A control method for maximum torque-current ratio of built-in permanent magnet synchronous motor

Abstract

The invention discloses a method for controlling the maximum torque-to-current ratio of a built-in permanent magnet synchronous motor, comprising: adopting a simple MTPA formula method, which can calculate the dq-axis reference current based on a constant parameter model in real time without mathematical approximation or lookup table. In addition, the virtual square wave signal is injected into the feedback current, and the MTPA criterion is extracted through the difference of the mechanical power before and after a square wave cycle, and the current deviation caused by the parameter change is corrected, without considering the influence of the real high frequency signal injected into the motor , without considering the impact of the filter on the dynamic performance of the system. Simulation results show that even though R and L d The change of will cause a certain Δi derror , but the combination of the formula method and the virtual square wave injection method can still track the MTPA trajectory more accurately. robustness.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a method for controlling the maximum torque-current ratio of a built-in permanent magnet synchronous motor. Background technique [0002] The built-in permanent magnet synchronous motor has the advantages of high efficiency, large power factor, high unit power density and fast dynamic response speed, and has been widely used in the field of electric propulsion ships, new energy vehicles, and household appliances. [0003] The performance characteristic of the built-in permanent magnet synchronous motor is asymmetric inductance, so compared with the surface-mounted permanent magnet synchronous motor, the built-in permanent magnet synchronous motor not only contains the same excitation torque, but also includes reluctance torque, electromagnetic The torque is related to the d-axis current, and the reluctance torque is related to both the d and q-axis currents. The use of zero...

AI Technical Summary

Problems solved by technology

This method has slow convergence speed, poor dynamic performance, and low torque control accuracy under the influence of torque disturbance and current / voltage harmonics

The high-frequency signal injection method processes and calculates the injected high-frequency signal and the response signal, extracts the MTPA criterion, and finally obtains the current or angle reference value, but its convergence performance and dynamic performance are poor

The virtual signal injection method superimposes a small-amplitude high-frequency sinusoidal component in the feedback current signal, and analyzes the inner relationship between the electromagnetic torque and the current vector angle by means of Taylor series expansion, and then configures a reasonable low-pass, The angle information corresponding to the MTPA control current can be extracted by using the cutoff frequency of the band-pass filter, but the use of the filter will cause a phase delay

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