Method for eliminating sampling delay error in motor system controlled by single current sensor

Abstract

The invention discloses a method for eliminating a sampling delay error in a motor system controlled by a single current sensor. The method comprises the following steps: 1, installing a single current sensor between a switching tube Q1 and a switching tube Q3 to construct the circuit topological structure of the single current sensor, 2, deducing a delay error expression [Delta]iSDE when sampling delay exists according to a PMSM three-phase current expression, 3, constructing a delta-gamma reference coordinate system, 4, based on the [Delta]iSDE and the delta-gamma reference coordinate system, converting the [Delta]iSDE into the delta-gamma reference coordinate system through coordinate transformation to obtain error components [Delta]i delta and [Delta] i gamma, and 5, directly filtering second harmonic components in [Delta] i delta and [delta] i gamma by applying a notch filter, and compensating a sampling delay error. According to the method, the sampling delay error in the single current sensor method can be eliminated without depending on motor parameters, and the phase current precision reconstructed in the single current sensor technology is improved.

Description

technical field [0001] The invention belongs to the field of motor control, and relates to a method for eliminating sampling delay errors in a motor system controlled by a single current sensor. The sampling delay error in the single current sensor method can be eliminated without depending on motor parameters. Background technique [0002] Due to its high power density, high reliability, and high precision, permanent magnet synchronous motors (PMSM) have been widely used in aerospace, deep-water servo, and electric vehicles in recent years. The traditional PMSM control method requires at least two current sensors to obtain two-phase current information to complete vector or closed-loop control. However, multiple current sensors will not only increase the volume and cost of the controller, but also may have sampling differences among them, causing current disturbances. [0003] Single current sensor technology, also known as phase current reconstruction technology, is a low...

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Problems solved by technology

However, when obtaining different phase current information, there must be a sampling delay problem between two samplings, which will cause a sampling delay error between the sampled current and the actual current

When traditional methods eliminate this kind of error method, control technologies such as current prediction are often used. Not only the algorithm is complex, but the calculation burden of the controller is increased, and there is a strong dependence on the parameters of the motor itself. When the motor parameters cannot be measured or the accuracy is not good High, especially in some extreme scenarios where motor parameters vary greatly, it is difficult for such methods to guarantee the accuracy of error compensation

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