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.

scholarly journals Intelligent Hybrid-Fuzzy Controller using VLLMS Based Shunt Active Filter

2020 ◽  
Vol 06 (09) ◽  
pp. 215-229
Author(s):  
Shaik Nagul Sharif and Sri Latha Veerla
Keyword(s):  
Power System ◽  
Fuzzy Logic Controller ◽  
Reactive Power ◽  
Fuzzy Controller ◽  
Pi Controller ◽  
Active Filter ◽  
Active Filters ◽  
Nonlinear Load ◽  
Shunt Active Filter ◽  
Non Linear

The power quality problem in the power system is increased with the use of non-linear devices. Due to the use of non-linear devices like power electronic converters, there is an increase in harmonic content in the source current. Due to this there is an increase in the losses, instability and poor voltage waveform. To mitigate the harmonics and provide the reactive power compensation, we use filters. There are different filters used in the power system. Passive filters provide limited compensation, so active filters can be used for variable compensation. In this work, a shunt active filter has been made adaptive using a Variable Leaky Least Mean Square (VLLMS) based controller. Proposed adaptive controller can be able to compensate for harmonic currents, power factor and nonlinear load unbalance. DC capacitor voltage has been regulated at a desired level using a PI controller and a self-charging circuit technique. But, this scheme as two disadvantages such as, tuning issues of current controller pre-requisites the traditional PI controller, which is controlled by intelligent based Hybrid-Fuzzy-Logic controller for achieving good performance features. The design concept of proposed intelligent Hybrid-Fuzzy controller for shunt active filter has been verified through simulation analysis and results are presented with proper comparisons.

scholarly journals Power Quality Improvement using Intelligent Fuzzy-VLLMS Based Shunt Active Filter

2020 ◽  
Vol 8 (6) ◽  
pp. 1004-1012
Keyword(s):  
Power System ◽  
Power Quality ◽  
Fuzzy Logic Controller ◽  
Reactive Power ◽  
Pi Controller ◽  
Active Filter ◽  
Active Filters ◽  
Nonlinear Load ◽  
Shunt Active Filter ◽  
Non Linear

The power quality problem in the power system is increased with the use of non-linear devices. Due to the use of non-linear devices like power electronic converters, there is an increase in harmonic content in the source current. Due to this there is an increase in the losses, instability and poor voltage waveform. To mitigate the harmonics and provide the reactive power compensation, we use filters. There are different filters used in the power system. Passive filters provide limited compensation, so active filters can be used for variable compensation. In this paper, a shunt active filter has been made adaptive using a Variable Leaky Least Mean Square (VLLMS) based controller. Proposed adaptive controller can be able to compensate for harmonic currents, power factor and nonlinear load unbalance. DC capacitor voltage has been regulated at a desired level using a PI controller and a self-charging circuit technique. But, this scheme has two disadvantages such as, tuning issues of current controller pre-requisites the traditional PI controller, which is controlled by intelligent based Fuzzy-Logic controller for achieving good performance features. The design concept of proposed intelligent Fuzzy controller for shunt active filter has been verified through simulation analysis and results are presented with proper comparisons.

scholarly journals Active and Reactive Power Compensation Control Strategy for VSC-HVDC Systems under Unbalanced Grid Conditions

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3140 ◽  
Author(s):  
Weiming Liu ◽  
Tingting Zheng ◽  
Ziwen Liu ◽  
Zhihua Fan ◽  
Yilong Kang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Disturbance Observer ◽  
Reactive Power ◽  
Operating Conditions ◽  
Voltage Source ◽  
Double Frequency ◽  
Compensation Control ◽  
Active And Reactive Power ◽  
Passivity Based Control ◽  
Unbalanced Grid

This paper presents a power compensation strategy to suppress the double frequency power ripples of Voltage source converter high-voltage direct current (VSC-HVDC) systems under unbalanced grid voltage conditions. The mathematical control equations of the double frequency ripple power of VSC under unbalanced operating conditions are firstly derived and established, where the dynamic behaviors of the double frequency ripples in active and reactive power are regarded as being driven by current-relevant components and voltage-relevant components, respectively. Based on the equations, a power compensation control strategy of VSC-HVDC is proposed via the passivity-based control with disturbance observer to suppress both the current-relevant and voltage-relevant components in the power ripples. With this control strategy, the double frequency ripples in active and reactive power are suppressed simultaneously and system performance is significantly enhanced with the implementation of the disturbance observer in the passivity-based control. Theoretical stability analysis and simulation cases show the effectiveness and superiority of the proposed strategy.

Droop Control Strategy for Voltage Source Converters Containing Renewable Power Sources

2020 ◽  
pp. 299-311
Author(s):  
Iván Andrade ◽  
Rubén Peña ◽  
Ramón Blasco-Gimenez ◽  
Javier Riedemann ◽  
Cristian Pesce
Keyword(s):  
Control Strategy ◽  
Voltage Source ◽  
Droop Control ◽  
Voltage Source Converters ◽  
Power Sources ◽  
Renewable Power

scholarly journals Fault Ride through Capability Augmentation of a DFIG-Based Wind Integrated VSC-HVDC System with Non-Superconducting Fault Current Limiter

2019 ◽  
Vol 11 (5) ◽  
pp. 1232 ◽  
Author(s):  
Md Alam ◽  
Mohammad Abido ◽  
Alaa Hussein ◽  
Ibrahim El-Amin
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Current Control ◽  
Control Mode ◽  
Voltage Source ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Hvdc System ◽  
Fault Ride Through ◽  
Current Limiter

This paper proposes a non-superconducting bridge-type fault current limiter (BFCL) as a potential solution to the fault problems of doubly fed induction generator (DFIG) integrated voltage source converter high-voltage DC (VSC-HVDC) transmission systems. As the VSC-HVDC and DFIG systems are vulnerable to AC/DC faults, a BFCL controller is developed to insert sizeable impedance during the inception of system disturbances. In the proposed control scheme, constant capacitor voltage is maintained by the stator VSC (SVSC) controller, while current extraction or injection is achieved by rotor VSC (RVSC) controller. Current control mode-based active and reactive power controllers for an HVDC system are developed. Balanced and different unbalanced faults are applied in the system to show the effectiveness of the proposed BFCL solution. A DFIG wind-based VSC-HVDC system, BFCL, and their controllers are implemented in a real time digital simulator (RTDS). The performance of the proposed BFCL control strategy in DFIG-based VSC-HVDC system is compared with a series dynamic braking resistor (SDBR). Comparative RTDS implementation results show that the proposed BFCL control strategy is very efficient in improving system fault ride through (FRT) capability and outperforms SDBR in all cases considered.

scholarly journals HIL-Assessed Fast and Accurate Single-Phase Power Calculation Algorithm for Voltage Source Inverters Supplying to High Total Demand Distortion Nonlinear Loads

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1643
Author(s):  
Jorge El Mariachet ◽  
Yajuan Guan ◽  
Jose Matas ◽  
Helena Martín ◽  
Mingshen Li ◽  
...  
Keyword(s):  
Steady State ◽  
Single Phase ◽  
Reactive Power ◽  
Dynamic Performance ◽  
Active Power ◽  
Voltage Source ◽  
Power Calculation ◽  
Calculation Algorithm ◽  
Nonlinear Loads ◽  
Voltage Source Inverters

The dynamic performance of the local control of single-phase voltage source inverters (VSIs) can be degraded when supplying to nonlinear loads (NLLs) in microgrids. When this control is based on the droop principles, a proper calculation of the active and reactive averaged powers (P–Q) is essential for a proficient dynamic response against abrupt NLL changes. In this work, a VSI supplying to an NLL was studied, focusing the attention on the P–Q calculation stage. This stage first generated the direct and in-quadrature signals from the measured load current through a second-order generalized integrator (SOGI). Then, the instantaneous power quantities were obtained by multiplying each filtered current by the output voltage, and filtered later by utilizing a SOGI to acquire the averaged P–Q parameters. The proposed algorithm was compared with previous proposals, while keeping the active power steady-state ripple constant, which resulted in a faster calculation of the averaged active power. In this case, the steady-state averaged reactive power presented less ripple than the best proposal to which it was compared. When reducing the velocity of the proposed algorithm for the active power, it also showed a reduction in its steady-state ripple. Simulations, hardware-in-the-loop, and experimental tests were carried out to verify the effectiveness of the proposal.

Modified DSTATCOM Topology with Reduced DC Link Voltage for Reactive and Harmonic Power Compensation of Unbalanced Nonlinear Load in Distribution System

2014 ◽  
Vol 15 (3) ◽  
pp. 263-277 ◽  
Author(s):  
Nagesh Geddada ◽  
Srinivas B. Karanki ◽  
Mahesh K. Mishra
Keyword(s):  
Distribution System ◽  
Experimental Studies ◽  
Current Control ◽  
Control Technique ◽  
Voltage Source ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Hysteresis Current Control ◽  
Switching Losses ◽  
Power Switches

Abstract This paper proposes a modified four-leg distribution static compensator (DSTATCOM) topology for compensation of unbalanced and nonlinear loads in three-phase four-wire distribution system. DSTATCOM, connected in parallel to the load, supplies reactive and harmonic powers demanded by unbalanced nonlinear loads. In this proposed topology, the voltage source inverter (VSI) of DSTATCOM is connected to point of common coupling (point of interconnection of source, load, DSTATCOM) through interface inductor and series capacitance, unlike the conventional topology which consists of interface inductor alone. Load compensation with a lower value of input DC link voltage of VSI is possible in this modified topology compared to conventional topology. A comparative study on modified and conventional topologies in terms of voltage rating of inverter power switches, switching losses in VSI and power rating of input DC capacitor of VSI is presented. The detailed design aspects of DC link capacitor and interface series capacitor are also presented. The reference filter currents are generated using instantaneous symmetrical component theory and are tracked using hysteresis current control technique. A detailed simulation study is carried out, to compare the compensation performances of conventional, modified topologies using PSCAD simulator and experimental studies are done to validate the simulation results.

scholarly journals Performance of Three Level H-Bridge Inverter in Grid Connected Solar PV for Multifunctional Operations using Different Control Techniques

2020 ◽  
Vol 9 (4) ◽  
pp. 1942-1950
Keyword(s):  
Power System ◽  
Power Factor ◽  
Reactive Power ◽  
Power Factor Correction ◽  
Solar Pv ◽  
Distribution Grid ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Control Techniques ◽  
Active And Reactive Power

This paper presents multifunctional operation capability of three level cascade H bridge inverter for grid connected solar pv application. The solar panel and inverter are modelled for unbalance and nonlinear loads with three control techniques (pq,dq,cpt) and its performance is simulated in the MATLAB environment using SIMULINK and Sim Power System (SPS) toolboxes. The performance of inverter is evaluated for harmonics elimination, power factor correction apart from active and reactive power support to grid and nonlinear load .Performance of three level H bridge inverter is evaluated for both PV mode and STATCOM mode using three control techniques for distribution grid.

scholarly journals Decentralize power sharing control strategy in islanded microgridsDecentralize power sharing control strategy in islanded microgrids

2020 ◽  
Vol 20 (2) ◽  
pp. 752
Author(s):  
Mubashir Hayat Khan ◽  
Shamsul Aizam Zulkifli ◽  
Erum Pathan ◽  
Elhassan Garba ◽  
Ronald Jackson ◽  
...  
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Pi Controller ◽  
Power Sharing ◽  
Control Technique ◽  
Droop Control ◽  
Low Load ◽  
Islanded Mode ◽  
The Stability ◽  
The Cost

<a name="_Hlk16093850"></a><span>Droop control technique is one of the renowned techniques which does not need any communication connection between Distibuted Generations (DG), hence the cost, as well as the reliability of the microgrid (MG) system can be reduced. MG is operated in two modes as their functionality and structure is concern. These are the grid connected or islanded (stand-alone) mode. DGs operating values may have different ratings of voltage, power and line impedance. The power sharing in these operatng conditions is not shared equally by all DGs connected in the system and also during load changes conditions power sharing accuracy is difficult to achieve. In this paper, a droop power control is used to balance the power sharing in islanded mode. As from the results, the active power sharing is equally shared from all DGs connected in the microgrid system. However, reactive power sharing accuracy always disturbed when there is impedance mismatch among the different DG feeders. The accuracy is done by monitoring the effects when load changes for low load to high load or vice versa. The Proportional Integral (PI) controller has been used to minimize the reactive power errors. At the end, the power droop is capable to share power accurately and results prove the stability and reliability of the proposed technique.</span>

scholarly journals A line-interactive UPS system implementation with series-parallel active power-line conditioning for three-phase, four-wire systems

2005 ◽  
Vol 16 (2) ◽  
pp. 200-210 ◽  
Author(s):  
Sérgio Augusto Oliveira da Silva ◽  
Pedro F. Donoso-Garcia ◽  
Porfírio C. Cortizo ◽  
Paulo F. Seixas
Keyword(s):  
Reactive Power ◽  
Current Source ◽  
Input Voltage ◽  
Power Line ◽  
Active Power ◽  
Active Filter ◽  
Active Filters ◽  
Voltage Source ◽  
Three Phase ◽  
Uninterruptible Power

This paper presents a three-phase line-interactive uninterruptible power supply (UPS) system with active series-parallel power-line conditioning capabilities. Synchronous reference frame (SRF)-based controller is used for harmonic and reactive power compensation generated from any configuration of non-linear loads. Under normal line conditions the UPS system works with universal filtering capabilities, such as compensating the input currents and output voltages. Two three-phase pulsewidth modulation (PWM) converters, called series and parallel active filters, are used to perform the series and parallel active power-line compensation. The series active filter works as sinusoidal current source in phase with the input voltage, drawing from utility sinusoidal and balanced input currents with low total harmonic distortion (THD). The parallel active filter works as sinusoidal voltage source in phase with the input voltage, providing regulated and sinusoidal output voltages with low THD. The performance of the UPS system is evaluated in three-phase, four-wire systems. Experimental results are presented to confirm the theoretical studies.

Sign in / Sign up

Export Citation Format

Share Document