Study of Failure Rate Model for a Large-Scale Water Supply Network in Southern China Based on Different Diameters

This paper studies on the electromagnetic transient model of doubly-fed wind turbinegrid-side converter under the imbalanced grid condition. And on this basis, the paper analysis theimpact of doubly-fed converter when grid voltage asymmetric drop. It puts forward a dual PLL anddual current control combination of doubly-fed converter grid side control strategy. This strategyachieves grid voltage positive and negative sequence fast separation when asymmetric grid voltagedrop occur, achieves the active output power secondary fluctuate suppression under the imbalancedgrid voltage condition, avoids DC voltage rise at the fault moment and also achieves converterreactive power support under the imbalanced grid fault. The simulation and experimental resultsshow that the proposed control strategy is correct and with the application value of engineering.