Real-Time Method for Detecting Harmonic and Reactive Currents of Single-Phase Circuits

According to the characteristics of single-phase circuits and demand of using active filter for real-time detecting harmonic and reactive currents, a detecting method based on Fryze＇s power definition is proposed. The results of theoretical analysis and simula- tion show that the proposed method is effective in realtime detecting of instantaneous harmonic and reactive currents in single-phase circuits. When only detecting the total reactive currents, this method does not need a phase-locked loop circuit, and it also can be used in some special applications to provide different compensations on the ground of different requirements of electric network. Compared with the other methods based on the theory of instantaneous reactive power, this method is simple and easy to realize.

Single-phase Thirteen-level Dual-boost Inverter Based Shunt Active Power Filter Control Using Resonant and Fuzzy Logic Controllers

This paper addresses the power quality improvement of a single-phase utility grid using a thirteen-level dualboost inverter(TLDBI)-shunt active filter(SAF).The TLDBI uses a single DC source of low voltage magnitude and five switched capacitor arrangement to achieve self-balanced thirteen level output voltages.Moreover,the charging and voltage balancing of the capacitor is achieved by proper switching sequence control in a series,through which boosted inverter output voltage levels are obtained.Compared with the tradional H-bridge multilevel inverters(MLIs),all the elements in the proposed TLDBI are able to withstand a voltage stress which is equal to the input DC source.This feature ensures the performance of the proposed TLDBI in high-frequency applications.The power at the electrical grid is highly affected by a wide range of non-linear loads.The proposed SAF is used for measuring and controlling the current flow from source to load.The difference between the targeted and actual currents from the utility grid is measured by using the modified synchronous reference frame(SRF)theory.The estimated error current is used by the controllers to predict the optimum suitable switching angle and modulation index(MI)to the TLDBI-SAF.In this paper,the traditional proportional-integral(PI)controller,fuzzy logic controller(FLC)and proportional resonant controller(PRC)are compared and the results are presented to validate the performance of SAF.The stability and robustness of the proposed controller is evaluated using Bode,Root locus,and Nyquist plots.The modeling and analysis of the proposed system are done using MATLAB/Simulink environments.The simulation results are presented in the various MI of TLDBI and also subjected to non-linear load conditions.The results are also compared to the claim novelty of the proposed study.

单相有源AC-DC变换器的统一算法及其应用(英文)

This paper discusses a novel boost single-phase active AC-DC converters, named low-end semi-controlled bridge AC-DC converter. By analysis, its topology and principle can be derived from the conventional single-phase power factor corrector （ PFC）. But it has also some differences, such as power device positions, inductor type, input voltage waveform detection and induction current detection, so its design is also different. The converter is implemented by employing two current detection approaches, i.e., current transformer detection and shunt resistor detection. Consequently, it can provide a steady DC output voltage with a low voltage ripple, approximately unitary input power factor and 2.5 kW output power. The experimental results show validity of the theoretical analysis.