Speed control method and motor controller of electric vehicle in speed control mode

Abstract

The invention discloses a speed regulating method of an electric vehicle in a speed control mode and a motor controller thereof. The speed regulating method comprises the following steps: the currentrotational speed of an electric motor in the electric vehicle is made to be different from a target rotational speed; the difference between the current rotational speed and the target rotational speed is adjusted by a PI regulator to obtain a regulating current; Assigning a value of the adjusting current to a torque command required when searching a 2D table corresponding to the motor; Calculating a mapping coefficient between the motor current and the motor torque in the form of a standard 1 value according to a preset current torque relation, and updating a lookup table step size of the 2Dtable according to the mapping coefficient; According to the current rotational speed and torque command of the motor, detecting a given direct-axis current component and a given quadrature-axis current component of the motor from the updated 2D table; According to the given direct-axis current component and the given quadrature-axis current component, the current output of the motor is controlledby the preset vector control algorithm. As can be seen, the present application accelerates the speed regulation speed; And the speed stability of the electric vehicle is improved, so that the speedand the ride comfort of the electric vehicle are improved when the electric vehicle is shifted.

Description

technical field [0001] The invention relates to the field of electric vehicle motor control, in particular to a speed regulation method and a motor controller for an electric vehicle in a speed control mode. Background technique [0002] At present, when an electric vehicle is running normally, its motor controller generally works in the torque control mode. Specifically, please refer to figure 1 , figure 1 It is a schematic diagram of the speed regulation of an electric vehicle in the torque control mode in the prior art. Depend on figure 1 It can be seen that the motor controller checks the speed-torque 2D table according to the current speed n of the motor and the torque command of the vehicle controller (in order to improve the efficiency of the motor, the manufacturer of the motor controller will calibrate the external characteristics of the motor in advance, It makes full use of the maximum torque-to-current ratio of the motor to generate a corresponding table with...

AI Technical Summary

Problems solved by technology

Since the output value of the speed loop PI regulator is per unit value of the current (per unit value, that is, per unit, referred to as pu, it is usually processed in Q format, such as Q12 format processing, that is, pu*2 12 ), there is no one-to-one correspondence between it and the actual torque of the motor as on the 2D table, so the speed control mode generally does not use the method of looking up the 2D table to output the current command, so the reluctance torque of the motor cannot be fully utilized. As a result, the motor cannot output torque with maximum power, so that the speed of speed regulation becomes slower and the time of speed regulation becomes longer

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