Self-learning method for interference characteristics of voltage source inverter of alternating current motor

Abstract

The invention discloses a self-learning method for interference characteristics of a voltage source inverter of an alternating current motor, and belongs to the field of motor control. The method comprises the steps: starting the motor to run in a steady state under the condition of no inverter interference compensation; adopting the inverter interference observer to obtain inverter interference of a d-q axis; converting the inverter interference of the d-q axis into the inverter interference under an ABC three-phase static coordinate system by utilizing Park transformation; converting fourier transform inverter interference to a frequency domain, and reconstructing third harmonic waves and odd integer multiples of third harmonic waves missing from the inverter interference obtained through ABC three-phase conversion from the frequency domain; and superposing the reconstructed harmonic waves to obtain complete inverter interference characteristics. The method is a universal method for automatically obtaining the interference characteristics of the alternating current motor inverter without manual calibration, the interference characteristics of the inverter are estimated and reconstructed through the inverter interference observer, accurate obtaining of the interference characteristics of the inverter under the conditions of no manual intervention and no additional hardware is achieved, and the automation level of product development is effectively improved.

Description

technical field [0001] The invention belongs to the field of motor control, and in particular relates to a self-learning method for interference characteristics of an AC motor voltage source inverter. Background technique [0002] At present, nearly 2 / 3 of the world's electric energy is consumed by motors, of which more than 90% are AC motors. Facing the goals of "carbon peak" and "carbon neutrality", larger-scale AC motors will be used in various fields of production and life, and intelligent high-performance AC motor control is essential. [0003] In the voltage-type inverter circuit commonly used in AC motor control, the non-linearity and parasitic parameters of the device, the interlock time of the upper and lower bridge arms, etc., are generally referred to as inverter interference, and these interferences will affect the normal inverter. The output of voltage causes current distortion, torque fluctuation and may cause additional stray loss, affecting the performance o...

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Problems solved by technology

Inverter interference compensation generally adopts the method of offline calibration, which not only requires additional measurement hardware, but also requires manual intervention, which wastes a lot of time and affects the development progress of motor system products

For example, "a method for torque compensation in low-speed dead zone of permanent magnet synchronous motor" is disclosed in Chinese patent literature, see publication number CN112398394A for details, using inverter interference compensation to improve the performance of the motor in the low-speed and light-load area, but the compensation required The required interference characteristics require a large number of off-line experiments; the "inverter dead zone compensation method and device" disclosed in the Chinese patent literature, see the announcement number CN111342695B for details, proposes an online real-time measurement of the inverter dead zone characteristics and compensation. method, but additional hardware is required to realize the real-time measurement of the inverter dead zone, and its significantly increased cost limits the practical application of this method; the "inverter compensation method, device and electrical equipment , storage medium”, see Publication No. CN112701941A for details. In this scheme, a method for online estimation and compensation of inverter disturbance by using voltage command and current feedback in the synchronously rotating d-q coordinate system is proposed. Although this method can save offline Calibration steps, but because the d-q axis variable lacks harmonic information of integer multiples of 3, this method cannot obtain the complete inverter interference characteristics, and must be applied in combination with the d-q axis compensation method proposed in the patent; this is serious Affects the generality of this inverter disturbance estimation method, and many higher performance compensation algorithms cannot be used

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