Flexible DC power grid single-ended line protection method based on time domain voltage traveling wave

• Main Authors: QIU XIAOXUAN, DAI ZHIHUI, QIN HAOYU, QIU HONGYI
• Format: Patent
• Language: Chinese; English
• Published: 27.09.2022
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The invention relates to a flexible DC power grid single-ended line protection method based on time-domain voltage traveling waves, and the method comprises the steps: forming a direction criterion according to the difference of a voltage traveling wave reflection coefficient under positive and negative direction short-circuit faults or lightning stroke interference, and avoiding the protection misoperation under a negative direction fault or lightning stroke; and secondly, analyzing a function model satisfied by fault voltage first traveling waves at the protection position under the internal short-circuit fault and the positive non-internal short-circuit fault by using a voltage traveling wave transfer function, and forming a complete line single-ended protection method by combining a starting criterion and a pole selection criterion according to different matching degrees between the fault first traveling waves and a reference function model. According to the method, a flexible direct-current power grid mo