scholarly journals LCL filter design for grid-connected single-phase flyback microinverter: a step by step guide

2021 ◽  
Vol 12 (3) ◽  
pp. 1632
Author(s):  
Muhamad Faizal Yaakub ◽  
Mohd Amran Mohd Radzi ◽  
Maaspaliza Azri ◽  
Faridah Hanim Mohd Noh
Keyword(s):  
Single Phase ◽  
Filter Design ◽  
Harmonic Distortion ◽  
Harmonic Suppression ◽  
Power Devices ◽  
Application Behavior ◽  
Resonance Frequencies ◽  
Parameter Variations ◽  
Key Aspects ◽  
Current Ripple

<span lang="EN-US">Recently, <em>LCL</em> has become amongst the most attractive filter used for grid-connected flyback inverters. Nonetheless, the switching of power devices in the inverter configuration creates harmonics that affect the end application behavior and might shorten its lifetime. Furthermore, the resonance frequencies produced by the <em>LCL</em> network contribute to the system instability. This paper proposes a step-by-step guide to designing an <em>LCL</em> filter by considering several key aspects such as the resonance frequency and maximum current ripple. A single-phase grid-connected flyback microinverter with an <em>LCL</em> filter was designed then constructed in the MATLAB/Simulink environment. Several different parameter variations and damping solutions were used to analyze the performance of the circuit. The simulation result shows a promising total harmonic distortion (THD) value below 5% and harmonic suppression up to 14%.</span>

Grid-Connected Control Strategy Based on Fixed Mi Coefficient for Single-Phase Photovoltaic System

2014 ◽  
Vol 494-495 ◽  
pp. 1764-1770
Author(s):  
Wen Jie Zhu ◽  
Fei Rong ◽  
An Luo ◽  
Yong Xu ◽  
An Ping Hu
Keyword(s):  
Control Strategy ◽  
Single Phase ◽  
Closed Loop ◽  
Harmonic Distortion ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Harmonic Suppression ◽  
Pv System ◽  
Simulation And Experiment ◽  
The Stability

This paper presents a grid-connected control strategy for single-phase photovoltaic (PV) system. Voltage source inverter (VSI) of a PV system is a core component which will produce some harmonics when the switch is operated between on and off continuously. To suppress harmonic distortion in the VSI output current, a fixed modulation index (MI) control loop based on PI controller is added to the traditional double closed-loop. The proposed method can fix the MI coefficient to be a large value in any conditions. The design of the controller and the stability of the grid-connected system are discussed in detail. Simulation and experiment results are presented to demonstrate the dynamic and precision performance of the controller for harmonic suppression when the proposed PV system is connected to the grid.

scholarly journals Design and Performance Evaluation of a Single-Phase Driven Ultrasonic Motor Using Bending-Bending Vibrations

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 853
Author(s):  
Dongmei Xu ◽  
Wenzhong Yang ◽  
Xuhui Zhang ◽  
Simiao Yu
Keyword(s):  
Single Phase ◽  
Oblique Line ◽  
Ultrasonic Motor ◽  
Vibration Modes ◽  
Bending Vibrations ◽  
Bending Vibration ◽  
Output Performance ◽  
Resonance Frequencies ◽  
And Performance ◽  
Line Trajectory

An ultrasonic motor as a kind of smart material drive actuator has potential in robots, aerocraft, medical operations, etc. The size of the ultrasonic motor and complex circuit limits the further application of ultrasonic motors. In this paper, a single-phase driven ultrasonic motor using Bending-Bending vibrations is proposed, which has advantages in structure miniaturization and circuit simplification. Hybrid bending vibration modes were used, which were excited by only single-phase voltage. The working principle based on an oblique line trajectory is illustrated. The working bending vibration modes and resonance frequencies of the bending vibration modes were calculated by the finite element method to verify the feasibility of the proposed ultrasonic motor. Additionally, the output performance was evaluated by experiment. This paper provides a single-phase driven ultrasonic motor using Bending-Bending vibrations, which has advantages in structure miniaturization and circuit simplification.

Damping Performance of Material Candidates for Service at 350K

2021 ◽  
Vol 315 ◽  
pp. 43-49
Author(s):  
Si Bin Zhang ◽  
Ze Chao Jiang ◽  
Qing Chao Tian
Keyword(s):  
Internal Friction ◽  
Single Phase ◽  
Vibration Reduction ◽  
Physical Parameters ◽  
Heating Rates ◽  
Friction Mechanism ◽  
Obvious Effect ◽  
Negative Linear Correlation ◽  
Resonance Frequencies ◽  
Damping Materials

Vibration systems require the damping materials operating at high service temperature. In this paper, damping performance of HT100, M2052 and S316L at 350K were evaluated by applying different frequencies, strain amplitudes and heating rates. It is found that the internal friction dependence of frequency of HT100, M2052 and S316L all show a characteristic of Check function, and the resonance frequency has a negative linear correlation with the material physical parameters. The strain amplitude as well as heating rate has no obvious effect on the resonance frequencies of the materials, but significantly enhance the internal friction of the interface damping alloys such as M2052 and HT100, but small on single-phase alloys such as S316L. The internal friction mechanism for HT100 and M2052 are of static hysteresis at 350K, and HT100 and M2052 are applicable candidates for working at temperatures around 350K from the viewpoint of vibration reduction.

scholarly journals Total Harmonic Distortion Oriented Finite Control Set Model Predictive Control for Single-Phase Inverters

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3467 ◽  
Author(s):  
Po Li ◽  
Ruiyu Li ◽  
Haifeng Feng
Keyword(s):  
Model Predictive Control ◽  
Cost Function ◽  
Predictive Control ◽  
Single Phase ◽  
Tracking Error ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Finite Control ◽  
Control Set ◽  
The Cost

Inverters are commonly controlled to generate AC current and Total Harmonic Distortion (THD) is the core index in judging the control effect. In this paper, a THD oriented Finite Control Set Model Predictive Control (FCS MPC) scheme is proposed for the single-phase inverter, where a optimization problem is solved to obtain the switching law for realization. Different from the traditional cost function, which focuses on the instantaneous deviation of amplitude between predictive current and its reference, we redesign a cost function that is the linear combination of the current fundamental tracking error, instantaneous THD value and DC component in one fundamental cycle (for 50 Hz, it is 0.02 s). Iterative method is developed for rapid calculation of this cost function. By choosing a switching state from a FCS to minimize the cost function, a FCS MPC is finally constructed. Simulation results in Matlab/Simulink and experimental results on rapid control prototype platform show the effect of this method. Analyses illustrate that, by choosing suitable weight of the cost function, the performance of this THD oriented FCS MPC method is better than the traditional one.

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