scholarly journals Design and Analysis of the STATCOM Based on Diode Clamped Multilevel Converter Using Model Predictive Current Control Strategy

2021 ◽  
Vol 23 (3) ◽  
pp. 221-228
Author(s):  
Raaed Faleh Hassan ◽  
Suha Sabah Shyaa
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Control Strategy ◽  
Control Algorithm ◽  
Reactive Power ◽  
Current Control ◽  
Multilevel Converter ◽  
Static Synchronous Compensator ◽  
Multi Level ◽  
And Control

In recent decades, multi-level converters have become popular and used in many power systems applications. Compared with conventional converters, multi-level converters contribute to reducing the voltage stress on the switching devices and enhancing the power quality delivered to the load. In this paper, the study of the five-level diode clamped multilevel converter based static synchronous compensator has been accomplished. Model Predictive current control strategy which a type of modern control algorithms was employed for driving the proposed compensator. The suggested five level converter controlled by model predictive current control is firstly examined to verify that this control algorithm is appropriate for achieving the desired performance. Then the proposed converter and control combination is employed and simulated as a static synchronous compensator in distributed power system. Moreover, in order to examine the robustness of this compensator, the load status is suggested to be heavy inductive. Simulation process has been performed using MATLAB – SIMULINK software package. The results show that the implemented configuration (converter and control algorithm) provides high power quality improvement with adequate reactive power compensation.

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.

A Multi-Level-Objective-Oriented Method for Coordination and Control of Voltage and Reactive Power in Distribution Network

2012 ◽  
Vol 263-266 ◽  
pp. 664-669
Author(s):  
Lin Xie ◽  
Yi Rong Su
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Distribution Network ◽  
Suboptimal Control ◽  
Good Effect ◽  
Power Network ◽  
Reactive Control ◽  
Multi Level ◽  
And Control ◽  
Coordination And Control

A multi-level-objective-oriented method for coordination and control of voltage/reactive power in distribution network is proposed. By referring to the demand for integrated voltage and reactive power control between county and district power network, three-level objective include regional voltage control of the gate area, gate power factor control and reactive control within the power station of the gate area. The control strategy of the adjusting unit based on the nine-zone theory is analyzed, and then the correspondence between the global AVQC and local VQC is discovered, based on which the optimal and suboptimal control strategy of the adjusting unit are proposed. Finally, three steps including urgently cutting off the capacitors, combinatorial control of the capacitors and combinational control of the transformer stalls are taken one after another to realize the coordination and control over the voltage and reactive power between the superior and inferior power network. This method is implemented in the AVQC system of TianJin Chengxi grid, which operates stably and has gained good effect.

scholarly journals Effect of Utility Voltage Distortion on the Performance of Different Control Strategies for Shunt Active Power Filter

2017 ◽  
Vol 2 (8) ◽  
pp. 27
Author(s):  
Ahmed Mohammed Attiya Soliman ◽  
Salah Kamal El-Sayed ◽  
M. A. Mehanna
Keyword(s):  
Power Quality ◽  
Control Strategy ◽  
Control Algorithm ◽  
Control Strategies ◽  
Active Power Filter ◽  
Active Power ◽  
Current Control ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Non Linear

The widespread use of power electronics in industrial, commercial and even residential electrical equipment like non-linear loads causes deterioration of the quality of the electric power supply with distortion of the supply voltage and in order to mitigate this quality the shunt active power filter (SAPF) is the suitable and effective solution for harmonic elimination and reactive power compensation and lead to power quality (PQ) improvement, therefor an effective and accurate current control technique is needed in order for a SAPF where control algorithm is the heart for SAPF to perform this function and its dynamic performance is mainly depends on these control strategy. This paper proposes three different current control strategies (CCS) based on instantaneous power theory and generalized fryze theory which used for the generation or extraction of the accurate reference current signals which comparing with the actual signals through hysteresis current technique (HCT) to produce suitable gating signals for SAPF and discusses the performance for these controllers when the supply bus voltage is distorted with scope on the efficient control algorithm. Matlab / Simulink simulation results are presented to validate the control strategy and demonstrate the effectiveness of SAPF to provide mitigation of power quality problems for non-linear load to reach an acceptable value comply with recommended standards.

scholarly journals A novel control strategy for power quality improvement in grid-connected solar photovoltaic system

2019 ◽  
Vol 15 (3) ◽  
pp. 1264
Author(s):  
Pankaj Gakhar ◽  
Manoj Gupta
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Control Strategy ◽  
Reactive Power ◽  
Harmonic Distortion ◽  
Pi Controller ◽  
Current Control ◽  
Total Harmonic Distortion ◽  
Solar Photovoltaic ◽  
Power Quality Improvement

<p>In this paper, a novel and dynamic, current control based inverter control strategy has been used for energy optimization and power quality improvement in a grid-connected solar photovoltaic plant using a PI controller. The output of the plant is delivered to the grid passing through a boost converter controlled by an MPPT controller and an inverter. The control strategy proposed offers the flexibility to keep control of active as well as reactive power being injected straight into the grid and also helps in mitigating the total harmonic distortion levels. Also, the effect of the conventional PI controller and PI controller optimized through Genetic Algorithm has been compared. The GA-PI controller has been found effective in reducing the Total Harmonic Distortion in the current injected in the grid. The effectiveness of the work has been observed by using a MATLAB/SIMULINK environment.</p>

scholarly journals Improving Power Quality by a Four-Wire Shunt Active Power Filter: A Case Study

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1951
Author(s):  
Mihaela Popescu ◽  
Alexandru Bitoleanu ◽  
Mihaita Linca ◽  
Constantin Vlad Suru
Keyword(s):  
Power Quality ◽  
Quality Indicators ◽  
Reactive Power ◽  
Control Method ◽  
Active Power Filter ◽  
Active Power ◽  
Current Control ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Unbalanced Load

This paper presents the use of a three-phase four-wire shunt active power filter to improve the power quality in the Department of Industrial Electronics of a large enterprise from Romania. The specificity is given by the predominant existence of single-phase consumers (such as personal computers, printers, lighting and AC equipment). In order to identify the power quality indicators and ways to improve them, an A-class analyzer was used to record the electrical quantities and energy parameters in the point of common coupling (PCC) with the nonlinear loads for 27 h. The analysis shows that, in order to improve the power quality in PCC, three goals must be achieved: the compensation of the distortion power, the compensation of the reactive power and the compensation of the load unbalance. By using the conceived three-leg shunt active power filter, controlled through the indirect current control method in an original variant, the power quality at the supply side is very much improved. In the proposed control algorithm, the prescribed active current is obtained as a sum of the loss current provided by the DC voltage and the equivalent active current of the unbalanced load. The performance associated with each objective of the compensation is presented and analyzed. The results show that all the power quality indicators meet the specific standards and regulations and prove the validity of the proposed solution.

The Research of Air Precooling System Based on Generalize Predictive Control Strategy

2013 ◽  
Vol 433-435 ◽  
pp. 1091-1098
Author(s):  
Wei Bo Yu ◽  
Cui Yuan Feng ◽  
Ting Ting Yang ◽  
Hong Jun Li
Keyword(s):  
Predictive Control ◽  
Control Strategy ◽  
Control Algorithm ◽  
Exchange Process ◽  
Generalized Predictive Control ◽  
Matlab Simulation ◽  
Control Effect ◽  
Heat Exchange Process ◽  
Complex Control System ◽  
And Control

The air precooling system heat exchange process is a complex control system with features such as: nonlinear, lag and random interference. So choose Generalized Predictive Control Algorithm that has low model dependence, good robustness and control effect, as well as easy to implement. But due to the large amount of calculation of traditional generalized predictive control and can't juggle quickness and overshoot problem, an improved generalized predictive control algorithm is proposed, then carry out the MATLAB simulation, the experimental results show that the algorithm can not only greatly reduce the amount of computation, but also can restrain the overshoot and its rapidity.

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.

An Application Seven-Level Converter for VSC-HVDC Station System

2015 ◽  
Vol 799-800 ◽  
pp. 1211-1216
Author(s):  
Narin Watanakul
Keyword(s):  
Process Control ◽  
Control Algorithm ◽  
Current Control ◽  
Multilevel Converter ◽  
Two Phase ◽  
Hvdc System ◽  
Hvdc Transmission ◽  
Data Process ◽  
Three Phase ◽  
Level Converter

This paper presents an application of an asynchronous back to back VSC-HVDC system. Which uses multilevel converter a 7-level Diode-Clamped SPWM converters topology technique for the realization of HVDC system, rated 300MVA (±300 kV). The controller has been proposed by using PQ control and feed-forward decoupled current control algorithm. The design and experimentally controllers of VSC in lab scaled test, MATLAB/Simulink program were performed VSC-HVDC transmission system, the simulation in order to evaluate transient performance, can be controlled independently under two phase to ground faulted and three phase to ground faulted conditions. The system are used as a guideline for analysing and design of the data process control with the PQ-control HVDC system.

Grid Connection Control of DFIG Wind Power Generation

2013 ◽  
Vol 373-375 ◽  
pp. 1287-1293
Author(s):  
Jian Wei Liang ◽  
Tao Wang
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Basic Structure ◽  
Grid Connection ◽  
Stator Flux ◽  
Set Up ◽  
Grid Side ◽  
Rotor Side Converter ◽  
Stator Flux Oriented ◽  
And Control

The paper is based on PSCAD/EMTDC. The basic structure and operation principle of DFIG are analyzed and the mathematical model of DFIG is established, based on which the control system of rotor-side and grid-side converters is set up. The stator flux-oriented vector control is adopted for rotor-side converter. The no-load grid connection is realized before cutting in and control strategy is switched after grid connection successfully. DFIG can meet grid connection condition quickly with the control strategy and is connected to grid with no current shock nearly. The output of active and reactive power can be regulated respectively.

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