scholarly journals Research on Harmonic Current Amplification Effect of Parallel APF Compensating Voltage Source Nonlinear Load

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3070
Author(s):  
Xueliang Wei ◽  
Cunzhong Li ◽  
Mingxuan Qi ◽  
Bingyang Luo ◽  
Xiangtian Deng ◽  
...  
Keyword(s):  
Reactive Power ◽  
System Structure ◽  
Voltage Source ◽  
Harmonic Current ◽  
Theoretical Derivation ◽  
Nonlinear Load ◽  
Amplification Effect ◽  
Fundamental Causes ◽  
Negative Effect ◽  
Current Amplification

A parallel active power filter (APF) is generally used to suppress dynamic harmonic current and compensate reactive power in the grid. However, parallel APF may have a negative effect on the load current when compensating the nonlinear load of a voltage source type, which may lead to the amplification effect of the load harmonic current. In this paper, the fundamental causes of harmonic current amplification were analyzed by studying the harmonic current amplification effect when a parallel APF compensates a nonlinear load. According to the results of the theoretical derivation, a feasible method to limit this current amplification effect by changing the system structure and the APF’s own control was proposed, and the corresponding design scheme is given. Finally, the correctness of the theoretical derivation of the harmonic current amplification effect and the feasibility of the proposed solution were proven through simulation and experiment.

scholarly journals Leaky-momentum control algorithm for voltage and frequency control of three-phase SEIG feeding isolated load

2021 ◽  
Author(s):  
Duli Chand Meena ◽  
◽  
Madhusudan Singh ◽  
Ashutosh K. Giri ◽  
◽  
...  
Keyword(s):  
Control Algorithm ◽  
Reactive Power ◽  
Frequency Control ◽  
Storage System ◽  
Operating Conditions ◽  
Control Technique ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Nonlinear Load ◽  
Three Phase

This paper dealt the implementation of a Leaky-Momentum Control Algorithm (LMA) for controlling a voltage source converter (VSC) to enhance the power quality of a three-phase self-excited induction generator (SEIG) used in a distributed generating system. This LMA technique operates the VSC to regulate voltage and frequency of SEIG within a permissible limit. The LMA control is implemented to reduce the higher demand of reactive power, harmonics distortions and balancing of loads under different operating conditions. During the electrical and mechanical dynamical conditions, the LMA technique is maintaining a constant voltage and frequency at point of common coupling (PCC). The proposed technique is a modified control technique of basic Leaky and Momentum Algorithms. This control has removed the drawbacks of Leaky and momentum algorithms. Moreover, it is observed that LMA performs better when there are uncertainties in input conditions. The whole system comprising SEIG, nonlinear load, voltage source converter and battery storage system is made in MATLAB /SIMULINK. It has shown promising performance under both dynamical state and steady state of the system.

A Reactive Power Generator Based on Voltage Source Inverter

2012 ◽  
Vol 260-261 ◽  
pp. 432-437
Author(s):  
Tao Song
Keyword(s):  
Power Systems ◽  
Power Factor ◽  
Reactive Power ◽  
Voltage Source ◽  
Total Power ◽  
Good Effect ◽  
Voltage Source Inverter ◽  
Nonlinear Load ◽  
Power Generator ◽  
Reactive Compensation

With the application of large scale nonlinear load in power systems, lots of harmonic are produced, causing the total power factor to decrease. Therefore, it needs to compensate the reactive power of power systems. The disadvantages of the widely applied static var compensator are that the size of the compensator is too large, and the control ability is poor when the capacity of power systems is small. So a reactive power generator based on voltage source inverter is proposed in this paper. The reactive power generator takes series connection of IGBTs as the main circuit structure, the inverter as core and DSP as controller. The close loop framework consists of human-computer interaction, measurements and feedback control. The inverter is controlled by a digital PI close loop controller to feed a phase adjustable current to power systems to compensate reactive power. The system’s structure is simple, the control is flexible, and the size is small. The test results show that the response of this reactive power generator is quick, and it can compensate the power factor to be 1 which means that it has good effect of static reactive compensation.

scholarly journals Hardware-in-the-Loop Implementation and Performance Evaluation of Three-Phase Hybrid Shunt Active Power Filter for Power Quality Improvement

2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Ayesha Khan ◽  
Mujtaba Hussain Jaffery ◽  
Yaqoob Javed ◽  
Jehangir Arshad ◽  
Ateeq Ur Rehman ◽  
...  
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Reactive Power ◽  
Voltage Source ◽  
Control Algorithms ◽  
System Response ◽  
Nonlinear Load ◽  
Power Filter ◽  
Three Phase ◽  
Internal Networks

The excessive use of nonlinear load causes electric current harmonics that ultimately downgrades the electrical power quality. If a failure exists due to internal integration of a power system in any one of the internal networks, it causes uncomplimentary consequences to the entire power system’s performance. This paper proposed a hybrid shunt active harmonic power filter (HSAHPF) design to reduce harmonic pollution. A digital controller HIL simulator has been modeled using a three-phase voltage source inverter to test the efficiency of HSAHPF and the performance of control algorithms. Moreover, the instantaneous active and reactive current theory (Id − Iq) and instantaneous active and reactive power theory (Pq0) control algorithms are implemented for the reference current generation in HSAHPF, resulting in reduced harmonic distortions, power factor improvement for a balanced nonlinear load. The control algorithms are further employed in Arduino MEGA to keep the factor of cost-effectiveness. The simulation of the proposed design has been developed in Simulink. The validation and testing of HSAHPF using controller HIL simulation prove the control algorithms’ ability to run in a portable embedded device. The statistical analysis of the proposed system response provides a minimum total harmonic distortion (THD) of 2.38 from 31.74 that lies in IEEE 519-1992 harmonic standards with an improved stability time of 0.04 s. The experimental verification and provided results of the HIL approach validate the proposed design. Significant mitigation of harmonics can be observed, consequently enhancing the power quality with power factor near unity.

scholarly journals Control shunt active filter based on dq frame using current model prediction

2019 ◽  
Vol 8 (4) ◽  
pp. 301
Author(s):  
Chi Nguyen Van ◽  
Hoang Dang Danh
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Current Model ◽  
Pi Controller ◽  
Active Filters ◽  
Voltage Source ◽  
Nonlinear Loads ◽  
Transient Time ◽  
Nonlinear Load ◽  
Power Sources

The nonlinear loads present more in the power systems in the practice today by developing of electronic technology and using the small distributed power sources (solar power, wind power etc.), this causes the increasing the high frequency switch devices etc. in the power network. Nonlinear loads cause non-sinusoidal currents and voltages with harmonic components, increasing the reactive power, overload of power lines and electrical devices, low power factor and affecting badly to the networks. Shunt active filters (SAF) with current controlled voltage source inverters (CCVSI) are used effectively to reduce the harmonics and to balance the phases sinusoidal source currents by generating the currents to compensate the harmonic currents caused by the nonlinear loads. In this paper we suppose a control strategy to generate the compensation currents of SAF by using the current model predictive engineering. This method is better than the control strategy using PI controller in term of transient time. The desired compensation currents can track exactly the reference compensation currents on the dq frame. The simulation results implemented on the nonlinear load, a full bridge rectifier and 3 phase unbalance load, show that the transient period decrease from 0.1s to 0.02s in comparing with PI controller. The experimental results proof that the THD of source currents decrease from 24.8% to 5.4% when using the proposed method.

Research on Harmonic Current Amplification of Parallel Capacitors in a 6kV Substation

2013 ◽  
Vol 722 ◽  
pp. 112-115
Author(s):  
Zhan Zhang ◽  
Na Guo
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Supply System ◽  
Harmonic Current ◽  
Nonlinear Load ◽  
Field Practice ◽  
Current Amplification

This paper investigated the cause of the harmonic current amplification in nonlinear load in a 6kV substations power supply system. The paper proposed that reactors could be series connected in the capacitors by-pass to restrain the amplification. The result from field practice showed that this method could overcome the harmonic current amplification efficiently.

Optimization Design on Power Filter of TCR Under Asymmetrical Voltage

2015 ◽  
Vol 9 (1) ◽  
pp. 591-599
Author(s):  
Ma Wenchuan ◽  
Zhitong Li ◽  
Chen Daochang ◽  
Qi Jiaming ◽  
Zhou Qiang ◽  
...  
Keyword(s):  
Optimization Design ◽  
Reactive Power ◽  
Estimation Method ◽  
Reactive Power Compensation ◽  
Harmonic Suppression ◽  
Matlab Simulation ◽  
Steel Mill ◽  
Harmonic Current ◽  
Third Harmonic ◽  
Power Filter

For resolving the problem that power filter cannot work normally because TCR (thyristor controlled reactor) generates extra third harmonic current under asymmetrical voltage, the paper proposes the estimation method of current capacity that TCR generates extra third harmonic current under asymmetrical voltage. Considering extra third harmonic current under asymmetrical voltage, Optimum method based on genetic algorithm is used to design the parameters of power filter. With reactive power compensation and harmonic suppression project of a steel mill as example, the proposed method is simulated by Matlab. Simulation results show optimized power filter can eliminate extra third harmonic current effects under asymmetrical voltage, meet the requirement of reactive power compensation, reduce harmonics current that load injects into system, and guarantee the power filter safe operation under asymmetrical voltage.

scholarly journals Distribution system power quality compensation using a HSeAPF based on SRF and SMC features

2021 ◽  
Author(s):  
Akram Qashou ◽  
Sufian Yousef ◽  
Abdallah A. Smadi ◽  
Amani A. AlOmari
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Reactive Power ◽  
Sliding Mode ◽  
Distribution Network ◽  
Harmonic Distortion ◽  
Phase Locked Loop ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Non Linear

AbstractThe purpose of this paper is to describe the design of a Hybrid Series Active Power Filter (HSeAPF) system to improve the quality of power on three-phase power distribution grids. The system controls are comprise of Pulse Width Modulation (PWM) based on the Synchronous Reference Frame (SRF) theory, and supported by Phase Locked Loop (PLL) for generating the switching pulses to control a Voltage Source Converter (VSC). The DC link voltage is controlled by Non-Linear Sliding Mode Control (SMC) for faster response and to ensure that it is maintained at a constant value. When this voltage is compared with Proportional Integral (PI), then the improvements made can be shown. The function of HSeAPF control is to eliminate voltage fluctuations, voltage swell/sag, and prevent voltage/current harmonics are produced by both non-linear loads and small inverters connected to the distribution network. A digital Phase Locked Loop that generates frequencies and an oscillating phase-locked output signal controls the voltage. The results from the simulation indicate that the HSeAPF can effectively suppress the dynamic and harmonic reactive power compensation system. Also, the distribution network has a low Total Harmonic Distortion (< 5%), demonstrating that the designed system is efficient, which is an essential requirement when it comes to the IEEE-519 and IEC 61,000–3-6 standards.

scholarly journals Hybrid Reference Current Generation Theory for Solar Fed UPFC System

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1527
Author(s):  
R. Senthil Kumar ◽  
K. Mohana Sundaram ◽  
K. S. Tamilselvan
Keyword(s):  
Neural Network ◽  
Power Factor ◽  
Reactive Power ◽  
Voltage Source ◽  
Unity Power Factor ◽  
Current Generation ◽  
Load Voltage ◽  
Reference Current Generation ◽  
Source Current

The extensive usage of power electronic components creates harmonics in the voltage and current, because of which, the quality of delivered power gets affected. Therefore, it is essential to improve the quality of power, as we reveal in this paper. The problems of load voltage, source current, and power factors are mitigated by utilizing the unified power flow controller (UPFC), in which a combination of series and shunt converters are combined through a DC-link capacitor. To retain the link voltage and to maximize the delivered power, a PV module is introduced with a high gain converter, named the switched clamped diode boost (SCDB) converter, in which the grey wolf optimization (GWO) algorithm is instigated for tracking the maximum power. To retain the link-voltage of the capacitor, the artificial neural network (ANN) is implemented. A proper control of UPFC is highly essential, which is achieved by the reference current generation with the aid of a hybrid algorithm. A genetic algorithm, hybridized with the radial basis function neural network (RBFNN), is utilized for the generation of a switching sequence, and the generated pulse has been given to both the series and shunt converters through the PWM generator. Thus, the source current and load voltage harmonics are mitigated with reactive power compensation, which results in attaining a unity power factor. The projected methodology is simulated by MATLAB and it is perceived that the total harmonic distortion (THD) of 0.84% is attained, with almost a unity power factor, and this is validated with FPGA Spartan 6E hardware.

scholarly journals A Novel Adaptive Control Approach Based on Available Headroom of the VSC-HVDC for Enhancement of the AC Voltage Stability

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3222
Author(s):  
Duc Nguyen Huu
Keyword(s):  
Adaptive Control ◽  
Voltage Stability ◽  
Reactive Power ◽  
Control Method ◽  
Offshore Wind ◽  
Voltage Source ◽  
Long Distance ◽  
Control Approach ◽  
Hvdc System ◽  
Voltage Support

Increasing offshore wind farms are rapidly installed and planned. However, this will pose a bottle neck challenge for long-distance transmission as well as inherent variation of their generating power outputs to the existing AC grid. VSC-HVDC links could be an effective and flexible method for this issue. With the growing use of voltage source converter high-voltage direct current (VSC-HVDC) technology, the hybrid VSC-HVDC and AC system will be a next-generation transmission network. This paper analyzes the contribution of the multi VSC-HVDC system on the AC voltage stability of the hybrid system. A key contribution of this research is proposing a novel adaptive control approach of the VSC-HVDC as a so-called dynamic reactive power booster to enhance the voltage stability of the AC system. The core idea is that the novel control system is automatically providing a reactive current based on dynamic frequency of the AC system to maximal AC voltage support. Based on the analysis, an adaptive control method applied to the multi VSC-HVDC system is proposed to realize maximum capacity of VSC for reactive power according to the change of the system frequency during severe faults of the AC grid. A representative hybrid AC-DC network based on Germany is developed. Detailed modeling of the hybrid AC-DC network and its proposed control is derived in PSCAD software. PSCAD simulation results and analysis verify the effective performance of this novel adaptive control of VSC-HVDC for voltage support. Thanks to this control scheme, the hybrid AC-DC network can avoid circumstances that lead to voltage instability.

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