含微网的配电网接线模式探讨

Evaluation of a Distribution Network Connection Mode Considering Micro-grid

随着微网技术的发展,更多电力用户倾向于使用微网这一新型供电模式以提升供电可靠性。传统配电网接线模式是否能适应微网用户的实际需要已成为电网规划中的棘手问题。为此,完成了基于接线模式的配电网规划,并通过建立隶属度函数从最大短路电流、最大支路电压降落、系统平均供电可靠率指标、单位负荷年费4个方面对含微网以及不含微网的各种配电网接线模式进行综合评价,由此给出含微网的配电网接线模式推荐意见。评价结果表明,从"单位微网容量(成本)对可靠性提升幅度"这个角度来看,单电源辐射状接线模式更适合使用微网的供电区域,如果从"综合评估最优"这个角度来看,不同母线出线连接开关站这一接线模式能最大限度地满足重要用户对于供电质量的需求。

With the development of micro-grid technology in China, more and more power users tend to use the new power supply technology （micro-grid） to improve its power reliability. Whether the traditional connection mode of distribution network is able to suit the actual needs of micro-grid users has become a real problem that can not be avoided in network planning. With regarding to this, a distribution network planning was conducted in order to evaluate the typical connection modes more scientifically. After that, a comprehensive evaluation of various connection modes was executed to find the most appropriate connection mode for micro-grid users. In the evaluation, four indices have been considered, which are： max short-circuit current, max voltage drop, average system availability index （ASAI） and annual fee per load unit. The result of the evaluation shows that the radial connection mode is more suitable for micro-grid users when considering economical efficiency. But if the reliability has the highest priority, the switch substation with 2 sources could meet the highest reliability requirement of the important power user.