提高主变负载率的大型用户变电站规划方法

New Substation Planning Method for Improving Step-down Transformer Capacity Factors

根据N-1原则目前大型用户变电站采用两台主变的规划方法,变压器平均负载率不超过50%。为进一步提高变压器利用率,文中利用变压器允许短时过载运行的特性,提出了3台主变的规划方法,其中一台主变备用,当正常运行的一台主变检修或故障时,另外一台主变在峰值负载下短时运行,同时投入备用主变。文中通过总拥有费用方法,综合考虑电网建设成本、运行成本与备用容量费,分析该规划方法的技术经济可行性,并通过实际案例验证了该方案对变压器利用率提高程度及经济效益。

The dominating substation designing method mainly focuses on satisfying the N-1 criteria,which leads to the transformer load average rate of less than 50%. In order to further improve the utilization rate of transformer,this paper proposes a planning method of three transformer. The method takes the advantage of overloading capabilities of the stand-by transformer,then reduces the capacities of the transformers along with the investment and operation costs simultaneously. The paper analyses the technical and economic feasibility of the planning method,and is tested using real-world case studies,through the total capital cost aspect,which considers the grid construction cost,operation cost and spare capacity.