容载比作为指导电网规划的重要指标，对变电站定容选址、线路规划建设起到决定性影响。计及多电压等级电网差异性提出了一种多层级电网协同规划的容载比优化配置方法。模型以建设成本为目标函数，考虑多电压等级变电站和线路协同规划，结合贝叶斯优化算法（Bayesian optimization algorithm，BOA）与遗传算法（genetic algorithms，GA），提出规划模型的BOA-GA求解算法。所提模型能够自动形成多电压等级电网规划方案，并测算多电压等级电网最优容载比配比和电网建设各部分最优投资配比。研究表明，长时间尺度下电网多电压等级容载比配比与电网整体建设投资大体呈现为二次函数关系，关系曲线呈向上开口的椭圆抛物面形状。实际地区配网算例证明，该模型能实现多电压等级容载比的优化配置和网架结构的自动规划，在满足各项技术指标的同时，电网建设成本显著减少，经济性得到有效提升，所提方法能为多电压等级电网协同规划提供有效的理论和方法指导。

The capacity-to-load ratio is an important indicator to guide the power grid planning, and has a decisive influence on the selection of substation capacities and the construction of power lines. A capacity-to-load ratio optimization method considering collaborative planning of multi-voltage level power grids is proposed in this paper, which aims to minimize the construction cost and takes into account the synergetic planning of substations and power lines of multi-voltage levels. By combining the Bayesian optimization algorithm (BOA) and genetic algorithms (GA), a BOA-GA solving algorithm for the planning model is proposed. This algorithm automatically generates planning schemes for multi-voltage level power grids, and obtains the optimal capacity-to-load ratio, as well as the optimal investment of the power grid construction. Additionally, the study reveals that the relationship between capacity-to-load ratio and the overall investment of power grid construction is a quadratic function over a long time scale, and the curve is a parabola going upwards. Case studies demonstrate that the proposed model can achieve optimal configuration of multi-voltage level capacity-to-load ratio and automatically plan the network structure. The construction cost is significantly reduced while various technical indicators are satisfied. The proposed method can provide effective theoretical and methodological guidance for multi-voltage level power grid synergetic planning.