通过日前多时段优化,可以为主动配电网中的分布式电源、无功补偿装置和储能装置安排合理高效的生产计划,以达到调节电压水平、提高能源资源利用率、节能降损的目的。首先建立基于三相Distflow潮流的辐射状配电网有功–无功协调动态优化模型。该模型考虑分布式电源出力、储能装置充放电功率、电容器阻投切等连续和离散决策变量,是一个典型的混合整数非凸非线性规划。该类模型缺乏严格高效的求解方法。为此,采用二阶锥松弛技术将其中的三相潮流方程进行凸化松弛,使得优化问题转化为可有效求解的混合整数二阶锥规划模型。最后,采用扩展的IEEE 33节点三相测试系统仿真计算,利用MOSEK等算法包求得电网中各设备动作时刻和投运容量,验证了所提方法寻优稳定、松弛精确、计算高效等特性。
With increasing penetration of distributed generation (DG), dynamic optimal operation of active distribution network (ADN) is indispensable. A three-phase active and reactive power coordinated dynamic optimization model is proposed in this paper, whose control variables include the output of DG, charge and discharge operation of energy storage system (ESS), operation of SVC and Capacitor Banks. This is a mixed integer nonconvex nonlinear programming problem and is hard to solve. In this paper, the second-order cone relaxation (SOC) technique is used to convexify the power flow equations in this optimization model. Consequently, the original model is converted to a mixed integer second-order cone programming (MISOCP) which can be solved efficiently by MOSEK. Numerical tests on the modified IEEE 33-bus system show this MISOCP based multi-period optimization model for ADN is exact and can be solved efficiently.