台区三相不平衡运行监测和治理分析

Operation Monitoring and Regulating Analysis of Three-phase Unbalance in LV Grid

摘要:

从当前台区三相不平衡监测和治理问题出发，开展了三相不平衡产生的根源及其对台区线损的影响分析。随后，针对三相不平衡监测，分析了仅关注配电变压器低压出口三相不平衡度和电量不平衡度两个常见做法存在的不足，并通过构建典型场景，测算了两个监测误区在反映台区线损率上的影响。针对各地常采用的三相不平衡集中补偿措施，分析了其在补偿三相不平衡度、降低损耗方面的局限性，并通过典型配电变压器和配电线路阻抗分析进行了验证。最后，针对上述分析的问题，本文提出了针对性的建议措施，为电网企业、配电网运营商开展低压电网三相平衡监测和治理，提供了思路和参考。

Abstract:

Aiming at the monitoring and regulating of three-phase unbalance in low-voltage (LV) grid, the causes of three-phase unbalance phenomenon and its influence on line loss are analyzed. Then, the shortcomings of two common practices in monitoring are analyzed, that is, focusing on the three-phase unbalance degree of the secondary winding of LV transformersand the unbalance degree of electric energy instead of real time power. After that, the limitations of the widely-used three-phase centralized unbalance compensation equipment are analyzed and verified by the impedance analysis of typical distribution transformer and distribution line. Finally, regarding the above-mentioned problems, the specific suggestions are proposed, which providesa reference for power grid enterprises and distribution network operators in monitoring and regulating of three-phase balanced in LV grid.