Motor control system and method without position sensor

Abstract

The invention relates to a motor control system and method without a position sensor. According to the invention, internal signals of a motor can be detected without needing the position sensor. In the motor control system without the position sensor, a high-frequency voltage signal injection unit injects a high-frequency voltage signal to a d axis in a synchronically rotating d-q coordinate system; the voltage signal is obtained by a Park inverse transformation unit; a voltage vector on a static coordinate system generates a power device pulse width signal through a space vector pulse width modulation algorithm; a three-phase current signal and a high-frequency injection signal are generated according to the power device pulse width signal; the three-phase current signal is filtered by using a band-pass filter to reserve the high-frequency injection signal; the high-frequency injection signal is subjected to Clarke transformation and Park transformation in turn to obtain current; the current is subjected to signal processing through a rotor position observer unit to obtain position and speed of a rotor. According to the invention, internal structure of a motor system is simplified, cost for the motor control system is greatly reduced, and stability of the motor is improved.

Description

technical field [0001] The invention relates to the field of motor controllers for automobiles, in particular to a motor controller without a position sensor that can detect internal signals of the motor without a position sensor. Background technique [0002] The motors of existing electric vehicles are mostly controlled by vector, and the principle is to map the phase voltage or current of the three-phase motor to a two-axis coordinate system. The rotor position information is needed in the vector control, and the motor of the existing electric vehicle usually obtains the rotor position information by setting a feedback device such as a resolver or an incremental encoder or a position sensor. Such a position sensor and its associated interface circuit increase the cost of the motor control system, and the position sensor and its associated wiring harness increase the complexity and assembly and maintenance time of the electric drive system of the vehicle; and installing th...

AI Technical Summary

Problems solved by technology

Such a position sensor and its associated interface circuit increase the cost of the motor control system, and the position sensor and its associated wiring harness increase the complexity and assembly and maintenance time of the electric drive system of the vehicle; and installing the position sensor in the motor , which reduces the stability and quality of the motor, increases the complexity of the motor system, makes it easy to damage, and affects the service life of the motor

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