Double correction software phase-lock loop implementation method

Abstract

A double correcting software PLL in the field of signal processing technology. The processes are as follows: base on the standard signal, utilize the output of parallel double low pass filter to get resection tangent function to correct frequency; base on the output signal of the frequency correcting tache, use he output of parallel double low pass filter to get resection tangent function to correct phase; design low pass filter to assure PLL's tracking speed and precision; adopt TM320C2407DSP to program and speed up the calculation. This invention adopts simple loop control, has high stability and fast tracking speed. The temporary state response time is less than 20ms. It precisely and quickly measures the voltage, base wave frequency and phase of the current of the electric system. It supplies the synchronous signals to the non-power compensator, the filter and micro-computer protective device.

Description

technical field

[0001] The invention relates to a method for realizing a phase-locked loop, specifically, a method for realizing a double-correction software phase-locked loop. It belongs to the technical field of signal processing. Background technique

[0002] At present, analog phase-locked loop and digital phase-locked loop technology are commonly used to obtain the initial phase and frequency of the system fundamental wave. Both the analog phase-locked loop and the digital phase-locked loop are implemented by hardware, and the analog phase-locked loop has problems such as DC zero drift, device saturation, loss of lock, jitter, and low reliability. The digital phase-locked loop also has high requirements on the device, and it is difficult to design a low-pass filter with a digital circuit, and it is difficult to improve the precision. More importantly, these two methods both rely on the detection of the zero-crossing moment, but the harmonics of the voltage and current...

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