Fig. 15
![Fig. 15](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs41601-021-00223-w/MediaObjects/41601_2021_223_Fig15_HTML.png)
Experimental results under a sudden change of 3Â Hz grid frequency. CH1, CH2, and CH3 show the responses of the proposed PLL, mEPLL, and modified SOGI-PLL, respectively. a Estimated phase error and b estimated grid frequency
Experimental results under a sudden change of 3Â Hz grid frequency. CH1, CH2, and CH3 show the responses of the proposed PLL, mEPLL, and modified SOGI-PLL, respectively. a Estimated phase error and b estimated grid frequency