An Improved Phase-Locked-Loop Control with Alternative Damping Factors for VSC Connected to Weak AC System

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static.hindawi.com/articles/jcse/volume-2016/9537342/figures/9537342.fig.005a.svgz" name="9537342.fig.005a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b>Rectifier</td></tr><tr class="fig-image" id="b"><td><object data="https://static.hindawi.com/articles/jcse/volume-2016/9537342/figures/9537342.fig.005b.svgz" name="9537342.fig.005b" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(b) </b>Inverter</td></tr></table>

<div>Root-locus of predominant poles with <svg height="9.39034pt" id="M102" style="vertical-align:-3.42943pt" version="1.1" viewbox="-0.0498162 -5.96091 7.69399 9.39034" width="7.69399pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M559 271C559 395 493 448 433 448C370 448 304 394 275 297C259 245 235 121 219 37C157 54 113 110 113 201C113 310 180 386 276 429L265 457C131 410 23 326 23 186C23 83 86 5 211 -10C180 -159 167 -220 158 -252L165 -261C198 -255 236 -246 251 -218L287 -5C421 9 559 119 559 271ZM484 273C484 144 400 40 293 33L352 331C364 389 382 406 405 406C431 406 484 370 484 273Z" id="g113-253"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="582" vert-adv-y="582"></glyph.data></g></svg> change.</div>

Journal of Control Science and Engineering

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Figure 5

Figure 5: An Improved Phase-Locked-Loop Control with Alternative Damping Factors for VSC Connected to Weak AC System 