scholarly journals An improved ip-iq harmonic detection method

2021 ◽  
Vol 248 ◽  
pp. 02045
Author(s):  
Yang Guoqing ◽  
Yan Kai ◽  
Wang Deyi ◽  
Chai Yuan ◽  
He Xu
Keyword(s):  
Reactive Power ◽  
Detection Method ◽  
Moving Average ◽  
Notch Filter ◽  
Positive Sequence ◽  
Harmonic Detection ◽  
Grid Voltage ◽  
Adaptive Notch Filter ◽  
Voltage Signal ◽  
Low Pass

The ip-iq harmonic detection method based on instantaneous reactive power has been widely used in active power filter (APF). However, the traditional ip-iq detection method has errors when the grid voltage is unbalanced and distorted. This paper proposes an improved ip-iq harmonic detection method, which uses adaptive notch filter (ANF) to extract the fundamental positive-sequence voltage signal, so that the phase locked loop (PLL) can still accurately obtain the phase information under bad grid conditions. At the same time, moving average filter (MAF) is used to replace low-pass filtering to reduce the detection delay. The simulation results show that the improved ip-iq detection method can accurately detect harmonic current under non-ideal grid voltage conditions, and has good dynamic characteristics.

scholarly journals A rapid harmonic detection method for grid-connected photovoltaic when three-phase voltage is unbalanced

2021 ◽  
Author(s):  
Tiezhou Wu ◽  
An Wang ◽  
Yawen Xu
Keyword(s):  
Phase Angle ◽  
Detection Method ◽  
Positive Sequence ◽  
Harmonic Detection ◽  
Phase Voltage ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Negative Sequence ◽  
Three Phase ◽  
Low Pass

Abstract By using power electronic devices, photovoltaic grid-connected power generation may inject harmonics into the power system. As the photovoltaic grid-connected inverter has the same basic structure as the active power filter, so the unified control of the photovoltaic grid and active filtering can be achieved. When the current unified control system compensates harmonics of the grid side, it mainly uses ip-iq harmonic detection method, which is based on instantaneous reactive power theory. When the three-phase voltage is unbalanced, the method has a large voltage phase angle detection error and the signal of the low-pass filter tracking system is long, detection time delay and even failure occur. This paper proposes an improved fast harmonic detection method. When phase deviation or amplitude change occurs to the three-phase voltage, the positive and negative-sequence voltages are simultaneously park transformed. The negative-sequence component is filtered by the current average module to obtain the fundamental amount of the voltage, then the phase angle of the positive-sequence voltage is accurately calculated to improve the harmonic current detection accuracy. Through the study of the integral method, it is found that the least common multiple of each harmonic period can be used as the integral interval, and the integral value is also zero, so the detection delay time is reduced by replacing the low-pass filter with an integration module. The simulation results show that the proposed harmonic detection algorithm can accurately detect harmonics when the three-phase voltage is unbalanced, and about 0.057 s improve the harmonic detection speed compared with the commonly used ip-iq method.

A Novel Harmonic Detection Method Based on Wavelet Analysis

2014 ◽  
Vol 945-949 ◽  
pp. 2057-2061
Author(s):  
Lei Wu ◽  
Ya Zhou Gao
Keyword(s):  
Wavelet Analysis ◽  
Lower Cost ◽  
Reactive Power ◽  
Electronic Device ◽  
Power Electronic ◽  
Harmonic Suppression ◽  
Harmonic Detection ◽  
Power Filter ◽  
Low Pass ◽  
Low Pass Filters

Active power filter (APF) is a new power electronic device used for reactive power compensation and dynamic harmonic suppression. Its performance depends on the highly precise detection of harmonic and reactive current. In view of the low pass filters defection in traditional ip-iq method, this paper proposes a wavelet filter based on wavelet analysis. This algorithm could attain higher detection precision with lower cost. The simulate results illustrate the efficiency and accuracy of it.

A Survey on Detecting Methods for Harmonic of Power System

2012 ◽  
Vol 614-615 ◽  
pp. 907-910
Author(s):  
Xue Song Zhou ◽  
Guang Zhu Chen ◽  
You Jie Ma
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Detection Method ◽  
Response Speed ◽  
Development Trend ◽  
Detection Methods ◽  
Detection Accuracy ◽  
Harmonic Detection ◽  
Advantages And Disadvantages ◽  
Power System Harmonics

This paper describes Detecting Methods for Harmonics of power system has been considered one of the serious harms for power system. The research of harmonics has obtained high attention among people. The researches of harmonics detection have many methods, such as Based on Fryze theory of harmonic power detection, Instantaneous reactive power theory detection method, Fourier Transformation harmonic detection method, wavelet transform detection method, neural networks harmonic detection method etc. Aiming at harmonic detection, the different detection methods of power system harmonics are summarized and compared. This paper reviews the existing harmonic detection methods, and discuss their advantages and disadvantages in terms of detection accuracy and response speed, and finally summarizes the development trend of the harmonic detection method.

scholarly journals Improved p-q Harmonic Detection Method for Hybrid Active Power Filter

2018 ◽  
Vol 8 (5) ◽  
pp. 2910 ◽  
Author(s):  
Chau Minh Thuyen
Keyword(s):  
Dynamic Response ◽  
Reactive Power ◽  
Detection Method ◽  
Active Power Filter ◽  
Active Power ◽  
Harmonic Detection ◽  
Harmonic Current ◽  
Transient Time ◽  
Power Filter ◽  
Hybrid Active Power Filter

<p>The accuratedetermination of the load harmonic current is one of the important factors, it decides to effect of harmonic filtering and reactive power compensation for Hybrid Active Power Filter. The p-q harmonic detection method has been widely used in determining the harmonic currents of Hybrid Active Power Filter. However, when using this method, the dynamic response of Hybrid Active Power Filter in the transient period will have a large transient time and overshoot whenever the load changes abruptly. Therefore, in this paper an improved p-q harmonic current detection method based on fuzzy logic is proposed, which aims to reduce the overshoot and transient time in transient duration of Hybrid Active Power Filter. In order to compare the dynamic response of conventional and improved p-q harmonic detection methods, simulation results have demonstrated that: the proposed method has a shorter response time, the magnitude of the supply current in the transient time is smaller and the overshoot of the fundamental active and reactive power components is very small. This has a practical significance that contributes to the stability of the Hybrid Active Power Filter system</p>

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.

The Selective Harmonic Detection for the Integration Photovoltaic Generation and Active Power Filter

2011 ◽  
Vol 58-60 ◽  
pp. 781-786
Author(s):  
Yan Dan Lin ◽  
Li Qing Tong ◽  
Yao Jie Sun
Keyword(s):  
Control Strategy ◽  
Detection Method ◽  
Active Power Filter ◽  
Active Power ◽  
Positive Sequence ◽  
Harmonic Detection ◽  
Power Filter ◽  
Three Phase ◽  
Frequency Domains ◽  
And Control

To improve the utilization of the inverter of the photovoltaic grid connected systems and decrease the harmonic of the grid, a novel selective harmonic detection method based on the synchronous rotator frame is proposed. Utilizing three-phase Park transform, the rotator vector is transferred to the static vector, and the synchronous harmonic is separated and acquired. The characteristic of negative and positive sequence harmonic is fleetly and exactly presented in all frequency domains. Additional, a new control strategy based on this harmonic detection is proposed for the integration photovoltaic grid connected generation and active power filter. Validity and practicality of the proposed selective harmonic detection method and control strategy are proved.

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