 and the 4th diode D4.
The series arm of first switch device T1 and the 3rd switching element T 3 and second switch device T2 and the 4th derailing switch
The series arm of part T4 is connected in parallel, the first diode D1, the second diode D2, the 3rd diode D3 and the 4th diode D4 point
Not with first switch device T1, second switch device T2, the 3rd switching element T 3 and 4 inverse parallel of the 4th switching element T, first opens
Close common port and second switch device T2 and the common port conduct of the 4th switching element T 4 of device T1 and the 3rd switching element T 3
The AC of change of current subelement 11, two series arms be connected in parallel after common port as change of current subelement 11 DC side.
Specifically, the change of current subelement 11 of said structure, if circuit failure free operation, under the control of the controller, opens when first
When closing device T1 and the 4th switching element T 4 and turning on, change of current subelement 11 puts into operation, 11 first exit of change of current subelement and
Equivalent to a DC source between the second exit;When first switch device T1 and second switch device T2 is turned on, or the 3rd opens
When closing device T3 and the 4th switching element T 4 and turning on, change of current subelement 11 is out of service, its first exit and the second exit
Between export 0 voltage.Arranged by said structure, when change of current subelement 11 is out of service, this can be controlled by controller and be changed
The first switch device T1 and second switch device T2, the 3rd switching element T 3 and the 4th switching element T 4 of stream subelement 11 replaces
Rotation is turned on uniform switching loss;If circuit breaks down, under control of the controller locking (shut-off) first switch device T1,
Second switch device T2, the 3rd switching element T 3 and the 4th switching element T 4, can cut off short circuit current, isolated fault.
, there is provided the structure of the third change of current subelement 11, including at least one the 3rd changes of current preferably, as shown in Figure 5
Electronic circuit, the 3rd change of current electronic circuit include first switch device T1, second switch device T2, the 3rd switching element T the 3, the 1st
Pole pipe D1, the second diode D2, the 3rd diode D3 and the 4th diode D4.
First switch device T1 and second switch device T2 are connected in series, the first diode D1 and the second diode D2 difference
With first switch device T1 and second switch device T2 inverse parallels, the 3rd diode D3 and 3 inverse parallel of the 3rd switching element T, and
The anode of the 3rd diode D3 be connected with the anode of the second diode D2 simultaneously, and the negative electrode of the 3rd diode D3 is while with the four or two
The anode connection of pole pipe D4, the negative electrode of the 4th diode D4 is connected with the negative electrode of the first diode D1, first switch device T1 with
AC of the colelctor electrode of the common port and the 3rd switching element T 3 of second switch device T2 as change of current subelement 11, the one or two
DC side of the anode of the negative electrode of pole pipe D1 and the 3rd diode D3 as change of current subelement 11.Specifically, said structure is changed
Stream subelement 11, if circuit failure free operation, under the control of the controller, the 3rd switching element T 3 is constantly on, if the
One switching element T 1 is turned on, second switch device T2 shut-offs, then change of current subelement 11 puts into operation;If first switch device T1 is closed
Disconnected, second switch device T2 conductings, change of current subelement 11 are out of service;If circuit breaks down, close under control of the controller
Lock (shut-off) first switch device T1, second switch device T2 and the 3rd switching element T 3, can cut off short circuit current, isolation event
Barrier.
, there is provided the structure of the 4th kind of change of current subelement 11, including at least one the 4th changes of current preferably, as shown in Figure 6
Electronic circuit, the 4th change of current electronic circuit include that first switch device T1, second switch device T2, the 3rd switching element T the 3, the 4th are opened
Close device T4, the 5th switching element T 5, the first diode D1, the second diode D2, the 3rd diode D3, the 4th diode D4,
5th diode D5, the 6th diode D6 and the 7th diode D7.
First switch device T1 and the 3rd switching element T 3 are connected in series, the first diode D1 and the 3rd diode D3 difference
With 3 inverse parallel of first switch device T1 and the 3rd switching element T;Second switch device T2 and the series connection of the 4th switching element T 4 connect
Connect, the second diode D2 and the 4th diode D4 respectively with 4 inverse parallel of second switch device T2 and the 4th switching element T;5th
The emitter stage of switching element T 5 is connected with the anode of the 3rd diode D3, the colelctor electrode and the second diode of the 5th switching element T 5
The negative electrode connection of D2, the 5th diode D5 and 5 inverse parallel of the 5th switching element T;The anode of the 6th diode D6 and the five or two pole
The negative electrode connection of pipe D5, the negative electrode of the 6th diode D6 are connected with the negative electrode of the first diode D1, the anode of the 7th diode D7
It is connected with the anode of the 4th diode D4, the negative electrode of the 7th diode D7 is connected with the anode of the 3rd diode D3, first switch
The common port of device T1 and the 3rd switching element T 3 and the common port of second switch device T2 and the 4th switching element T 4 are used as changing
The AC of stream subelement 11, the anode of the negative electrode and the 3rd diode D3 of the first diode D1 is used as the one of change of current subelement 11
Individual DC side, another direct current of the anode of the negative electrode and the 4th diode D4 of the second diode D2 as change of current subelement 11
Side.
Table 1
Specifically, as shown in table 1, the change of current subelement 11 of said structure, the 1st kind of situation of normal work, in controller control
Under system, first switch device T1 conductings, second switch device T2 shut-offs, the 3rd switching element T 3 are turned off, the 4th switching element T 4
Conducting, the 5th switching element T 5 are turned on (10011), upper half module corresponding voltage Uc input, lower half module corresponding voltage Uc input.
Change of current subelement 11 puts into voltage altogether for 2Uc.
The 2nd kind of situation of normal work, under control of the controller, first switch device T1 conductings, second switch device T2 are led
Logical, the 3rd switching element T 3 is turned off, and the 4th switching element T 4 is turned off, when the 5th switching element T 5 is turned on (11001), upper half module
Corresponding voltage Uc puts into, and lower half module cuts out, and corresponding voltage is 0.Change of current subelement 11 puts into voltage altogether for Uc.
The 3rd kind of situation of normal work, under control of the controller, first switch device T1 shut-offs, second switch device T2 are closed
Disconnected, the 3rd switching element T 3 is turned on, and the 4th switching element T 4 is turned on, and the 5th switching element T 5 is turned on (00111), lower half module pair
Voltage Uc is answered to put into, upper half module cuts out, and corresponding voltage is 0.Change of current subelement 11 puts into voltage altogether for Uc.
The 4th kind of situation of normal work, under control of the controller, first switch device T1 shut-offs, second switch device T2 are led
Logical, the 3rd switching element T 3 is turned on, and the 4th switching element T 4 is turned off, and the 5th switching element T 5 is turned on (01101), and upper half module is cut
Go out, corresponding voltage is 0.Lower half module cuts out, and corresponding voltage is 0.Change of current subelement 11 puts into voltage altogether for 0.
Therefore, during circuit failure free operation, first switch device T1 and second switch device can be controlled by controller
Part T2 replaces rotation conducting with the 3rd switching element T 3 and the 4th switching element T 4, with uniform switching loss.
When circuit malfunctions, first switch device T1 is controlled by controller and (is closed to 5 locking of the 5th switching element T
It is disconnected), short circuit current, isolated fault can be cut off.
Preferably, the ac-dc conversion circuit in the present embodiment, change of current subelement 11 include at least one combination change of current
Circuit.
Combination change of current electronic circuit is changed by the first change of current electronic circuit, the second change of current electronic circuit, the 3rd change of current electronic circuit and the 4th
Any two or multiple combinations in stream electronic circuit is constituted.
Specifically, the change of current subelement 11 in every converting branch, can be the first change of current electronic circuit, second change of current son electricity
Any one in road, the 3rd change of current electronic circuit, the 4th change of current electronic circuit or combination change of current electronic circuit, or above-mentioned five
The combinative structure constituted after the structure combination in any for planting or possessing identical function.
Preferably, the ac-dc conversion circuit in the present embodiment, first switch device T1, second switch device T2, the 3rd
Switching element T 3, the 4th switching element T 4 and the 5th switching element T 5 can select insulated gate bipolar transistor.Insulated gate is double
Bipolar transistor integrates the advantage of MOSFET and GTR, and with input impedance height, switching speed is fast, drive circuit is simple, logical
State voltage is low, the advantages of high-voltage large current can be born.There can certainly be switch from audion, IGCT, metal-oxide-semiconductor etc.
The connection in series-parallel of the device of function or above-mentioned switching device.
Preferably, as shown in fig. 7, ac-dc conversion circuit in the present embodiment, also including at least one direct current capacitors,
With the outfan of AC/DC converting units 14 or it is in series or in parallel after the outfan of AC/DC converting units 14 be connected, and will
The outfan of direct current capacitors is used as isolation conversion DC interface.Specifically, connected by the outfan in AC/DC converting units 14
Direct current capacitors is connect, power swing can be further offset, makes the unidirectional current after the isolation conversion of output more stable.And Jing
Coupling unit 13 has counteracted most of power swing, and direct current capacitors need to only choose the direct current capacitors of minimum capacitance i.e.
Can.
Preferably, the ac-dc conversion circuit in the present embodiment, per total positive pole of the change of current subelement 11 of phase cascade Connection
The positive pole of DC interface is connected together as, is connected together as per total negative pole of the change of current subelement 11 of phase cascade Connection
The negative pole of DC interface.
Preferably, the ac-dc conversion circuit in the present embodiment, also including the 2nd DC/AC converting units, and isolates conversion
DC interface connects, and using the outfan of the 2nd DC/AC converting units as isolation conversion exchange interface.Specifically, the 2nd DC/
AC converting units can select prior art in any one DC/AC change-over circuit by isolate conversion DC interface output every
DC inverter after changing is into low-voltage AC.
Ac-dc conversion circuit in the present embodiment, can be provided simultaneously with exchanging interface, DC interface, isolation conversion direct current
Interface exchanges interface with isolation conversion, disclosure satisfy that the requirement of the various application occasions such as mesolow DC distribution net.