Strong anti-interference wide-range alternating current permanent magnet synchronous motor current sampling circuit

Abstract

The invention relates to a strong anti-interference wide-range permanent magnet synchronous motor current sampling circuit. The strong anti-interference wide-range permanent magnet synchronous motor current sampling circuit comprises a Hall current sensor unit, a fully differential amplifier conditioning unit, a Delta-Sigma modulation unit and an MCU micro control unit. The Hall current sensor unit converts the acquired current of the alternating current permanent magnet synchronous motor into an alternating voltage signal; the fully differential amplifier conditioning unit conditions the alternating voltage signal to obtain a differential voltage signal; the Delta-Sigma modulation unit is used for converting the differential voltage signal into a high-speed single-bit data stream; and theMCU micro-control unit restores the high-speed single-bit data stream into an original current waveform. According to the sampling circuit provided by the invention, on the basis that the phase current detection precision of the alternating current permanent magnet synchronous motor can be improved, wide-range sampling is realized when the alternating current permanent magnet synchronous motor runs at low frequency until overloading, and strong anti-interference capability is achieved, so that rapid, accurate and dynamic control of the alternating current servo control system on the alternating current permanent magnet synchronous motor is improved, and the reliability and safety of the system are improved.

Description

technical field [0001] The invention relates to the technical field of sampling circuits, in particular to a current sampling circuit of a strong anti-interference and wide-range AC permanent magnet synchronous motor. Background technique [0002] Nowadays, AC permanent magnet synchronous motor has occupied a pivotal position in industrial production because of its excellent performance, and AC servo drive as the control system of permanent magnet synchronous motor, its own advantages and disadvantages will directly affect the performance of the drive motor. Use performance. [0003] In the AC servo drive control system, a typical three-closed-loop control structure is generally adopted, including position loop, speed loop and current loop. Among them, the current loop is the innermost link, and it is necessary to accurately reproduce the actual current to ensure the fastest dynamic adjustment of the motor and the fast response of the motor torque. [0004] In order to bet...

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Problems solved by technology

[0006] The currently commonly used AC permanent magnet synchronous motor current sampling method has the following disadvantages: the resistance + linear optocoupler method is not suitable for high-current drive occasions, and it cannot guarantee the overload operation of the motor while having low-frequency sampling; the current transformer sampling method Due to poor low-frequency characteristics, the low-frequency current sampling error is large, which cannot meet the low-frequency and high-performance operation requirements of the motor; the Hall-type current sensor sampling method has good linearity, but once a sensor with a large range is selected, its detection accuracy will be greatly reduced, and Since the current sensor is made according to the Hall effect, once it is subjected to external electromagnetic interference, the current sampling will be abnormal, which will lead to the performance degradation of the AC servo system

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