考虑聚合节点高阶非线性电压支撑特性的潮流算法

Power flow calculation method considering high-order nonlinear voltage support characteristics model of integrate bus

随着高比例新能源渗透与大规模电力电子设备的广泛应用,电网中同时具备源荷双重属性的广义聚合节点的功率、电压特性会发生本质变化,常规以恒功率、恒阻抗、恒电流为分量加权组合的单纯负荷节点模型,已无法满足新形势下潮流计算精确性的更高要求。据此,提出一种考虑源荷聚合节点高阶非线性的潮流模型及其求解算法:采用高阶多项式形式解析节点非线性功率电压特性,引入潮流平衡方程,在Newton-Raphson法的基础上,推导和重构Jacobian矩阵,通过迭代计算完成求解。当阶数足够高时,能够高精度刻画和解析任意非线性节点电压特性,常规的幂指数模型等也可转换为高阶多项式形式以实现系统分析计算。算例分析中以包含电炉的聚合节点为例,分别考虑仅含恒功率、恒电流、恒阻抗的单纯负荷节点以及5阶非线性节点模型,在IEEE 14节点系统进行测试,验证了所提方法的可行性和有效性。

With the penetration of high proportion of new energy and the wide application of large-scale power electronic equipment,the power and voltage characteristics of generalized aggregation buses with both source-charge attributes in the power grid have changed fundamentally.The conventional simple load bus model with constant power,constant impedance and constant current as component weight combination can no longer meet the higher requirements of power flow calculation accuracy under the new situation.Therefore,this paper presents a power flow model and solving algorithm considering the high-order nonlinear of the source load aggregation bus.The nonlinear power and voltage characteristics of the bus are analyzed in the form of high-order polynomial,the power flow balance equation is introduced,and the Jacobian matrix is derived and reconstructed on the basis of Newton-Raphson method.When the order is high enough,it can describe and analyze the voltage characteristics of any nonlinear bus with high precision,and the conventional power exponential model can also be converted into high-order polynomial form to realize the system analysis and calculation.In the example analysis,the aggregation bus containing the electric furnace is taken as an example,and the simple load bus containing only constant power,constant current and constant impedance and the fifth-order nonlinear bus model are considered respectively.The feasibility and effectiveness of the proposed method are verified in the IEEE 14 bus system.