Papers by Keyword: Non-Sinusoidal

Abstract: In the modern society, with the rapid development of industrial technology and information industry, electrical loads become more and more complex. As a result, the harmonics and reactive power problems have become increasingly serious. In the non-sinusoidal conditions, conventional power definitions don’t work well any more. Power theory is one of the foundations of financial accounts for energy, evaluation of the efficiency of power transmission and control of current compensation. Among them, the instantaneous reactive power theory is regarded as one of the most promising power theories. What’s more, it has been improved. Based on the three-phase three-wire system and four kinds of different supply voltage conditions, this paper compares the instantaneous reactive power theory (pq theory) with the extension pq theory. At last, the simulation results are presented. As a conclusion, the extension pq theory is the improvement of the pq theory and has a wider applicability.

Abstract: The multi-phase inverter modulation and control method is a hotspot of multiphase systems. There is no general space vector modulation available due to the inherent difficulty in synthesizing more than one independent space vector simultaneously in different d-p planes. This paper established the distribution model of five-phase inverter space vector from a novel perspective of magnetic motive force (MMF) equivalence. And then a multi-dimensional SVPMW method applicable to the non-sinusoidal voltage output was proposed based on the obtained space vector distribution laws. The proposed multi-dimensional SVPWM method effectively improves the fundamental modulation range and is suitable for five-phase inverter non-sinusoidal modulation.

Abstract: The paper describes the composition and working principle of the mold oscillation control system. The mathematical model of hydraulic servo control system is established. The total system transfer function is established by MATLAB program. By using the SIMULINK module, we determined various components’ parameter values. We got different simulation curves and Bode plots by inputting non- sinusoidal function and carrying out the dynamic simulation to the mold oscillation mathematical model, we also analyzed stability of the whole system to verify the accuracy of system design.

Abstract: Matrix rectifier (AC-DC MC) is a four-quadrant AC-DC power converter device with compact topology. This paper concerns the influence of abnormal power supply conditions to the matrix rectifier. The input and output performances of matrix rectifier with pure sinusoidal supply voltages are discussed. The input currents are symmetrical sinusoidal without any low-order components. But due to the absence of DC capacitors, the abnormal conditions at input side affect the input and output performances directly, which introduce ripples into the DC output and cause the distortion of input currents. In this paper, the low-order harmonic components in input currents, and ripples at output side are theoretically analyzed under conditions that the input voltages are unbalanced and non-sinusoidal respectively. The simulation research is carried out to verify the theoretical analysis, and the results, which demonstrated the analysis conclusions, are given.