CN201378803Y - Cascade multilevel converter - Google Patents
Cascade multilevel converter Download PDFInfo
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- CN201378803Y CN201378803Y CN200920105556U CN200920105556U CN201378803Y CN 201378803 Y CN201378803 Y CN 201378803Y CN 200920105556 U CN200920105556 U CN 200920105556U CN 200920105556 U CN200920105556 U CN 200920105556U CN 201378803 Y CN201378803 Y CN 201378803Y
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Abstract
The utility model relates to a cascade multilevel converter, which comprises: a PWM rectifier, wherein the input end of the PWM rectifier is connected with a power network, the output end of the PWM rectifier is connected with a DC bus, the DC bus is connected with the input end of an inverter, and the inverter can supply power for an AC motor; a control unit, wherein information interaction can be processed between the control unit and the PWM rectifier, so that a plurality of capacitor voltages between the voltages on both sides of the PWM rectifier and the DC bus are balanced, the input power factor on the side of the power network is equal to 1, and the alternating current of the inverter, which is provided with alterable output frequency, can be controlled. The utility model needs not the phase-shifting transformer, has the advantages of small volume, light weight, low cost, four-quadrant operation capacity and obvious economic benefit, and is applicable for being popularized and applied.
Description
Technical field
The utility model relates to a kind of power electronics high-voltage large-capacity multi-level converter topological structure, is meant a kind of cascade multi-level converter especially.
Background technology
The alternating current machine of high-voltage large-capacity is widely used in the industrial circles such as steel rolling, papermaking, cement, coal, railway and boats and ships.Multilevel converter carries out frequency control to alternating current machine, not only can reach purpose of energy saving, can also improve process conditions, improve production efficiency and product quality.
At present, the multi-level converter that the high-power AC motor frequency control is used mainly includes two kinds: a kind of is the middle pressure three-level converter that adopts the diode clamp formula, and another is a H bridge cascaded high-voltage multi-level converter.Three-level converter control voltage is the alternating current machine of 3kV and the following grade of 3kV, and H bridge cascade multi-level converter major control voltage is the big capacity high alternating current machine of 6kV～10kV grade.
Though the transformer in the three-level converter is fairly simple, harmonic wave of output voltage is also lower, (general high voltage refers to the problem of difficulty of 6kV～10kV), even if gone up high pressure, the capacitance voltage of three-level converter also is difficult to reach balance but three-level converter exist to be gone up high pressure.
And H bridge cascade connection type converter is gone up high pressure easily, and input side has adopted the phase shifting transformer of special manufacturing, by the synergistic effect of this phase shifting transformer, can produce sinusoidal current on line side, make its power factor near 1, avoided harmonic pollution simultaneously electrical network.But, also there are some problems in H bridge cascade multi-level converter, such as: because each the power cell front end in the H bridge cascade multi-level converter has adopted diode not control rectification, therefore when alternating current machine is braked, converter can not be realized four quadrant running, i.e. the energy feedback grid; The tap of phase shifting transformer is many in addition, and weight and volume is big, and the cost height.
Summary of the invention
At the problems referred to above, the purpose of this utility model provides a kind of transformer that do not need, and can realize the intelligent cascade multi-level converter of four quadrant running.
For achieving the above object, the utility model is taked following technical scheme: a kind of cascade multi-level converter, it is characterized in that comprising: the input of a pulse width modulation rectifier links to each other with electrical network, the output of described pulse width modulation rectifier connects dc bus, described dc bus connects the input of an inverter, and described inverter is powered to alternating current machine; One control unit and described pulse width modulation rectifier carry out information interaction, control the voltage at described pulse width modulation rectifier two ends and the capacitance voltage between the described dc bus and reach balance, control grid side input power factor is 1, and controls the variable alternating current of described inverter output frequency.
In the described pulse width modulation rectifier, described electrical network flows to the many level brachium pontis that is connected with described inductance with alternating current by inductance; One electric current and voltage detecting unit connects the input of described pulse width modulation rectifier, and its electric current, voltage signal that described electrical network is imported in the described pulse width modulation rectifier detects, and sends described control unit to.
Described many level brachium pontis comprises the odd number elementary cell, described elementary cell comprises the device for power switching of a plurality of series connection, this series circuit is parallel with a clamping capacitance and a voltage sensor simultaneously, described voltage sensor detects the voltage signal at described clamping capacitance two ends, sends described control unit to.
Described control unit comprises: a modulus acquisition module, receive the signal that electric current and voltage detecting unit in the described pulse width modulation rectifier and voltage sensor are carried, and be converted into digital signal; One switch acquisition module is gathered the overcurrent and the overheating fault signal of described device for power switching; One digital signal microprocessor, comprise a balance of voltage module and a pulse-width modulation generation module, described balance of voltage module receives signal and the calculating that described modulus acquisition module transmits, draw the deviation between described pulse width modulation rectifier both end voltage and the normal value, described afterwards pulse-width modulation generation module sends a pulse width modulation controlled pulse signal and an auxiliary control signal according to described deviation; When there is fault in described digital signal microprocessor at described device for power switching, receive the fault-signal that described switch acquisition module transmits, in time send the corresponding protection instruction; One switching value output module receives auxiliary control signal and protection instruction that described digital signal microprocessor transmits; One pulse-width modulation expansion module receives the pulse width modulation controlled pulse signal that described pulse-width modulation output module transmits, and the auxiliary control signal of described switching value output module transmission, and expands described pulse width modulation controlled pulse signal; At least one drive circuit, receive pulse width modulation controlled pulse signal and expansion once more that described pulse-width modulation expansion module transmits, to drive corresponding device for power switching conducting or shutoff in described pulse width modulation rectifier and the inverter, making the voltage at described pulse width modulation rectifier two ends and the capacitance voltage balance between the described dc bus and grid side input power factor is 1, and controls the variable alternating current of described inverter output frequency.
Described inverter comprises at least one described many level brachium pontis, and it receives the direct current that described pulse width modulation rectifier is carried, and is converted into the alternating current and the output of changeable frequency.
Described pulse width modulation rectifier and described inverter are back to back structure.
The utility model is owing to take above technical scheme, and it has the following advantages: 1, because the utility model has saved phase shifting transformer, therefore reduced volume and weight, reduced cost.2, owing to preset a balance of voltage module and a pulse-width modulation generation module in the control unit that the utility model adopts, it can monitor in real time and control the alternating current of input pulse width modulation rectifier, the alternating current of inverter output and the voltage at device for power switching two ends, therefore improved the quality of power factor of electric network and inverter output voltage waveform, guarantee the capacitance voltage balance, be easy to control the alternating current machine of high-voltage large-capacity and many level.3, because pulse width modulation rectifier and inverter that the utility model adopts are back to back structure, therefore when alternating current machine was braked, converter can be realized four quadrant running, has improved the service efficiency of alternating current machine.The utility model volume is little, and is in light weight, and cost is low, can also four quadrant running, have tangible economic benefit, and be applicable to different mesohigh speed regualtion of AC motor field.
Description of drawings
Fig. 1 is the block diagram of the utility model converter
Fig. 2 is the structure chart of the utility model pulse width modulation rectifier
Fig. 3 is the structure chart of the utility model inverter
Fig. 4 is the structure chart of many level of the utility model brachium pontis
Fig. 5 is one of structure chart of elementary cell in the utility model two level brachium pontis
Fig. 6 is one of structure chart of elementary cell in the utility model two level brachium pontis
Fig. 7 is the structure chart of the temporary location of the utility model two level brachium pontis
Fig. 8 is the block diagram of the utility model control unit
Fig. 9 is the composition diagram of the utility model digital signal microprocessor
Embodiment
Below in conjunction with drawings and Examples the utility model is described in detail.
As shown in Figure 1, the utility model comprises a pulse width modulation rectifier 10, dc bus 20, an inverter 30 and a control unit 40. Input 11,12 on the pulse width modulation rectifier 10 all links to each other with electrical network with 13, output on the pulse width modulation rectifier 10 connects a positive dc bus P and the negative dc bus N in the dc bus 20 respectively, be in series with a plurality of electric capacity 21 between dc bus P and the dc bus N, and the positive pole of electric capacity 21 connects dc bus P, and dc bus P and dc bus N all are connected the input of inverter 30 simultaneously.Three-phase alternating current Usa, Usb and the Usc of electrical network output, be delivered to pulse width modulation rectifier 10 by input 11,12 and 13 respectively, be converted into the direct current of amplitude stability through pulse width modulation rectifier 10, this direct current is sent to inverter 30 by dc bus 20, process inverter 30 is converted into alternating current Ua, Ub and the Uc of changeable frequency, flows to the power supply of three phase alternating current motor (not shown) by the output on the inverter 30 31,32 and 33 respectively again.The output phase of alternating current Ua, Ub and Uc is corresponding to the input phase of alternating current Usa, Usb and Usc.
In said process, carry out information interaction between control unit 40 and the pulse width modulation rectifier 10, make the voltage at pulse width modulation rectifier 10 two ends and electric capacity 21 balances of voltage between the dc bus 20, make grid side three-phase alternating current Usa, Usb and Usc input power factor be 1 simultaneously, and the variable alternating current of control inverter 30 output frequencies.
In the foregoing description, pulse width modulation rectifier 10 and inverter 30 are provided with back-to-back, so the utility model realized the four-quadrant motion, i.e. the two-way flow of energy, thus improved the service efficiency of three phase alternating current motor.
As shown in Figure 2, pulse width modulation rectifier 10 comprises many level brachium pontis 14, inductance 15 and the electric current and voltage detecting unit 16 of three-phase cascade connection type.Wherein, input 11,12 is connected level brachium pontis 14 more than three by three inductance 15 respectively with 13, and three-phase alternating current Usa, the Usb of electrical network output and Usc are transported to more than three in the level brachium pontis 14 by three inductance 15 respectively.Electric current and voltage detecting unit 16 connects inputs 11,12 and 13, and voltage sensor by wherein and electric current, the voltage signal 17 in the current sensor senses electrical network input pulse width modulation rectifier 10 send these signals to control unit 40 again.In the present embodiment, voltage sensor and the current sensor of forming electric current and voltage detecting unit 16 are checkout equipment of the prior art.
As shown in Figure 3, inverter 30 comprises many level brachium pontis 14 of three-phase cascade connection type, the direct current of pulse width modulation rectifier 10 outputs is transported to respectively in many level brachium pontis 14 of inverter 30 accordingly, many level brachium pontis 14 is under the control of control unit 40, the direct current of input is converted into the alternating current of changeable frequency, exports to three phase alternating current motor.
As shown in Figure 4, in the foregoing description, each mutually more level brachium pontis 14 comprises the elementary cell 141 of the individual series connection of M (M is an odd number), and (M+1)/2 elementary cell 141 is decided to be temporary location.Wherein, each elementary cell 141 is provided with a terminal X1 and a terminal X2, and temporary location is provided with a terminal X1, a terminal X2 and a terminal X3.
As Fig. 5, shown in Figure 6, in the foregoing description, each elementary cell 141 comprises device for power switching 1411, a clamping capacitance 1412 and a voltage sensor 1413 of two series connection, clamping capacitance 1412 and voltage sensor 1413 respectively with device for power switching 1411 parallel connections of connecting, therefore voltage sensor 1413 can detect the voltage signal 1414 at clamping capacitance 1412 two ends, sends control unit 40 to.The voltage and the voltage that equals pulse width modulation rectifier 10 two ends at each clamping capacitance 1412 two ends in each mutually more level brachium pontis 14.Terminal X1 is used to connect the terminal X2 or the dc bus P of another elementary cell 141; Terminal X2 is used to connect the terminal X1 or the dc bus N of another elementary cell 141; Terminal X3 in the temporary location connects electrical network or three phase alternating current motor by inductance 15.In the foregoing description, terminal X1 in the elementary cell 141 beyond the temporary location and definite mode of terminal X2 are as follows: an end of the series circuit that is made of two device for power switching 1411 is provided with a terminal X1 or a terminal X2, corresponding therewith, the midpoint of above-mentioned series circuit is provided with a terminal X2 or a terminal X1.
As shown in Figure 7, the definite mode that is decided to be terminal X1, the terminal X2 of the elementary cell 141 of temporary location and terminal X3 is as follows: the two ends of the series circuit that is made of device for power switching 1411 are provided with a terminal X1 and a terminal X2 respectively, and the midpoint of above-mentioned series circuit is provided with a terminal X3.
In the foregoing description, the device for power switching 1411 in the elementary cell 141 can be connected in series for four, also can be connected in series for a plurality of.The kind of device for power switching 1411 is the differences according to each elementary cell 1411 output voltage grade, select corresponding power semiconductor switch, such as IGBT (InsulatedGate Bipolar Transistor, igbt), IGCT (Intergrated GateCommutated Thyristors, integrated gate commutated thyristor) etc.
As shown in Figure 8, control unit 40 comprises a digital signal microprocessor 41, a modulus acquisition module 42, a switch acquisition module 43, some switching value output modules 44, a pulse-width modulation output module 45, a pulse-width modulation expansion module 46, some drive circuits 47 and a man machine communication interface 48.
As shown in Figure 9, that digital signal microprocessor 41 adopts is High Performance DSP (digital signalprocessor, digital signal processor) chip, the model of producing such as TI company is the dsp chip of TMS320F2812, preset a balance of voltage module 411 and a pulse-width modulation generation module 412 in it, digital signal microprocessor 41 is finished keyboard by the man machine communication interface 48 of serial and is shown and to communicate by letter with PC and the function of monitoring.
Switch acquisition module 43 is gathered the fault-signal when device for power switching 1411 exists overcurrent, fault such as overheated, and sends to digital signal microprocessor 41, makes digital signal microprocessor 41 in time send protection and instructs, take safeguard measure; When device for power switching 1411 did not have overcurrent, fault such as overheated, switch acquisition module 43 was not worked.Switching value output module 44 is the I/O interface simultaneously, but the switching value control signal of receiving digital signals microprocessor 41 outputs, and auxiliary pulse-width modulation expansion module 46 carries out signal extension.
Electric current, voltage signal signal 17 and the voltage signal 1414 of 411 pairs of inputs of balance of voltage module of presetting in the digital signal microprocessor 41 calculate, deviation between the normal value that draws voltage signal 1414 and preset, pulse-width modulation generation module 412 is according to this deviation afterwards, send a pulse width modulation controlled pulse signal to pulse-width modulation output module 45 and an auxiliary control signal to switching value output module 44.When digital signal microprocessor 41 receives the fault-signal of switch acquisition module 43 transmission; the fault-signal of 41 pairs of inputs of digital signal microprocessor is judged; send the corresponding protection instruction; such as: instructions such as shutdown or the operation of reduction power; give switching value output module 44; switching value output module 44 is controlled the switching of respective switch 49, the instruction that comes combine digital signal microprocessor 41 to send by relay 48.
Pulse-width modulation output module 45 is one 6 tunnel pulse-width modulation output interface, and its pulse width modulation controlled pulse signal with digital signal microprocessor 41 outputs flows to pulse-width modulation expansion module 46.Pulse-width modulation expansion module 46 is under the assist control of switching value output module 44,6 * M road pulse width modulation controlled pulse signal of pulse-width modulation output module 45 outputs is divided into two-way 3 * M road pulse width modulation controlled pulse signal, and M is the number of the elementary cell 141 of every mutually more level brachium pontis 14 series connection.Wherein each road pulse width modulation controlled pulse signal is by corresponding driving circuit 47, drive circuit 47 expands to this road pulse width modulation controlled pulse signal the pulse width modulation controlled pulse signal of 2 tunnel complementations once more, to drive corresponding device for power switching 1411 conductings or shutoff in pulse width modulation rectifier 10 and the inverter 30, make the voltage at pulse width modulation rectifier 10 two ends and electric capacity 21 voltages between the dc bus 20 reach balance, making net side input power factor is 1, and makes the variable alternating current of inverter 30 output frequencies.Pulse-width modulation expansion module 46 in the present embodiment is Field Programmable Gate Array (FPGA, FieldProgrammable Gate Array) or CPLD (CPLD, Complex ProgrammableLogic Device), EPM7128S chip such as altera corp's production, it expands to 6 * M road with the pulse width modulation controlled pulse signal, exports again.
In the various embodiments described above; the structure of each parts, the position is set and connects and all can change to some extent; on the basis of technical solutions of the utility model,, should not get rid of outside protection range of the present utility model improvement and the equivalents that individual component is carried out.
Claims (8)
1, a kind of cascade multi-level converter, it is characterized in that comprising: the input of a pulse width modulation rectifier links to each other with electrical network, the output of described pulse width modulation rectifier connects dc bus, and described dc bus connects the input of an inverter, and described inverter is powered to alternating current machine; One control unit and described pulse width modulation rectifier carry out information interaction, control the voltage at described pulse width modulation rectifier two ends and the capacitance voltage between the described dc bus and reach balance, control grid side input power factor is 1, and controls the variable alternating current of described inverter output frequency.
2, a kind of cascade multi-level converter as claimed in claim 1 is characterized in that: in the described pulse width modulation rectifier, described electrical network flows to the many level brachium pontis that is connected with described inductance with alternating current by inductance; One electric current and voltage detecting unit connects the input of described pulse width modulation rectifier, and its electric current, voltage signal that described electrical network is imported in the described pulse width modulation rectifier detects, and sends described control unit to.
3, a kind of cascade multi-level converter as claimed in claim 2, it is characterized in that: described many level brachium pontis comprises the odd number elementary cell, described elementary cell comprises the device for power switching of a plurality of series connection, this series circuit is parallel with a clamping capacitance and a voltage sensor simultaneously, described voltage sensor detects the voltage signal at described clamping capacitance two ends, sends described control unit to.
4, as claim 1 or 2 or 3 described a kind of cascade multi-level converters, it is characterized in that: described control unit comprises:
One modulus acquisition module receives the signal that electric current and voltage detecting unit in the described pulse width modulation rectifier and voltage sensor are carried, and is converted into digital signal;
One switch acquisition module is gathered the overcurrent and the overheating fault signal of described device for power switching;
One digital signal microprocessor, comprise a balance of voltage module and a pulse-width modulation generation module, described balance of voltage module receives signal and the calculating that described modulus acquisition module transmits, draw the deviation between described pulse width modulation rectifier both end voltage and the normal value, described afterwards pulse-width modulation generation module sends a pulse width modulation controlled pulse signal and an auxiliary control signal according to described deviation; When there is fault in described digital signal microprocessor at described device for power switching, receive the fault-signal that described switch acquisition module transmits, in time send the corresponding protection instruction;
One switching value output module receives auxiliary control signal and protection instruction that described digital signal microprocessor transmits;
One pulse-width modulation expansion module receives the pulse width modulation controlled pulse signal that described pulse-width modulation output module transmits, and the auxiliary control signal of described switching value output module transmission, and expands described pulse width modulation controlled pulse signal;
At least one drive circuit, receive pulse width modulation controlled pulse signal and expansion once more that described pulse-width modulation expansion module transmits, to drive corresponding device for power switching conducting or shutoff in described pulse width modulation rectifier and the inverter, making the voltage at described pulse width modulation rectifier two ends and the capacitance voltage balance between the described dc bus and grid side input power factor is 1, and controls the variable alternating current of described inverter output frequency.
5, as claim 1 or 2 or 3 described a kind of cascade multi-level converters, it is characterized in that: described inverter comprises at least one described many level brachium pontis, it receives the direct current that described pulse width modulation rectifier is carried, and is converted into the alternating current and the output of changeable frequency.
6, a kind of cascade multi-level converter as claimed in claim 4 is characterized in that: described inverter comprises at least one described many level brachium pontis, and it receives the direct current that described pulse width modulation rectifier is carried, and is converted into the alternating current and the output of changeable frequency.
7, as claim 1 or 2 or 3 or 6 described a kind of cascade multi-level converters, it is characterized in that: described pulse width modulation rectifier and described inverter are back to back structure.
8, a kind of cascade multi-level converter as claimed in claim 5 is characterized in that: described pulse width modulation rectifier and described inverter are back to back structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920105556U CN201378803Y (en) | 2009-02-24 | 2009-02-24 | Cascade multilevel converter |
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| Application Number | Priority Date | Filing Date | Title |
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| CN200920105556U CN201378803Y (en) | 2009-02-24 | 2009-02-24 | Cascade multilevel converter |
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| CN201378803Y true CN201378803Y (en) | 2010-01-06 |
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| CN200920105556U Expired - Fee Related CN201378803Y (en) | 2009-02-24 | 2009-02-24 | Cascade multilevel converter |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102035401A (en) * | 2010-12-30 | 2011-04-27 | 中国科学院等离子体物理研究所 | Fully-controlled bridge topology structure for medium and high voltage motor drive |
| CN102231531A (en) * | 2011-06-23 | 2011-11-02 | 中电普瑞科技有限公司 | Wind electric field electrical network voltage disturbance simulation generating device |
| WO2012010068A1 (en) * | 2010-07-22 | 2012-01-26 | 荣信电力电子股份有限公司 | Topology of power-generation and grid-integration of transformerless hydraulic generator |
| US10218285B2 (en) | 2015-10-19 | 2019-02-26 | Siemens Aktiengesellschaft | Medium voltage hybrid multilevel converter and method for controlling a medium voltage hybrid multilevel converter |
-
2009
- 2009-02-24 CN CN200920105556U patent/CN201378803Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012010068A1 (en) * | 2010-07-22 | 2012-01-26 | 荣信电力电子股份有限公司 | Topology of power-generation and grid-integration of transformerless hydraulic generator |
| CN102035401A (en) * | 2010-12-30 | 2011-04-27 | 中国科学院等离子体物理研究所 | Fully-controlled bridge topology structure for medium and high voltage motor drive |
| CN102231531A (en) * | 2011-06-23 | 2011-11-02 | 中电普瑞科技有限公司 | Wind electric field electrical network voltage disturbance simulation generating device |
| CN102231531B (en) * | 2011-06-23 | 2013-11-13 | 中电普瑞科技有限公司 | Wind electric field electrical network voltage disturbance simulation generating device |
| US10218285B2 (en) | 2015-10-19 | 2019-02-26 | Siemens Aktiengesellschaft | Medium voltage hybrid multilevel converter and method for controlling a medium voltage hybrid multilevel converter |
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Granted publication date: 20100106 Termination date: 20180224 |
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