摘要
双有源桥(dual-active-bridge,DAB)DC-DC变换器作为电力电子变压器(power electronic transformer,PET)的核心组成部件,其控制性能直接影响PET的运行稳定性和可靠性。目前,一般采用单移相(singlephaseshift,SPS)方法对其有功功率进行双向调节,同时使二次侧直流母线电压保持稳定。而DAB二次侧直流母线电压的稳定性除了受输出级功率波动的影响外,还与一次侧直流母线电压扰动有关?本文同时考虑这2个影响因素,以三级式PET为例提出了一种基于系统功率平衡的控制策略?根据DAB的有功功率计算公式引入移相比因子,利用PI控制器实时调整移相比因子的大小,实现了对DAB二次侧直流母线电压的控制;将一次侧直流母线电压加入前向控制通道,使其与被控对象中的相同因子抵消,从而抑制了一次侧直流母线电压扰动的影响;考虑滤波电感的瞬时能量波动,计算出输出级逆变器的瞬时有功功率,并将其作为前馈扰动项加入到控制环路中,能有效衰减输出级功率变化引起的二次侧直流母线电压波动。最后,在一台380V/15kW的实验室样机上通过仿真和实验,对所提控制策略的稳态和动态响应性能进行了验证,证明了其有效性,同时,该方法还可推广到高压大容量PET应用中。
As the core component of the power electronic transformer(PET), the dual-active-bridge(DAB) DC-DC converter directly affects the stability and reliability of PET operation. At present, the single phase shift(SPS) method is generally used to adjust the active power flows in both directions while stabilizing the secondary-side DC-link voltage of DAB. In addition to the power fluctuation of the output stage, the stability of the secondary-side DC-link voltage is also related to the disturbance of the primary-side DC-link voltage of DAB. Considering these two factors simultaneously, a control strategy based on system power balance is proposed in this paper. According to the active power calculation of the DAB, a phase-shift factor is introduced, which is adjusted in real time by a PI controller to control the secondary-side DC-link voltage. By adding the primary-side DC-link voltage to the forward control channel, it can be offset with the same factor in the plant model, thereby the impact of the primary-side DC-link voltage disturbance can be suppressed. Moreover, a power feed-forward scheme, which takes the energy changes of filter inductors of the output stage into consideration, is provided to attenuate the secondary-side DC-link voltage fluctuation caused by the output-stage power change. Finally, simulations and experiments performed on a 380 V/15 k W prototype verify the effectiveness of the proposed control strategy, and this method can also be extended to high-voltage high-power PET applications.
作者
文武松
赵争鸣
聂金铜
魏树生
莫昕
袁立强
WEN Wusong;ZHAO Zhengming;NIE Jintong;WEI Shusheng;MO Xin;YUAN Liqiang(State Key Lab of Control and Simulation of Power System and Generation Equipment(Department of Electrical Engineering,Tsinghua University),Haidian District,Beijing 100084,China)
出处
《电网技术》
EI
CSCD
北大核心
2020年第8期2971-2978,共8页
Power System Technology
基金
国家重点研发计划项目(2017YFB0903200)。
关键词
双有源桥
电力电子变压器
功率平衡
直流母线电压
dual-active-bridge
power electronic transformer
power balance
DC-link voltage
