摘要
电力电子变压器(power electronic transformer,PET)可实现多电压等级和电能形态变换,将在柔性直流配电网中发挥重要作用。随着电力电子器件开关频率的不断提高,死区的影响已不容忽略。目前,针对死区的分析均基于仿真效率极低的详细模型,而采用平均值建模思想的加速模型虽然可以考虑死区的整体影响,但无法准确反映PET内部暂态特性。为在反映开关死区精度的同时提高效率,需要在PET的电磁暂态等效模型中集成开关死区的功能。基于此,该文以多有源桥型PET拓扑为例,首先基于其等效电路的生成过程和开关死区的控制策略,将死区分为单侧死区和双侧死区,并分别进行等效建模。随后针对不同的死区设置和控制参数,建立不同模式的多有源桥型PET的死区电磁暂态等效模型。最后,在PSCAD/EMTDC仿真软件中搭建电磁暂态详细和等效模型,对比结果表明,考虑死区的PET等效模型可以提高整体仿真精度,并且具有较高的加速比,因此可以更好地满足工程测试和仿真需求。
Power electronic transformer(PET)can realize multi-voltage level and power form transformation,and will play an important role in flexible DC distribution network.With the increasing switching frequency of power electronic devices,the effect of dead time cannot be ignored.The current analysis of the dead zone is based on detailed models with extremely low simulation efficiency;while the acceleration model using the average value modeling idea can consider the overall impact of the dead zone,but cannot accurately reflect the internal transient characteristics of the PET.In order to improve the efficiency while reflecting the accuracy of the switching dead time,it is necessary to integrate the function of the switching dead time in the electromagnetic transient equivalent model of the PET.Therefore,this paper takes the multi-active bridge PET topology as an example.First,based on the generation process of its equivalent circuit and the control strategy of the switch dead time,the dead time is divided into unilateral dead zone and bilateral dead zone,and the equivalent models are established respectively.Then,according to different dead time settings and control parameters,the dead time electromagnetic transient equivalent model of multi-active bridge PET under different modes is established.Finally,the comparison between the detailed model and the equivalent model built in PSCAD/EMTDC shows that the PET equivalent model considering the dead time can improve the overall simulation accuracy and has a higher speedup ratio,so it can meet the needs of engineering testing simulation requirements.
作者
王晓婷
冯谟可
许建中
赵成勇
WANG Xiaoting;FENG Moke;XU Jianzhong;ZHAO Chengyong(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2023年第15期5995-6004,共10页
Proceedings of the CSEE
基金
北京市自然科学基金项目(3222059)。
关键词
电力电子变压器
多有源桥
死区时间
电流过零点
等效建模
power electronic transformer
multiple active bridge
dead time
current zero-crossing
equivalent modeling
