| 摘要: |
| 微网中由于不同的实体独立测量电压，会出现多个PT并联运行的情况。孤岛模式下的微网，失去了主网中性点消弧线圈或小电阻的电压钳位，并联运行的PT更容易发生铁磁谐振。为了提高微网孤岛运行的安全性，深入分析了多PT铁磁谐振的产生机理，同时提出了铁磁谐振的抑制技术。分析表明:通过串一、二次消谐电阻的措施不能可靠消谐，而采用投入一个经消谐电阻接地的中性点的方案具有更好的效果。根据微网的实际运行情况，研究了消谐电阻的选择方法及其控制技术。EMTP/ATP仿真和实际运行验证了所提出方案的有效性。 |
| 关键词: 微网 孤岛模式 电磁式电压互感器 铁磁谐振 消谐措施 |
| DOI：10.19783/j.cnki.pspc.181488 |
| 投稿时间：2018-11-29修订日期：2019-04-08 |
| 基金项目:国家自然科学基金项目资助(51777067) |
|
| Research on multi-PT ferroresonance in island microgrid |
| QI Zheng,LI Hongyi |
| (North China Electric Power University, Beijing 102206, China) |
| Abstract: |
| In microgrids, different entities will measure the voltages independently, which could cause that multiple PTs operate in parallel. In the island mode, the arc suppression coil or small resistant connected at neutral point in the main network that can clamp the voltage will be disconnected, and ferroresonance more likely occurs in this case. In order to improve the security of island mode of microgrid, this paper analyzes the mechanism of multi-PT ferroresonance and proposes suppression technology of ferroresonance. The analysis shows that ferroresonance cannot be reliably eliminated by using a series resistance in primary or secondary winding, however, can be reliably eliminated by using a ferroresonance-constraining resistance connected at neutral point. Based on the operation condition of microgrids, the selection and control of ferroresonance-constraining resistance are studied. The effectiveness of the scheme in the paper is verified by EMTP/ATP and practical operation. This work is supported by National Natural Science Foundation of China (No. 51777067). |
| Key words: microgrid island mode electromagnetic voltage transformer ferroresonance ferroresonance suppression measures |
