scholarly journals Model Predictive Current Control with Asymmetric Stacked Multilevel Inverter and LCL-Filter Based STATCOM

2021 ◽  
Vol 3 (2) ◽  
pp. 19-30
Author(s):  
Mostafa Q. Kasim ◽  
Raaed Faleh Hassan
Keyword(s):  
Power Factor ◽  
Control Strategy ◽  
Reactive Power ◽  
Current Control ◽  
Multilevel Inverter ◽  
Harmonic Current ◽  
Source Power ◽  
Current Harmonics ◽  
Source Current ◽  
Sampling Instant

The work presented in this paper deals with a proposal of a new topology of a multilevel inverter to act as a Static synchronous Compensator (STATCOM). The proposed inverter is the five-level Asymmetric Stacked Multi-Level Inverter (ASMLI). One of the essential features of this inverter that distinguishes it from the conventional types is that it achieves the required voltage levels with fewer switching devices, leading to simplifying the control process. Moreover, the work includes using a Finite Control Set Model Predictive Current Control (FCS-MPCC) to control the proposed structure. The FCS-MPCC control strategy performs the finite optimization process at the current sampling instant to provide the optimum switching states to the inverter at the next sampling instant. Therefore, this control strategy allows injecting harmonic current and reactive power compensation to reduce source current distortion and improve the voltage profile and power factor. The optimization mechanism reduces the cost function, which is a function of measuring the network current's deviation from the reference value and how the capacitor voltage deviates from the required values. LCL-filter was used to connect this setup to the grid, and its resonance was actively damped using the multivariable capabilities of the FCS-MPCC. The proposed control framework was simulated using MATLAB/Simulink 9.1 environment and tested in a distorted and healthy network compared to a conventional two-level converter with RL-filter. The STATCOM was used to inject reactive power to raise the source power factor to unity and reduce source current harmonics by injecting harmonic current. The proposed prototype could absorb 70% of source current harmonics, which is nearly 25% better than a conventional inverter, inject an appropriate amount of reactive power, and raise the source power factor to unity in two case scenarios. The performance achieved was promising at steady-state operation and speedy response during transients with balanced capacitors voltages.

scholarly journals Design and Simulation of three Phase three Wire Shunt Active Filter using Instantaneous PQ Theory

2020 ◽  
Vol 15 (1) ◽  
pp. 181-186
Author(s):  
Tilak Giri ◽  
Ram Prasad Pandey ◽  
Sabin Bhandari ◽  
Sujan Moktan ◽  
Lagat Karki
Keyword(s):  
Power Factor ◽  
Communication Systems ◽  
Reactive Power ◽  
Active Filter ◽  
Shunt Active Filter ◽  
Current Harmonics ◽  
Passive Filter ◽  
Three Phase ◽  
Wide Range ◽  
Source Current

Due to intensive use of power converters and other non-linear loads, power quality is degrading. The presence of harmonics in the power lines result in greater power losses in distribution, interference problems in communication systems. Non linearity reduces the efficiency and power factor of the system. As the power factor reduces, the reactive power demanded from the supply increases which have no any contribution in energy transfer, so compensation is required. For this, shunt passive filter has been developed but it is bulky and frequency dependent and has many drawbacks. In contrast to passive filter, shunt active filter (SAF) has been developed which is smaller and has wide range of applications. In this paper, shunt active filter based on p-q theory is demonstrated for compensating reactive power and current harmonics. Simulation has been done with and without SAF and results are presented and ended with recommendation and conclusion. An effort is made to reduce the THD of the source current below 5% (specified by IEEE).

A Reference Compensation Current Control of Grid-Connected Inverter for Three-Phase Distributed Generators

2013 ◽  
Vol 433-435 ◽  
pp. 1183-1187 ◽  
Author(s):  
Shao Ru Zhang ◽  
Shao Yuan Li
Keyword(s):  
Control Strategy ◽  
Distribution Systems ◽  
Reactive Power ◽  
Neutral Current ◽  
Power Converter ◽  
Active Power ◽  
Current Control ◽  
Renewable Energy Resources ◽  
Current Harmonics ◽  
Grid Connected Inverter

Renewable energy resources (RES) are being increasingly connected in distribution systems by utilizing power electronic converters. However, the extensive use of power electronics has resulted in a rise in power quality (PQ) concerns faced by the utility. A novel control strategy implementing reference compensation current was proposed in this paper. So that these grid-connected inverters can achieve maximum benefits when they installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1) power converter to transfer active power from RES to the grid, and 2) load reactive power demand support; 3) current harmonics compensation at PCC; and 4) current unbalance and neutral current compensation in case of 3-phase 4-wire system. Moreover, with adequate control of grid-interfacing inverter, all the four objectives can be accomplished either individually or simultaneously. Simulation results show the validity and capability of the novel proposed control strategy.

A NOVEL CONTROL STRATEGY FOR SERIES-SHUNT POWER QUALITY COMPENSATOR

2015 ◽  
pp. 148-153
Author(s):  
DEVENDRA LAXMAN RAOKHANDE ◽  
DADGONDA PATIL
Keyword(s):  
Power Quality ◽  
High Voltage ◽  
Power Factor ◽  
Control Strategy ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Current Harmonics ◽  
Synchronous Reference Frame ◽  
Uninterruptible Power ◽  
Traction System

Advancement and extensive use of power electronic devices such as, fast switching uncontrolled/controlled convertors, invertors and cyclo-converters, high voltage power convertors used in HVDC, high voltage drives in traction system, arc furnaces, modern single phase electronic equipments like Compact Fluorescent Lamps (CFLs), Uninterruptible Power Supply (UPS), Personal Computers (PCs), printers, battery chargers, fax machines, photocopiers etc. creates power quality problems, the measure of it was voltage and current harmonics, poor power factor, imbalance, reactive power compensation, voltage regulation etc. Ideally power system network must be electrically clean, harmonics free, balanced, sinusoidal with unity power factor and regulated. This work deals with the performance of Series-Shunt Power Quality Compensator (SSPQC) under distorted source voltages and load currents. In this work a novel control strategy of Synchronous Reference Frame (SRF) used to extract the fundamental reference voltage component and the ICC based technique used to predict source current which simplifies the computation and amplifies the system performance.

PENURAS KUASA AKTIF PIRAU SATU FASA MENGGUNAKAN STRATEGI KAWALAN RINGKAS

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Yushaizad Yusof ◽  
Radin Zaim Radin Umar ◽  
Nasrudin Abd. Rahim
Keyword(s):  
Power Factor ◽  
Control Strategy ◽  
Single Phase ◽  
Active Power Filter ◽  
Fast Time ◽  
Shunt Active Power Filter ◽  
Current Harmonics ◽  
Power Filter ◽  
Simulink Simulation ◽  
Source Current

This paper describes a single phase shunt active power filter system used in compensating current harmonics and improving electrical line’s power factor via simplified control strategy based on estimation of nonlinear load’s equivalent resistance. By employing MATLAB Simulink simulation tool, the proposed control strategy successfully compensated source current harmonics and corrected line power factor to near unity. Moreover, analysis on the system performance indicated that the system’s achieved fast time response, stabilized system and near zero steady state error. To verify the proposed system, experimental results also presented.

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 Decoupled Control of Three Phase Grid Connected Solar PV System

2019 ◽  
Vol 9 (2) ◽  
pp. 4218-4222
Keyword(s):  
Solar Energy ◽  
Power Factor ◽  
Control Strategy ◽  
Reactive Power ◽  
Standard Test ◽  
Effective Control ◽  
Solar Pv ◽  
Pv System ◽  
Three Phase ◽  
Decoupled Control

A reliable grid connected Photovoltaic (PV) system require effective control schemes for efficient use of solar energy. This paper presents a three-phase grid tied PV system with decoupled real and reactive power control to achieve desired power factor with Maximum Power Point Tracking (MPPT) controller to get maximum solar energy. The synchronous reference frame (dq) control along with decoupling concept is used to control the DC-AC inverter output, while the Phase Locked Loop (PLL) synchronization technique is used to monitor and synchronize the voltage and current at the grid side. The DC-DC converter with Incremental Conductance (InC) based MPPT model is also designed in this paper due to better accuracy compared to Perturb & Observe (P&O) algorithm. The simulation is performed in MATLAB/SIMULINK and a 31.5 kW PV system is modelled to get 30 kW power with the help of MPPT at Standard Test Conditions (STC). Any power factor value between 0.85 lagging to 0.9 leading can be obtained by changingreference q current in this inverter control strategy. The simulation results show that the change of reactive powerdoes not affecttheactive power values of the system, which verifies the effectiveness of the decoupled control strategy of the inverter.

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 Voltage Ride through Control Strategy of Modular Multilevel Converter under Unbalanced Voltage Sag

2019 ◽  
Vol 9 (3) ◽  
pp. 551
Author(s):  
Seyed Hakimi ◽  
Amin Hajizadeh
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Current Control ◽  
Adaptive Robust Control ◽  
Voltage Sag ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Control Approach ◽  
Control Loops ◽  
Unbalanced Voltage

This paper develops modeling and describes a control strategy for a modular multilevel converter (MMC) for grid-connected renewable energy systems. The proposed model can be used to simulate MMC activity during normal and faulty situations. Firstly, a dynamic model of a grid-connected MMC (GC-MMC), based upon the symmetrical component of voltages and currents, was designed. Then an adaptive robust control approach was established in order to follow the reference currents of the converter and stabilize the submodule (SM) capacitor voltage. The positive and negative sequences of reference currents that were given from the demanded active and reactive power during grid voltage disturbance and a normal situation were then utilized in control loops. Finally, the numerical results for the performance of the MMC throughout voltage sag conditions and the effect of uncertainties on the filter parameters during changing power demands were evaluated. The results specified that the current control strategy is more potent under voltage sag situations and able to fulfill the stability requirements of the MMC.

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