摘要
Abstract
When power electronic transformer (PET) supplies power to the unbalanced or non-linear loads,the voltage amplitude and frequency of the output-side in PET may be unstable,and even affect the power supply reliability of the PET.Aiming at demands of large output capacity,adjustable capacity modules,and high-quality power supply of PET,and for avoiding the limitations of single inverter output module in handling asymmetric or non-linear loads,a dual-module control strategy with high power quality for parallel output sides (inverters) of PET is proposed.In which,one of the inverter modules in output side is regarded as a voltage source and adopts double closed-loop control strategy of voltage and current,it provides stable output voltage of PET and stabilizes the voltage reference values of the output sides for other inverter modules,which can not only compensate for negative sequence current,harmonics and reactive current to reduce the negative impacts on the output voltage of PET,but also provide active power and reactive power in accordance with established power distribution strategy for output side modules.Other output-side inverter modules treated as current sources adopt the current compensation control strategy.They are used to enlargc the output current and enhance the capacity of PET.Taking two parallel output-side inverter modules as an example,the proposed high power quality control strategy is analyzed theoretically.It is concluded that the proposed strategy can improve the output capacity of the PET,greatly reduce the adverse effects of asymmetric loads on the output voltage stability of PET and effectively enhance the adaptability,capacity expansion and power supply reliability of PET.The simulation results verify the effectiveness of the proposed control strategy.关键词
电力电子变压器/输出侧/并联模块/高电能质量/电压电流双闭环控制/电流补偿控制Key words
power electronic transformer/output side/parallel modules/high power quality/voltage-current double closed-loop control/current compensation control分类
信息技术与安全科学
