Summary of the invention
For one of addressing the above problem, the invention provides a kind of electric automobile overspeed protection control method, system and electric automobile, it can initiatively provide the resistance that makes its deceleration for car load, thereby guarantees the electric automobile safety traffic.
For achieving the above object, the invention provides a kind of electric automobile overspeed protection control method, it may further comprise the steps:
1) the monitoring current rotational speed N of motor and current vehicle speed V;
2) judge that whether the current rotational speed N of motor is greater than default protection rotational speed N
1, if not, then return step 1); If then forward step 3) to;
3) obtain overspeed protection torque T q_regens according to the current rotational speed N of motor and current vehicle speed V, and slow down based on Tq_regens control motor.
Wherein, in step 3), judge whether accelerator pedal is in the state that is operated, if not, then enter the treatment progress that accelerator pedal is not operated; If then enter the treatment progress that accelerator pedal is operated.
Wherein, the treatment progress that is not operated of accelerator pedal comprises:
311) based on the current rotational speed N of motor and current vehicle speed V, obtain the overspeed protection moment of torsion, that is:
Drive rotational speed N based on the current rotational speed N of motor and recovery
2, obtain the second speed discrepancy N
Diff2Obtain the first torque coefficient s1 according to the current rotational speed N of motor; Obtain the second torque coefficient s2 according to current vehicle speed V;
Obtain conventional regeneration braking output torque Tq_regen based on the current rotational speed N of motor, s1 and s2;
According to the second speed discrepancy N
Diff2Obtain the 3rd torque coefficient s3 with current vehicle speed V;
Obtain revising torque T q_corr based on the current rotational speed N of motor and the 3rd torque coefficient s3;
Tq_regen obtains described overspeed protection torque T q_regens, wherein said overspeed protection torque T q_regens=Tq_regen+Tq_corr with revising torque T q_corr based on conventional regeneration braking output torque;
312) slow down according to Tq_regens control motor;
313) the current rotational speed N of motor after detection is slowed down, and whether the current rotational speed N of motor after the judgement deceleration is less than recovering the driving rotational speed N
2If,, then enter conventional drive pattern; If not, then return step 311).
Wherein, the treatment progress that is not operated of accelerator pedal comprises:
321) based on the current rotational speed N of motor and current vehicle speed V, obtain the overspeed protection moment of torsion, that is:
Calculate the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2
According to N
Diff1And N
Diff2Obtain the 4th torque coefficient s4;
Obtain the 5th torque coefficient s5 according to current vehicle speed V;
Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 4th torque coefficient s4 and the 5th torque coefficient s5;
322) slow down according to Tq_regens control motor;
323) the current rotational speed N of motor after detection is slowed down, and whether the current rotational speed N of motor after the judgement deceleration is less than recovering the driving rotational speed N
2If,, then enter conventional drive pattern; If not, then return step 321).
Wherein, in the treatment progress that accelerator pedal is operated, be 0 with the driving torque unloading earlier, then carry out following step:
331) based on the current rotational speed N of motor and current vehicle speed V, obtain the overspeed protection moment of torsion, that is:
Calculate the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2
According to N
Diff1And N
Diff2Obtain the 6th torque coefficient s6;
Obtain the 7th torque coefficient s7 according to current vehicle speed V;
Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 6th torque coefficient s6 and the 7th torque coefficient s7;
332) slow down according to Tq_regens control motor;
333) judge whether accelerator pedal still is in the state that is operated, if not, then detect the current rotational speed N of motor after slowing down, and judge whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2If,, then enter conventional drive pattern; If not, then enter the treatment progress that accelerator pedal is not operated;
If then detect the current rotational speed N of motor after slowing down, and whether the current rotational speed N of motor after the judgement deceleration is less than the protection rotational speed N
1If,, then the current rotational speed N of motor after slowing down is carried out PID control so that the current rotational speed N of motor is maintained the protection rotational speed N
1Near, be in the state that is not operated until accelerator pedal; If not, then return step 331).
For this reason, the invention provides a kind of electric automobile overspeed protection control system, it comprises monitoring means, control unit and performance element, wherein:
Monitoring means is used for the monitoring current rotational speed N of motor and current vehicle speed V, and the current rotational speed N of motor and current vehicle speed V are sent to control unit;
Control unit comprises judge module and control and processing module, wherein:
Judge module is used for judging that whether the current rotational speed N of motor is greater than default protection rotational speed N
1, and with judged result be sent to control and processing module;
Control and processing module are used for working as the current rotational speed N of motor greater than the protection rotational speed N
1The time, determine overspeed protection torque T q_regens based on the current rotational speed N of motor and current vehicle speed V, and the execution signal that will include overspeed protection torque T q_regens is sent to performance element;
Performance element is used for slowing down according to described execution signal control motor.
Wherein, judge module also is used for judging whether accelerator pedal is operated, and judged result is sent to described control and processing module;
When the current rotational speed N of motor greater than the protection rotational speed N
1The time, control and processing module enter the operational mode that operational mode that accelerator pedal is operated or accelerator pedal are not operated according to the state of accelerator pedal.
Wherein, in the operational mode that accelerator pedal is not operated, described control unit is carried out following operation:
Control and processing module obtain the overspeed protection moment of torsion based on the current rotational speed N of motor and current vehicle speed V, that is:
Drive rotational speed N based on the current rotational speed N of motor and recovery
2Obtain the second speed discrepancy N
Diff2Obtain the first torque coefficient s1 according to the current rotational speed N of motor; Obtain the second torque coefficient s2 according to current vehicle speed V;
Obtain conventional regeneration braking output torque Tq_regen based on the current rotational speed N of motor, s1 and s2;
According to the second speed discrepancy N
Diff2Obtain the 3rd torque coefficient s3 with current vehicle speed V;
Obtain revising torque T q_corr based on the current rotational speed N of motor and the 3rd torque coefficient s3;
Tq_regen obtains described overspeed protection torque T q_regens, wherein overspeed protection torque T q_regens=Tq_regen+Tq_corr with revising torque T q_corr based on conventional regeneration braking output torque;
The execution signal that control and processing module will include described overspeed protection torque T q_regens is sent to performance element with the deceleration of control motor;
Judge module is used for also judging whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2, and judged result is sent to described control and processing module;
If the current rotational speed N of motor after slowing down is less than recovering to drive rotational speed N
2, then described control and processing module are sent the conventional instruction that drives, and make vehicle enter conventional drive pattern; If the current rotational speed N of motor after slowing down is more than or equal to recovering to drive rotational speed N
2, then described control and processing module recomputate overspeed protection torque T q_regens based on the current rotational speed N of motor after slowing down, and send it to performance element with control motor continuation deceleration.
Wherein, in the operational mode that accelerator pedal is not operated, control unit is carried out following operation:
Described control and processing module obtain the overspeed protection moment of torsion based on the current rotational speed N of motor and current vehicle speed V, that is:
Calculate the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2
According to N
Diff1And N
Diff2Obtain the 4th torque coefficient s4, obtain the second torque coefficient s2 according to current vehicle speed V;
Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 4th torque coefficient s4 and the 5th torque coefficient s5;
The execution signal that control and processing module will include described overspeed protection torque T q_regens is sent to performance element with the deceleration of control motor;
Judge module is used for also judging whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2, and judged result is sent to described control and processing module;
If the current rotational speed N of motor after slowing down is less than recovering to drive rotational speed N
2, then control and processing module are sent the conventional instruction that drives, and make vehicle enter conventional driving condition; If the current rotational speed N of motor after slowing down is more than or equal to recovering to drive rotational speed N
2, then control and processing module recomputate overspeed protection torque T q_regens based on the current rotational speed N of motor after slowing down, and send it to performance element with control motor continuation deceleration.
Wherein, in the operational mode that accelerator pedal is operated, described control unit indication performance element earlier is 0 with the driving torque unloading, then carries out following operation:
Control and processing module obtain the overspeed protection moment of torsion based on the current rotational speed N of motor and current vehicle speed V, that is:
Calculate the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2
According to N
Diff1And N
Diff2Obtain the 6th torque coefficient s6, obtain the 7th torque coefficient s7 according to current vehicle speed V;
Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 6th torque coefficient s6 and the 7th torque coefficient s7;
The execution signal that control and processing module will include described overspeed protection torque T q_regens is sent to performance element with the deceleration of control motor;
Judge module judges whether accelerator pedal still is in the state that is operated, and if not, judges further then whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2If,, then enter conventional drive pattern; If not, the operational mode control motor that then is not operated with described accelerator pedal slows down;
If whether the current rotational speed N of motor after then judgement is slowed down is less than the protection rotational speed N
1If,, then the current rotational speed N of motor is carried out PID control it is maintained the protection rotational speed N
1Near, be in the state that is not operated until accelerator pedal; If not, then make described control and processing module recomputate overspeed protection torque T q_regens, and send it to performance element with control motor continuation deceleration.
For this reason, the invention provides a kind of electric automobile, it comprises above-mentioned any described electric automobile overspeed protection control system.
With respect to prior art, the present invention has following beneficial effect:
Electric automobile overspeed protection control method provided by the invention is when the current rotational speed N of motor reaches default protection rotational speed N
1The time, obtain reactive torque Tq_regens that motor is initiatively slowed down according to the current rotational speed N of motor and current vehicle speed V, and reduce the trend that motor speed increases by applying this reactive torque Tq_regens, and then reduce motor speed.Like this, not only can effectively avoid the vehicle problem that (especially when long descending or stepping on accelerator pedal descending) increases because the motor speed that the gravity effect causes speeds with the speed of a motor vehicle when descending; But also can avoid vehicle frequently to disconnect the problem of drive system because of the hypervelocity fault, and adopt this method to need not car load is carried out power-on and power-off again, thereby guaranteed the driving continuity of vehicle, also further avoided disconnecting car load power suddenly because exceeding the speed limit and connected the driver psychology fear that causes, and then improved safety-type and the reliability of vehicle drive.
Similarly, electric automobile overspeed protection control system provided by the invention and electric automobile, when the current rotational speed N of motor greater than default protection rotational speed N
1The time, control and processing module obtain reactive torque that vehicle is initiatively slowed down according to the current rotational speed N of motor and current vehicle speed V, and are slowed down by performance element control motor.Like this, not only can effectively avoid the vehicle problem that (especially when long descending or stepping on accelerator pedal descending) increases because the motor speed that the gravity effect causes speeds with the speed of a motor vehicle when descending; But also can avoid vehicle frequently to disconnect drive system because of the hypervelocity fault, and need not car load is carried out power-on and power-off again, thereby guaranteed the driving continuity of vehicle, also further avoided disconnecting car load power suddenly because exceeding the speed limit and connected the driver psychology fear that causes, and then improved safety-type and the reliability of vehicle drive.
Embodiment
For making those skilled in the art understand technical scheme of the present invention better, the electric automobile overspeed protection control method, system and the electric automobile that come the embodiment of the invention is provided below in conjunction with accompanying drawing are described in detail.
The electric automobile overspeed protection control method that the embodiment of the invention one provides as shown in Figure 1, may further comprise the steps:
Step s1, the monitoring current rotational speed N of motor and current vehicle speed V.
In service in the conventional driving of electric motor car, detect the current rotational speed N of motor and current rotating speed V in real time.So-called conventional the driving refers to that the current rotational speed N of motor is less than the protection rotational speed N
1And the type of drive that vehicle adopts when being in normal transport condition.
Step s2 judges that whether the current rotational speed N of motor is greater than default protection rotational speed N
1If,, then enter step s3; If not, then return step s1, continue the monitoring current rotational speed N of motor and current vehicle speed V, and keep conventional driving process.
Step s3 obtains overspeed protection torque T q_regens according to the current rotational speed N of motor and current vehicle speed V, and slows down based on Tq_regens control motor.
The electric automobile overspeed protection control method that present embodiment provides is to reach default protection rotational speed N at current motor speed N
1The time, obtain making the overspeed protection torque T q_regens of motor counter-rotating in real time according to the current rotational speed N of motor and current vehicle speed V, and reduce the trend that motor speed increases by this, and then reduce motor speed and current vehicle speed, thereby guarantee the safety traffic of vehicle.
The flow chart of the electric automobile overspeed protection control method that Fig. 2 provides for the embodiment of the invention two.
Present embodiment provides the electric automobile overspeed protection control method that provides among electric automobile overspeed protection control method and Fig. 1 to compare, and comprises that equally step s1 is to step s3.Because s1 and step s2 have had in above-described embodiment one and have described in detail, do not repeat them here.Only the step s3 in the present embodiment is described in detail below.
Among the step s3 of present embodiment, reach default protection rotational speed N at current motor speed N
1The time, obtain overspeed protection torque T q_regens according to the current rotational speed N of motor and current vehicle speed V, and slow down based on Tq_regens control motor.This step s3 specifically comprises step s30, step s31 and step s32.
Wherein, in step s30, judge whether accelerator pedal is in the state that is operated, if not, then enter the treatment progress step s31 that accelerator pedal is not operated; If then enter the treatment progress step s32 that accelerator pedal is operated.
Step s31 comprises the treatment progress that accelerator pedal is not operated, and it specifically comprises step s311, step s312 and step s313.
Wherein, in step s311, based on the current rotational speed N of motor and current vehicle speed V, obtain overspeed protection torque T q_regens.Seeing also Fig. 3 a below is elaborated with the acquisition methods to overspeed protection torque T q_regens.Fig. 3 a is the flow chart of the first kind of acquisition methods of overspeed protection moment of torsion when accelerator pedal is not operated in the electric automobile overspeed protection control method among Fig. 2; shown in Fig. 3 a; when accelerator pedal was not operated, obtaining of overspeed protection torque T q_regens may further comprise the steps:
Drive rotational speed N based on the current rotational speed N of motor and recovery
2, obtain the second speed discrepancy N
Diff2, N
Diff2=N-N
2
Obtain the first torque coefficient s1 according to the current rotational speed N of motor; Obtain the second torque coefficient s2 according to current vehicle speed V; Obtain conventional regeneration braking output torque Tq_regen based on the current rotational speed N of motor, s1 and s2;
According to the second speed discrepancy N
Diff2Obtain the 3rd torque coefficient s3 with current vehicle speed V; Obtain revising torque T q_corr based on the current rotational speed N of motor and the 3rd torque coefficient s3;
Tq_regen obtains described overspeed protection torque T q_regens, wherein overspeed protection torque T q_regens=Tq_regen+Tq_corr with revising torque T q_corr based on conventional regeneration braking output torque.
Wherein, conventional regeneration braking output torque Tq_regen can reduce the trend that motor speed speeds, on this basis, and based on the second speed discrepancy N
Diff2Obtain to revise torque T q_corr with current vehicle speed V, thereby conventional regeneration braking output torque Tq_regen is revised, to reach the purpose that the restriction motor speed rises.
Please return Fig. 2, the treatment progress that continues accelerator pedal shown in the step s31 is not operated describes.
In step s312, slow down according to the Tq_regens control motor that obtains among the step s311.
In step s313, detect the current rotational speed N of motor after slowing down, and judge whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2If current rotational speed N is less than recovering to drive rotational speed N
2, then enter conventional drive pattern; If being not less than, current rotational speed N recovers to drive rotational speed N
2, then return step s311, regain overspeed protection torque T q_regens, continue to slow down with the control motor.
Corresponding to step s31, step s32 comprises the treatment progress that accelerator pedal is operated, and it specifically comprises step s321, step s322, step s323 and step s324.
Step s321 is 0 with the driving torque unloading.If the current rotational speed N of motor has exceeded default protection rotational speed N
1, but accelerator pedal still is operated, and at this moment, is 0 with the driving torque unloading rapidly, to be forced to vehicle deceleration.
Step s322 based on the current rotational speed N of motor and current vehicle speed V, obtains the overspeed protection moment of torsion.Seeing also Fig. 4 below is elaborated with the acquisition methods to overspeed protection torque T q_regens.Fig. 4 is the flow chart of the overspeed protection moment of torsion acquisition methods when accelerator pedal is operated in the electric automobile overspeed protection control method among Fig. 2, and as shown in Figure 4, when accelerator pedal was operated, obtaining of overspeed protection torque T q_regens may further comprise the steps:
Calculate the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2, N wherein
Diff1=N-N
1, N
Diff2=N-N
2
According to N
Diff1And N
Diff2Obtain the 6th torque coefficient s6;
Obtain the 7th torque coefficient s7 according to current vehicle speed V;
Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 6th torque coefficient s6 and the 7th torque coefficient s7.
Please return Fig. 2, the treatment progress that continues accelerator pedal shown in the step s32 is operated describes.
In step s323, slow down according to the Tq_regens control motor that obtains among the step s322.
In step s324, judge whether accelerator pedal still is in the state that is operated, if judgement place accelerator pedal unclamps, then enter the step s313 in the treatment progress that accelerator pedal is not operated, detect the current rotational speed N of motor after slowing down, and judge whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2, if N<N
2, then enter conventional drive pattern; If N>=N
2, then return the treatment progress step s31 that accelerator pedal is not operated.
If judgement place accelerator pedal still is in the state that is operated, then detect the current rotational speed N of motor after slowing down, and whether the current rotational speed N of motor after further judgement is slowed down is less than the protection rotational speed N
1If,, then the current rotational speed N of motor after slowing down is carried out PID control so that the current rotational speed N of motor is maintained the protection rotational speed N
1Near, released until accelerator pedal; If not, then return step s322, obtain overspeed protection torque T q_regens again.
Alternately, the step s311 in the present embodiment can adopt another kind of method to obtain the overspeed protection moment of torsion.Particularly, see also Fig. 3 b, Fig. 3 b is the flow chart of the second kind of acquisition methods of overspeed protection moment of torsion when accelerator pedal is not operated in the electric automobile overspeed protection control method among Fig. 2.
Shown in Fig. 3 b, in step s311 ', based on the current rotational speed N of motor and current vehicle speed V, obtain overspeed protection torque T q_regens.Concrete computational process is as follows:
Calculate the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2, N wherein
Diff1=N-N
1, N
Diff2=N-N
2
According to N
Diff1And N
Diff2Obtain the 4th torque coefficient s4;
Obtain the 5th torque coefficient s5 according to current vehicle speed V;
Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 4th torque coefficient s4 and the 5th torque coefficient s5.
Alternatively, in present embodiment step s2, when judging that the current rotational speed N of motor is greater than default protection rotational speed N
1The time, can be 1 with the set of hypervelocity flag bit.Corresponding with it, in step s313, the current rotational speed N of motor after slowing down is less than recovering to drive rotational speed N
2The time, the flag bit that will exceed the speed limit earlier is reset to 0, turns back to conventional drive pattern again.By the hypervelocity flag bit is set, guarantee to have only when the current rotational speed N of motor to reach the protection rotational speed N
1After just for vehicle increases the resistance that initiatively slows down, reduce system's probability of failure, thereby improve stability and the reliability of system.
Be understood that easily, the above-mentioned first torque coefficient s1, the second torque coefficient s2, the 3rd torque coefficient s3, the 4th torque coefficient s4, the 5th torque coefficient s5, the 6th torque coefficient s6 and the 7th torque coefficient s7 can by arbitrarily with separately independent variable between corresponding functional relation obtain, as default form or formula etc., do not do concrete restriction at this.
In the present embodiment, when the current rotational speed N of motor greater than default protection rotational speed N
1The time, also comprise the step that gives a warning to the driver, to remind the current rotating speed of driver's motor too fast, vehicle will enter the process of autonomous deceleration, recover conventional drive pattern up to vehicle, panic with this psychology of avoiding the driver to cause because vehicle slows down automatically, the comfortableness of raising vehicle drive.
The electric automobile overspeed protection control method that present embodiment provides, in the current rotational speed N of motor greater than default protection rotational speed N
1The time, in conjunction with the state of accelerator pedal, to know driver's driving intention, enter the operational mode that operational mode that accelerator pedal is not operated or accelerator pedal are operated, initiatively be provided as the reactive torque Tq_regens that vehicle slows down, motor speed N be down to recover to drive rotational speed N
2Below or by PID control motor speed N is maintained higher protection rotational speed N
1Near, thereby avoid vehicle to damage or frequently disconnect drive system because hypervelocity causes drive system, even the accident that leads to because of hypervelocity had both guaranteed vehicle driving safety, had guaranteed the continuity of driving again.
As another technical scheme, the present invention also provides a kind of electric automobile overspeed protection control system.The block diagram of the electric automobile overspeed protection control system that Fig. 5 provides for the embodiment of the invention, as shown in Figure 5, electric automobile overspeed protection control system comprises monitoring means 1, control unit 2 and performance element 3.
Monitoring means 1 is used for the monitoring current rotational speed N of motor and current vehicle speed V, and the current rotational speed N of motor and current vehicle speed V are sent to control unit 2.In actual applications, the current rotational speed N of motor can adopt electric machine controller MCU (Motor Control Unit) or speed probe to obtain in real time, and current vehicle speed V can adopt entire car controller VMS (Vehicle Management System) to calculate in real time.
Control unit 2 comprises judge module 21 and control and processing module 22, and wherein: judge module 21 is used for judging that whether the current rotational speed N of motor is greater than default protection rotational speed N
1, and with judged result be sent to control and processing module 22; Control and processing module 22 are used for working as the current rotational speed N of motor greater than the protection rotational speed N
1The time, determine overspeed protection torque T q_regens based on the current rotational speed N of motor and current vehicle speed V, and the execution signal that will include overspeed protection torque T q_regens is sent to performance element 3.In actual applications, realize the current rotational speed N of motor and protection rotational speed N by entire car controller VMS
1Between the size judgement and the function of control and processing module 22.
Performance element 3 is used for slowing down according to carrying out signal control motor.In actual applications, performance element 3 can adopt electric machine controller MCU to realize.
In the present embodiment, judge module 21 also is used for judging whether accelerator pedal is operated, and judged result is sent to described control and processing module 22; When the current rotational speed N of motor greater than the protection rotational speed N
1The time, control and processing module 22 enter the operational mode that operational mode that accelerator pedal is operated or accelerator pedal are not operated according to the state of accelerator pedal.In actual applications, can adopt the transducer that is arranged on the accelerator pedal to carry out the accelerator pedal status detection, and enter the operational mode that operational mode that accelerator pedal is operated or accelerator pedal are not operated by entire car controller VMS control.
In the operational mode that accelerator pedal is not operated, control unit 2 is carried out following operation: the control in the control unit 2 and processing module 22 obtain overspeed protection torque T q_regens based on the current rotational speed N of motor and current vehicle speed V, and the execution signal that will include overspeed protection torque T q_regens is sent to performance element 3 and slows down with the control motor; Judge module 21 in the control unit 2 is used for also judging whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2, and with judged result be sent to control and processing module 22; If the current rotational speed N of motor after slowing down is less than recovering to drive rotational speed N
2, then control and processing module 22 are sent the conventional instruction that drives, and make vehicle enter conventional drive pattern; If the current rotational speed N of motor after slowing down is more than or equal to recovering to drive rotational speed N
2, then control and processing module 22 recomputate overspeed protection torque T q_regens based on the current rotational speed N of motor after slowing down, and send it to performance element 3 with control motor continuation deceleration.
Be similar to previously described electric automobile overspeed protection control method; in the electric automobile overspeed protection control system that the embodiment of the invention provides; when being in the operational mode that accelerator pedal is not operated, the method that control and processing module 22 obtain overspeed protection torque T q_regens also can be one of following two kinds of methods.
Method one, control and processing module 22 are based on the current rotational speed N of motor and recover the driving rotational speed N
2Obtain the second speed discrepancy N
Diff2Obtain the first torque coefficient s1 according to the current rotational speed N of motor; Obtain the second torque coefficient s2 according to current vehicle speed V; Obtain conventional regeneration braking output torque Tq_regen based on the current rotational speed N of motor, s1 and s2; According to the second speed discrepancy N
Diff2Obtain the 3rd torque coefficient s3 with current vehicle speed V; Obtain revising torque T q_corr based on the current rotational speed N of motor and the 3rd torque coefficient s3; Tq_regen obtains described overspeed protection torque T q_regens, wherein overspeed protection torque T q_regens=Tq_regen+Tq_corr with revising torque T q_corr based on conventional regeneration braking output torque.
Method two, control and processing module 22 are calculated the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2According to N
Diff1And N
Diff2Obtain the 4th torque coefficient s4, obtain the second torque coefficient s2 according to current vehicle speed V; Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 4th torque coefficient s4 and the 5th torque coefficient s5.
In the operational mode that accelerator pedal is operated, control unit 2 indication performance element 4 earlier is 0 with the driving torque unloading, then carries out following operation: control and processing module 22 obtain the overspeed protection moment of torsion based on the current rotational speed N of motor and current vehicle speed V; The execution signal that control and processing module 22 will include described overspeed protection torque T q_regens is sent to performance element 3 with the deceleration of control motor; Judge module 21 judges whether accelerator pedal still is in the state that is operated, and if not, judges further then whether the current rotational speed N of motor after slowing down drives rotational speed N less than recovery
2If,, then enter conventional drive pattern; If not, the operational mode control motor that then is not operated with accelerator pedal slows down; If whether the current rotational speed N of motor after then judgement is slowed down is less than the protection rotational speed N
1If,, then the current rotational speed N of motor is carried out PID control it is maintained the protection rotational speed N
1Near, be in the state that is not operated until accelerator pedal; If not, then make control and processing module 22 recomputate overspeed protection torque T q_regens, and send it to performance element 3 with control motor continuation deceleration.
Wherein, corresponding to the electric automobile overspeed protection control method that the embodiment of the invention provides, in the operational mode that accelerator pedal is operated, the concrete grammar that control and processing module 22 obtain overspeed protection torque T q_regens is:
Control and processing module 22 are calculated the current rotational speed N of motor and protection rotational speed N
1Between the first speed discrepancy N
Diff1, the current rotational speed N of motor with recover to drive rotational speed N
2Between the second speed discrepancy N
Diff2According to N
Diff1And N
Diff2Obtain the 6th torque coefficient s6, obtain the 7th torque coefficient s7 according to current vehicle speed V; Obtain overspeed protection torque T q_regens based on the current rotational speed N of motor, the 6th torque coefficient s6 and the 7th torque coefficient s7.
Be understood that easily, carry out exchanges data by car load CAN (Controller Area Network) network between judge module 21 and control and the processing module 22 in monitoring means 1, control unit 2, performance element 3 and the control unit 2.
Need to prove; in actual applications; the electric automobile overspeed protection control system that the embodiment of the invention provides also comprises battery management system BMS (Battery Management System), is used for to control and processing module 22 (entire car controller VMS) feedback battery status information.In addition, when vehicle entered the regenerative braking state, the energy that the braking of management car load power source storing, regenerating is reclaimed with the raising energy utilization ratio, thereby was saved cost.
In the present embodiment, judge that the current rotational speed N of motors is greater than default protection rotational speed N when judge module 21
1The time, control and processing module 22 can be 1 with the hypervelocity mark position.Corresponding with it, judge the current rotational speed N of motor after slowing down when judge module 22 and drive rotational speed N less than recovery
2The time, controller processing module 22 flag bit that will exceed the speed limit earlier is reset to 0, turns back to conventional drive pattern again.By the hypervelocity flag bit is set, guarantee to have only when the current rotational speed N of motor to reach the protection rotational speed N
1After just for vehicle increases the resistance that initiatively slows down, reduce system's probability of failure, thereby improve stability and the reliability of system.
Need to prove, the above-mentioned first torque coefficient s1, the second torque coefficient s2, the 3rd torque coefficient s3, the 4th torque coefficient s4, the 5th torque coefficient s5, the 6th torque coefficient s6 and the 7th torque coefficient s7 can obtain by the respective function relation between foundation in control and processing module 22 and the independent variable separately, as default formula or the corresponding form of opening relationships etc., do not do concrete restriction at this.In actual applications, above-mentioned respective function relation can be arranged in the entire car controller VMS.
Be understood that easily, when judge module 21 judges that the current rotational speed N of motor is greater than default protection rotational speed N
1The time, control and processing module 22 also indicate performance element 3 to give a warning to the driver with blow a whistle, glimmer warning light or other any-modes, to remind the current rotating speed of driver's motor too fast, vehicle will enter the process of autonomous deceleration, recover conventional drive pattern up to vehicle, the psychology of avoiding the driver to cause because vehicle slows down automatically is panic, improves the comfortableness of vehicle drive.
As another technical scheme; the present invention also provides a kind of electric automobile; it comprises any one electric automobile overspeed protection control system that the above embodiment of the present invention provides, or any one electric automobile overspeed protection control method that adopts the above embodiment of the present invention to provide.
Also need to prove: above embodiment only in order to technical scheme of the present invention to be described, is not intended to limit; Although with reference to previous embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment puts down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of various embodiments of the present invention technical scheme.