Summary of the invention
The technical problem to be solved in the present invention is, defect out of control appears in the above-mentioned traction electric machine for prior art, provides a kind of traction electric machine of avoiding to occur traction electric machine control device out of control and method.
The technical solution adopted for the present invention to solve the technical problems is: construct a kind of traction electric machine control device, comprises coordinate transformation unit, the first computing unit, the first adjuster, the second adjuster, the second computing unit, the 4th computing unit, the 3rd adjuster and space vector pulse width modulation inverter; The three-phase current of described traction electric machine is converted to the orthogonal feedback torque electric current of two-phase and feedback excitation electric current by described coordinate transformation unit; Extraneous demand torque current and described feedback torque electric current enter described first computing unit respectively and subtract each other, and described first computing unit exports the torque current deviation obtained to described first adjuster; Described first adjuster carries out proportional integral adjustment to described torque current deviation and exports the quadrature-axis voltage value obtained to described second computing unit; Extraneous demand exciting current and described feedback excitation electric current enter described 4th computing unit respectively and subtract each other, and described 4th computing unit exports the exciting current deviation obtained to described 3rd adjuster; Described 3rd adjuster carries out proportional integral adjustment to described exciting current deviation and exports the stator voltage direct axis component obtained to described space vector pulse width modulation inverter in order to control described traction electric machine; Described feedback torque electric current and feedback excitation electric current also enter described second adjuster respectively, described second adjuster processes described feedback torque electric current, feedback excitation electric current and the extraneous demand torque that enters described second adjuster respectively, and exports the voltage-regulation amount obtained to described second computing unit; Described quadrature-axis voltage value and described voltage-regulation amount are carried out superposing and are exported the stator voltage quadrature axis component obtained to described space vector pulse width modulation inverter in order to control described traction electric machine by described second computing unit.
In traction electric machine control device of the present invention, described second adjuster is stator voltage quadrature axis component adjuster.
In traction electric machine control device of the present invention, described second adjuster comprises feedback torque computing unit, torque deviation computing unit and first integrator; Described feedback torque electric current and feedback excitation electric current enter described feedback torque computing unit respectively, and described feedback torque computing unit exports the feedback torque calculated to described torque deviation computing unit; Described extraneous demand torque enters described torque deviation computing unit and subtracts each other with described feedback torque, and described torque deviation computing unit exports the torque deviation obtained to described first integrator; Described first integrator is carried out integration to described torque deviation and is exported the voltage-regulation amount obtained to described second computing unit.
In traction electric machine control device of the present invention, also comprise the 3rd computing unit and the weak magnestat for exporting weak magnetoelectricity stream; Described extraneous demand exciting current enters described 3rd computing unit respectively with described weak magnetoelectricity stream and superposes, and described 3rd computing unit exports the first exciting current deviation obtained to described 4th computing unit; Described first exciting current deviation is subtracted each other with the feedback excitation electric current entering described 4th computing unit, and described 4th computing unit exports the second exciting current deviation obtained to described 3rd adjuster; Described 3rd adjuster carries out proportional integral adjustment to described second exciting current deviation and exports the stator voltage direct axis component obtained to described space vector pulse width modulation inverter; Described stator voltage direct axis component and stator voltage quadrature axis component also enter described weak magnestat respectively, and described weak magnestat processes described stator voltage direct axis component, stator voltage quadrature axis component and the weak magnetic voltage threshold preset that enters described weak magnestat and exports the described weak magnetoelectricity stream obtained to described 3rd computing unit respectively.
In traction electric machine control device of the present invention, described weak magnestat comprises square root unit, voltage deviation computing unit, second integral device and clipping unit; Described stator voltage direct axis component and stator voltage quadrature axis component enter described square root unit respectively, the quadratic sum of described square root unit to described stator voltage direct axis component and stator voltage quadrature axis component carries out extraction of square root computing, and exports the stator terminal voltage obtained to described voltage deviation computing unit; The described weak magnetic voltage threshold preset enters described voltage deviation computing unit and subtracts each other with described stator terminal voltage, and described voltage deviation computing unit exports the voltage deviation obtained to described second integral device; Described second integral device carries out integration to described voltage deviation and exports the integration current obtained to described clipping unit; Described clipping unit carries out amplitude limiting processing to described integration current and exports the described weak magnetoelectricity stream obtained to described 3rd computing unit.
In traction electric machine control device of the present invention, the amplitude of the described weak magnetoelectricity stream that described clipping unit exports is arranged on-10 peace ~ 0 peaces.
The invention still further relates to a kind of method utilizing above-mentioned traction electric machine control device, comprise the steps:
A) when the voltage of space vector pulse width modulation inverter is greater than weak magnetic voltage threshold, weak magnetic adjustment is carried out to reduce magnetic flux to stop space vector pulse width modulation contravarianter voltage saturated; Or/and
B) when the voltage of space vector pulse width modulation inverter is greater than DC bus-bar voltage, the adjustment of stator voltage quadrature axis component is carried out.
Utilize in the method for above-mentioned traction electric machine control device of the present invention, described step B) comprise further:
B1) calculate the quadratic sum of described stator voltage direct axis component and stator voltage quadrature axis component and judge that whether space vector pulse width modulation contravarianter voltage is saturated, in this way, performing step B2); Otherwise, perform normal control program;
B2) feedback torque value is calculated, and judge whether described extraneous demand torque is greater than described feedback torque value, in this way, described stator voltage direct axis component and stator voltage quadrature axis component is made to be respectively the output valve of the 3rd adjuster and the first adjuster described in the saturated back of space vector pulse width modulation contravarianter voltage; Otherwise, perform step B3);
B3) judge whether described extraneous demand torque is less than described feedback torque value, in this way, by the adjustment of described second adjuster, stator voltage quadrature axis component is reduced, perform step B4); Otherwise, perform normal control program;
B4) calculate the quadratic sum of described stator voltage direct axis component and stator voltage quadrature axis component and judge that whether space vector pulse width modulation contravarianter voltage is saturated, in this way, described stator voltage direct axis component and stator voltage quadrature axis component is made to be respectively the output valve of the 3rd adjuster and the first adjuster described in the saturated back of space vector pulse width modulation contravarianter voltage; Otherwise, perform normal control program.
Utilize in the method for above-mentioned traction electric machine control device of the present invention, described weak magnetic voltage threshold is more than or equal to 0.95 times of described DC bus-bar voltage and is less than described DC bus-bar voltage.
Utilize in the method for above-mentioned traction electric machine control device of the present invention, described steps A) comprise further:
A1) judge whether described stator terminal voltage is greater than described weak magnetic voltage threshold, in this way, obtained the weak magnetoelectricity stream of a negative sense by the adjustment of described weak magnestat, perform steps A 2); Otherwise, perform steps A 3);
A2) the weak magnetoelectricity stream of described negative sense superposes with described exciting current, and described exciting current is reduced to weaken magnetic flux;
A3) judge whether described stator terminal voltage is less than described weak magnetic voltage threshold, in this way, the weak magnetoelectricity stream being made output by the adjustment of above-mentioned weak magnestat is 0; Otherwise, perform normal control program.
Implement traction electric machine control device of the present invention and method, there is following beneficial effect: owing to using the second adjuster and weak magnestat, when space vector pulse width modulation contravarianter voltage is greater than the weak magnetic voltage threshold preset, the weak magnetoelectricity stream being increased negative sense by the adjustment of weak magnestat weakens exciting current, to stop the saturated of space vector pulse width modulation contravarianter voltage; When space vector pulse width modulation contravarianter voltage is saturated, if extraneous demand torque is greater than feedback torque, stator voltage direct axis component and stator voltage quadrature axis component is made to be respectively the value of the saturated back of space vector pulse width modulation contravarianter voltage by the adjustment of the second adjuster, to make space vector pulse width modulation contravarianter voltage can not be saturated, if extraneous demand torque is less than feedback torque, by the adjustment of the second adjuster, stator voltage quadrature axis component is reduced, saturated to make space vector pulse width modulation contravarianter voltage exit; So it avoids traction electric machine appearance out of control.
Embodiment
Can understand for the ease of those of ordinary skill in the art and implement the present invention, below in conjunction with accompanying drawing, embodiments of the present invention is further illustrated.
In traction electric machine control device of the present invention and embodiment of the method, the structural representation of its device as shown in Figure 1, in Fig. 1, this traction electric machine control device comprises coordinate transformation unit 1, first computing unit 2, first adjuster 3, second adjuster 4, second computing unit 5, the 4th computing unit 6, the 3rd adjuster 7 and space vector pulse width modulation inverter 8; Wherein, the three-phase current of traction electric machine is converted to the orthogonal feedback torque electric current of two-phase and feedback excitation electric current by coordinate transformation unit 1, for convenience, above-mentioned three-phase current is labeled as ia, ib and ic respectively, feedback torque electric current is labeled as iq_fdb, feedback excitation electric current is labeled as id_fdb, and also namely the magnitude of current (ia, ib and ic) under a-b-c coordinate is transformed to the magnitude of current (id_fdb, iq_fdb) under d-q two phase coordinates by coordinate transformation unit 1; Extraneous demand torque current (being labeled as iq_ref) and iq_fdb enter the first computing unit 2 respectively and subtract each other, and the first computing unit 2 exports the torque current deviation obtained to first adjuster 3; Specifically, iq_ref and iq_fdb enters the first computing unit 2 respectively, and in the first computing unit 2, iq_ref deducts iq_fdb and obtains torque current deviation, and the first computing unit 2 exports torque current deviation to first adjuster 3.First 3 pairs, adjuster torque current deviation is carried out proportional integral adjustment and is exported the quadrature-axis voltage value obtained to second computing unit 5, and in the present embodiment, the first adjuster 3 is proportional integrator.It is worth mentioning that, for convenience, in Fig. 1, depict the block diagram of traction electric machine, but this traction electric machine control device does not comprise above-mentioned traction electric machine.
Extraneous demand exciting current and i_fdb enter the 4th computing unit 6 respectively and subtract each other, and the 4th computing unit 6 exports the exciting current deviation obtained to the 3rd adjuster 7; Specifically, extraneous demand exciting current and id_fdb enter the 4th computing unit 6 respectively, in the 4th computing unit 6, extraneous demand exciting current deducts id_fdb and obtains exciting current deviation, and the 4th computing unit 6 exports exciting current deviation to the 3rd adjuster 7.3rd 7 pairs, adjuster exciting current deviation is carried out proportional integral adjustment and is exported the stator voltage direct axis component obtained to space vector pulse width modulation inverter 8 in order to control traction electric machine; In the present embodiment, the 3rd adjuster 7 is proportional integrator.Iq_fdb and id_fdb also enters the second adjuster 4 respectively, second adjuster 4 processes iq_fdb, id_fdb and the extraneous demand torque that enters the second adjuster 4 respectively, and exporting the voltage-regulation amount obtained to second computing unit 5, above-mentioned voltage-regulation amount is exactly stator rotating coordinate system q shaft voltage regulated quantity in fact.How to process above-mentioned iq_fdb, id_fdb and extraneous demand torque in the second adjuster 4 about in the present embodiment, follow-up meeting has a detailed description.In the present embodiment, the second adjuster 4 is stator voltage quadrature axis component adjuster.Quadrature-axis voltage value and voltage-regulation amount are carried out superposing and are exported the stator voltage quadrature axis component obtained to space vector pulse width modulation inverter 8 in order to control traction electric machine by the second computing unit 5.In Fig. 1, above-mentioned extraneous demand exciting current is labeled as id_ref, and stator voltage direct axis component is labeled as Vd, and stator voltage quadrature axis component is labeled as Vq, and voltage-regulation amount is labeled as Vq_regulator; Above-mentioned second adjuster 4(stator voltage quadrature axis component adjuster) be correspondingly expressed as Vq adjuster.
In the other situation of the present embodiment, another structural representation of this traction electric machine control device as shown in Figure 2.Compared to Figure 1, this traction electric machine control device also comprises the 3rd computing unit 9 and weak magnestat 10 to Fig. 2, and above-mentioned weak magnestat 10 is for exporting weak magnetoelectricity stream.Id_ref enters the 3rd computing unit 9 respectively with weak magnetoelectricity stream and superposes, and the 3rd computing unit 9 exports the first exciting current deviation obtained to the 4th computing unit 6; Specifically, id_ref and weak magnetoelectricity stream enter the 3rd computing unit 9 respectively, and in the 3rd computing unit 9, id_ref superposes with weak magnetoelectricity stream and obtains the first exciting current deviation, and the 3rd computing unit 9 exports the first exciting current deviation to the 4th computing unit 6.First exciting current deviation is subtracted each other with the id_fdb entering the 4th computing unit 6, and the 4th computing unit 6 exports the second exciting current deviation obtained to the 3rd adjuster 7; Specifically, first exciting current deviation and id_fdb enter the 4th computing unit 6 respectively, in the 4th computing unit 6, the first exciting current deviation deducts id_fdb and obtains the second exciting current deviation, and the 4th computing unit 6 exports the second exciting current deviation to the 3rd adjuster 7.3rd adjuster 7 carries out proportional integral adjustment to the second exciting current deviation and exports the Vd obtained to space vector pulse width modulation inverter 8; Vd and Vq also enters weak magnestat 10 respectively, and weak magnestat 10 processes Vd, Vq and the weak magnetic voltage threshold preset that enters weak magnestat 10 and exports the weak magnetoelectricity stream obtained to the 3rd computing unit 9 respectively.In the present embodiment, according to the difference of different traction electric machine weak magnetic property, the weak magnetic voltage threshold preset can set.In Fig. 2, weak magnetoelectricity is failed to be sold at auction and is designated as id_fw.
Fig. 3 is the structural representation of the second adjuster in the present embodiment; In Fig. 3, the second adjuster 3 comprises feedback torque computing unit 41, torque deviation computing unit 42 and first integrator 43; Iq_fdb and id_fdb enters feedback torque computing unit 41 respectively, and feedback torque computing unit 41 exports the feedback torque calculated to torque deviation computing unit 42; Extraneous demand torque enters torque deviation computing unit 42 and subtracts each other with feedback torque, and torque deviation computing unit 42 exports the torque deviation obtained to first integrator 43; Specifically, extraneous demand torque and feedback torque enter torque deviation computing unit 42 respectively, in torque deviation computing unit 42, extraneous demand torque deducts feedback torque and obtains torque deviation, and torque deviation computing unit 42 exports torque deviation to first integrator 43.First integrator 43 pairs of torque deviations carry out integration and export the Vq_regulator obtained to second computing unit 5.In Fig. 3, above-mentioned feedback torque and extraneous demand torque are labeled as Torque_fdb and Torque_demand respectively.It is worth mentioning that, in the present embodiment, when calculating in feedback torque computing unit 41, the computing formula of Torque_fdb is Torque_fdb=1.5*np*Lm
2/ Lr*id_fdb*iq_fdb, wherein, np is the number of pole-pairs of traction electric machine, and Lm is the mutual inductance of stator rotating coordinate system d axle and q axle, and Lr is the self-induction of rotor at q axle; First integrator 43 is KI_Vq/s, and wherein, KI_Vq is Vq adjuster integral constant, and s is the Laplace transform factor.
Fig. 4 is the structural representation of weak magnestat in the present embodiment, and in Fig. 4, weak magnestat 10 comprises square root unit 101, voltage deviation computing unit 102, second integral device 103 and clipping unit 104; Wherein, Vd and Vq enters square root unit 101 respectively, and the quadratic sum of square root unit 101 couples of Vd and Vq carries out extraction of square root computing, and exports the stator terminal voltage obtained to voltage deviation computing unit 102; Specifically, Vd and Vq enters square root unit 101 respectively, in square root unit 101, calculates
value can obtain stator terminal voltage, square root unit 101 exports stator terminal voltage to voltage deviation computing unit 102.The weak magnetic voltage threshold preset enters voltage deviation computing unit 102 and subtracts each other with stator terminal voltage, and voltage deviation computing unit 102 exports the voltage deviation obtained to second integral device 103; Specifically, the weak magnetic voltage threshold preset and stator terminal voltage enter voltage deviation computing unit 102 respectively, in voltage deviation computing unit 102, weak magnetic voltage threshold deducts stator terminal voltage and obtains voltage deviation, and voltage deviation computing unit 102 exports voltage deviation to second integral device 103.Above-mentioned weak magnetic voltage threshold can set according to actual conditions, and weak magnetic voltage threshold is more than or equal to 0.95 times of DC bus-bar voltage and is less than DC bus-bar voltage, and DC bus-bar voltage is labeled as V
dC, in the present embodiment, weak magnetic voltage threshold is set to 0.98V
dC.Second integral device 103 pairs of voltage deviations carry out integration and export the integration current obtained to clipping unit 104, it is worth mentioning that, second integral device 103 is KI_fw/s, and wherein, KI_fw is weak magnetoelectricity stream integral controller constant, and s is the Laplace transform factor.Clipping unit 104 pairs of integration currents carry out amplitude limiting processing and export the id_fw obtained to the 3rd computing unit; In the present embodiment, clipping unit 104 has done the amplitude limiting processing of negative sense, namely clipping unit 104 can not export the id_fw of forward, when integration current is timing, after clipping unit 104, its id_fw size exported from clipping unit 104 is 0, and the amplitude of the id_fw that clipping unit 104 exports is arranged on-10 peace ~ 0 peaces.
The present embodiment also relates to a kind of method utilizing above-mentioned traction electric machine control device, and as shown in Figure 5, in Fig. 5, this utilizes the method for above-mentioned traction electric machine control device to comprise the steps: to the flow chart of the method
Step S11 is when the voltage of space vector pulse width modulation inverter is greater than weak magnetic voltage threshold, carry out weak magnetic adjustment to reduce magnetic flux to stop space vector pulse width modulation contravarianter voltage saturated: in this step, when the voltage of space vector pulse width modulation inverter is greater than weak magnetic voltage threshold, carry out weak magnetic adjustment to reduce magnetic flux to stop space vector pulse width modulation contravarianter voltage saturated, carry out weak magnetic adjustment and mainly obtain the weak magnetoelectricity stream of a negative sense to weaken extraneous demand exciting current, thus reduction magnetic flux stops space vector pulse width modulation contravarianter voltage saturated.It is worth mentioning that, weak magnetic voltage threshold is more than or equal to 0.95 times of DC bus-bar voltage and is less than DC bus-bar voltage (DC bus-bar voltage is labeled as V
dC), in the present embodiment, weak magnetic voltage threshold is set to 0.98V
dC, certainly, in the other situation of the present embodiment, weak magnetic voltage threshold can be arranged according to actual needs.About in this step when the voltage of space vector pulse width modulation inverter is greater than weak magnetic voltage threshold, how specifically carry out weak magnetic adjustment to reduce magnetic flux to stop space vector pulse width modulation contravarianter voltage saturated, refer to Fig. 6, also can be described after a while.
Step S12 is when the voltage of space vector pulse width modulation inverter is greater than DC bus-bar voltage, carry out the adjustment of stator voltage quadrature axis component: in this step, when the voltage of space vector pulse width modulation inverter is greater than DC bus-bar voltage, carry out the adjustment of stator voltage quadrature axis component, also namely when the voltage of space vector pulse width modulation inverter is greater than V
dCshi Jinhang Vq regulates (utilizing Vq adjuster to regulate), about in this step when the voltage of space vector pulse width modulation inverter is greater than DC bus-bar voltage, how specifically carry out the adjustment of stator voltage quadrature axis component, refer to Fig. 7, also can be described after a while.
It is worth mentioning that, under the certain situation of the present embodiment, only can perform step S11, also only can perform step S12, also can all perform by step S11 and step S12.When step S11 and step S12 performs, can sequencing be had, such as: after first performing step S11, perform step S12, or perform step S11 after first performing step S12; Certainly, the execution of step S11 and step S12 also can be parallel (namely separate).
For the present embodiment, when the above-mentioned voltage when space vector pulse width modulation inverter is greater than weak magnetic voltage threshold, carry out weak magnetic adjustment to reduce magnetic flux to stop particular flow sheet that space vector pulse width modulation contravarianter voltage is saturated as shown in Figure 6, it comprises:
Step S101 judges whether stator terminal voltage is greater than weak magnetic voltage threshold: in this step, judges whether stator terminal voltage is greater than weak magnetic voltage threshold, and in the present embodiment, weak magnetic voltage threshold is 0.98 times of DC bus-bar voltage, and namely weak magnetic voltage threshold is 0.98V
dC; Due to the rising along with extraneous demand torque (i.e. extraneous demand torque), stator terminal voltage constantly raises, and in this step, judges whether stator terminal voltage is greater than weak magnetic voltage threshold, judges exactly
or Vd
2+ Vq
2>(0.98V
dC)
2whether set up, in this step, if the result judged is yes, then perform step S102; If the result judged is no, then perform step S104.
Step S102 obtains the weak magnetoelectricity stream of a negative sense by the adjustment of weak magnestat: if the judged result of above-mentioned steps S101 is yes, then perform this step.Because stator terminal voltage is greater than weak magnetic voltage threshold, also when namely stator terminal voltage reaches the weak magnetic voltage threshold of setting, then enter weak magnetic and regulate the stage, now weak magnetic voltage threshold deducts the voltage deviation that stator terminal voltage obtains and is less than 0, through the adjustment of second integral device and the amplitude limit effect of clipping unit, obtain the weak magnetoelectricity stream of a negative sense, also namely weak magnestat exports the weak magnetoelectricity stream of a negative sense.Execute this step, perform step S103.
The weak magnetoelectricity stream of the above-mentioned negative sense of step S103 superposes with extraneous demand exciting current, extraneous demand exciting current is reduced to weaken magnetic flux: in this step, the weak magnetoelectricity stream of above-mentioned negative sense superposes with extraneous demand exciting current, and extraneous demand exciting current is reduced to weaken magnetic flux; Specifically, the weak magnetoelectricity stream of the negative sense exported from weak magnestat and extraneous demand exciting current carry out synthesizing (namely superposing) the 3rd computing unit, then extraneous demand exciting current reduces, thus reaches the object weakening magnetic flux.
Step S104 judges whether stator terminal voltage is less than weak magnetic voltage threshold: if the judged result of above-mentioned steps S101 is no, then perform this step.In the present embodiment, weak magnetic voltage threshold is 0.98 times of DC bus-bar voltage, and namely weak magnetic voltage threshold is 0.98V
dC; In this step, judge whether stator terminal voltage is less than weak magnetic voltage threshold, judges exactly
or Vd
2+ Vq
2<(0.98V
dC)
2whether set up, in this step, if the result judged is yes, then perform step S105; If the result judged is no, then perform step S106.
Step S105 makes the weak magnetoelectricity stream of output be 0 by the adjustment of above-mentioned weak magnestat: if the judged result of above-mentioned steps S104 is yes, then perform this step.Because stator terminal voltage is less than weak magnetic voltage threshold, also namely when stator terminal voltage does not reach weak magnetic voltage threshold, now weak magnetic voltage threshold deducts the voltage deviation that stator terminal voltage obtains and is greater than 0, through the adjustment of second integral device, then obtaining electric current from the output of second integral device is just, then through the amplitude limit effect of clipping unit, the weak magnetoelectricity stream that its weak magnestat exports is 0, so now weak magnestat does not participate in the process regulating extraneous demand exciting current.
Step S106 performs normal control program: if the judged result of above-mentioned steps S104 is no, then perform this step.In this step, perform normal control program.
For the present embodiment, when the above-mentioned voltage when space vector pulse width modulation inverter is greater than DC bus-bar voltage, as shown in Figure 7, it comprises the particular flow sheet of stator voltage quadrature axis component regulating step:
Step S201 calculates the quadratic sum of stator voltage direct axis component and stator voltage quadrature axis component and judges that whether space vector pulse width modulation contravarianter voltage is saturated: in this step, calculate the quadratic sum of stator voltage direct axis component and stator voltage quadrature axis component and judge that whether space vector pulse width modulation contravarianter voltage is saturated, namely calculating Vd
2+ Vq
2value, and judge Vd
2+ Vq
2whether be more than or equal to V
dC 2if, Vd
2+ Vq
2equal V
dC 2, then decision space Vector Pulse Width Modulation contravarianter voltage is saturated, otherwise, then decision space Vector Pulse Width Modulation contravarianter voltage unsaturation.In this step, if the result judged is yes, namely space vector pulse width modulation contravarianter voltage is saturated, then perform step S202; If the result judged is no, namely space vector pulse width modulation contravarianter voltage unsaturation, then return step S106.
Step S202 calculates feedback torque value, and judges whether extraneous demand torque is greater than feedback torque value: if the judged result of above-mentioned steps S201 is yes, then perform this step.In this step, calculate feedback torque value, and judge whether extraneous demand torque is greater than feedback torque value; Specifically, feedback torque value (i.e. the feedback torque value of the saturated back of space vector pulse width modulation contravarianter voltage or feedback torque value) is calculated in feedback torque computing unit, and judge whether extraneous demand torque is greater than feedback torque value, in this step, if the result judged is yes, then perform step S203; If the result judged is no, then perform step S204.
Step S203 makes stator voltage direct axis component and stator voltage quadrature axis component be respectively the output valve of the saturated back of space vector pulse width modulation contravarianter voltage the 3rd adjuster and the first adjuster: if the judged result of above-mentioned steps S202 is yes, then perform this step.In this step, stator voltage direct axis component and stator voltage quadrature axis component is made to be respectively the output valve of the saturated back of space vector pulse width modulation contravarianter voltage the 3rd adjuster and the first adjuster, specifically, when space vector pulse width modulation contravarianter voltage reaches capacity, if now extraneous demand torque is still greater than the feedback torque value entering voltage saturation back, then torque deviation is greater than 0, and torque deviation is through the effect of the integral element of first integrator, Vq constantly increases, and causes Vd
2+ Vq
2>V
dC 2, then at this moment make Vd and Vq keep entering the value of voltage saturation back, also namely the 3rd adjuster and the first adjuster retain the scene value entering voltage saturation back respectively, and now system no longer responds the response that extraneous demand torque increases.
Step S204 judges whether extraneous demand torque is less than feedback torque value: if the judged result of above-mentioned steps S202 is no, then perform this step.In this step, judge whether extraneous demand torque is less than feedback torque value, if the result judged is yes, then perform step S205; If the result judged is no, then return step S106.
Step S205 makes stator voltage quadrature axis component reduce by the adjustment of the second adjuster: if the judged result of above-mentioned steps S204 is yes, then perform this step.In this step, by the adjustment of the second adjuster, stator voltage quadrature axis component is reduced, specifically, when extraneous demand torque reduces, if start to be less than the feedback torque entering voltage saturation back, then torque deviation is less than 0, and torque deviation is through the effect of the integral element of first integrator, Vq reduces, and causes Vd
2+ Vq
2<V
dC 2, then space vector pulse width modulation inverter exits saturated, and the adjustment of Vd and Vq recovers normal mode.Execute this step, perform step S206.
Step S206 calculates the quadratic sum of stator voltage direct axis component and stator voltage quadrature axis component and judges that whether space vector pulse width modulation contravarianter voltage is saturated: in this step, calculate the quadratic sum of stator voltage direct axis component and stator voltage quadrature axis component and judge that whether space vector pulse width modulation contravarianter voltage is saturated, namely calculating Vd
2+ Vq
2value, and judge Vd
2+ Vq
2whether be more than or equal to V
dC 2if, Vd
2+ Vq
2equal V
dC 2, then decision space Vector Pulse Width Modulation contravarianter voltage is saturated, otherwise, then decision space Vector Pulse Width Modulation contravarianter voltage unsaturation.In this step, if the result judged is that space vector pulse width modulation contravarianter voltage is saturated, then return step S203; If the result judged is space vector pulse width modulation contravarianter voltage unsaturation, then return step S106.
In a word, in the present embodiment, when the increase along with rotating speed, space vector pulse width modulation contravarianter voltage raise and close to DC bus-bar voltage time, by the adjustment of weak magnestat, increase weak magnetoelectricity stream to weaken extraneous demand exciting current, thus reduce magnetic flux, stop the saturated of space vector pulse width modulation contravarianter voltage.Due to the restriction by weak magnetoelectricity stream, when the adjustment of weak magnestat cannot stop space vector pulse width modulation contravarianter voltage saturated, now scene value (i.e. output valve) of the saturated back of recording voltage the 3rd adjuster and the first adjuster, make the output valve of Vd and Vq constant, no longer respond extraneous changes in demand, space vector pulse width modulation contravarianter voltage would not be made so saturated and cause the out of control of modulation waveform.When demand rotating speed reduces or extraneous demand torque (i.e. extraneous demand torque) reduces, regulated the size of Vq by the torque deviation between the torque of current outside demand and the feedback torque entering voltage saturation back; When extraneous demand torque is less than the value of the feedback torque of voltage saturation back, through the adjustment of Vq adjuster, Vq reduces, calculate the value of Vd2+Vq2 and judge that whether space vector pulse width modulation contravarianter voltage is saturated, if saturated, proceeding the adjustment of Vq adjuster, i.e. scene value (i.e. output valve) of the saturated back of recording voltage the 3rd adjuster and the first adjuster, make the output valve of Vd and Vq constant, no longer respond extraneous changes in demand, maintain current state; If exit saturated, then return to normal control program, so it is out of control that traction electric machine can be avoided to occur.
The above embodiment only have expressed several execution mode of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with claims.