scholarly journals Nonlinear Control of Back-to-Back VSC-HVDC System via Command-Filter Backstepping

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jie Huang ◽  
Dezhi Xu ◽  
Wenxu Yan ◽  
Le Ge ◽  
Xiaodong Yuan
Keyword(s):  
Reactive Power ◽  
Dynamic Performance ◽  
Input Saturation ◽  
Stability And Convergence ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Hvdc System ◽  
Pid Algorithm ◽  
Voltage Balance ◽  
Command Filter

This paper proposed a command-filtered backstepping controller to improve the dynamic performance of back-to-back voltage-source-converter high voltage direct current (BTB VSC-HVDC). First, the principle and model of BTB VSC-HVDC in abc and d-q frame are described. Then, backstepping method is applied to design a controller to maintain the voltage balance and realize coordinated control of active and reactive power. Meanwhile, command filter is introduced to deal with the problem of input saturation and explosion of complexity in conventional backstepping, and a filter compensation signal is designed to diminish the adverse effects caused by the command filter. Next, the stability and convergence of the whole system are proved via the Lyapunov theorem of asymptotic stability. Finally, simulation results are given to demonstrate that proposed controller has a better dynamic performance and stronger robustness compared to the traditional PID algorithm, which also proves the effectiveness and possibility of the designed controller.

scholarly journals Research on Serial VSC-LCC Hybrid HVdc Control Strategy and Filter Design Scheme

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2260
Author(s):  
Fan Cheng ◽  
Lijun Xie ◽  
Zhibing Wang
Keyword(s):  
Reactive Power ◽  
Filter Design ◽  
Control Strategies ◽  
Short Circuit ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Level Control ◽  
Hvdc System ◽  
High Voltage Direct Current ◽  
Design Scheme

This paper investigated the characteristics of a novel type of hybrid high voltage direct current (HVdc) converter, which is composed by line commutated converter series with voltage source converter. The system and valve level control strategies are introduced, which can provide ac system voltage support. A novel filter design scheme composed by resonant filers for hybrid HVdc are also proposed, which can decrease the capacity of reactive power compensation equipment without deteriorate harmonic characteristics. The ac voltage of HVdc fluctuation level caused by transmitted power variation will be effectively reduced, with the coordination between filter design scheme and converter control. In addition, the influence of ac grid strength is also analyzed by equivalent source internal impedance represented by short circuit ratio (SCR). Finally, the +800 kV/1600 MW hybrid HVdc system connecting two ac grids under different SCR cases are studied, and the PSCAD/EMTDC simulation results have validated the effectiveness for proposed strategy.

scholarly journals Vector Control of VSC HVDC System under Single Line to Ground Fault Condition

2018 ◽  
Vol 7 (1) ◽  
pp. 59
Author(s):  
Prabodha Kumar Rath ◽  
Kanhu Charan Bhuyan
Keyword(s):  
Vector Control ◽  
Reactive Power ◽  
Control Method ◽  
System Stability ◽  
Control Technique ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Control Loop ◽  
Hvdc System ◽  
Ground Fault

<span lang="EN-US">This paper proposes a model of a VSC (voltage source converter) based Back to Back HVDC system and its control technique under fault condition. From the mathematical model of the system relationship between the controlling and the controlled variables is determined to control the system parameters. An appropriate vector control technique is used to control active and reactive power and to maintain DC link voltage. The proposed controlling unit consists of outer control loop and inner control loop which effectively damped out the system oscillation and maintains the system stability. The validity of the model and the feasibility of the control method have been proved by the simulation results. In this paper the system performance is studied under fault condition is studied.</span>

scholarly journals Power Stability Analysis and Evaluation Criteria of Dual-Infeed HVDC with LCC-HVDC and VSC-HVDC

2021 ◽  
Vol 11 (13) ◽  
pp. 5847
Author(s):  
Xinglong Wu ◽  
Zheng Xu ◽  
Zheren Zhang
Keyword(s):  
Reactive Power ◽  
Short Circuit ◽  
Evaluation Criteria ◽  
Stability Margin ◽  
Control Mode ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Power Stability ◽  
Hvdc System ◽  
Voltage Control Mode

This paper analyzes the power stability of the hybrid dual-infeed high-voltage direct-current (HVDC) system containing a line commutated converter-based HVDC (LCC-HVDC) and a voltage source converter-based HVDC (VSC-HVDC). First, the concept and the calculation method of power stability for the hybrid dual-infeed HVDC system are introduced. Second, the influence of VSC-HVDC on the power stability of the system is investigated. Third, the relationship between the power stability and the effective short circuit ratio (ESCR) is discussed under different system parameters. Then, the value range of the critical effective short circuit ratio is determined. Finally, the evaluation criteria of power stability are proposed. The results show that the evaluation criteria of the single-infeed LCC-HVDC system can still be used, if the VSC-HVDC is in constant AC voltage control mode; if the VSC-HVDC is in constant reactive power control mode, the hybrid dual-infeed HVDC system cannot operate stably when the ESCR is less than 2.0 and can operate stably with high power stability margin when the ESCR is greater than 3.0. The ESCR index can still be used to measure the power stability of the hybrid dual-infeed HVDC system.

scholarly journals Dynamic Performance Analysis of VSC-HVDC Based Modular Multilevel Converter under Fault

2021 ◽  
Vol 54 (1) ◽  
pp. 187-194
Author(s):  
Abdelhalim Yahiaoui ◽  
Koussaila Iffouzar ◽  
Kaci Ghedamsi ◽  
Kamal Himour
Keyword(s):  
Power Transmission ◽  
Dynamic Performance ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
System Control ◽  
Hvdc System ◽  
Power Transmission Systems ◽  
Multi Level ◽  
Level Converter ◽  
Dynamic Performance Analysis

The use of high voltage direct current based voltage source converter (VSC-HVDC) in power transmission systems knows a great progress in recent years. Above all, with the new generation of power electronics converters such as the modular multi-level converter (MMC), with his scalable structure it can theoretically meet any voltage level requirement, which allows to increase the size of the power transferred compared to conventional converters. In this sense, this paper presents a study of a VSC-HVDC system based on a modular multi-level converter (MMC). The main objective of this work is to analyze the performance of the VSC-HVDC system based MMC without the AC filters and its control in the event of a fault, during set point changes and unbalanced grid conditions. After realization a mathematical model of the system studied and its control, simulations are done over in Simpower System/Matlab. The results obtained confirm the robustness of the system control and the system gives a good energy quality, that manifests by a good output currant and voltage curves with no need to use a voluminous AC filter.

Design, Control, and Modeling of a New Voltage Source Converter for HVDC System

2013 ◽  
Vol 14 (2) ◽  
pp. 123-138
Author(s):  
Madhan Mohan ◽  
Bhim Singh ◽  
Bijaya Ketan Panigrahi
Keyword(s):  
Power Control ◽  
Fundamental Frequency ◽  
Reactive Power ◽  
Control Method ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Reactive Power Control ◽  
Hvdc System ◽  
Active And Reactive Power ◽  
The Dead

Abstract: A New Voltage Source Converter (VSC) based on neutral clamped three-level circuit is proposed for High Voltage DC (HVDC) system. The proposed VSC is designed in a multipulse configuration. The converter is operated by Fundamental Frequency Switching (FFS). A new control method is developed for achieving all the necessary control aspects of HVDC system such as independent real and reactive power control, bidirectional real and reactive power control. The basic of the control method is varying the pulse width and by keeping the dc link voltage constant. The steady state and dynamic performances of HVDC system interconnecting two different frequencies network are demonstrated for active and reactive power control. Total number of transformers used in this system are reduced to half in comparison with the two-level VSCs for both active and reactive power control. The performance of the HVDC system is improved in terms of reduced harmonics level even at fundamental frequency switching. The harmonic performance of the designed converter is also studied for different value of the dead angle (β), and the optimized range of the dead angle is achieved for varying reactive power requirement. Simulation results are presented for the designed three level multipulse voltage source converters with the proposed control algorithm.

Grid interfaced solar-wind hybrid power generating systems using fuzzy-based TOGI control technique for power quality improvement

2021 ◽  
pp. 1-12
Author(s):  
Dinanath Prasad ◽  
Narendra Kumar ◽  
Rakhi Sharma
Keyword(s):  
Solar Wind ◽  
Fuzzy Logic ◽  
Power Quality ◽  
Reactive Power ◽  
Dynamic Performance ◽  
Energy System ◽  
Control Technique ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Hybrid Renewable Energy System

This paper bestows 3-phase grid interfaced solar-wind hybrid renewable energy system (RES), feeding three-phase loads. The proposed system includes solar photovoltaic, permanent magnet based synchronous generator (PMSG), DC-DC converter, maximum power point tracker (MPPT) based on incremental conductance, three phases IGBT based voltage source converter (VSC), with a third order generalized integrator (TOGI) control technique. This control technique bestows multifunctional capabilities as harmonic mitigations, load balancing, and reactive power compensation. A fundamental component of load current is extracted by TOGI based controller, and further it is utilized to provide switching pulses to VSC for power quality enrichment. The fuzzy logic-based controller is used for loss computation of VSC as well as for maintaining DC link voltage. Moreover, fuzzy logic provides better dynamic performance compared to conventional PI controller. The results are presented in many aspects for linear and nonlinear loads such as, intermittent nature of solar and wind as well as disturbances in the system. A comparative analysis between proposed TOGI based controller and conventional control algorithm has been presented. Test results are performed by using MATLAB/ Simulink environment and demonstrate, AC-grid current is maintained within the IEEE-519 standard.

scholarly journals Power Quality Enhancement in Windfarm by using STATCOM

2020 ◽  
Vol 8 (5) ◽  
pp. 596-601
Keyword(s):  
Wind Turbine ◽  
Power Flow ◽  
Reactive Power ◽  
Dynamic Performance ◽  
Active Power ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dc Microgrid ◽  
Active Power Flow ◽  
Shunt Compensation

A FACTS (Flexible AC Transmission) controlled device, STATCOM is the best solution for power compensation in the area of microgrid system. It regulates the reactive power by injecting the reactive current in to the ac/dc hybrid microgrid terminals. The STATCOM is applicable for shunt compensation which has a great role in dynamic performance by controlling its reactive power. The proposed work demonstrated about the enhancement of voltage sag during fault condition. It can improve the wind turbine performance. The main objective for the STATCOM application in windfarm is to improve the system voltage by supplying or absorbing the reactive power into hybrid ac /dc microgrid system. During steady state operation, the fundamental component of the VSC (Voltage source converter) voltage in phase with system voltage, which shows uncontrol action on active power flow. If there is change between these two voltages (lead or lag), then STATCOM can generates (or absorbs) reactive power. This phase shift leads to flow of active power which is responsible for increase or decreases of capacitor voltage. Assumption has been taken by considering the fixed speed of wind turbine. The performance of windfarm with and without STATCOM is examined and analyzed under fault condition by using MATLAB Simulink 2016.

Inductor Saturation Compensation in Three-Phase Three-Wire Voltage-Source Converters via Inverse System Dynamics-I

2020 ◽  
Author(s):  
Ziya Özkan ◽  
Ahmet Masum Hava
Keyword(s):  
Dynamic Model ◽  
Dynamic Performance ◽  
Current Control ◽  
Inverse System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Two Phase ◽  
Inverse Dynamic ◽  
Three Phase ◽  
Steady State Current

In three-phase three-wire (3P3W) voltage-source converter (VSC) systems, utilization of filter inductors with deep saturation characteristics is often advantageous due to the improved size, cost, and efficiency. However, with the use of conventional synchronous frame current control (CSCC) methods, the inductor saturation results in significant dynamic performance loss and poor steady-state current waveform quality. This paper proposes an inverse dynamic model based compensation (IDMBC) method to overcome these performance issues. Accordingly, a review of inductor saturation and core materials is performed, and the motivation on the use of saturable inductors is clarified. Then, two-phase exact modelling of the 3P3W VSC control system is obtained and the drawbacks of CSCC have been demonstrated analytically. Based on the exact modelling, the inverse system dynamic model of the nonlinear system is obtained and employed such that the nonlinear plant is converted to a fictitious linear inductor system for linear current regulators to perform satisfactorily.

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