Method and system for compensating dead zone effects of inverter of permanent magnet synchronous motor

Abstract

The invention discloses a method and system for compensating dead zone effects of an inverter of a permanent magnet synchronous motor. The method comprises the steps of real-time collection and synchronous uploading of signals; and on-line compensation of the dead zone effects of the inverter. As for any current sampling period, an analysis and processing process comprises the following steps of collected signal receiving and synchronous saving, analysis and processing time judgment, on-line observation of disturbance voltage of the dead zone effects of the inverter and the compensation of the dead zone effects of the inverter. The system comprises a data processor, a current detection unit, a first signal acquisition circuit, a rotation angle detection unit, a second signal acquisition circuit, a data storage unit and a parameter input unit, wherein the data storage unit and the parameter input unit are respectively connected with the data processor. The method and system is reasonable in design, simple in compensation method and step, convenient to achieve, low in input cost, good in compensation effects and capable of effectively solving the problem that the existing method for compensating dead zone effects of the inverter of the permanent magnet synchronous motor (PMSM) is big in input cost, complex in compensation step, poor in compensation effects and the like.

Description

technical field [0001] The invention belongs to the technical field of PMSM inverter dead zone effect compensation, and in particular relates to a permanent magnet synchronous motor inverter dead zone effect compensation method and system. Background technique [0002] In the PMSM speed control system based on voltage space vector (SVPWM, that is, voltage space vector pulse modulation technology) control, the two switch tubes on the same bridge arm of the inverter (specifically, the three-phase inverter bridge) must be turned on alternately to It meets the working requirements, but due to the non-linear characteristics of the inverter, the two switching tubes of the same bridge arm will cause a straight-through phenomenon instantaneously. Therefore, in order to prevent the direct short-circuit phenomenon of the inverter bridge arm, a fixed switching delay time must be inserted between the control signals of the upper and lower switching tubes of the same bridge arm. However,...

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Problems solved by technology

[0004] First, the compensation method based on the polarity of the current: the dead zone effect compensation method needs to detect the polarity of the current, but due to the back electromotive force of the permanent magnet synchronous motor and the dead zone time during the dead zone, it is easy to cause the zero-crossing clamping of the motor phase current, Therefore, it is difficult to accurately detect the instantaneous current pole

Therefore, although the compensation method is simple, it is difficult to achieve the compensation effect required by the control system of the permanent magnet synchronous motor.

[0005] Second, the dead zone effect compensation based on the offline experiment of a specific load: the dead zone effect compensation method must be compensated based on the known operating parameters of the load, so this compensation method requires a large number of offline experiments to determine the phase angle of the current and the compensated voltage. Although this method is suitable for specific load conditions, it is not conducive to the application requirements of the actual speed control system

[0006] Third, use the observer to compensate the dead zone effect online: For example, in the case of known load information, rely on the high-resolution position sensor to design the observer to realize the dead zone effect compensation, but the dead zone effect compensation method is not suitable for variable loads and the algorithm is complicated; or the observer designed only for the harmonic components (mainly the 5th and 7th harmonics) caused by the dead zone effect can only eliminate specific harmonics, but this method can only partially eliminate the harmonic components caused by the dead zone Harmonics of

[0007] Fourth, compensation for dead zone effect based on hardware circuit: This compensation method needs to design auxiliary hardware circuit to compensate for dead zone effect, thus greatly increasing system cost

[0008] To sum up, the existing PMSM inverter dead-zone effect compensation methods have various defects and deficiencies such as high input cost, complicated compensation method steps, and poor compensation effect to varying degrees.

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