CN102739097A - Method and circuit utilizing low-voltage inversion to realize high-voltage inversion, and high-voltage converter - Google Patents
Method and circuit utilizing low-voltage inversion to realize high-voltage inversion, and high-voltage converter Download PDFInfo
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- CN102739097A CN102739097A CN2011100864895A CN201110086489A CN102739097A CN 102739097 A CN102739097 A CN 102739097A CN 2011100864895 A CN2011100864895 A CN 2011100864895A CN 201110086489 A CN201110086489 A CN 201110086489A CN 102739097 A CN102739097 A CN 102739097A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
- H02M7/49—Combination of the output voltage waveforms of a plurality of converters
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Abstract
The invention discloses a method and a circuit utilizing low-voltage inversion to realize high-voltage inversion, and a high-voltage converter. The method comprises: that dc voltages are set as input of three-phase low-voltage inversion circuits, wherein the number of the circuits is M, and the dc voltages are isolated from each other electrically; that three phase output voltages of each low-voltage inversion circuit are connected in series to corresponding phases in a direct manner or through coupling of a transformer, thereby acquiring three phase high-voltage ac outputs; that two phases of three output phases of three three-phase low-voltage inversion circuits are directly connected in series to high-voltage output ends of the corresponding phases respectively, and sharing output ends of the two phases of the three low-voltage inversion circuits are used as three phase output ends of a high-voltage inversion circuit; and that each three-phase low-voltage inversion circuit inverts inputted dc voltage into three-phase symmetrical pulse width modulation PWM ac output voltage in a PWM manner. According to the invention, output of any three or more than three three-phase low-voltage inverters can be connected in series to high-voltage ac output through coupling of the transformer.
Description
Technical field
The present invention relates to power electronic technology; Relate in particular to and a kind ofly realize high-voltage inverted method, circuit and high tension transformer, be specially: by three-phase power inverse method through transformer coupled series connection acquisition High Level AC Voltage of the output of a plurality of three-phase low pressure inverter circuits, circuit with based on the high tension transformer of this method, circuit with the low pressure inversion.
Background technology
As the important component part of electric power energy-saving technology, the high-tension electricity converter technique receives extensive concern just day by day.Core component as power converter; The electric pressure of solid-state electronic power switch such as insulated gate electrode triode (IGBT) has reached 6500V; Can realize exchanging the power conversions below the 2500V, but for higher line voltage, power conversions still can't directly be carried out.
The method of power converter comprises method of " AC-DC " (rectification) and the method for " DC-AC " (inversion).Limited by the withstand voltage and cost of electronic power switch,, generally adopt the high-voltage inverted method of multipleization of units in series pulse width modulation (PWM) in the occasion of middle and high voltage.This inverse method is reverse into the multichannel low-voltage DC that is isolated from each other the low-pressure single-phase alternating current of same way; These low-pressure single-phase alternating current electricity are divided into three groups of symmetry again; Each road single-phase alternating current of each group is connected successively and can be obtained the output of single-phase high voltage alternating voltage; One end of three road high-voltage alternating high pressure output links together, and an other end is respectively as three outputs of High AC voltage.By the PWM allocation strategy of certain low pressure inverter, can obtain three symmetrical multi-level high-voltage alternating voltages at three outputs.
Adopt the high-voltage inverter output voltage wave mode of this inverse method good, the output voltage rate of change is low, the cost of material is low, easy to maintenance.But; Because each low pressure inverter all is single-phase output, and each road low-voltage dc voltage obtains through over commutation, filtering often, when output frequency is low; The fluctuation of direct voltage is bigger; Cause the output harmonic wave electric current to increase,, also can have influence on the startability and the low-speed running performance of motor if the load of high tension transformer is a motor.Can improve though increase dc filter capacitor, this can worsen the input current characteristic of converter simultaneously.In addition, the prime filter capacitor capacity of lower pressure transducer is big, price is high, the life-span is short, the high-voltage inverter cost is risen, and increased the maintenance workload in the actual use.
Above-mentioned deficiency to the high-voltage inverted method of multipleization of units in series PWM; E.Cengelci had proposed a kind of three-phase low pressure inverter output improves output AC voltage through transformer coupled series connection middle pressure converter main circuit design in " A New Medium-voltage PWM Inverter Topology for Adjustable-speed Drives, IEEE Paper No.IPCSD 98-83 " in 1998.
Figure 1A is the main circuit connection sketch map of pressing inverter in this, and the above-mentioned middle inverter of pressing comprises three three-phase low pressure inverters (belonging to lower pressure transducer) 2A, 2B, 2C and three single- phase transformers 31,32,33.The direct current input of three three-phase low pressure inverters (like 2A) is isolated from each other, voltage equates (like V
DCA); Each low pressure inverter (like 2A) with low-voltage dc voltage (like V
DCA) be reverse into needed three-phase alternating current; The inverter bridge of each lower pressure transducer 2A, 2B, 2C all adopts PWM control, and the pwm signal reference wave to inductive switch in each inverter bridge is identical, and carrier waveform is identical and phase place differs 120 ° each other; Each three-phase lower pressure transducer (like 2A) has respectively in an output (like the u1) conduct presses the output of inverter to be connected to load, like motor 5; Other two outputs (like v1 and w1) then are connected output coupling transformer (as 32,33).Wherein, Three single- phase coupling transformer 31,32,33 turn ratioes among Figure 1A all are 1: 1; And work in w-u, v-w, the u-v phase of three-phase lower pressure transducer respectively; So can realize with a three-phase transformer 3A, shown in Figure 1B, press 1/3 of inverter power output during the power of this three-phase transformer only is equivalent to.
By the transformer coupled series system of above-mentioned low pressure inverter output, the output voltage of medium voltage transformation device is respectively:
U
UV＝U
UV1+U
UV2+U
UV3，
U
VW＝U
VW1+U
VW2+U
VW3，
U
UW=U
WU1+ U
WU2+ U
WU3Thereby output is improved.
Said each low pressure inverter adopts the misphase modulation, and the output voltage ripple of each low pressure inverter can be cancelled out each other, and presses inverter can realize many level outputs in making, like this, has not only reduced output current ripple, has also reduced the rate of change of output voltage.
The middle pressure inverter of above-mentioned three-phase low pressure output transformer of inverter coupling series connection directly adopts three-phase inversion; Improve the dc voltage fluctuation problem that the single-phase inversion of multipleization of units in series PWM high-voltage inverter causes, and then can reduce the quantity of prime filter capacitor in the inverter.But shortcoming is to realize three grades of stacks, is difficult to directly realize the high-tension electricity inversion by the low pressure inverter.
If the nested mode through above-mentioned three-phase low pressure output transformer of inverter coupling series connection obtains high pressure output; As shown in Figure 2, promptly earlier press inverter by three three- phase coupling transformer 3A, 3B, 3C coupling series connection in realizing three by the output of nine three-phase low pressure inverter 2A～2I, press the output of inverter to obtain high pressure output through the mode of one-level three-phase transformer 3D coupling series connection again in three; Then coupling transformer quantity increases to 4; The kind of transformer be increased to 2 kinds (transformer 3A～3C power is 1/9 of high-voltage inverter power output, transformer 3D power be high-voltage inverter power 1/3), gross power is brought up to 2/3 of main transformer; Like this; Not only increased cost, and can only realize 3,9, a 27... three-phase low pressure inversion combination, use underaction.
Summary of the invention
In view of this; Main purpose of the present invention is to provide a kind of and realizes high-voltage inverted method, circuit and high tension transformer with the low pressure inversion; To overcome the many deficiency of high-voltage inverted method of multipleization of units in series PWM and existing three-phase low pressure inverter output, can realize any three and above three-phase low pressure inversion output high-voltage alternating output through transformer coupled series connection through the middle pressure inverting of three-phase transformer coupling series connection.
For achieving the above object, technical scheme of the present invention is achieved in that
A kind of high-voltage inverted method of low pressure inversion realization of utilizing, this method comprises the steps:
A, the input of M three-phase low pressure inverter circuit is made as the electric direct voltage that is isolated from each other;
The three-phase output voltage of B, each low pressure inverter circuit, directly series connection or be connected in series to corresponding phase through the single-phase transformer coupling exchanges output to obtain three-phase high-voltage respectively; Winding through single-phase transformer between the output of said each low pressure inverter circuit connects;
C, two in the output of the three-phase of three three-phase low pressure inverter circuits directly is connected in series to the high-voltage alternating output of corresponding phase mutually respectively, this two public output of exporting mutually that then will said three low pressure inverter circuits is respectively as the three-phase output end of high-voltage inverter circuit;
D, last; The mode through pulse width modulation (PWM) respectively with each three-phase low pressure inverter circuit again; The direct voltage of input is reverse into three symmetrical PWM ac output voltages; The interchange PWM voltage reference phase of wave of the corresponding output of each three-phase low pressure inverter circuit is same, and carrier waveform is identical, phase place differs 360 °/M successively; Wherein, M is the natural number more than or equal to 3.
Wherein, the output of the said acquisition three-phase high-voltage of step B electric current is specially:
B1, said M is subtracted MOD (M; 3) output of the part of individual low pressure inverter circuit directly is connected in series to corresponding phase high-voltage alternating output mutually; All the other outputs are connected in series to corresponding phase high-voltage alternating output after isolating through single-phase transformer coupling mutually, and said MOD (M, 3) expression M is divided by 3 remainder;
If the number M of B2 low pressure inverter circuit is not 3 integral multiple, also there is remaining low pressure inverter circuit, its all three outputs are mutually respectively through being connected in series to corresponding phase high-voltage alternating output after the single-phase transformer coupling isolation.
Described single-phase transformer structure is identical, and 3 said single-phase transformers that belong to different output phases respectively are combined into a three-phase transformer, isolates if the said three-phase transformer of whole employings is realized coupling, then needs Ceil (2M/3) to subtract 1 three-phase transformer at least; Wherein, M is the natural number more than or equal to 3, and said Ceil () is the ceiling function, representes real number to rounding greatly.
A kind of high-voltage inverted circuit of low pressure inversion realization that utilizes, said circuit comprises: M three-phase low pressure inverter circuit, Ceil (2M/3) subtract 1 three-phase transformer; The input voltage of said each three-phase low pressure inverter circuit is a direct current, and electrical isolation each other; Said M three-phase low pressure inverter circuit is divided into 3 groups at most:
First group comprises 3 three-phase low pressure inverter circuits; Wherein each low pressure inverter circuit correspondence of having two outputs directly to be connected in series to high-voltage inverter circuit is mutually respectively exported mutually, during the correspondence that remaining output is connected in series to high-voltage inverter circuit after coupling is isolated through three-phase transformer is respectively mutually exported mutually;
If M is not 3 integral multiple, also there be second group in the low pressure inverter circuit, comprises the individual low pressure inverter circuit of MOD (M, 3), and said MOD (M, 3) expression M is divided by 3 remainder; During the three-phase output of second group of each low pressure inverter circuit is exported through the correspondence that is connected in series to high-voltage inverter circuit after the three-phase transformer coupling isolation respectively mutually;
If M is the natural number more than or equal to 6; Other low pressure inverter circuit is as the 3rd group; Wherein each low pressure inverter circuit output directly is connected in series to the correspondence output phase of high-voltage inverter circuit mutually, and two other output is connected in series in the correspondence output mutually of high-voltage inverter circuit after coupling is isolated through three-phase transformer respectively mutually;
Between the output of said each low pressure inverter circuit, directly do not connect;
Said first group of each low pressure inverter circuit directly connected the common port of two phases of output respectively as the three-phase output end of high-voltage inverter circuit;
Wherein, M is the natural number more than or equal to 3; Said Ceil () is the ceiling function, representes real number to rounding greatly.
Said M three-phase low pressure inverter circuit structure is identical; Each three-phase low pressure inverter circuit is reverse into three symmetrical PWM ac output voltages, the interchange PWM voltage reference ripple of the corresponding output of each three-phase low pressure inverter circuit through the PWM mode with the direct voltage of output respectively.
All umber of turns of all said three-phase transformers are identical.
A kind of high tension transformer is characterized in that, comprises a main transformer, a 3N three-phase lower pressure transducer, a 2N-1 three-phase output transformer and a master controller; Said phase shift main transformer is many secondary of three-phase winding transformer; Its former limit winding connect three-phase high-voltage electrical network, secondary winding comprise be electrically isolated from one another, 3N road that output voltage equates; Every road is symmetrical three-phase output, all has one road secondary winding to be connected with it for each three-phase lower pressure transducer; The output of said lower pressure transducer links to each other with the load of high tension transformer or the winding of three-phase coupling transformer respectively; Each lower pressure transducer links to each other with master controller respectively; Wherein, N is a natural number.
Wherein, said main transformer is a three-phase phase-shifting transformer, has the phase difference of 20/N degree between its each road secondary winding; Perhaps,
The secondary winding is divided into the L group, and said group of interior each road secondary winding phase place is identical, and each is organized, and phase place differs the 60/L degree successively between the secondary winding, and wherein, N, L are natural number, and 3N is the integral multiple of L.
Said lower pressure transducer comprises that three-phase do not control rectifier bridge (21), DC filtering circuit (22), three-phase fully-controlled inverter bridge (23) and control Driver Circuit (24); Wherein, The AC side a of three-phase commutation bridge (21), b, c hold the input as lower pressure transducer; The road three-phase secondary winding that connects the phase shift main transformer; Its DC side p, n end is connected with the DC side of DC filtering circuit (22) and three-phase fully-controlled inverter bridge (23), and the AC side u of three-phase fully-controlled inverter bridge (23), v, w hold the output as this lower pressure transducer; Control Driver Circuit (24) is connected with master controller through optical fiber, receives the pwm signal of autonomous controller, controls the solid-state power switch (231～236) of three-phase fully-controlled inverter bridge (23), and the operation information of this lower pressure transducer is sent to master controller.
Six umber of turns of said each three-phase output transformer are identical; Each former limit winding of three-phase output transformer connects two outputs of same lower pressure transducer; Each secondary winding of three-phase output transformer is connected in series respectively into the correspondence of high tension transformer to be exported mutually.
The reference wave of the inversion control pwm signal of corresponding solid-state switch is identical in the three-phase fully-controlled inverter bridge (23) of said each three-phase lower pressure transducer, and the identical and phase place of carrier wave shape differs the 120/N degree successively, and wherein, N is a natural number.
Provided by the present invention with high-voltage inverted method, circuit and the high tension transformer of low pressure inversion realization, have the following advantages:
1, directly adopts the inversion of three-phase low pressure, improved the dc voltage fluctuation problem that the single-phase inversion of unit multipleization PWM high-voltage inverter causes, and then can reduce the quantity of prime filter capacitor in the inverter;
2, can realize any three grades and above three-phase inversion stack, can directly realize the inversion of three-phase high-voltage electric power by three-phase low pressure inverter;
3, compare through the nested scheme of transformer coupled series connection with three three-phase low pressure inverter outputs, the total capacity of output transformer obviously reduces, and uses more flexible.
Description of drawings
Figure 1A is for pressing the converter main circuit sketch map in the existing transformer coupled series connection;
Figure 1B is for pressing the three-phase output transformer sketch map of inverter in the existing transformer coupled series connection;
Fig. 2 is the transformer coupled series connection high-voltage inverter of a two-level nested main circuit sketch map;
Fig. 3 A is the present invention's 4 low pressure output transformer of inverter coupling series connection high-voltage inverter circuit sketch map;
Fig. 3 B is the present invention's 4 low pressure inverters output coupling series connection high-voltage inverter circuit series relationship sketch map;
Fig. 3 C is the three-phase output transformer sketch map of the present invention's 4 low pressure inverters output coupling series connection high-voltage inverter circuit;
Fig. 3 D is the present invention's 4 low pressure inverters output coupling series connection high-voltage inverter circuit output voltage synthetic waveform sketch map;
Fig. 4 A is the present invention's 6 low pressure output transformer of inverter coupling series connection high-voltage inverter circuit sketch map;
Fig. 4 B is the present invention's 6 low pressure inverters output coupling series connection high-voltage inverter circuit series relationship figure;
Fig. 4 C is the three-phase output transformer sketch map of the present invention's 6 low pressure inverters output coupling series connection high-voltage inverter circuit;
Fig. 5 A is the present invention's 6 low pressure output transformer of inverter coupling series connection high tension transformer main circuit sketch map;
Fig. 5 B is a three-phase lower pressure transducer circuit diagram of the present invention;
Fig. 5 C is the synthetic sketch map of the present invention's 6 low pressure output transformer of inverter coupling series connection high tension transformer output voltage;
Fig. 5 D is the synthetic sketch map of the present invention's 6 low pressure output transformer of inverter coupling series connection high tension transformer input current;
Fig. 6 A is 9 lower pressure transducer couplings of the present invention series connection high tension transformer main circuit sketch map;
Fig. 6 B is the corresponding three-phase output transformer wiring schematic diagram of Fig. 6 A
Fig. 6 C is the high tension transformer voltage coupling series relationship figure shown in Fig. 6 A, Fig. 6 B.
[critical piece symbol description]
1: the phase shift main transformer
11: the former limit of three-phase winding
12A-12I: secondary winding
2A-2I: three-phase low pressure inverter (circuit)
21: three-phase commutation bridge
22: the DC filtering circuit
23: three-phase (full control) inverter bridge
24: control Driver Circuit
31-39: single-phase output transformer
3A-3E: three-phase output transformer
4, master controller
5: motor
6, high-voltage fence.
Embodiment
Below in conjunction with accompanying drawing and embodiments of the invention method of the present invention, circuit and high tension transformer are done further detailed explanation.
The invention provides a kind of method that adopts any three-phase low pressure inverter output more than three or three through the output of transformer coupled series connection acquisition high-voltage alternating, describe high-voltage inverter circuit based on this high-voltage inverted method below in conjunction with concrete circuit.
Fig. 3 A is the high-voltage inverter circuit sketch map that the embodiment of the invention adopts 4 three-phase low pressure inverter circuits to realize, the input voltage of these 4 low pressure inverter circuits (like 2A) all is that direct voltage is (like V
DCA), and electrical isolation each other.
Fig. 3 B has provided the method for the output of 4 three-phase low pressure inverter circuits through transformer coupled series connection; The corresponding output of oval symbolic representation among the figure directly is connected in series in the output mutually of high-voltage inverter, and block symbol representes that then corresponding output is through being connected in series to after the transformer coupled isolation in the output mutually of high-voltage inverter; Symbol in ellipse and the square frame is then represented the source of voltage; Represent the output voltage u1-v1 of this component of voltage of series connection in the high-voltage inverter circuit U-V output mutually like the uv1 in the ellipse from three-phase low pressure inverter circuit 2A; Wu2 in the square frame representes this component of voltage during high-voltage inverter circuit W-U output mutually from the w2-u2 of three-phase low pressure inverter circuit 2B, and other is similar.
The three-phase output voltage of each low pressure inverter circuit (like 2A) (like u1-v1, v1-w1, w1-u1) is connected in series to U-V, V-W, the W-U phase of high-voltage inverter circuit respectively, exchanges output to obtain three-phase high-voltage; Wherein three low pressure inverter circuit 2A, 2B, 2C have two output phases respectively, as the u1-v1 of 2A mutually with w1-u1 mutually, the u2-v2 of 2B mutually with v2-w2 mutually, the v3-w3 phase of 2C and w3-u3 mutually, among the correspondence that directly is connected in series to high-voltage inverter circuit is exported mutually; All the other output phases of these three low pressure inverter circuits are like the v1-w1 phase of 2A, the w2-u2 phase of 2B, the u3-v3 phase of 2C, in then exporting mutually through V-W, W-U, the U-V that is connected in series to high-voltage inverter circuit after transformer 32,33, the 31 coupling isolation respectively.
In Fig. 3 A, have 4 three-phase low pressure inverter circuits; Because 4 is not 3 integral multiple; Also there is a low pressure inverter circuit 2D, during its all three output phase u4-v4, v4-w4, w4-u4 export through the interchange that is connected in series to high-voltage inverter circuit U-V, V-W, W-U phase after transformer 34,35, the 36 coupling isolation respectively respectively;
Among Fig. 3 A, between the output of each low pressure inverter circuit, there is not direct connection; Three-phase low pressure inverter circuit 2A wherein, 2B, 2C, respectively have two mutually output (like u1-v1 and the w1-u1 of 2A, the u2-v2 of 2B and the v3-w3 and w3-u3 of v2-w2, the 2C) high-voltage inverter circuit that directly is connected in series to corresponding phase exchange and export; Low pressure inverter circuit 2A, 2B, 2C this two mutually the common port u1, v2, w3 of output respectively as U, V, the W three-phase output end of high-voltage inverter circuit.
Each three-phase low pressure inverter circuit (like 2A) is respectively through the PWM mode, with the direct voltage of input (like V
DCA) be reverse into three symmetrical PWM ac output voltages (like u1-v1, v1-w1 and w1-u1); The interchange PWM voltage reference phase of wave of three-phase low pressure inverter circuit 2A, 2B, 2C, the corresponding output of 2D together; Carrier waveform is identical, phase place differs 90 ° (360 °/4) successively; Can make each corresponding phase of each low pressure inverter circuit like this; But pulse consistent with phase place staggered successively like the low frequency component waveform of the output PWM voltage of the u4-v4 of the u3-v3 of the u2-v2 of the u1-v1 of 2A, 2B, 2C, 2D, and the carrier component that the correspondence of each low pressure inverter circuit is exported mutually can be cancelled out each other, like this; Many level outputs of high-voltage inverter circuit have not only been realized; Reduce the rate of change of high-voltage inverter circuit output voltage, and reduced output ripple voltage, thereby can adopt lower PWM modulating frequency to realize more satisfactory high-voltage alternating output.
Fig. 3 D has provided the PWM output voltage of each low pressure inverter circuit and the waveform sketch map of high-voltage inverter circuit output voltage; Wherein RefU, RefV be respectively low pressure inverter circuit (comprising 2A, 2B, 2C, 2D) U mutually with V PWM reference wave mutually; C1, C2, C3, C4 are respectively the PWM carrier waves of low pressure inverter circuit 2A, 2B, 2C, 2D, V
UV1, V
UV2, V
UV3, V
UV4Be respectively the voltage between the output u1-v1, u2-v2, u3-v3, u4-v4 of the corresponding high-voltage inverter circuit U-V of low pressure inverter circuit 2A, 2B, 2C, 2D phase, V
UVBe the voltage between the high-voltage inverter circuit output U-V.The input direct voltage of 4 three-phase low pressure inverter circuits among the figure is identical, and its output is through the coupling series connection of transformer, and the level number of output voltage can reach 9 grades.Shown in Fig. 3 D:
V
UV＝V
UV1+V
UV2+V
UV3+V
UV4
V
VW＝V
VW1+V
VW2+V
VW3+V
VW4
V
WU＝V
WU1+V
WU2+V
WU3+V
WU4
It is thus clear that high-voltage inverter circuit is output as 4 times of low pressure inverter circuit.
If above-mentioned each low pressure inversion unit adopts different input direct voltages, the level number of output voltage then can be more, and high-voltage inverted method provided by the invention also can be suitable for.In addition, what adopt among Fig. 3 D is the sine pulse width modulation (PWM) modulation, if adopt other modulator approach, also can not have influence on the validity of method provided by the invention.
In Fig. 3 B; Comprise the v1-w1 of 2A, the w2-u2 of 2B, the u3-v3 of 2C and u4-v4, v4-w4, the w4-u4 of inverter circuit 2D through the be coupled output voltage of three-phase low pressure inverter circuit of series connection of transformer; Can find out that each phase in the corresponding three-phase high-voltage output respectively has two-way voltage output (like v1-w1 and v4-w4), therefore can realize the isolation coupling of this 6 road voltage with two three-phase transformers.Fig. 3 C has provided a kind of mode of connection that realizes three tunnel voltage isolation with three-phase transformer; One of them transformer 3A realizes the voltage coupling output of v1-w1, w2-u2, u3-v3, and another one transformer 3B realizes the voltage coupling output of u4-v4, v4-w4, w4-u4.If adopt single-phase transformer coupling output; The power of each single-phase transformer all is low pressure inverter circuit power output
, needs 6 transformers altogether; If with two three-phase transformer coupling outputs, the power of each transformer all equals low pressure inverter circuit power output; The employing three-phase transformer is realized, can reduce the gross power of coupling transformer.
The low pressure inversion output that Fig. 3 B provides not is unique through transformer coupled tandem compound mode, a kind of series system that Fig. 3 B just provides.
The number of supposing the low pressure inverter circuit of employing is M, if all adopt three-phase transformer to realize the coupling isolation, then the number of three-phase transformer is at least Ceil (2M/3)-1; Here, said Ceil () is the ceiling function, the expression to real number to rounding greatly, like Ceil (3.1)=4, Ceil (3.9)=4.In Fig. 3 B, the number M of low pressure inverter circuit=4 then need the quantity of three-phase transformer to be at least 2, shown in Fig. 3 C.Increase the transformer number and also can realize series connection output, but economical inadequately.
As another embodiment.Fig. 4 A provides the scheme of the output of 6 low pressure three-phase inverting circuits of a usefulness through the inversion of 9 single-phase transformer coupling series connection realization three-phase high-voltages, and Fig. 4 B is corresponding low pressure inverter circuit output voltage series system sketch map.Above-mentioned 9 single-phase output transformers also can replace with three three-phase transformers, and Fig. 4 C has provided a kind of implementation.
6 three-phase low pressure inverter circuits of Fig. 4 A are exported the scheme contrast of 4 three-phase low pressure inverter circuits shown in the coupling high-voltage inverted scheme of series connection and Fig. 3 A, have following difference:
1) needs of the input of the direct voltage of 6 tunnel mutual electrical isolation as each low pressure inverter circuit;
2) 6 three-phase low pressure inverter circuits being arranged, is 3 integral multiple, and all low pressure inverter circuits all have the part output voltage directly to be connected in series in the output voltage of high-voltage inverter circuit; 3 three-phase low pressure inverter circuit 2A, 2B, 2C; There are two outputs directly to be connected in series to corresponding high pressure phase output mutually respectively; Other 3 three-phase low pressure inverter circuit 2D, 2E, 2F; Have an output directly to be connected in series to corresponding high pressure phase output mutually respectively, other output then is connected in series in the corresponding high pressure phase output through transformer coupled respectively mutually;
3) the interchange PWM carrier phase of three-phase low pressure inverter circuit differs 60 ° (promptly 360 °/6) successively;
4) output voltage of high-voltage inverter circuit is 6 times of low pressure inverter circuit, and level number can reach 13 grades;
5) number of output coupling three-phase transformer is 3.
The situation of the characteristic of others and 4 three-phase low pressure inverter circuits is identical or drawn by the situation of 4 low pressure inverter circuits easily.
A plurality of three-phase low pressure inverter output of the present invention can be applied in the high tension transformer through the high-voltage inverted method of transformer coupled series connection, realizes that " AC-AC " of three-phase high-voltage alternating current changed, to be applied to field such as speed regualtion of AC motor.
For this reason; The present invention also provides a kind of three-phase high-voltage power converter; Please refer to Fig. 5 A, high-tension electricity converter as shown in the figure comprises phase shift main transformer 1, six (N=2) three-phase lower pressure transducer 2A～2F, three three be coupled output transformer 3A～3C and master controllers 4.
Phase shift main transformer 1 is many secondary of three-phase winding transformer; Its former limit winding 11 terminals connect three-phase high-voltage electrical network 6 as the input of high tension transformer, and the secondary winding comprises six road 12A～12F; Six tunnel outputs are electrically isolated from one another, voltage equates, the three-phase output symmetry of each road (like 12A); For each three-phase lower pressure transducer (like 2A), all there is one road secondary winding (like 12A) to be connected with it.(have phase difference between the 12A～12F), phase place differs 10 ° (promptly 60 °/6=10 °) to each road secondary winding successively.
Fig. 5 B is the electrical block diagram of above-mentioned three-phase lower pressure transducer, and each three-phase lower pressure transducer (like 2A) comprises that three-phase do not control rectifier bridge 21, DC filtering circuit 22, three-phase fully-controlled inverter bridge 23 and control Driver Circuit 24.The AC side a of three-phase commutation bridge 21, b, c are as the input of lower pressure transducer; The road three-phase secondary winding (like 12A) that connects phase shift main transformer 1; Its DC side p, n are connected with the DC side of DC filtering circuit 22 and three phase inverter bridge 23, and the AC side u of three phase inverter bridge 23, v, w are as the output of this lower pressure transducer (like 2A).Control Driver Circuit 24 is connected with master controller 4 through optical fiber, receives the solid-state power switch 231～236 of the pwm signal control three phase inverter bridge 23 of autonomous controller 4, and the operation information of this lower pressure transducer (like 2A) is sent to master controller 4.
High tension transformer has 6 three-phase lower pressure transducer 2A～2F, and the winding diagram of corresponding three-phase output transformer is with Fig. 4 C.The output of lower pressure transducer (like 2A) is connected with the load 5 of high tension transformer or the winding of three-phase coupling transformer (like 3A, 3B, 3C) respectively.With Fig. 5 A is example, and lower pressure transducer 2A, 2B, 2C respectively have an output u1, v2, w3 to connect terminals of load respectively, and two other output then is connected respectively to former limit winding and the 3B of three-phase output transformer 3A, the secondary winding of 3C; And the output of lower pressure transducer 2D, 2E, 2F is connected respectively to former limit winding and the secondary winding of output transformer 3B, 3C.All six umber of turns of three three-phase output transformer 3A, 3B, 3C are identical, and three secondary windings are independent lead-in wire all; Each secondary winding of output transformer (like the v1-u4 of 3B) is connected in series corresponding phase (U-V) output of going into high tension transformer respectively.Certainly, three are coupled also has other connected mode between output transformer 3A, 3B, 3C and the lower pressure transducer 2A-2F, provide this connected mode as illustration at this.
For the connected mode of above-mentioned coupling output transformer, figure is with Fig. 4 B for its voltage compositive relation, and the output of the three-phase line voltage of high tension transformer is respectively:
V
UV＝V
UV1+V
UV2+V
UV3+V
UV4+V
UV5+V
UV6
V
VW＝V
VW1+V
VW2+V
VW3+V
VW4+V
VW5+V
VW6
V
WU＝V
WU1+V
WU2+V
WU3+V
WU4+V
WU5+V
WU6
Wherein: V
UVBe the U of high tension transformer, the line voltage between the V phase, and V
UV1～V
UV6Be respectively the U of low voltage frequency converter 2A～2F, the line voltage between the V phase; Other U
VW, U
WUSimilar, repeat no more.
Solid-state switch 231～236 all adopts pwm signal to control in the inverter bridge 23 of lower pressure transducer (like 2A); The reference wave of the pwm signal of the corresponding solid-state switch of each lower pressure transducer (as 231) is identical; Its carrier frequency is identical and have a phase difference; The high tension transformers of six lower pressure transducer output coupling series connection describing for Fig. 5 A, PWM carrier phase differ 60 ° (N=2,120 °/2=60 °) successively.Adopt above-mentioned combinations of modulation mode, the low frequency component of the output voltage of each lower pressure transducer is identical, and potential pulse staggers each other.Voltage composite formula in conjunction with the front can draw, and adopts 6 lower pressure transducer, and through transformer coupled series connection output, the output voltage of high tension transformer equals 6 times of lower pressure transducer output voltage.In addition, the line voltage of different lower pressure transducer can only change successively, makes high tension transformer be able to many level outputs, thereby has limited the output voltage rate of change.
That Fig. 5 C describes is the output voltage synthetic waveform figure between six grades of lower pressure transducer coupling output high tension transformer U, the V phase; Wherein RefU, RefV are respectively U, the V phase PWM reference waves of lower pressure transducer inverter bridge; C1 ..., C6 be respectively lower pressure transducer 2A ... the PWM carrier wave of 2F inverter bridge (phase place differs 60 ° successively), V
UV1..., V
UV6Be respectively lower pressure transducer 2A ..., the U of 2F, the V line voltage between mutually, V
UVBe the U of high tension transformer, the line voltage between the V phase, can find out that from Fig. 5 C the output line voltage current potential number of high tension transformer can reach 13.
Each lower pressure transducer 2A, 2B ..., main transformer secondary winding 12A that 2F is corresponding ..., the voltage-phase between the 12F differs 10 ° successively; Not only can make each three-phase lower pressure transducer (2A ..., 2F) DC bus-bar voltage pulsation cancel out each other; Thereby the dc ripple voltage that reduces lower pressure transducer is to the high tension transformer output voltage influence; And make lower pressure transducer (2A, 2B ..., 2F) the primary current phase place of the main transformer 1 that causes staggers 10 ° successively, can improve the input current characteristic of high voltage converter.That Fig. 5 D provides is the A phase input current synthetic waveform figure of the high tension transformer of six grades of lower pressure transducer output coupling series connection, wherein I
A1... I
A6Be respectively lower pressure transducer 2A, 2B ..., the main transformer A phase primary current component that causes of 2F, I
ABe total A phase primary current, obviously, I
AThe primary current component that causes with each lower pressure transducer is (like I
A1) compare, harmonic current significantly reduces.
The output of nine 660V three-phase lower pressure transducer is through five three-phase transformer coupling series connection; Can realize the high tension transformer of 6KV electric pressure; Fig. 6 A is depicted as the main circuit sketch map of 9 three-phase lower pressure transducer coupling series connection high tension transformers; Fig. 6 B is depicted as corresponding three-phase output transformer external wiring diagram, and Fig. 6 C is depicted as this high tension transformer output coupling series relationship figure.In this case; Because the secondary winding quantity of phase shift main transformer is more; Can take the phase shift system that divides into groups; For example: nine three-phase secondary windings are divided into three groups (L=3), and the output voltage phase place of three secondary windings (like 12A, 12B, 12C) of every group is identical, and the output voltage phase place of respectively organizing the secondary winding differs 20 ° (60 °/3) successively.The inversion PWM carrier phase of each lower pressure transducer stagger successively 40 ° (N=3,120 °/3).Adopt the coupling tandem plan of this nine lower pressure transducer; The power of each three-phase output transformer is roughly 1/9 of main transformer; The gross power of 5 output transformers is 5/9 of a main transformer; Compare with the lower pressure transducer two-level nested coupling output scheme that Fig. 2 describes, the output transformer total capacity has reduced by 1/6.
The above is merely preferred embodiment of the present invention, is not to be used to limit protection scope of the present invention.
Claims (11)
1. one kind is utilized the low pressure inversion to realize high-voltage inverted method, it is characterized in that this method comprises the steps:
A, the input of M three-phase low pressure inverter circuit is made as the electric direct voltage that is isolated from each other;
The three-phase output voltage of B, each low pressure inverter circuit, directly series connection or be connected in series to corresponding phase through the single-phase transformer coupling exchanges output to obtain three-phase high-voltage respectively; Winding through single-phase transformer between the output of said each low pressure inverter circuit connects;
C, two in the output of the three-phase of three three-phase low pressure inverter circuits directly is connected in series to the high-voltage alternating output of corresponding phase mutually respectively, this two public output of exporting mutually that then will said three low pressure inverter circuits is respectively as the three-phase output end of high-voltage inverter circuit;
D, last; The mode through pulse width modulation (PWM) respectively with each three-phase low pressure inverter circuit again; The direct voltage of input is reverse into three symmetrical PWM ac output voltages; The interchange PWM voltage reference phase of wave of the corresponding output of each three-phase low pressure inverter circuit is same, and carrier waveform is identical, phase place differs 360 °/M successively; Wherein, M is the natural number more than or equal to 3.
2. the high-voltage inverted method of low pressure inversion realization of utilizing according to claim 1 is characterized in that the output of the said acquisition three-phase high-voltage of step B electric current is specially:
B 1, said M is subtracted MOD (M; 3) output of the part of individual low pressure inverter circuit directly is connected in series to corresponding phase high-voltage alternating output mutually; All the other outputs are connected in series to corresponding phase high-voltage alternating output after isolating through single-phase transformer coupling mutually, and said MOD (M, 3) expression M is divided by 3 remainder;
If the number M of B2 low pressure inverter circuit is not 3 integral multiple, also there is remaining low pressure inverter circuit, its all three outputs are mutually respectively through being connected in series to corresponding phase high-voltage alternating output after the single-phase transformer coupling isolation.
3. the high-voltage inverted method of low pressure inversion realization of utilizing according to claim 1; It is characterized in that; Described single-phase transformer structure is identical; 3 said single-phase transformers that belong to different output phases respectively are combined into a three-phase transformer, isolate, then need Ceil (2M/3) to subtract 1 three-phase transformer at least if the said three-phase transformer of whole employings is realized coupling; Wherein, M is the natural number more than or equal to 3, and said Ceil () is the ceiling function, representes real number to rounding greatly.
4. one kind is utilized the low pressure inversion to realize high-voltage inverted circuit, and it is characterized in that said circuit comprises: M three-phase low pressure inverter circuit, Ceil (2M/3) subtract 1 three-phase transformer; The input voltage of said each three-phase low pressure inverter circuit is a direct current, and electrical isolation each other; Said M three-phase low pressure inverter circuit is divided into 3 groups at most:
First group comprises 3 three-phase low pressure inverter circuits; Wherein each low pressure inverter circuit correspondence of having two outputs directly to be connected in series to high-voltage inverter circuit is mutually respectively exported mutually, during the correspondence that remaining output is connected in series to high-voltage inverter circuit after coupling is isolated through three-phase transformer is respectively mutually exported mutually;
If M is not 3 integral multiple, also there be second group in the low pressure inverter circuit, comprises the individual low pressure inverter circuit of MOD (M, 3), and said MOD (M, 3) expression M is divided by 3 remainder; During the three-phase output of second group of each low pressure inverter circuit is exported through the correspondence that is connected in series to high-voltage inverter circuit after the three-phase transformer coupling isolation respectively mutually;
If M is the natural number more than or equal to 6; Other low pressure inverter circuit is as the 3rd group; Wherein each low pressure inverter circuit output directly is connected in series to the correspondence output phase of high-voltage inverter circuit mutually, and two other output is connected in series in the correspondence output mutually of high-voltage inverter circuit after coupling is isolated through three-phase transformer respectively mutually;
Between the output of said each low pressure inverter circuit, directly do not connect;
Said first group of each low pressure inverter circuit directly connected the common port of two phases of output respectively as the three-phase output end of high-voltage inverter circuit;
Wherein, M is the natural number more than or equal to 3; Said Ceil () is the ceiling function, representes real number to rounding greatly.
5. the high-voltage inverted circuit of low pressure inversion realization that utilizes according to claim 4 is characterized in that said M three-phase low pressure inverter circuit structure is identical; Each three-phase low pressure inverter circuit is reverse into three symmetrical PWM ac output voltages, the interchange PWM voltage reference ripple of the corresponding output of each three-phase low pressure inverter circuit through the PWM mode with the direct voltage of output respectively.
6. the high-voltage inverted circuit of low pressure inversion realization that utilizes according to claim 4 is characterized in that all umber of turns of all said three-phase transformers are identical.
7. a high tension transformer is characterized in that, comprises a main transformer, a 3N three-phase lower pressure transducer, a 2N-1 three-phase output transformer and a master controller; Said phase shift main transformer is many secondary of three-phase winding transformer; Its former limit winding connect three-phase high-voltage electrical network, secondary winding comprise be electrically isolated from one another, 3N road that output voltage equates; Every road is symmetrical three-phase output, all has one road secondary winding to be connected with it for each three-phase lower pressure transducer; The output of said lower pressure transducer links to each other with the load of high tension transformer or the winding of three-phase coupling transformer respectively; Each lower pressure transducer links to each other with master controller respectively; Wherein, N is a natural number.
8. high tension transformer according to claim 7 is characterized in that, said main transformer is a three-phase phase-shifting transformer, has the phase difference of 20/N degree between its each road secondary winding; Perhaps,
The secondary winding is divided into the L group, and said group of interior each road secondary winding phase place is identical, and each is organized, and phase place differs the 60/L degree successively between the secondary winding, and wherein, N, L are natural number, and 3N is the integral multiple of L.
9. high tension transformer according to claim 7 is characterized in that, said lower pressure transducer comprises that three-phase do not control rectifier bridge (21), DC filtering circuit (22), three-phase fully-controlled inverter bridge (23) and control Driver Circuit (24); Wherein, The AC side a of three-phase commutation bridge (21), b, c hold the input as lower pressure transducer; The road three-phase secondary winding that connects the phase shift main transformer; Its DC side p, n end is connected with the DC side of DC filtering circuit (22) and three-phase fully-controlled inverter bridge (23), and the AC side u of three-phase fully-controlled inverter bridge (23), v, w hold the output as this lower pressure transducer; Control Driver Circuit (24) is connected with master controller through optical fiber, receives the pwm signal of autonomous controller, controls the solid-state power switch (231～236) of three-phase fully-controlled inverter bridge (23), and the operation information of this lower pressure transducer is sent to master controller.
10. high tension transformer according to claim 7 is characterized in that, six umber of turns of said each three-phase output transformer are identical; Each former limit winding of three-phase output transformer connects two outputs of same lower pressure transducer; Each secondary winding of three-phase output transformer is connected in series respectively into the correspondence of high tension transformer to be exported mutually.
11. according to Claim 8 or 9 described high tension transformers; It is characterized in that; The reference wave of the inversion control pwm signal of corresponding solid-state switch is identical in the three-phase fully-controlled inverter bridge (23) of said each three-phase lower pressure transducer; Identical and the phase place of carrier wave shape differs the 120/N degree successively, and wherein, N is a natural number.
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| PCT/CN2012/073586 WO2012136145A1 (en) | 2011-04-07 | 2012-04-06 | Method, circuit, and high-voltage transformer for implementing high-voltage inversion by using low-voltage inversion |
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| WO2012136145A1 (en) | 2012-10-11 |
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