Electric vehicle motor torque estimation method and system and vehicle

Abstract

The invention discloses an electric vehicle motor torque estimation method and system and a vehicle. The method comprises the following steps of extracting a motor d-axis flux linkage change value deltapsid at the current moment from a d-axis flux linkage, and because deltapsif=deltapsid, substituting deltapsif into a formula Te=deltapsif*K+Te0, namely estimating a torque value Te at the current moment. The curve function Te=deltapsif*K+Te0 is obtained by connecting a torque sensor and a flux linkage measuring instrument on a rack, acquiring different flux linkages and torques corresponding to the flux linkages and fitting the flux linkages and the torques, and Te is a torque value at the current moment; deltapsif is a permanent magnet flux linkage change value of the motor; Te0 is an execution torque; and K is a coefficient value obtained by fitting. The method for estimating the motor torque of the electric vehicle can estimate the motor torque in real time, and the estimation result is more accurate.

Description

technical field [0001] The invention relates to the technical field of motors, in particular to a method and system for estimating motor torque of an electric vehicle, and a vehicle. Background technique [0002] With the development of electric vehicles, more and more people pay attention to their safety. The high safety of a car is the premise of all driving, and it is also an indispensable condition for future automatic driving. A high-safety car has a strong Market competitiveness, and one of the essential conditions for improving vehicle safety is to know the real torque value currently output by the electric vehicle, and then compare it with the required execution torque to determine whether the vehicle is running normally. As the public pays more and more attention to the safety performance of electric vehicles, the research on the estimation algorithm of electric vehicle drive motor torque is imperative; [0003] Domestic torque monitoring mainly consists of two typ...

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Problems solved by technology

[0003] Domestic torque monitoring mainly consists of two types, one is to reversely calculate the torque through the vehicle power, and the other is to directly calculate the output torque of the motor through the motor parameters, because the power of the electrical appliance cannot be accurately calculated, and the voltage of the power battery is required and current conditions, multi-platform cooperation is required, resulting in inaccurate calculations

The second is to obtain the torque of the motor through a formula, but this formula is an idealized formula, and the parameters change with the use of the motor, temperature, etc., resulting in inaccurate real-time estimated torque values, thus affecting the judgment of the vehicle driving condition

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