A power quality comprehensive compensation strategy for retrofit structure of advanced traction power supply system (ATPSS) is proposed in this paper. Firstly, the mathematical model of converter in ATPSS is established. Then focusing on the negative sequence and harmonic power quality problems analyzed in retrofit structure, power quality comprehensive compensation strategy is investigated. Finally, simulations and experimental results verify the effectiveness of comprehensive compensation control strategy.

The high-speed Electric Multiple Units(EMUs) is widely used in railway transportation. The secondary voltage ripple on the DC-Link of the traction converter endangers the safety of the rolling stock. The existing passive secondary voltage ripple suppression devices are larger and heavier. In this paper, an active filter and its control strategy for the CRH3 EMUs traction converter are proposed, whick can absorb secondary pulsating power with smaller size and less weight. The proposed active filter meets the design requirements for pulsating power and key parameters are calculated. A simulation model based on Matlab/Simulink verifies the active secondary voltage ripple suppression strategy for single-phase rectifier. An experimental platform based on the FPGA controller is built to verify the correctness and effectiveness of the proposed strategy. It is shown that the size and weight reduction of the secondary voltage ripple suppression devices can be achieved without affecting the performance.

The random Fourier filter-based filtered-x least mean square (RF-FxLMS) algorithm has been proposed for the nonlinear active noise control (NANC) system to reduce the computational burden of the kernel filter. However, the RF-FxLMS algorithm markedly fluctuates when dealing with impulsive noise. In addition, the computing cost for the RF-FxLMS algorithm is still pricey in practice. In this work, a random Fourier filter based filtered-x generalized hyperbolic secant function (RF-FxGHSF) algorithm is presented to deal with impulsive noise. In virtue of the bilinear scheme, a cascaded random Fourier filter model is designed for concise computations, and the cascaded RF-FxGHSF (CRF-FxGHSF) algorithm is derived. Moreover, the steady-state convergence conditions are analyzed. The calculation complexity of the proposed algorithms is compared, and experiments emphatically analyze the principle for the presented model. Numerical simulations with α-stable noise and real noise carried out in different nonlinear path scenarios verify the convergence ability of proposed algorithms.