Zero-crossing detection circuit

Abstract

The invention relates to the field of semiconductors, and more particularly to a zero-crossing detection circuit. The zero-crossing detection circuit has a coupling unit having a first input terminal and a second input terminal and used for coupling and outputting an input signal between the first input terminal and the second input terminal; a filter unit connected to the coupling unit and used for receiving the input signal outputted from the coupling unit and filtering the input signal to form a filter signal output; a detection unit connected with the filter unit and used for receiving the filter signal and computing the filter signal according to a predetermined computing method to form detection phase information. The detection phase information V3 acquires the phase information V2 of the signal of the input terminal of the filter unit, and the phase information of the input signal V1 of the first and second input terminals is calculated by the phase information V2 of the signal of the input terminal of the filter unit, and whether zero crossing occurs is determined by determining the phase information of the input signal V1 at the first and second input terminals. The zero-crossing detection circuit makes a zero crossing signal have high precision, and is low in power consumption and fast in convergence speed.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a zero-crossing detection circuit. Background technique [0002] Zero-crossing information is very important in the field of power carrier. It can confirm the phase through zero-crossing information and clarify the topological relationship of the entire station area. [0003] At present, power companies need to provide zero-crossing information, and power line carrier zero-crossing detection is currently realized through optocoupler circuits, but the optocoupler circuit makes the accuracy of zero-crossing signals relatively poor, and the jitter of zero-crossing signals is relatively severe. The load will also increase the power consumption. If the jitter of the zero-crossing signal and the power consumption of the load are reduced, too many electronic devices are required, thereby increasing the detection cost. At the same time, after the AC signal passes through the carrier optoc...

AI Technical Summary

Problems solved by technology

[0005] like figure 1 as shown, figure 1 in the zero-crossing detection circuit, although the figure 1 Fewer electronic devices are used in the system, but the load of the peripheral circuit will increase more power consumption and waste electric energy

At the same time, the disadvantage of optocoupler 2 is that the signal will be seriously attenuated and distorted, which is more difficult for the accuracy of detection.

[0006] like figure 2 shown, although figure 2 reduces load power dissipation, but figure 2 However, more electronic devices are added to the zero-crossing detection circuit, which will increase the cost of detection, and the structure is complicated and not easy to maintain and protect.

At the same time, the defects of the optocoupler 2 cannot be avoided, and neither the existing technology nor the combination of the two existing technologies can achieve a better detection effect.

Images