含VSC-HVDC交直流系统精确化离散最优潮流的研究

原对偶内点法在求解含电压源换流器的高压输电(Voltage source converter based high voltage direct current，VSC-HVDC)的交直流系统最优潮流(Optimal power flow，OPF)问题时，有较高的效率与准确性，但是无法很好地解决含离散变量的OPF(如无功优化)，而智能算法在解决此类问题时易于陷入局部最优解，同时计算时间过长。因此提出一种含离散惩罚函数的混合内点法算法。算法的主要思想是以内点法为框架，对连续变量进行优化，在当对偶间隙小于一定值时，对离散量的计算中引入罚函数，同时随着迭代量差值的变化随时调整罚函数的罚因子的大小。通过算例表明，该算法稳定性高，寻优能力强，能够很好地解决含VSC-HVDC交直流系统的离散变量的优化问题。

Study of accurate discrete OPF problem of AC/DC system equipped with VSC-HVDC

Primal-dual interior point method has higher efficiency and accuracy while solving OPF problem of AC/DC system with VSC-HVDC, but it cannot solve the OPF problem with discrete variables (such as reactive power optimization), the intelligent algorithm is easy to fall into local optimal solution when solving the problem and cost too much time. Therefore, a hybrid interior point method with discrete penalty function is proposed. The main idea of this algorithm takes interior point method as framework, and optimizes the continuous variable. When the duality gap is less than a certain value, it introduces the penalty function into discrete variables calculation, and at the same time adjusts the penalty factor as the iteration difference change. The numerical example shows that the algorithm has good stability, strong ability of searching and can solve the optimization problem of the AC/DC system with VSC-HVDC containing discrete variables.