Optimized Design of Double-Loops Controller for Single-Phase Pulse Rectifier without LC Resonant Filter Circuit

Abstract

Research on the lightweight issue of DC-link is an important direction in modern AC drive electric locomotive. Canceling LC filter circuit is an important way to achieve the goal of lightweight. Therefore, this paper focuses on single-phase pulse rectifier without LC filter circuit. The generation mechanism of DC voltage ripple and network-side current harmonics in grid-side converter is derived. Then, aiming to eliminate the current harmonics, the N-order notch filter and PR controller are introduced to the double-loops controller. The loop of voltage outer controller with N-order notch filter can filter out the ripple of DC-side voltage effectively without affecting the dynamic performance of the controller system. Meanwhile, the loop of current inner controller with PR controller can achieve zero steady-state error control to both the fundamental and harmonic current, and can suppress the low order harmonics in the line current effectively. Analysis shows that replacing the original L2C2 filter circuit with software controller is feasible. Finally, the validity and effectiveness of the proposed scheme are verified in computer simulation.

Archives of Electrical Engineering

“…For example, in references [6] and [7], a C-type filter is proposed to solve the problem of harmonic resonance and low frequency characteristic harmonics by establishing a mathematical model and optimizing topological structure respectively, which can effectively solve the problem of harmonic without introducing any power loss. In order to reduce the influence of the beat frequency voltage on the control system and suppress the low-order current harmonics, the method of adding a double-traction network frequency 100 Hz notch filter is adopted in the voltage signal feedback link at the DC side in references [8] and [9]. References [10], [11] and [12] use a repetitive controller in the current inner loop, which reduces the current harmonics on the grid side, but also lowers the dynamic performance of the system.…”