Abstract:
The traction converter modulation generates switching-frequencies current harmonics. The trapped filters can eliminate these switching harmonics, reducing total inductance and filter size. Nonetheless, in comparison with the typical inductor-capacitor-inductor (LCL) filter, the trap inductor needs a larger magnetic core. Moreover, the trapped filter has not been analyzed in the traction systems. This paper proposes a magnetic integrated inductor-trap-inductor (LLCL) filter to decrease the filter\'s size and investigate its application in traction converters. In fact, the application range of this filter is quite broad, and it can be used in various electrical power systems, including industrial power systems, renewable energy systems, transportation systems, and building power systems. The LC-trap may be formed by connecting the equivalent trap inductor, introduced through the magnetic coupling between inverter-side and grid-side inductors, in series with the filter capacitor. Furthermore, for H-bridge unipolar pulse width modulation (PWM) traction converters, the prominent switching harmonics are concentrated at the double switching frequencies. Therefore, the stability zone is expanded by moving the resonance above the Nyquist frequency. The presented filter\'s features and design are thoroughly analyzed. The proposed method is finally validated by the MATLAB/Simulink simulation and hardware-in-the-loop (HIL) experimental results. Compared to the discrete windings, the integrated ones can save two magnetic cores. Furthermore, the proposed filter can meet IEEE criteria with 0.3% for all the harmonics and total harmonic distortion (THD) of 2.15% of the grid-side current.
摘要:
牵引变流器调制产生开关频率电流谐波。陷波滤波器可以消除这些开关谐波,减少总电感和滤波器的大小。尽管如此,与典型的电感-电容-电感(LCL)滤波器相比,陷波电感器需要更大的磁芯。此外,捕获的过滤器尚未在牵引系统中进行分析。本文提出了一种磁集成电感-陷波-电感(LLCL)滤波器,以减小滤波器的尺寸,并研究其在牵引变流器中的应用。事实上,这种过滤器的应用范围相当广泛,它可以用于各种电力系统,包括工业电力系统,可再生能源系统,运输系统,建设电力系统。LC陷波器可以通过连接等效陷波电感器来形成,通过逆变器侧和电网侧电感器之间的磁耦合引入,与滤波电容串联。此外,对于H桥单极脉宽调制(PWM)牵引变流器,突出的开关谐波集中在双开关频率。因此,通过将共振移动到奈奎斯特频率以上来扩大稳定区。全面分析了所提出的过滤器的功能和设计。最后通过MATLAB/Simulink仿真和硬件在环(HIL)实验结果验证了所提出的方法。与离散绕组相比,集成的可以节省两个磁芯。此外,所提出的滤波器可以满足IEEE标准,对于所有谐波和总谐波失真(THD)为电网侧电流的2.15%。