Method for improving power grid voltage phase monitoring dynamic performance of single-phase digital phase-locked loop

Abstract

The invention discloses a method for improving the power grid voltage phase monitoring dynamic performance of a single-phase digital phase-locked loop. In a control system characterized in that a phase-locked loop is needed by a single phase to obtain power grid voltage phase information, a frequency-locked loop configured by a generalized second-order integrator obtains power grid voltage frequency information, and the frequency is input as a phase-locked loop reference frequency, so that an improved phase-locked loop is provided, and the dynamic performance of the phase-locked loop is improved. According to the invention, the dynamic response speed of the phase-locked loop is improved, and the power grid voltage phase tracing speed of the phase-locked loop is increased when the power grid voltage phase jumps or the frequency fluctuates, so that the unfavorable influences of phase jumping and frequency fluctuation on a current transformer are reduced, and the performance of the current transformer is improved.

Description

technical field [0001] The invention relates to a phase-locked loop for obtaining the voltage phase of a grid, and is suitable for all application occasions where the phase-locked loop is required to obtain the voltage phase. Background technique [0002] In applications such as new energy grid connection, UPS power supply, and AC drive electric locomotives, obtaining frequency and phase information of the power grid quickly and accurately is crucial to system control and reliable and stable operation. The phase-locked loop is an effective means to realize the above-mentioned frequency and phase fast detection. According to different implementation methods, phase-locked loops can be divided into software phase-locked loops and hardware phase-locked loops. The hardware phase-locked loop is also the traditional zero-crossing comparison phase detection method. Although this method is simple to implement, the phase-locking effect is poor and the ability to resist harmonic inter...

AI Technical Summary

Problems solved by technology

[0007] For all the phase detection methods mentioned above, the reference grid voltage and frequency are a fixed value. When the phase and frequency of the grid change, the phase angle of the output is adjusted by adjusting the PI link, which will significantly increase the adjustment burden and is not conducive to the performance of the phase-locked loop. improvement

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