Detection Experiment Research of Harmonic Current for Single-Phase Active Power Filter

2014 ◽  
Vol 701-702 ◽  
pp. 297-302
Author(s):  
He Feng Shao ◽  
Hui Min Quan
Keyword(s):  
Single Phase ◽  
Moving Average ◽  
Response Speed ◽  
Superior Performance ◽  
Phase System ◽  
Harmonic Current ◽  
Reactive Component ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

In order to solve the problem of detecting harmonic and reactive currents of single-phase APF, the paper gives a detection method for real time harmonic current and reactive current. In the paper, it makes use of some characteristics of triangle function, and calculates the amplitude of active and reactive component from load current. Then the DC component can be extracted by using a low-pass filter, namely the required active component and reactive component. This paper analyzes the characteristics of two kinds of low pass filter, and selects the superior performance moving average filter for experiment. The paper introduces the design of the software and hardware process. The circuit configuration of the proposed approach used in the single-phase system is simple, its dynamic response speed is fast and its detection precision is high. The result of the experiment shows that the proposed approach is feasible and valid.

Comparison and Analysis on Two Improved Detecting Methods for Harmonics without PLL in Single-Phase Circuit

2011 ◽  
Vol 130-134 ◽  
pp. 3928-3932
Author(s):  
Ju Xia Ding ◽  
Xiu Feng Zhang ◽  
Hua Jun Zhang
Keyword(s):  
Single Phase ◽  
Continuous Process ◽  
Response Speed ◽  
Theoretical Method ◽  
Phase Lock Loop ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Average Theory ◽  
Detecting Method

In order to reduce the error of the phase lock-loop (PLL) and compensate the delay of the low pass filter on harmonics detection, In the paper, a detecting-method without PLL in single-phase circuit is researched. In this method, the PLL and LPF are omitted, the feedback and average theory are used, so that the problem of detecting accuracy induced by PLL and real-time induced by LPF is solved. It is testified through comparison, analysis and simulation, that both methods can reduce the latency, improve dynamic response speed, the feedback method can reduce the delay in a dynamic, continuous process, while the average theoretical method can reduce the delay quantitatively.

The Design of the Single-Phase Inverter Based on DSP (TMS320F2812)

2014 ◽  
Vol 989-994 ◽  
pp. 3231-3235
Author(s):  
Zhao Xia Zhou ◽  
Jia En Huang
Keyword(s):  
Single Phase ◽  
Closed Loop ◽  
Optical Coupling ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Output ◽  
Low Pass ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
Single Phase Inverter

This paper designs a single-phase inverter.Battery as a 12V DC input, and output for the 24V,50 HZ standard AC wave. The load is resistive.The power supply adopts the Boost booster and two full-bridge inverter transform. For the control circuit, the preceding Boost converter using tl494 chip control closed-loop feedback and for the inverter part, adopting the 6N137 to finish the optical coupling isolation.Then,through the DSP (TMS320F2812) to complete the output of SPWM modulation.And the modulated SPWM signal can drive chip IR211 conducting the full bridge inverter. Finally, through a low-pass filter output the standard sine AC inverter power.

scholarly journals Evaluation of Moving Average Window Technique as Low-pass Filter in Microprocessor-Based Protecting Relays

2017 ◽  
Vol 7 (6) ◽  
pp. 2177-2183
Author(s):  
N. Khodabakhshi-Javinani ◽  
H. Askarian Abyaneh
Keyword(s):  
Moving Average ◽  
Least Square ◽  
Main Process ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Dc Offset ◽  
Signal Flow Graphs ◽  
Window Technique ◽  
Low Pass ◽  
Flow Graphs

Over the last decades, with the increase in the use of harmonic source devices, the filtering process has received more attention than ever before. Digital relays operate according to accurate thresholds and precise setting values. In signal flow graphs of relays, the low-pass filter plays a crucial role in pre-filtering and purifying waveforms performance estimating techniques to estimate the expected impedances, currents, voltage etc. The main process is conducted in the CPU through methods such as Man and Morrison, Fourier, Walsh-based techniques, least-square methods etc. To purify waveforms polluted with low-order harmonics, it is necessary to design and embed cutting frequency in a narrow band which would be costly. In this article, a technique is presented which is able to eliminate specified harmonics, noise and DC offset, attenuate whole harmonic order and hand low-pass filtered signals to CPU. The proposed method is evaluated by eight case studies and compared with first and second order low-pass filter.

scholarly journals Improved harmonic detection method based on ip-iq theory

2021 ◽  
Vol 261 ◽  
pp. 01028
Author(s):  
Zhisen Yao ◽  
Guige Gao
Keyword(s):  
Detection Method ◽  
Phase Error ◽  
Response Speed ◽  
Detection Accuracy ◽  
Harmonic Detection ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
In Series ◽  
Filtering Effect

Based on the traditional ip-iq harmonic detection theory, the accuracy of harmonic detection is easily affected by the phase-locked loop (PLL) output phase error, and the single low-pass filter (LPF) detection accuracy and filtering effect cannot be simultaneously. In this paper, an improved harmonic detection method based on the second-order generalized integrator-frequency locked loop (SOGI-FLL) technique is proposed to generate sine and cosine signals with the same frequency as the grid voltage; The traditional low-pass filter and average filter are used in series to improve the response speed and accuracy. Through theoretical analysis of the improved harmonic detection method and simulation in MATLAB environment, the theory and simulation results prove the effectiveness of the improved method.

Harmonic Analysis of a Single Phase Modulated Inverter

2016 ◽  
Vol 2 (3) ◽  
pp. 607 ◽  
Author(s):  
Md. Imran Azim ◽  
S. M. Mohiuddin
Keyword(s):  
Communication Networks ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Motor Drives ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Electric Motor Drives ◽  
Output Terminal ◽  
Low Pass ◽  
Torque Pulsations

<p>This paper portrays an approach of an analysis that provides information regarding the presence of harmonics at the inverter output terminal. It is certainly true that harmonics cause unbalance and excessive neutral currents, interference in nearby communication networks and disturbance to other consumers. More importantly, torque pulsations in electric motor drives are caused by them. Thus, the minimization of the harmonics contained in the output of a single phase current controlled inverter undergoing hysteresis modulation technique is important so as to get rid of these detrimental effects. A model of an LC low pass filter has been provided in this paper for harmonics reduction purpose, as it blocks the harmonics and passes approximately a sinusoidal output. Moreover, the paper contains the method of Fast Fourier Transform (FFT) for fulfilling the desire of understanding not only the fundamental component but also the harmonics component flawlessly. It has been found from the simulation that the Total Harmonic Distortion (THD) in ideal case is 0%. On the other contrary, during the presence of harmonics, it steeps to 41.415% that can be mitigated to 0.0092% by implementing an LC low pass filter in a precise manner.</p>

Based on Delay Compensation System for Shunt Active Power Filter Research

2013 ◽  
Vol 860-863 ◽  
pp. 2050-2053
Author(s):  
Xin Yao ◽  
Zai Lin Yao ◽  
Xin Ying Teng
Keyword(s):  
Compensation System ◽  
Matlab Simulation ◽  
Harmonic Detection ◽  
Delay Compensation ◽  
Harmonic Current ◽  
Shunt Active Power Filter ◽  
Harmonic Compensation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

APF harmonic detection is the study of the most important parts of the core , quickly and accurately detect the harmonic current is able to quickly output harmonic compensation circuit current of the premise. Delay compensation system is based on the increase in the method specified time compensation angle , which can accurately detect the harmonic current at the same time , the low-pass filter to minimize the time delay generated by MATLAB simulation, the use of delay compensation system active Filter harmonic Detection and Compensation excellent performance, while ensuring high precision detection and compensation while ensuring at the same time , and fully complete filter real-time functionality .

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