scholarly journals Linearly Decoupled Control of a Dynamic Voltage Restorer without Energy Storage

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1794
Author(s):  
Luis Ramon Merchan-Villalba ◽  
Jose Merced Lozano-Garcia ◽  
Juan Gabriel Avina-Cervantes ◽  
Hector Javier Estrada-Garcia ◽  
Alejandro Pizano-Martinez ◽  
...  
Keyword(s):  
Power Quality ◽  
Control Strategy ◽  
Supply Voltage ◽  
Matrix Converter ◽  
Operating Conditions ◽  
System Stability ◽  
Linear Control ◽  
Dynamic Voltage Restorer ◽  
Voltage Restorer ◽  
Dynamic Voltage

This paper presents the design of a decoupled linear control strategy for a Dynamic Voltage Restorer (DVR) that utilizes a Matrix Converter (MC) as its core element and obtains the compensation energy directly from the power system. This DVR is intended to cope with power quality problems present in supply system voltages such as balanced and unbalanced variations (sags and swells), and harmonic distortion. The dynamic model of the complete system that includes the Matrix Converter, the input filters and the electrical grid, is performed in the synchronous reference frame (dq0), to have constant signals at the fundamental frequency, in order to design the proposed linear control strategy. The coupling in the dq components of the system output signals caused by the Park Transformation, is eliminated by a change of variable proposed for the controller design, giving rise to a decoupled linear control. In this way, the strategy developed makes it possible to establish an adequate transient response for the converter in terms of convergence speed and overshoot magnitude, in addition to ensuring closed-loop system stability under bounded operating conditions. Unlike other proposals that utilize complex modulation strategies to control the MC under adverse conditions at the input terminals, in this case, the ability to generate fully controllable output voltages, regardless of the condition of the input signals, is provided by the designed linear controller. This allows the development of a multifunctional compensator with a simple control that could be of easy implementation. In order to verify the performance of the control strategy developed, and the effectiveness of the proposed DVR to mitigate the power quality problems already mentioned, several case studies are presented. The operational capacity of the MC is demonstrated by the obtained simulation results, which clearly reveals the capability of the DVR to eliminate voltage swells up to 50% and sags less than 50%. The compensation limit reached for sags is 37%. In relation to compensation for unbalanced voltage variations, the DVR manages to reduce the voltage imbalance from 11.11% to 0.37%. Finally, with regard to the operation of the DVR as an active voltage filter, the compensator is capable of reducing a THD of 20% calculated on the supply voltage, to a value of 1.53% measured at the load terminals. In the last two cases, the DVR mitigates disturbances to a level below the criteria established in the IEEE standard for power quality. Results obtained from numerical simulations performed in MATLAB/Simulink serve to validate the proposal, given that for each condition analyzed, the MC had succesfully generated the adequate compensation voltages, thus corroborating the robustness and effectiveness of the control strategy developed in this proposal.

A Matrix Converter for Compensating Unbalanced and Harmonic Input Voltages

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Jose M. Lozano ◽  
Juan M. Ramirez
Keyword(s):  
Power Quality ◽  
Distribution Systems ◽  
Harmonic Distortion ◽  
Matrix Converter ◽  
Space Vector Modulation ◽  
Dynamic Voltage Restorer ◽  
Voltage Restorer ◽  
Svm Algorithm ◽  
Dynamic Voltage ◽  
Vector Modulation

A dynamic voltage restorer (DVR) based on an AC-AC converter is presented. It is able to compensate different common disturbances in distribution systems, with the purpose of improving the power quality delivered to the users. A prototype has been assembled to test the feasibility of the proposition. In this paper a modulation strategy based on the well known space vector modulation (SVM) algorithm is presented in order to synthesize controllable voltages in magnitude and waveform for compensation purposes. Unbalanced and harmonic distortion conditions in the supply voltages are taken into account. These results positively confirm the design, simulation, assembling, and expectations about the device.

scholarly journals Multifunctional Dynamic Voltage Restorer for Power Quality Improvement

2018 ◽  
Author(s):  
Dung Vo Tien ◽  
Radomir Gono ◽  
Zbigniew Leonowicz
Keyword(s):  
Power Quality ◽  
Power Distribution ◽  
Distribution System ◽  
Short Circuit ◽  
Operating Conditions ◽  
Dynamic Voltage Restorer ◽  
Efficient Operation ◽  
Power Distribution System ◽  
Voltage Restorer ◽  
Dynamic Voltage

Power quality is a major concern in electrical power systems. The power quality disturbances such as sags, swells, harmonic distortion and other interruptions have impact on the electrical devices and machines and in severe cases can cause serious damages. Therefore it is required to recognize and compensate all types of disturbances at an earliest to ensure normal and efficient operation of the power system. To solve these problems, many types of power devices are used. At the present time, one of those devices, Dynamic Voltage Restorer (DVR) is the most efficient and effective device used in power distribution system. In this paper, design and modeling of a new structure of multifunctional DVR for voltage correction is presented. The performance of the device under different conditions such as voltage swell, voltage sag due to symmetrical and unsymmetrical short circuit, starting of motors, and voltage distortion are described. Simulation result shows the superior capability of proposed DVR to improve power quality under different operating conditions. The proposed new DVR controller is able to detect the voltage disturbances and control the converter to inject appropriate voltages independently for each phase and compensate to load voltage through three single- phase transformers.

A Novel Control Strategy Based Dynamic Voltage Restorer for Compensation of Voltage Harmonics in Distribution System

2017 ◽  
Vol 7 (2) ◽  
pp. 338 ◽  
Author(s):  
Syed Suraya ◽  
P. Sujatha P ◽  
Bharat Kumar. P
Keyword(s):  
Power Quality ◽  
Control Strategy ◽  
Distribution System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dynamic Voltage Restorer ◽  
Voltage Restorer ◽  
Ideal System ◽  
Dynamic Voltage ◽  
Voltage Harmonics

Power quality is one of the areas that the power sector is worried about. Power quality is the measure of practical system resemblance to ideal system. Voltage quality can be defined as the maintenance of voltage waveform shape close to ideal shape with proper magnitude and frequency. Even a slight change in voltage of the system can cause serious damage to the power system. Sensitive loads cannot adjust for small change in voltage. This paper presents Dynamic Voltage Restorer (DVR) for voltage harmonic suppression along with sag/swell compensation in distribution system. DVR is a voltage source converter which sends compensating signals when operated through switches of voltage source converter. This paper presents a novel control strategy to control DVR to block out the voltage harmonics in distribution system. The models and results are developed using MATLAB/SIMULINK software and comparative analysis of source voltage harmonics and load voltage harmonics during sag/swell compensation was tabulated.

Proposed on Transformer-Less Dynamic Voltage Restorer

2015 ◽  
Vol 785 ◽  
pp. 409-413
Author(s):  
Eimi Diyana Rosli ◽  
Rijalul Fahmi bin Mustapa ◽  
M.N. Hidayat
Keyword(s):  
Power Quality ◽  
Single Phase ◽  
Matrix Converter ◽  
Voltage Sag ◽  
Dynamic Voltage Restorer ◽  
Matlab Simulink ◽  
Voltage Restorer ◽  
Dynamic Voltage ◽  
Mitigation Methods ◽  
Mitigation Technique

Power delivered to consumer from utilities is susceptible to power quality problems. The most common power quality problems are voltage sag. Modern equipment nowadays are prone to problems associated with voltage sag. Such problems can be apprehended by several mitigation methods. This paper will discuss voltage sag mitigation method by eliminating the injection transformer in ordinary Dynamic Voltage Restorer (DVR) and applying Single Phase Matrix Converter (SPMC) in a single phase DVR topologies. The objective of this paper is to investigate the potential mitigation method without the injection transformer in the DVR topology. DVR circuit will be constructed and simulated using MATLAB/SIMULINK software. It is hoped that the result of this work will provide a simpler mitigation technique where existing DVR topology can be constructed with less component that provides unnecessary losses in the DVR itself.IndexTerms—Injection Transformer, DVR, SPMC, MATLAB/SIMULINK.

SOFC-Supported Hybrid PSOGSA-Optimized Dynamic Voltage Restorer for Power Quality Enhancement

2021 ◽  
pp. 2250006
Author(s):  
P. Sathish Babu ◽  
C. K. Sundarabalan ◽  
C. Balasundar
Keyword(s):  
Power Quality ◽  
Control Method ◽  
Supply Voltage ◽  
Test System ◽  
Pi Controller ◽  
Optimal Method ◽  
Dynamic Voltage Restorer ◽  
Voltage Restorer ◽  
Dynamic Voltage ◽  
Tuning Methods

A novel optimal method of a Dynamic Voltage Restorer (DVR) supported by solid oxide fuel cell (SOFC) and its simplified topological structure are proposed. DVR is a power-electronic converter-based device, and the objective of the DVR control system is to minimize supply voltage variations at the load terminals. This is attained by generating a compensating voltage at the series injection transformer. Conventional controllers are mathematical model-based; also, the particular system varies widely, and nonlinear factors make the PI controller tuning more challenging to some extent. As a result, an intelligent PI optimization control method is essential. This paper proposes Hybrid PSOGSA to search for optimal values of two PI control parameters for the [Formula: see text]–[Formula: see text]-axis components by considering a novel bi-objective function. The performance of the test system is analyzed for five test scenarios using the proposed PI controller with SPSO-optimized and Ziegler–Nichols tuning methods. DVR system provides an excellent control performance in the transient and steady states for compensating the sensitive load voltages with almost zero steady-state errors. Simulation results show that the proposed approach can provide improved performance than PSO-optimized and classical PI controllers for the power quality indices measured.

scholarly journals Enhancing Doubly Fed Induction Generator Low-Voltage Ride-Through Capability Using Dynamic Voltage Restorer with Adaptive Noise Cancellation Technique

2022 ◽  
Vol 14 (2) ◽  
pp. 859
Author(s):  
Mohamed Adel Ahmed ◽  
Tarek Kandil ◽  
Emad M. Ahmed
Keyword(s):  
Low Voltage ◽  
Operating Conditions ◽  
System Stability ◽  
Dynamic Voltage Restorer ◽  
Low Voltage Ride Through ◽  
Voltage Restorer ◽  
Dynamic Voltage ◽  
Utility Grid ◽  
Adaptive Noise ◽  
Doubly Fed

Some of the major challenges facing micro-grids (MGs) during their connection with the utility grid are maintaining power system stability and reliability. One term that is frequently discussed in literature is the low-voltage ride-through (LVRT) capability, as it is required by the utility grid to maintain its proper operation and system stability. Furthermore, due to their inherent advantages, doubly fed induction generators (DFIGs) have been widely installed on many wind farms. However, grid voltage dips and distortion have a negative impact on the operation of the DFIG. A dynamic voltage restorer (DVR) is a commonly used device that can enhance the LVRT capability of DFIG compared to shunt capacitors and static synchronous compensator (STATCOM). DVR implements a series compensation during fault conditions by injecting the proper voltage at the point of common coupling (PCC) in order to preserve stable terminal voltage. In this paper, we propose a DVR control method based on the adaptive noise cancelation (ANC) technique to compensate for both voltage variation and harmonic mitigation at DFIG terminals. Additionally, we propose an online control of the DC side voltage of the DVR using pulse width modulation (PWM) rectifier to reduce both the size of the storage element and the solid-state switches of the DVR, aiming to reduce its overall cost. A thorough analysis of the operation and response of the proposed DVR is performed using MATLAB/SIMULINK under different operating conditions of the grid. The simulation results verify the superiority and robustness of the proposed technique to enhance the LVRT capability of the DFIG during system transients and faults.

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