CN203691269U - N-input three-phase 3N+3 switching group MMC (Modular Multilevel Converter) rectifier - Google Patents

Abstract

The utility model provides an N-input three-phase 3N+3 switching group MMC (Modular Multilevel Converter) rectifier. The rectifier comprises N three-phase input alternating-current power supplies, N three-phase alternating-current inductors, a first bridge arm, a second bridge arm, a third bridge arm and a rectification load. Each of the first bridge arm, the second bridge arm and the third bridge arm is formed by connecting N+1 switching groups and two inductors in series. Each switching group is formed by connecting n power switching units in series and the three ends of the kth three-phase alternating-current power supply serve as the input of the kth circuit, wherein k is selected between 1 and N. The rectifier is controlled through carrier phase-shifting PWM and the N inputting alternating-current power supplies are converted into alternating current inputting of N circuits of 2n+1 levels. After currents are rectified and overlapped, the load is powered. The voltage stress borne by each switching tube in an MMC power switching unit is only 1/n of the voltage of the direct-current power supply and the problem of voltage sharing of the switching tubes is solved. The N-input three-phase 3N+3 switching group MMC rectifier is applicable to high-voltage and large-power occasions and occasions of inputting of multiple three-phase alternating-current power supplies.

Description

N input three-phase 3N+3 switches set MMC rectifier

Technical field

The utility model relates to module combination multi-level converter (MMC) field, is specifically related to a kind of N input three-phase 3N+3 switches set MMC rectifier.

Background technology

, under this trend, there is the direction of two kinds of improvement rectifiers: reduce passive device or improve rectifier topology structure to reduce active device as the new development that reduces active device direction at present power rectifier forward miniaturization, high reliability and low-loss future development.Three-phase 3N+3 switching rectifier has reduced 3N-3 switch and corresponding drive circuit with respect to traditional 6N switching rectifier, in the application of considering cost and volume, occupies certain advantage.But the N road three-phase input of 3N+3 switching rectifier is all converted to two level, input AC waveform is poor.In addition, the half that the voltage stress that in 3N+3 switch, each switch bears is DC bus-bar voltage, and there is the voltage-sharing of 3N+3 switching tube, this has limited the application of three-phase 3N+3 switching rectifier in high pressure and large-power occasions greatly.

In recent years, multilevel technology is constantly promoted, and successful Application is at the industrial circle such as such as high voltage direct current transmission, Electric Drive, active power filtering, static synchroballistic, common voltage-type multi-level rectifier topology is broadly divided into case bit-type and the large class of unit cascaded type two at present.Module combination multi-level converter (Modular Multilevel Converter, MMC) as a kind of novel many level topology, except having advantages of traditional multi-level rectifier, module combination multi-level rectifier adopts Modular Structure Design, is convenient to System Expansion and redundancy of effort; Have unbalanced operation ability, fault traversing and recovery capability, system reliability is high; Owing to having common DC bus, module combination multi-level rectifier is particularly useful for HVDC (High Voltage Direct Current) transmission system application.But, in the time of the three-phase AC line of N bar different frequency connected, needing 2N MMC rectifier, this has increased engineering cost greatly.

Utility model content

The purpose of this utility model is to overcome above-mentioned the deficiencies in the prior art, proposes a kind of N input three-phase 3N+3 switches set MMC rectifier.

The technical solution adopted in the utility model is as follows.

N input three-phase 3N+3 switches set MMC rectifier comprises N three-phase input ac power, a N three-phase alternating current inductance, the first brachium pontis, the second brachium pontis, the 3rd brachium pontis and load; Described the first brachium pontis is in series by N+1 switches set and 2 inductance, and described the second brachium pontis is in series by N+1 switches set and 2 inductance, and described the 3rd brachium pontis is in series by N+1 switches set and 2 inductance; I switches set of the first brachium pontis is in series by n power switch unit, i switches set of the second brachium pontis is in series by n power switch unit, i switches set of the 3rd brachium pontis is in series by n power switch unit, and wherein the value of i is 1～N+1; Three ends of k three-phase input ac power are as the input of k road, and wherein the value of k is 1～N, N>2, and n is positive integer.

In above-mentioned N input three-phase 3N+3 switches set MMC rectifier, two inductance of the first brachium pontis intercouple, and form a pair of coupling inductance; Two inductance of the second brachium pontis intercouple, and form a pair of coupling inductance; Two inductance of the 3rd brachium pontis intercouple, and form a pair of coupling inductance.

In above-mentioned N input three-phase 3N+3 switches set MMC rectifier, the lower end of the 1st switches set of the first brachium pontis and one end of the first inductance of the first brachium pontis are connected, and in the first brachium pontis, the other end of the first inductance of 2 inductance is connected with the upper end of the 2nd switches set of the first brachium pontis; The lower end of i switches set of the first brachium pontis is connected with one end of the lower end of the upper end of i+1 switches set of the first brachium pontis and the second inductance of the first brachium pontis, and the other end of the second inductance of the first brachium pontis is connected with the upper end of N+1 switches set of the first brachium pontis; The circuit structure of the circuit structure of the second brachium pontis, the circuit structure of the 3rd brachium pontis and the first brachium pontis is in full accord; One end of the w phase power supply of one end of u phase power supply of k three-phase input ac power and one end of the v phase power supply of k three-phase input ac power, a k three-phase input ac power is connected, the other end of the u phase power supply of k three-phase input ac power is connected with one end of the u phase inductance of k three-phase alternating current inductance, the upper end of the other end of the u phase inductance of k three-phase alternating current inductance and k+1 switches set of the first brachium pontis; The other end of the v phase power supply of k three-phase input ac power is connected with one end of the v phase inductance of k three-phase alternating current inductance, and the other end of the v phase inductance of k three-phase alternating current inductance is connected with the upper end of k+1 switches set of the second brachium pontis; The other end of the w phase power supply of k three-phase input ac power is connected with one end of the w phase inductance of k three-phase alternating current inductance, the other end of the w phase inductance of k three-phase alternating current inductance is connected with the upper end of k+1 switches set of the 3rd brachium pontis, and wherein the value of k is 1～N-1; One end of the w phase power supply of one end of u phase power supply of N three-phase input ac power and one end of the v phase power supply of N three-phase input ac power, a N three-phase input ac power is connected, the other end of the u phase power supply of N three-phase input ac power is connected with one end of the u phase inductance of N three-phase alternating current inductance, the lower end of the other end of the u phase inductance of N three-phase alternating current inductance and N+1 switches set of the first brachium pontis; The other end of the v phase power supply of N three-phase input ac power is connected with one end of the v phase inductance of N three-phase alternating current inductance, and the other end of the v phase inductance of N three-phase alternating current inductance is connected with the lower end of N+1 switches set of the second brachium pontis; The other end of the w phase power supply of N three-phase input ac power is connected with one end of the w phase inductance of N three-phase alternating current inductance, and the other end of the w phase inductance of N three-phase alternating current inductance is connected with the lower end of N+1 switches set of the 3rd brachium pontis; The upper end of the upper end of the upper end of the 1st switches set of the first brachium pontis and the 1st switches set of the second brachium pontis, the 1st switches set of the 3rd brachium pontis, one end of load are connected, the lower end of the lower end of the lower end of the other end of load and N+1 switches set of the first brachium pontis, N+1 switches set of the second brachium pontis, N+1 switches set of the 3rd brachium pontis, hold and be connected.

In above-mentioned N input three-phase 3N+3 switches set MMC rectifier, power switch unit is made up of the first switching tube, second switch pipe, the first diode, the second diode and electric capacity.Wherein, the positive pole of electric capacity is connected with the collector electrode of the first switching tube, the negative electrode of the first diode, the emitter of the first switching tube is connected with the anode of the first diode, the collector electrode of second switch pipe, the negative electrode of the second diode, and the emitter of second switch pipe is connected with the anode of the second diode, the negative pole of electric capacity; The collector electrode of second switch pipe is as the first output, and the emitter of second switch pipe is as the second output.

In above-mentioned N input three-phase 3N+3 switches set MMC rectifier, the second output of j power switch unit of i switches set of the first brachium pontis is connected with the first output of j+1 power switch unit of i switches set of the first brachium pontis, wherein j value is 1～n-1, and i value is 1～N+1; The second output of j power switch unit of i switches set of the second brachium pontis is connected with the first output of j+1 power switch unit of i switches set of the second brachium pontis; The second output of j power switch unit of i switches set of the 3rd brachium pontis is connected with the first output of j+1 power switch unit of i switches set of the 3rd brachium pontis.

In the control method of above-mentioned N input three-phase 3N+3 switches set MMC rectifier, adopt phase-shifting carrier wave PWM to control the opening and turn-offing of each switching tube of each switches set, each switches set of the second brachium pontis and each switches set of the 3rd brachium pontis of the first brachium pontis, wherein i value is 1～N+1; J power switch unit of j power switch unit of j power switch unit of i switches set of the first brachium pontis, i switches set of the second brachium pontis and i switches set of the 3rd brachium pontis all adopts identical triangular wave as j carrier wave C _j, wherein the value of j is 1～n; N carrier wave 360 °/n of lagging phase angle successively; The end of the first brachium pontis of k three-phase input ac power adopts k sinusoidal wave R of the first brachium pontis _sukk direct current biasing R superposes _dokobtain k modulating wave R of the first brachium pontis _suk+ R _dok, wherein the value of k is 1～N; The end of the second brachium pontis of k load adopts k sinusoidal wave R of the second brachium pontis _svkk direct current biasing R superposes _dokobtain k modulating wave R of the second brachium pontis _svk+ R _dok; The end of the 3rd brachium pontis of k load adopts k sinusoidal wave R of the 3rd brachium pontis _swkk direct current biasing R superposes _dokobtain k modulating wave R of the 3rd brachium pontis _swk+ R _dok; The k of a first brachium pontis sinusoidal wave R _suk, the second brachium pontis k sinusoidal wave R _svkk the sinusoidal wave R with the 3rd brachium pontis _swkphase place differs 120 ° successively.

In above-mentioned control method, k modulating wave R of the first brachium pontis _suk+ R _dokwith j carrier wave C _jby k comparator, as k modulating wave R of the first brachium pontis _suk+ R _dokbe greater than j carrier wave C _jtime, k comparator output high level, as k modulating wave R of the first brachium pontis _suk+ R _dokbe less than j carrier wave C _jtime, k comparator output low level, wherein the value of k is 1～N; The output of the 1st comparator is as the control level of the second switch pipe gate pole of j power switch unit of the 1st switches set of the first brachium pontis; The output of k-1 comparator is by k-1 not gate, the output of k-1 not gate and the output of k comparator obtain the control level of the second switch pipe gate pole of j power switch unit of k switches set of the first brachium pontis by k-1 XOR gate, wherein the value of k is 2～N; The output of N comparator obtains the control level of the second switch pipe gate pole of j power switch unit of N+1 switches set of the first brachium pontis by N not gate; K modulating wave R of the second brachium pontis _svk+ R _dokwith j carrier wave C _jby N+k comparator, as k modulating wave R of the second brachium pontis _svk+ R _dokbe greater than j carrier wave C _jtime, N+k comparator output high level, as k modulating wave R of the second brachium pontis _svk+ R _dokbe less than j carrier wave C _jtime, N+k comparator output low level, wherein the value of k is 1～N; The output of N+1 comparator is as the control level of the second switch pipe gate pole of j power switch unit of the 1st switches set of the second brachium pontis; The output of N+k-1 comparator is by N+k-1 not gate, the output of N+k-1 not gate and the output of N+k comparator obtain the control level of the second switch pipe gate pole of j power switch unit of k switches set of the second brachium pontis by N-1+k-1 XOR gate, wherein the value of k is 2～N; The output of 2*N comparator obtains the control level of the second switch pipe gate pole of j power switch unit of N+1 switches set of the second brachium pontis by 2*N not gate; K modulating wave R of the 3rd brachium pontis _swk+ R _dokwith j carrier wave C _jby 2*N+k comparator, as k modulating wave R of the 3rd brachium pontis _swk+ R _dokbe greater than j carrier wave C _jtime, 2*N+k comparator output high level, as k modulating wave R of the 3rd brachium pontis _swk+ R _dokbe less than j carrier wave C _jtime, 2*N+k comparator output low level, wherein the value of k is 1～N; The output of 2*N+1 comparator is as the control level of the second switch pipe gate pole of j power switch unit of the 1st switches set of the 3rd brachium pontis; The output of 2*N+k-1 comparator is by 2*N+k-1 not gate, the output of 2*N+k-1 not gate and the output of 2*N+k comparator obtain the control level of the second switch pipe gate pole of j power switch unit of k switches set of the 3rd brachium pontis by 2* (N-1)+k-1 XOR gate, wherein the value of k is 2～N; The output of 3*N comparator obtains the control level of the second switch pipe gate pole of j power switch unit of N+1 switches set of the 3rd brachium pontis by 3*N not gate.

The mode of operation of N input three-phase 3N+3 switches set MMC rectifier comprises same mode of operation and alien frequencies mode of operation frequently, and in frequency mode of operation, the frequency of N road three-phase input is identical, and amplitude is not identical; In alien frequencies mode of operation, the frequency of N road three-phase input and amplitude are all different.

Compared with prior art, the advantage the utlity model has is: N road three-phase input ac power is all converted to the interchange input that N route voltage is 2n+1 level, input current waveform is of high quality, the voltage stress that in power switch unit, each switching tube bears is only the 1/n of DC bus-bar voltage, can ensure that the voltage that in the rectifier course of work, all switching tubes bear equates, has well solved the voltage-sharing of switching tube simultaneously.Compare with existing three-phase 3N+3 switching rectifier, the N road three-phase input ac power of N input three-phase 3N+3 switches set MMC rectifier provided by the utility model is all converted to the interchange input that N route voltage is 2n+1 level, and the quality of input AC waveform is greatly improved.In addition, the voltage stress bearing of each switching tube is only the 1/n of DC bus-bar voltage, and control method provided by the utility model equates the voltage that in the rectifier course of work, all switching tubes bear, well solved the voltage-sharing of switching tube, this will be very beneficial for the application of N input three-phase 3N+3 switches set MMC rectifier in high pressure and large-power occasions.Compare with existing MMC rectifier, N provided by the utility model input three-phase 3N+3 switches set MMC rectifier has the three-phase alternating current output of N road, can be directly used in being connected of three-phase AC line of N bar different frequency, greatly reduces engineering cost.

Brief description of the drawings

Fig. 1 is the circuit structure diagram of N input three-phase 3N+3 switches set MMC rectifier of the present utility model;

Fig. 2 is the circuit structure diagram of the switch power unit of the N input three-phase 3N+3 switches set MMC rectifier shown in Fig. 1;

Fig. 3 is the phase-shifting carrier wave PWM control structure figure of the N input three-phase 3N+3 switches set MMC rectifier shown in Fig. 1;

Fig. 4 a, 4b are that three input three-phase twelvemo pass group MMC inverters work in respectively with the modulating wave under frequency mode of operation and alien frequencies mode of operation;

Fig. 5 a, 5b are that three input three-phase twelvemo passes are organized nine level MMC inverters and worked in the simulation waveform figure of mode of operation and alien frequencies mode of operation frequently.

Embodiment

For further setting forth content of the present utility model and feature, below in conjunction with accompanying drawing, specific embodiments of the present utility model is specifically described.But enforcement of the present utility model is not limited to this.

With reference to figure 1, N input three-phase 3N+3 switches set MMC rectifier of the present utility model, comprises N three-phase input ac power (u _u1, u _v1, u _w1, u _u2, u _v2, u _w2..., u _uN, u _vN, u _wN), a N three-phase alternating current inductance (L _u1, L _v1, L _w1, L _u2, L _v2, L _w2..., L _uN, L _vN, L _wN), the first brachium pontis, the second brachium pontis, the 3rd brachium pontis and load R; Described the first brachium pontis is by N+1 switches set (B _u1, B _u2..., B _{u (N+1)}) and 2 inductance (L _u1, L _u2) be in series, described the second brachium pontis is by N+1 switches set (B _v1, B _v2..., B _{v (N+1)}) and 2 inductance (L _v1, L _v2) be in series, described the 3rd brachium pontis is by N+1 switches set (B _w1, B _w2..., B _{w (N+1)}) and 2 inductance (L _w1, L _w2) be in series; I switches set B of the first brachium pontis _uiby n power switch unit (SM _bui1, SM _bui2..., SM _buin) be in series, i switches set B of the second brachium pontis _viby n power switch unit (SM _bvi1, SM _bvi2..., SM _bvin) be in series, i switches set B of the 3rd brachium pontis _wiby n power switch unit (SM _bwi1, SM _bwi2..., SM _bwin) be in series, wherein the value of i is 1～N+1; Three ends of k three-phase input ac power are as the input of k road, and wherein the value of k is 1～N, N>2.

The 1st switches set B of the first brachium pontis _u1lower end p and the first inductance L of the first brachium pontis _u1one end connect, the first inductance L of the first brachium pontis _u1the other end and the 2nd switches set B of the first brachium pontis _u2upper end o connect; I switches set B of the first brachium pontis _uilower end and i+1 switches set B of the first brachium pontis _{u (i+1)}upper end connect, wherein the value of i is 2～N-1; N switches set B of the first brachium pontis _uNlower end and the second inductance L of the first brachium pontis _u2one end connect, the second inductance L of the first brachium pontis _u2the other end and N+1 switches set B of the first brachium pontis _{u (N+1)}upper end connect; The circuit structure of the circuit structure of the second brachium pontis, the circuit structure of the 3rd brachium pontis and the first brachium pontis is in full accord; The u phase power supply u of k three-phase input ac power _ukthe v phase power supply u of one end and k three-phase input ac power _vkone end, the w phase power supply u of a k three-phase input ac power _wkone end connect, the u phase power supply u of k three-phase input ac power _ukthe other end and the u phase inductance L of k three-phase alternating current inductance _ukone end connect, the u phase inductance L of k three-phase alternating current inductance _ukthe other end and k+1 switches set B of the first brachium pontis _{u (k+1)}upper end; The v phase power supply u of k three-phase input ac power _vkthe other end and the v phase inductance L of k three-phase alternating current inductance _vkone end connect, the v phase inductance L of k three-phase alternating current inductance _vkthe other end and k+1 switches set B of the second brachium pontis _{v (k+1)}upper end connect; The w phase power supply u of k three-phase input ac power _wkthe other end and the w phase inductance L of k three-phase alternating current inductance _wkone end connect, the w phase inductance L of k three-phase alternating current inductance _wkthe other end and k+1 switches set B of the 3rd brachium pontis _{w (k+1)}upper end connect, wherein the value of k is 1～N-1; The u phase power supply u of N three-phase input ac power _uNthe v phase power supply u of one end and N three-phase input ac power _vNone end, the w phase power supply u of a N three-phase input ac power _wNone end connect, the u phase power supply u of N three-phase input ac power _uNthe other end and the u phase inductance L of N three-phase alternating current inductance _uNone end connect, the u phase inductance L of N three-phase alternating current inductance _uNthe other end and N+1 switches set B of the first brachium pontis _{u (N+1)}lower end; The v phase power supply u of N three-phase input ac power _vNthe other end and the v phase inductance L of N three-phase alternating current inductance _vNone end connect, the v phase inductance L of N three-phase alternating current inductance _vNthe other end and N+1 switches set B of the second brachium pontis _{v (N+1)}lower end connect; The w phase power supply u of N three-phase input ac power _wNthe other end and the w phase inductance L of N three-phase alternating current inductance _wNone end connect, the w phase inductance L of N three-phase alternating current inductance _wNthe other end and N+1 switches set B of the 3rd brachium pontis _{w (N+1)}lower end connect; The 1st switches set B of the first brachium pontis _u1upper end and the 1st switches set B of the second brachium pontis _v1upper end, the 1st switches set B of the 3rd brachium pontis _w1one end of upper end, load R connect, N+1 switches set B of the other end of load R and the first brachium pontis _{u (N+1)}lower end, N+1 switches set B of the second brachium pontis _{v (N+1)}lower end, N+1 switches set B of the 3rd brachium pontis _{w (N+1)}lower end, hold G connect.

Fig. 2 illustrates the circuit structure diagram of the switch power unit of the N input three-phase 3N+3 switches set MMC rectifier shown in Fig. 1.Power switch unit is by the first switching tube S ₁, second switch pipe S ₂, the first diode D ₁, the second diode D ₂and capacitor C _sMform.Wherein, capacitor C _sMpositive pole and the first switching tube S ₁collector electrode, the first diode D ₁negative electrode connect, the first switching tube S ₁emitter and the first diode D ₁anode, second switch pipe S ₂collector electrode, the second diode D ₂negative electrode connect, second switch pipe S ₂emitter and the second diode D ₂anode, capacitor C _sMnegative pole connect; Second switch pipe S ₂collector electrode as the first output, second switch pipe S ₂emitter as the second output.

As shown in Figure 1, i switches set B of the first brachium pontis _uij power switch unit SM _buijthe second output and i switches set B of the first brachium pontis _uij+1 power switch unit SM _{bui (j+1)}first output connect, wherein j value is 1～n-1, i value is 1～N+1; I switches set B of the second brachium pontis _vij power switch unit SM _bvijthe second output and i switches set B of the second brachium pontis _vij+1 power switch unit SM _{bvi (j+1)}first output connect; I switches set B of the 3rd brachium pontis _vij power switch unit SM _bvijthe second output and i switches set B of the 3rd brachium pontis _vij+1 power switch unit SM _{bvi (j+1)}first output connect.

Make the u phase voltage source of k three-phase input ac power be

the v phase voltage source of k three-phase input ac power is

the w phase voltage source of k three-phase input ac power is

:

In formula, U _ofor output voltage.

N input three-phase 3N+3 switches set MMC rectifier shown in Fig. 1 adopts phase-shifting carrier wave PWM to control, as shown in Figure 2.

Adopt phase-shifting carrier wave PWM to control each switches set B of the first brachium pontis _ui, the second brachium pontis each switches set B _vieach switches set B with the 3rd brachium pontis _withe opening and turn-offing of each switching tube, wherein i value is 1～N+1; I switches set B of the first brachium pontis _uij power switch unit SM _buij, the second brachium pontis i switches set B _vij power switch unit SM _bviji the switches set B with the 3rd brachium pontis _wij power switch unit SM _bwijall adopt identical triangular wave as j carrier wave C _j, wherein the value of j is 1～n; N carrier wave (C ₁, C ₂..., C _n) 360 °/n of lagging phase angle successively; The end a of the first brachium pontis of k three-phase input ac power _ukadopt k sinusoidal wave R of the first brachium pontis _sukk direct current biasing R superposes _dokobtain k modulating wave R of the first brachium pontis _suk+ R _dok, wherein the value of k is 1～N; The end a of the second brachium pontis of k load _vkadopt k sinusoidal wave R of the second brachium pontis _svkk direct current biasing R superposes _dokobtain k modulating wave R of the second brachium pontis _svk+ R _dok; The end a of the 3rd brachium pontis of k load _wkadopt k sinusoidal wave R of the 3rd brachium pontis _swkk direct current biasing R superposes _dokobtain k modulating wave R of the 3rd brachium pontis _swk+ R _dok; The k of a first brachium pontis sinusoidal wave R _suk, the second brachium pontis k sinusoidal wave R _svkk the sinusoidal wave R with the 3rd brachium pontis _swkphase place differs 120 ° successively.

K modulating wave R of the first brachium pontis _suk+ R _dokwith j carrier wave C _jby k comparator, as k modulating wave R of the first brachium pontis _suk+ R _dokbe greater than j carrier wave C _jtime, k comparator output high level, as k modulating wave R of the first brachium pontis _suk+ R _dokbe less than j carrier wave C _jtime, k comparator output low level, wherein the value of k is 1～N; The output of the 1st comparator is as the 1st switches set B of the first brachium pontis _u1j power switch unit SM _bu1jsecond switch pipe S ₂the control level S of gate pole _bu1j; The output of k-1 comparator is by k-1 not gate, and the output of k-1 not gate and the output of k comparator obtain k switches set B of the first brachium pontis by k-1 XOR gate _ukj power switch unit SM _bukjsecond switch pipe S ₂the control level S of gate pole _bukj, wherein the value of k is 2～N; The output of N comparator obtains N+1 switches set B of the first brachium pontis by N not gate _{u (N+1)}j power switch unit SM _{bu (N+1) j}second switch pipe S ₂the control level S of gate pole _{bu (N+1) j}; K modulating wave R of the second brachium pontis _svk+ R _dokwith j carrier wave C _jby N+k comparator, as k modulating wave R of the second brachium pontis _svk+ R _dokbe greater than j carrier wave C _jtime, N+k comparator output high level, as k modulating wave R of the second brachium pontis _svk+ R _dokbe less than j carrier wave C _jtime, N+k comparator output low level, wherein the value of k is 1～N; The output of N+1 comparator is as the 1st switches set B of the second brachium pontis _v1j power switch unit SM _bv1jsecond switch pipe S ₂the control level S of gate pole _bv1j; The output of N+k-1 comparator is by N+k-1 not gate, and the output of N+k-1 not gate and the output of N+k comparator obtain k switches set B of the second brachium pontis by N-1+k-1 XOR gate _vkj power switch unit SM _bvkjsecond switch pipe S ₂the control level S of gate pole _bvkj, wherein the value of k is 2～N; The output of 2*N comparator obtains N+1 switches set B of the second brachium pontis by 2*N not gate _{v (N+1)}j power switch unit SM _{bv (N+1) j}second switch pipe S ₂the control level S of gate pole _{bv (N+1) j}; K modulating wave R of the 3rd brachium pontis _swk+ R _dokwith j carrier wave C _jby 2*N+k comparator, as k modulating wave R of the 3rd brachium pontis _swk+ R _dokbe greater than j carrier wave C _jtime, 2*N+k comparator output high level, as k modulating wave R of the 3rd brachium pontis _swk+ R _dokbe less than j carrier wave C _jtime, 2*N+k comparator output low level, wherein the value of k is 1～N; The output of 2*N+1 comparator is as the 1st switches set B of the 3rd brachium pontis _w1j power switch unit SM _bw1jsecond switch pipe S ₂the control level S of gate pole _bw1j; The output of 2*N+k-1 comparator is by 2*N+k-1 not gate, and the output of 2*N+k-1 not gate and the output of 2*N+k comparator obtain k switches set B of the 3rd brachium pontis by 2* (N-1)+k-1 XOR gate _wkj power switch unit SM _bwkjsecond switch pipe S ₂the control level S of gate pole _bwkj, wherein the value of k is 2～N; The output of 3*N comparator obtains N+1 switches set B of the 3rd brachium pontis by 3*N not gate _{w (N+1)}j power switch unit SM _{bw (N+1) j}second switch pipe S ₂the control level S of gate pole _{bw (N+1) j}.

Each brachium pontis that described control method can ensure described rectifier each time be carved with the output voltage u of n power switch unit _sM=E, the output voltage u of N*n power switch unit _sM=0, meet $\underset{i=1}{\overset{N+1}{\mathrm{\Σ}}}{u}_{\mathrm{Bui}}=U_o,\underset{i=1}{\overset{N+1}{\mathrm{\Σ}}}{u}_{\mathrm{Bvi}}=U_o$ With $\underset{i=1}{\overset{N+1}{\mathrm{\Σ}}}{u}_{\mathrm{Bwi}}=U_o,$ Wherein u _buibe the output voltage of i switches set of the first brachium pontis, u _bvibe the output voltage of i switches set of the second brachium pontis, u _bwibe the output voltage of i switches set of the 3rd brachium pontis, E is capacitor C in each power switch unit _sMon voltage, and have E=U _o/ n, the voltage stress that in power switch unit, each switching tube bears is only the 1/n of DC bus-bar voltage, can ensure that the voltage that in the rectifier course of work, all switching tubes bear equates, has well solved the voltage-sharing of switching tube simultaneously.

Taking three input three-phase twelvemo pass group MMC inverters as example, Fig. 4 a illustrates that it works in the 1st the modulating wave R with the first brachium pontis under frequency mode of operation _su1+ R _do1, the first brachium pontis the 2nd modulating wave R _su2+ R _do1, the first brachium pontis the 3rd modulating wave R _su3+ R _do1with j carrier wave C _jrelation.Can find out the 1st sinusoidal wave R of the first brachium pontis from Fig. 4 a _su1, the first brachium pontis the 2nd sinusoidal wave R _su2the 3rd the sinusoidal wave R with the first brachium pontis _su3frequency identical, amplitude is not identical.Fig. 4 b illustrates that it works in the 1st modulating wave R of the first brachium pontis under alien frequencies mode of operation _su1+ R _do1, the first brachium pontis the 2nd modulating wave R _su2+ R _do1, the first brachium pontis the 3rd modulating wave R _su3+ R _do1with j carrier wave C _jrelation.Can find out the 1st sinusoidal wave R of the first brachium pontis from Fig. 4 b _su1, the first brachium pontis the 2nd sinusoidal wave R _su2the 3rd the sinusoidal wave R with the first brachium pontis _su3frequency and amplitude all not identical.The 1st modulating wave R of the second brachium pontis _sv1+ R _do1, the second brachium pontis the 2nd modulating wave R _sv2+ R _do1, the second brachium pontis the 3rd modulating wave R _sv3+ R _do1with j carrier wave C _jrelation and the 1st modulating wave R of the first brachium pontis _su1+ R _do1, the first brachium pontis the 2nd modulating wave R _su2+ R _do1, the first brachium pontis the 3rd modulating wave R _su3+ R _do1with j carrier wave C _jrelation identical; The 1st modulating wave R of the 3rd brachium pontis _sw1+ R _do1, the 3rd brachium pontis the 2nd modulating wave R _sw2+ R _do1, the 3rd brachium pontis the 3rd modulating wave R _sw3+ R _do1with j carrier wave C _jrelation and the first brachium pontis the 1st modulating wave R _su1+ R _do1, the first brachium pontis the 2nd modulating wave R _su2+ R _do1, the first brachium pontis the 3rd modulating wave R _su3+ R _do1with j carrier wave C _jrelation identical.

Fig. 5 a is that three input three-phase twelvemo passes are organized nine level MMC rectifiers (N=3, n=4) and worked in the simulation waveform figure of mode of operation frequently, is 3 phase voltage (u of the 1st three-phase input ac power successively _u1, u _v1, u _w1), the 1st 3 line voltage (u that three-phase input ac power provides _uv1, u _vw1, u _wu1), 3 phase voltage (u of the 2nd three-phase input ac power _u2, u _v2, u _w2), the 2nd 3 line voltage (u that three-phase input ac power provides _uv2, u _vw2, u _wu2), 3 phase voltage (u of the 3rd three-phase input ac power _u3, u _v3, u _w3), the 3rd 3 line voltage (u that three-phase input ac power provides _uv3, u _vw3, u _wu3), output voltage U _o, from 3 phase voltage (u of visible the 1st the three-phase input ac power of Fig. 5 a _u1, u _v1, u _w1), 3 phase voltage (u of the 2nd three-phase input ac power _u2, u _v2, u _w2) and 3 phase voltage (u of the 3rd three-phase input ac power _u3, u _v3, u _w3) frequency identical, amplitude is not identical; Fig. 5 b is the simulation waveform figure that nine level MMC rectifiers are organized and work in alien frequencies mode of operation in three input three-phase twelvemo passes, is 3 phase voltage (u of the 1st three-phase input ac power successively _u1, u _v1, u _w1), the 1st 3 line voltage (u that three-phase input ac power provides _uv1, u _vw1, u _wu1), 3 phase voltage (u of the 2nd three-phase input ac power _u2, u _v2, u _w2), the 2nd 3 line voltage (u that three-phase input ac power provides _uv2, u _vw2, u _wu2), 3 phase voltage (u of the 3rd three-phase input ac power _u3, u _v3, u _w3), the 3rd 3 line voltage (u that three-phase input ac power provides _uv3, u _vw3, u _wu3), output voltage U _o, from 3 phase voltage (u of visible the 1st the three-phase input ac power of Fig. 5 a _u1, u _v1, u _w1), 3 phase voltage (u of the 2nd three-phase input ac power _u2, u _v2, u _w2) and 3 phase voltage (u of the 3rd three-phase input ac power _u3, u _v3, u _w3) frequency and amplitude all not identical.

Above-described embodiment is preferably execution mode of the utility model; but execution mode of the present utility model is not limited by the examples; other any do not deviate from change, the modification done under Spirit Essence of the present utility model and principle, substitutes, combination, simplify; all should be equivalent substitute mode, within being included in protection range of the present utility model.

Claims (5)

1.N input three-phase 3N+3 switches set MMC rectifier, is characterized in that: comprise N three-phase input ac power ( u _u1 , u _v1 , u _w1 , u _u2 , u _v2 , u _w2 ..., u _uN , u _vN , u _wN ), a N three-phase alternating current inductance ( l _u1 , l _v1 , l _w1 , l _u2 , l _v2 , l _w2 ..., l _uN , l _vN , l _wN ), the first brachium pontis, the second brachium pontis, the 3rd brachium pontis and load ( r); Described the first brachium pontis is by N+1 switches set (B _u1, B _u2..., B _{u (N+1)}) and 2 inductance ( l _u1 , l _u2 ) be in series, described the second brachium pontis is by N+1 switches set (B _v1, B _v2..., B _{v (N+1)}) and 2 inductance ( l _v1 , l _v2 ) be in series, described the 3rd brachium pontis is by N+1 switches set (B _w1, B _w2..., B _{w (N+1)}) and 2 inductance ( l _w1 , l _w2 ) be in series; I switches set (B of the first brachium pontis _ui) by n power switch unit (SM _bui1, SM _bui2..., SM _buin) be in series, i switches set (B of the second brachium pontis _vi) by n power switch unit (SM _bvi1, SM _bvi2..., SM _bvin) be in series, i switches set (B of the 3rd brachium pontis _wi) by n power switch unit (SM _bwi1, SM _bwi2..., SM _bwin) be in series, wherein the value of i is 1 ~ N+1; Three ends of k three-phase input ac power are as the input of k road, and wherein the value of k is 1 ~ N, N>2, and n is positive integer.

2. N according to claim 1 input three-phase 3N+3 switches set MMC rectifier, is characterized in that: two inductance of the first brachium pontis ( l _u1 , l _u2 ) intercouple, form a pair of coupling inductance; Two inductance of the second brachium pontis ( l _v1 , l _v2 ) intercouple, form a pair of coupling inductance; Two inductance of the 3rd brachium pontis ( l _w1 , l _w2 ) intercouple, form a pair of coupling inductance.

3. N input three-phase 3N+3 switches set MMC rectifier according to claim 1, is characterized in that: the 1st switches set (B of the first brachium pontis _u1) lower end (p) and the first brachium pontis in 2 inductance the first inductance ( l _u1 ) one end connect, the first inductance of the first brachium pontis ( l _u1 ) the other end and the 2nd switches set (B of the first brachium pontis _u2) upper end (o) connect; I switches set (B of the first brachium pontis _ui) lower end and i+1 switches set (B of the first brachium pontis _{u (i+1)}) upper end (connect, wherein the value of i is 2 ~ N-1; N switches set (B of the first brachium pontis _uN) lower end and the second inductance of the first brachium pontis ( l _u2 ) one end connect, the second inductance of the first brachium pontis ( l _u2 ) the other end and N+1 switches set (B of the first brachium pontis _{u (N+1)}) upper end connect; The circuit structure of the circuit structure of the second brachium pontis, the circuit structure of the 3rd brachium pontis and the first brachium pontis is in full accord; The u phase power supply of k three-phase input ac power ( u _uk ) one end and k three-phase input ac power v phase power supply ( u _vk ) one end, a k three-phase input ac power w phase power supply ( u _wk ) one end connect, the u phase power supply of k three-phase input ac power ( u _uk ) the other end and the u phase inductance of k three-phase alternating current inductance ( l _uk ) one end connect, the u phase inductance of k three-phase alternating current inductance ( l _uk ) the other end and k+1 switches set (B of the first brachium pontis _{u (k+1)}) upper end; The v phase power supply of k three-phase input ac power ( u _vk ) the other end and the v phase inductance of k three-phase alternating current inductance ( l _vk ) one end connect, the v phase inductance of k three-phase alternating current inductance ( l _vk ) the other end and k+1 switches set (B of the second brachium pontis _{v (k+1)}) upper end connect; The w phase power supply of k three-phase input ac power ( u _wk ) the other end and the w phase inductance of k three-phase alternating current inductance ( l _wk ) one end connect, the w phase inductance of k three-phase alternating current inductance ( l _wk ) the other end and k+1 switches set (B of the 3rd brachium pontis _{w (k+1)}) upper end connect, wherein the value of k is 1 ~ N-1; The u phase power supply of N three-phase input ac power ( u _uN ) one end and N three-phase input ac power v phase power supply ( u _vN ) one end, a N three-phase input ac power w phase power supply ( u _wN ) one end connect, the u phase power supply of N three-phase input ac power ( u _uN ) the other end and the u phase inductance of N three-phase alternating current inductance ( l _uN ) one end connect, the u phase inductance of N three-phase alternating current inductance ( l _uN ) the other end and N+1 switches set (B of the first brachium pontis _{u (N+1)}) lower end; The v phase power supply of N three-phase input ac power ( u _vN ) the other end and the v phase inductance of N three-phase alternating current inductance ( l _vN ) one end connect, the v phase inductance of N three-phase alternating current inductance ( l _vN ) the other end and N+1 switches set (B of the second brachium pontis _{v (N+1)}) lower end connect; The w phase power supply of N three-phase input ac power ( u _wN ) the other end and the w phase inductance of N three-phase alternating current inductance ( l _wN ) one end connect, the w phase inductance of N three-phase alternating current inductance ( l _wN ) the other end and N+1 switches set (B of the 3rd brachium pontis _{w (N+1)}) lower end connect; The 1st switches set (B of the first brachium pontis _u1) upper end and the 1st switches set (B of the second brachium pontis _v1) upper end, the 1st switches set (B of the 3rd brachium pontis _w1) upper end, load ( r) one end connect, load ( r) the other end and N+1 switches set (B of the first brachium pontis _{u (N+1)}) lower end, N+1 switches set (B of the second brachium pontis _{v (N+1)}) lower end, N+1 switches set (B of the 3rd brachium pontis _{w (N+1)}) lower end, hold ( g) connect.

4. N according to claim 1 input three-phase 3N+3 switches set MMC rectifier, is characterized in that: power switch unit by the first switching tube ( s ₁ ), second switch pipe ( s ₂ ), the first diode ( d ₁ ), the second diode ( d ₂ ) and electric capacity ( c _sM ) form, wherein, electric capacity (C _sM) positive pole and the first switching tube ( s ₁ ) collector electrode, the first diode ( d ₁ ) negative electrode connect, the first switching tube ( s ₁ ) emitter and the first diode ( d ₁ ) anode, second switch pipe ( s ₂ ) collector electrode, the second diode ( d ₂ ) negative electrode connect, second switch pipe ( s ₂ ) emitter and the second diode ( d ₂ ) anode, electric capacity ( c _sM ) negative pole connect; Second switch pipe ( s ₂ ) collector electrode as the first output, second switch pipe ( s ₂ ) emitter as the second output.

5. N input three-phase 3N+3 switches set MMC rectifier according to claim 1, is characterized in that: i switches set (B of the first brachium pontis _ui) j power switch unit (SM _buij) the second output and i switches set (B of the first brachium pontis _ui) j+1 power switch unit (SM _{bui (j+1)}) first output connect, wherein j value is 1 ~ n-1, i value is 1 ~ N+1; I switches set (B of the second brachium pontis _vi) j power switch unit (SM _bvij) the second output and i switches set (B of the second brachium pontis _vi) j+1 power switch unit (SM _{bvi (j+1)}) first output connect; I switches set (B of the 3rd brachium pontis _vi) j power switch unit (SM _bvij) the second output and i switches set (B of the 3rd brachium pontis _vi) j+1 power switch unit (SM _{bvi (j+1)}) first output connect.

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