Phase-locked loop based on comb filter

Abstract

The embodiment of the invention discloses a phase-locked loop based on a comb filter. According to the phase-locked loop, a moving average filter in a traditional phase-locked loop is replaced by thecomb filter; the comb filter has a plurality of zero poles at non-origin positions. The distance among the zero poles is relatively low. When a signal frequency deviates from a zero frequency, signalsare hardly influenced due to mutual cancellation effect among the zero poles, so the phase lag at the position of the zero frequency can be effectively compensated. The phase margin of the comb filter is greater than the phase margin of the moving average filter, so the technical problem that the phase lag exists at the position of the zero pole frequency of the current phase-locked loop and thephase margin of the current phase-locked loop is relatively low is solved.

Description

technical field [0001] The invention relates to the field of power control, in particular to a phase-locked loop based on a comb filter. Background technique [0002] When all kinds of electric energy metering devices are used in harsh grid conditions, in order to achieve reliable and stable grid-connected operation of their own devices and avoid interference from harmonic components in the grid voltage, it is necessary to accurately, quickly and correctly obtain the positive voltage fundamental wave of the three-phase grid voltage. sequence phase and frequency information. [0003] In various grid-connected devices, in order to control the output active and reactive power, the phase information of the grid voltage is very important, so the performance of the phase-locked loop directly affects the performance of the entire system, and has a great impact on the steady-state accuracy and The requirements for dynamic response and suppression of harmonic distortion are getting ...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a phase-locked loop based on a comb filter, which solves the technical problems of the phase lag and small phase margin at the zero frequency of the front phase-locked loop

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