Based on System Delay Time to Compensate for Harmonic Current Detection Method Research

2012 ◽  
Vol 614-615 ◽  
pp. 953-956
Author(s):  
Xin Yao ◽  
Zai Lin Yao ◽  
Xin Ying Teng
Keyword(s):  
Reactive Power ◽  
Detection Method ◽  
Matlab Simulation ◽  
System Delay ◽  
Harmonic Current ◽  
Harmonic Compensation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Pros And Cons

Harmonic detection is one of the most important core part of Active Power Filter,which can quickly and accurately detect the harmonic current that is the premise of circuit to quickly output harmonic compensation current,therefore the pros and cons of the detection method,a direct impact on the effect of harmonic compensation.Time compensation method is to add a specific time compensation angle based on the method of instantaneous reactive power compensation,so that it can accurately detect the harmonic currents at the same time,minimize the low-pass filter time delay.By MATLAB simulation,the results show high detection accuracy.And to ensure detection and compensation,while fully to improve the real-time function of the filter.

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 .

scholarly journals An Improved ip − iq Harmonic Detection Method Based on Time-Varying Integral Duration

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jifang Li ◽  
Jidong Wang ◽  
Kunlin Song ◽  
Zhen Feng
Keyword(s):  
Detection Method ◽  
Integration Time ◽  
Detection Accuracy ◽  
Harmonic Suppression ◽  
Harmonic Detection ◽  
Response Delay ◽  
Harmonic Current ◽  
Harmonic Compensation ◽  
Pass Filter ◽  
Low Pass Filter

By analyzing harmonic related to instantaneous active current and instantaneous reactive current, we propose an improved harmonic detection method to remedy long response delay and low detection accuracy corresponding to harmonic of power system. This method introduces a series connection scheme composed of Low-Pass Filter (LPF) and a current average module firstly. Then, detection accuracy of harmonic current is enhanced by adaptive tuning cut-off frequency of LPF and integration time which was obtained by proposed algorithm of the current average module. Moreover, feedback loop is introduced to compensated delay caused by LPF. Simulations including uncontrollable rectifier and three-phase voltage type inverter show proposed method has many advantages such as high detection accuracy, low response delay and good generality. Our method provides reliable harmonic current detection for later harmonic suppression and harmonic compensation.

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.

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.

Design of Fast Second-Order IIR Low-Pass Filter Based on Parameter Optimization

2014 ◽  
Vol 644-650 ◽  
pp. 4382-4386 ◽  
Author(s):  
Qi Rui Li ◽  
Ming Ming Jiang ◽  
Bing Luo ◽  
Xiao Ping Hu ◽  
Kang Hua Tang
Keyword(s):  
Operation Time ◽  
Digital Signal ◽  
Second Order ◽  
Filter Coefficient ◽  
Matlab Simulation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filtering Algorithm ◽  
Low Pass ◽  
Fast Filter

Second-order IIR low-pass filter is widely used in digital signal processing. A fast filter algorithm without multiplication is proposed for it in this paper. A configuration method for the filter coefficient of fast algorithm is put forward, considering the characteristic of second-order IIR low-pass filter coefficient and the filter’s mathematical model. A performance analysis of fast second-order IIR low-pass filter without multiplication is shown in the paper, and the performance of the fast filter is shown by example using MATLAB simulation. What’s more, the algorithm’s rapidity is verified by an implementation of the filter on FPGA, which turns out that fast filtering algorithm takes only 54.7% of common algorithm’s operation time to realize the same filer function.

Digital Filter Design in Power’s Harmonic Wave Detection

2011 ◽  
Vol 84-85 ◽  
pp. 457-460
Author(s):  
Yu Liang Liu ◽  
Yu Lian Zhang ◽  
S. Chen
Keyword(s):  
Reactive Power ◽  
Filter Design ◽  
Harmonic Wave ◽  
Harmonic Signal ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Digital Filter Design ◽  
Instantaneous Reactive Power Theory ◽  
Main Motive ◽  
Low Pass

Pollution harness of industry power mainly depends on high-accuracy harmonic signal detection. In this paper digital filtering technology and instantaneous reactive power theory are used to detect power harmonic signal and the main motive is to reduce the computation amount. A low-pass filter with Butterworth style is designed and its effectiveness to detect the second-order harmonic wave is shown by numerical simulation.

Detection for Rective Current Based on the Instantaneous Reactive Power Theory

2012 ◽  
Vol 433-440 ◽  
pp. 6565-6571
Author(s):  
Xiao Cui Lei ◽  
Guang Zeng ◽  
Jing Gang Zhang
Keyword(s):  
Single Phase ◽  
Reactive Power ◽  
Phase Locked Loop ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Power Theory ◽  
Instantaneous Reactive Power Theory ◽  
Three Phase ◽  
Reactive Current ◽  
Low Pass

Three-phase circuit instantaneous reactive power theory has received a successful application in detecting harmonic and reactive current timely, the ip-iq and d-q method of first proposed require the phase-locked loop and low-pass filter. The paper make corresponding improvement on the basis of the method based on amplitude integration which only can detect fundamental current , propose a method which can detect the active and reactive current, and the method based on amplitude integration can detect fundamental current of single-phase circuit directly, and simulation. The simulation results show that the method can detect the harmonic and reactive current accurately and timely, and is suitable for various circumstances that three-phase power supply distortion and asymmetry and so on, and when only detecting the harmonic current, it does not require the phase-locked loop and low-pass filter, while detecting the harmonic and reactive current, increases the phase-locked loop; when the method based on amplitude integration is directly used to detect single-phase fundamental current, the phase-locked loop and low-pass filter are not required. The paper deduces the theory of the method and researches on simulation analysis.

Improved Voltage Sag Detection Method and Optimal Design for the Digital Low-Pass Filter in Small UAVs

2015 ◽  
Author(s):  
Shuiqiang Pei ◽  
Xiaoguang Hu ◽  
Guofeng Zhang ◽  
Li Fu
Keyword(s):  
Real Time ◽  
Detection Method ◽  
Voltage Sag ◽  
Dynamic Voltage Restorer ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Voltage Restorer ◽  
Voltage Sag Detection ◽  
Low Pass ◽  
Dynamic Voltage

Real-time and accurate detection of the voltage sag characteristics is the premise to achieve dynamic voltage restorer compensation. An improved αβ-dq transformation detection method is presented for the limitations of traditional detection methods. In this method, the α-axis component of the αβ static coordinate system is deduced according to the single-phase voltage. The virtual β-axis component is constructed from the derivative of the α-axis component. The magnitudes, duration, phase-angle jump of the voltage sag are detected quickly and accurately by αβ-dq transformation and low-pass filter. The original data is real-time, which ensures faster detection response speed and reduces the computation greatly. In addition, an optimization design method for digital low-pass filter is presented against the contradictions existing in real-time and filtering effect of common low-pass filter. This adopts inertial filter to improve the characteristics of Butterworth low-pass filter and enable them to better adapt to the needs of the voltage sag detection thus improving the real-time quality and precision of dynamic voltage restorer.

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