Device and method for detecting zero crossing point of inductive current

Abstract

The invention provides a device for detecting a zero crossing point of inductive current, aiming at the technical problem that the direction of inductive current can not be accurately judged by independently adopting a digital signal processor (DSP) hardware capture module (CAP) and a hysteresis comparison method. The device comprises a current sensor, a partial pressure conditioning module, a voltage following module, a pull-up bias module, a DSP module, an input module and a liquid crystal display (LCD) module. According to the invention, the phase locking function of a single-phase phase-locked loop based on a second-order generalized integrator (SOGI) is adopted, so that the phase locking for the inductive current can be realized, and the zero crossing point and the direction of the inductive current can be further detected. Through the device, the defects that separately using a hardware or software method is adopted are overcome; and equipment is simple, detection is convenient and fast and reliability is high.

Description

technical field [0001] The invention belongs to the technical field of circuit detection, and in particular relates to a detection device and a detection method for an inductor current zero-crossing point for judging the current direction. Background technique [0002] The inductor current is a pulsating current at the switching frequency level. The larger the inductor current ripple is, the more zero crossings there will be at the zero point. How to accurately determine the direction of the inductor current, especially in the case of dead zone compensation, is the difficulty of our research. At present, there are two methods for judging the direction of the inductor current: one uses the hardware capture module (CAP) in the DSP to directly compare with the zero value, but this method uses a low-pass filter on the hardware, which causes damage to the detected signal The time delay makes it impossible to accurately judge the zero-crossing point and direction of the current; ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the technical problem that the DSP hardware capture module (CAP) and the hysteresis comparison method cannot accurately determine the direction of the inductor current, the present invention provides a software and hardware method that combines a detection device for the zero-crossing point of the inductor current with software detection to realize the detection of the inductor current. Phase-locking of the current, and then determine the zero-crossing point and direction of the inductor current

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