Noise and disturbance inhibition method for optical voltage sensor based on dual closed-loop detection

Abstract

The invention discloses a noise and disturbance inhibition method for an optical voltage sensor based on dual closed-loop detection, belonging to the technical field of fiber voltage sensors. The method comprises that a mathematic model of an optical voltage sensor system is established based on a four-mode modulation technology; a state equation and a dynamic equation of the system are established; and a feedback gain matrix Kc is determined, so that the optical voltage sensor closed-loop system satisfies the index stability. Based on the four-mode modulation technology, the method combines influential factors which influence the detection precision for the optical voltage sensor to provide a robustness control scheme, so that cross interference between two closed loops can be realized, and the optical voltage sensor can be widely applied to power systems.

Description

technical field [0001] The invention belongs to the technical field of optical fiber voltage transformers, and in particular relates to a method for suppressing noise and disturbance of an optical voltage sensor based on double closed-loop detection. Background technique [0002] The digital closed-loop detection scheme enables the closed-loop feedback signal of the optical voltage sensor and the closed-loop input signal to improve the linearity of voltage measurement at the zero point of the nonlinear sinusoidal interference light intensity signal, and solves the influence of light source power fluctuations on the scale factor, achieving a large Dynamic range and excellent bias stability. However, when the ambient temperature changes, the modulation coefficient of the phase modulator of the feedback execution unit will change accordingly, affecting the measurement accuracy, scale factor linearity and repeatability of the optical voltage sensor. In order to accurately track...

AI Technical Summary

Problems solved by technology

[0003] However, while the four-state modulation realizes the real-time fast closed-loop of the double-closed-loop detection loop, it also introduces the crosstalk of the double-closed loop, which greatly reduces the detection accuracy of the optical voltage sensor; and the digital closed-loop detection scheme makes the optical voltage sensor closed-loop While the signal is at the zero point, the closed-loop error signal becomes a weak signal with a lot of noise. In addition, the cross-interference in the double-closed-loop dynamic tracking process using four-state modulation technology makes the realization of high-precision optical voltage sensor a very difficult task. big challenge

Especially due to disturbance, noise and other reasons, it is difficult to improve the measurement accuracy of optical voltage sensors

In particular, the dual closed-loop noise and disturbance model based on four-state modulation technology is unclear (no reports at home and abroad), and it is difficult to optimize the closed-loop detection algorithm, which restricts the development of high-precision optical voltage sensors

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