A motor torque zero-crossing anti-shake control method for new energy vehicles

Abstract

The invention relates to a motor torque zero-crossing anti-shake control method for a new energy vehicle. Step 1: judging whether the motor torque is in a zero-crossing condition; step 2: limiting the torque output slope to reduce the torque zero-crossing shock; step 3: Judging whether the requested torque has a zero-crossing condition again within the time limit of the torque output slope; Step 4: Judging whether the time limit of the torque output slope has expired; Step 5: Judging whether the difference between the requested torque and the torque after passing the limit torque output slope is not is less than the first preset threshold; Step 6: use the follow-up control algorithm to obtain the output torque; Step 7: determine whether the difference between the current output torque and the requested torque is less than the second preset threshold; Step 8: complete the torque zero-crossing control, and return to the step 1. Wait for the next torque zero-crossing condition. Compared with the prior art, the present invention has the advantages of predictable torque zero-crossing conditions, faster torque response speed, improved driving experience and vehicle dynamics.

Description

technical field [0001] The invention relates to the field of anti-shake control of new energy vehicles, in particular to a motor torque zero-crossing anti-shake control method for new energy vehicles. Background technique [0002] The permanent magnet synchronous motor integrates drive and power generation functions, and is widely used in the field of new energy vehicles. The accuracy of torque command control of new energy motors and the problem of torque jitter in response, especially the jitter problem of torque command zero crossing, produce non- The expected power shock will seriously affect the driving comfort and shift smoothness of new energy vehicles, and seriously affect the driving experience of new energy vehicles. The anti-shake problem of new energy motor torque zero-crossing is a technical problem that needs to be solved in the field of new energy vehicle control. [0003] At present, the control methods for the zero-crossing of the torque of the new energy m...

AI Technical Summary

Problems solved by technology

[0003] At present, the control methods for the zero-crossing torque of the new energy motor can be divided into two types: one is to judge whether there is a zero-crossing torque of the new energy motor through the vehicle controller (VCU), when the motor torque is in the zero-crossing condition, The VCU smoothes the torque request command of the motor, and sends the smoothed torque command to the motor controller (PEU) through the CAN network, and then the motor control performs torque control on the motor according to the smoothed torque command. The control method can suppress the torque jitter when the motor torque crosses zero to a certain extent, smooth the change of the motor torque, and weaken the speed fluctuation and torque impact caused by the change of the motor torque direction, but it has the following disadvantages: VCU has a lag in detecting the motor torque zero crossing , it is impossible to predict the torque zero crossing. When the motor zero crossing is detected, the torque shock has already occurred; because the vehicle controller and the motor controller communicate through the CAN network with a period of 10ms, and the torque command is smoothly issued through the VCU, the control time period is too long , making the torque response speed and response accuracy worse, and the effect of suppressing the motor torque zero-crossing jitter is limited

[0004] The other is to judge whether the torque command crosses zero through the motor controller. Torque zero crossing includes motor positive torque to negative torque zero crossing and negative torque to positive torque zero crossing. When the torque is detected to be zero crossing, limit the torque to rise or fall The slope of the torque command is changed to achieve the effect of smoothing the zero-crossing torque, which can reduce the vibration of the zero-crossing torque. For example, Chinese patent CN109159673A discloses an optimization method for the zero-crossing shock of the motor torque of a new energy vehicle, but there is The following disadvantages: When the motor torque is in the zero-crossing condition, the motor vibration of the torque zero-crossing can be reduced by reducing the torque rise or fall slope, but it also significantly reduces the torque response speed, which has a great impact on the dynamic performance of new energy vehicles

[0005] No matter what kind of new energy motor torque zero-crossing control method, there are defects that the occurrence of zero-crossing conditions cannot be predicted and the torque response speed is slow

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