The optimum installation of distributed generation (DG) units in distribution systems has always been challenging due to the continually increase of electrical energy demands. However, the improper installation of DG units may have negative impact on the power quality of the distribution system. Voltage sag is one of the most important power quality problems, which has the bad effects on the performances of different loads, especially on sensitive and uninterruptible loads. To mitigate the voltage sag problem in distribution systems, a new formulation is proposed for optimal location and sizing of DG units. Particle swarm optimization algorithm is employed to solve the problem. The minimization of the total power losses, total cost of DG units, improvement of the voltage profile, and the reduction in the voltage sag effect are considered as the main objectives. To involve the voltage sag occurrence in distribution system, a penalty is considered for interruption of each type of available load. Different types of load models such as industrial, residential and commercial loads are considered in the system. For the demonstration of the effectiveness of the proposed algorithm, 34-bus test system is considered as the case study. The proposed method results are shown that there is about 72% reduction in total power losses in the optimal configuration of DG units in the distribution system. It is observed that the total number of disturbed buses decreases to 4, which is equal to 12%, as the number of DG units increases. It can be seen that the total cost of the system is reduced from 36.250 to 31.824 M$, when the optimum number of DG units is increased from 1 to 5. The simulation results show the effectiveness of the proposed algorithm.

中文翻译：

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考虑各种负载类型，优化配电系统中的 DG 单元以最小化电压暂降

由于电能需求的不断增加，分布式发电 (DG) 装置在配电系统中的最佳安装一直具有挑战性。但是，DG机组安装不当可能会对配电系统的电能质量产生负面影响。电压暂降是最重要的电能质量问题之一，它对不同负载，尤其是敏感和不间断负载的性能产生不利影响。为了缓解配电系统中的电压骤降问题，提出了一种新的公式来优化 DG 单元的位置和尺寸。采用粒子群优化算法解决该问题。最小化总功率损耗、DG 装置的总成本、改善电压曲线、减少电压骤降效应被认为是主要目标。为了涉及配电系统中电压骤降的发生，考虑对每种可用负载的中断进行惩罚。系统中考虑了不同类型的负载模型，例如工业、住宅和商业负载。为了证明所提出算法的有效性，34 总线测试系统被视为案例研究。所提出的方法结果表明，在配电系统中 DG 机组的优化配置中，总功率损耗降低了约 72%。可以观察到，随着 DG 单元数量的增加，受干扰母线的总数减少到 4 条，相当于 12%。可以看出，系统的总成本从 36.250 降低到 31.824 M$，