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 new energy vehicles. The motor torque zero-crossing anti-shake control method comprises the steps that 1, judging whether motor torque is in a zero-crossing working condition; 2, limiting the torque output slope, and reducing torque zero-crossing impact; 3, judging whether the request torque generates the zero-crossing working condition again within the time of limiting the torque output slope; 4, judging whether the time for limiting the torque output slope is overtime or not; 5, judging whether a torque difference value between the request torque and the limited torque output slope is smaller than a first preset threshold value; 6, obtaining an output torque by adopting a following control algorithm; 7, judging whether the difference value between the current output torque and the request torque is smaller than a second preset threshold value; and step 8, completing torque zero-crossing control, returning to the step 1, and waiting for a next torque zero-crossing working condition. Compared with the prior art, the method has the advantages that the torque zero-crossing working condition can be predicted, the torque response speed is high, and the driving experience and the automobile dynamic property are improved.

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 the drive and power generation functions, and is widely used in the field of new energy vehicles. The accuracy of the torque command control of the new energy motor and the response to the torque jitter, especially the jitter of the torque command zero crossing point, are very serious. The expected power shock will seriously affect the driving comfort and shifting smoothness of new energy vehicles, and seriously affect the driving experience of new energy vehicles. The anti-vibration 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 torque of the n...

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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