基于低压智能塑壳开关的低压台区三相不平衡换相治理方法

Three-phase Unbalance Commutation Control Method of Low Voltage Platform Area Based on Low Voltage Intelligent Plastic Case Switch

配电网是连接用户的最后关卡,其电能质量的好坏直接影响用户的体验,而三相不平衡是电能质量问题中非常重要的一种。为了有效降低低压台区的三相不平衡度,提升用户的用电体验,基于低压智能塑壳开关的功能应用和三相不平衡评价指标,在对比了目前国内外低压配电网三相不平衡问题解决方案的优劣势后,提出了一种低压台区负荷自动换相三相不平衡治理方法。首先,获取配电变压器低压侧各相序历史负荷电流、换相开关侧负荷相序及历史负荷电流;其次,根据历史负荷电流进行配电变压器低压侧和换相开关侧的负荷电流预测;最后,构建负荷转移模型并计算,将结果下发至换相开关进行换相,实现三相不平衡的治理。实际应用案例表明,提出的方法可以有效改善台区的三相不平衡情况,对配电网电能质量的提升有着很大的作用。

Distribution network is the last checkpoint to connect users, and its power quality directly affects users′ experience, and threephase imbalance is one of the most important ones. In order to effectively reduce the low pressure area of the three-phase imbalance degree,improve the power of the user experience, based on low voltage molded case switches the function of the application and unbalanced threephase evaluation index, in contrast the low voltage distribution network at home and abroad the advantages and disadvantages of three phase unbalanced problem solution, a low pressure area commutation three-phase unbalanced load automatic control method was proposed. Firstly,the historical load current of each phase sequence on the low-voltage side of the distribution transformer, the phase sequence and historical load current on the commutation switch side were obtained. Secondly, the load current prediction of low voltage side and commutation switch side of distribution transformer was made according to the historical load current. Finally, the load transfer model was constructed and calculated, and the results were sent to the commutation switch for commutation, so as to realize the governance of three-phase imbalance. The practical application cases show that the method can effectively improve the three-phase imbalance of the power distribution network, and has a great role in improving the power quality of the distribution network.