scholarly journals Parallel Resonance Mechanism Analysis and Suppression of Inductance-Capacitance-Inductance Grid-Connected Inverters

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1656 ◽  
Author(s):  
Tao ◽  
Zhou ◽  
Zhang ◽  
Zheng
Keyword(s):  
Resonance Frequency ◽  
Superposition Principle ◽  
Notch Filter ◽  
Distribution Networks ◽  
Resonance Problem ◽  
Mechanism Analysis ◽  
New Energy ◽  
Digital Notch Filter ◽  
Parallel Resonance ◽  
Capacitance Current

The resonance problem of multi-paralleled grid-connected inverters with inductance-capacitance-inductance (LCL) filters is a core matter which bothers the safety and stability operation of new energy distribution networks. Based on the impedance model of the paralleled system of two inverters, the influence of inverters on grid-connected current was analyzed through the superposition principle, and the grid-connected current was decomposed. The resonant mechanism generated by interactive current and the common current was studied, and the resonance frequency characteristics were compared and analyzed by a paralleled system using the same and differently rated power inverters. Based on the resonance frequency generated by interactive current, a digital notch filter was introduced into the traditional capacitance current active damping control scheme, which realized the non-static control of base wave signal and satisfied the standard of multi-paralleled grid-connected inverters with LCL filters. Finally, simulation results verified the correctness and validity of the proposed strategy.

scholarly journals Design and Implementation of the Isolated Bidirectional DC-DC Converter

2021 ◽  
Vol 2125 (1) ◽  
pp. 012056
Author(s):  
Yiyang Yuan
Keyword(s):  
Power Flow ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Fault Isolation ◽  
Energy Access ◽  
Power Flow Control ◽  
Electrical Isolation ◽  
New Energy ◽  
Converter Topology ◽  
Increasing Demand

Abstract With the development of intelligent distribution networks and the increasing demand for new energy access, the isolated bidirectional dc-dc converter has become a key link in modern energy transformation systems. In order to realize the functions of electrical transformation and electrical isolation of dc voltage, this paper proposes a structure of isolated bidirectional dc-dc converter, and analyzes it in detail. The proposed isolated bidirectional dc-dc converter can not only realize voltage transformation, but also have voltage regulation and fault isolation functions. Finally, based on the MATLAB/Simulink simulation platform, the proposed isolated bidirectional dc-dc converter topology is built and verified by simulation. The structure of isolated bidirectional dc-dc converter not only has the functions of voltage transformation and electrical isolation, but also has fault isolation, power flow control and other functions.

Series and Parallel Resonance Problem of Wideband Frequency Harmonic and Its Elimination Strategy

2014 ◽  
Vol 29 (4) ◽  
pp. 1941-1952 ◽  
Author(s):  
Zhikang Shuai ◽  
Dingguo Liu ◽  
John Shen ◽  
Chunming Tu ◽  
Ying Cheng ◽  
...  
Keyword(s):  
Resonance Problem ◽  
Parallel Resonance ◽  
Frequency Harmonic

scholarly journals An approach of adaptive notch filtering design for electrocardiogram noise cancellation

2021 ◽  
Vol 22 (3) ◽  
pp. 1303
Author(s):  
Rahmad Hidayat ◽  
Ninik Sri Lestari ◽  
Herawati Herawati ◽  
Givy Devira Ramady ◽  
Sudarmanto Sudarmanto ◽  
...  
Keyword(s):  
Notch Filter ◽  
Ecg Signal ◽  
Least Mean Square ◽  
Heart Activity ◽  
Frequency Range ◽  
Biomedical Signal ◽  
Nlms Algorithm ◽  
Digital Notch Filter ◽  
Notch Filtering ◽  
Electrocardiogram Ecg

An electrocardiogram (ECG) is a means of measuring and monitoring important signals from heart activity. One of the major biomedical signal issues such as ECG is the issue of separating the desired signal from noise or interference. Different kinds of digital filters are used to distinguish the signal components from the unwanted frequency range to the ECG signal. To address the question of noise to the ECG signal, in this paper the digital notch filter IIR 47 Hz is designed and simulated to demonstrate the elimination of 47 Hz noise to obtain an accurate ECG signal. The full architecture of the structure and coefficient of the IIR notch filter was carried out using the FDA Tool. Then the model is finished with the help of Simulink and the MATLAB script was to filter out the 47 Hz noise from the signal of ECG. For this purpose, the normalized least mean square (NLMS) algorithm was used. The results indicate that before being filtered and after being filtered it clearly shows the elimination of 47 Hz noise in the signal of the ECG. These results also show the accuracy of the design technique and provide an easy model to filter out noise in the ECG signal.

scholarly journals “Triple-Alls” Distribution Network Information Model and Platform Design

2020 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Jianfeng Wang ◽  
Liang Chen ◽  
Liqin Shi ◽  
Dao’an Zhang ◽  
Hao Liu
Keyword(s):  
Power Distribution ◽  
Large Scale ◽  
Distribution Network ◽  
Distribution Networks ◽  
Information Model ◽  
Power Distribution Network ◽  
Platform Design ◽  
Network Information ◽  
Sensing Technology ◽  
New Energy

In recent years, large-scale new energy sources have been connected to the power distribution network, and the ubiquitous power IoT sensing technology has developed rapidly. At the same time, the increase in energy consumption has placed higher requirements on the consumption of new energy, which has led to the “Triple-Alls” (All access, All sensing, All consumption) requirements of the distribution network. To this end, this paper conducts a series of studies on the “Triple-Alls” distribution network: First, it analyzes the characteristics and key technologies of the “Triple-Alls” distribution network by comparing with traditional distribution networks, and then establishes energy storage, photovoltaic, and wind power. Information model of “Triple-Alls” distribution network. Then, a platform design scheme meeting the requirements is constructed. Finally, the application functions of “All access”, “All sensing” and “All consumption” in the distribution network are explained in detail.

scholarly journals Velocity Control of Traveling-Wave Ultrasonic Motors Based on Stator Vibration Amplitude

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5326 ◽  
Author(s):  
Zhiwei Fang ◽  
Tianyue Yang ◽  
Yuanfei Zhu ◽  
Shiyang Li ◽  
Ming Yang
Keyword(s):  
Resonance Frequency ◽  
Linear Relationship ◽  
Traveling Wave ◽  
Vibration Amplitude ◽  
Target Velocity ◽  
Velocity Control ◽  
Load Range ◽  
Ultrasonic Motors ◽  
Parallel Resonance ◽  
Transformer Ratio

Nonlinearity and resonance frequency shift make it difficult to control the operation of the traveling-wave ultrasonic motors (TWUSMs) in a wide velocity and load range. In this paper, a velocity control scheme based on the stator vibration amplitude and the parallel resonance frequency (VCBVF) of TWUSMs is proposed. Then, the stator vibration amplitude (SVA) and parallel resonance frequency ( f p ) are detected by a transformer ratio-arm bridge. Based on the linear relationship between the velocity and the SVA of TWUSMs, the proposed scheme achieves the control of the mechanical loop and the electrical loop. The linear relationship between the velocity and the SVA makes the mechanical loop achieve the target velocity efficiently, according to the SVA, and the electrical loop could provide the target SVA quickly. Experimental results show that the response time of velocity is 3–4 ms under different load torques and the overshoot is less than 22%. In addition, the proposed scheme improves the efficiency of TWUSMs due to f p tracking. Due to directing the SVA control, the proposed scheme can heighten the velocity response and the load adaptability of TWUSMs, and promote the application of TWUSMs under various conditions.

scholarly journals A Langasite Crystal Microbalance Coated with Graphene Oxide-Platinum Nanocomposite as a Volatile Organic Compound Sensor: Detection and Discrimination Characteristics

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 334 ◽  
Author(s):  
Ainan Leong ◽  
Tridib Saha ◽  
Varghese Swamy ◽  
Narayanan Ramakrishnan
Keyword(s):  
Graphene Oxide ◽  
Resonance Frequency ◽  
Film Surface ◽  
Series Resonance ◽  
Wave Resonator ◽  
Resonance Frequencies ◽  
Volatile Organic ◽  
Sensitivity And Selectivity ◽  
In Series ◽  
Parallel Resonance

We propose a novel langasite crystal microbalance (LCM) sensor with a graphene-based sensing medium to detect and discriminate volatile organic compounds (VOCs) at room temperature. A thin film of graphene oxide embedded with Pt nanostructures (GO-Pt nanocomposite) was deposited on the electrode surface of the LCM, a thickness-shear acoustic wave resonator. Ethyl acetate, acetic acid, and ethanol were chosen as typical VOCs for this study. Sensitivity and selectivity of coated LCM were investigated for different concentrations of the VOCs by analysing the resonant properties of the sensor. When exposed to VOCs, a negative shift in series resonance frequency was observed due to the mass loading of VOC molecules. Simultaneously, changes in equivalent resistance and parallel resonance frequency of the sensor were also observed due to the interaction of VOCs with charge carriers on the GO-Pt nanocomposite film surface. This dual measurement of both series and parallel resonance frequencies allowed for detection and discrimination of VOCs. Moreover, the high thermal stability of langasite makes the proposed sensor suitable even for harsh environmental conditions.

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