scholarly journals Novel Transient Power Control Schemes for BTB VSCs to Improve Angle Stability

2018 ◽  
Vol 8 (8) ◽  
pp. 1350 ◽  
Author(s):  
Sungyoon Song ◽  
Sungchul Hwang ◽  
Baekkyeong Ko ◽  
Seungtae Cha ◽  
Gilsoo Jang
Keyword(s):  
Power Control ◽  
Communication Systems ◽  
Control Strategies ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Python Language ◽  
Control Scheme ◽  
Control Schemes ◽  
Angle Stability ◽  
Ac Transmission

This paper proposes two novel power control strategies to improve the angle stability of generators using a Back-to-Back (BTB) system-based voltage source converter (VSC). The proposed power control strategies have two communication systems: a bus angle monitoring system and a special protection system (SPS), respectively. The first power control strategy can emulate the behaviour of the ac transmission to improve the angle stability while supporting the ac voltage at the primary level of the control structure. The second power control scheme uses an SPS signal to contribute stability to the power system under severe contingencies involving the other generators. The results for the proposed control scheme were validated using the PSS/E software package with a sub-module written in the Python language, and the simple assistant power control with two communication systems is shown to improve the angle stability. In conclusion, BTB VSCs can contribute their power control strategies to ac grid in addition to offering several existing advantages, which makes them applicable for use in the commensurate protection of large ac grid.

scholarly journals Analysis of Six Active Power Control Strategies of Interconnected Grids with VSC-HVDC

2019 ◽  
Vol 9 (1) ◽  
pp. 183 ◽  
Author(s):  
Sungyoon Song ◽  
Minhan Yoon ◽  
Gilsoo Jang
Keyword(s):  
Power Control ◽  
Rate Control ◽  
Control Strategies ◽  
Active Power ◽  
Ramp Rate ◽  
Active Power Control ◽  
Interaction Factor ◽  
Control Schemes ◽  
Angle Stability ◽  
Step Control

In this paper, the generator angle stability of several active power control schemes of a voltage-source converter (VSC)-based high-voltage DC (HVDC) is evaluated for two interconnected AC systems. Excluding frequency control, there has been no detailed analysis of interconnected grids depending upon the converter power control, so six different types of active power control of the VSC-HVDC are defined and analyzed in this paper. For each TSO (transmission system operator), the applicable schemes of two kinds of step control and four kinds of ramp-rate control with a droop characteristic are included in this research. Furthermore, in order to effectively evaluate the angle stability, the Generators-VSC Interaction Factor (GVIF) index is newly implemented to distinguish the participating generators (PGs) group which reacts to the converter power change. As a result, the transient stabilities of the two power systems are evaluated and the suitable active power control strategies are determined for two TSOs. Simulation studies are performed using the PSS®E program to analyze the power system transient stability and various active power control schemes of the VSC-HVDC. The results provide useful information indicating that the ramp-rate control shows a more stable characteristic than the step-control for interconnected grids; thus, a converter having a certain ramp-rate slope similar to that of the other generator shows more stable results in several cases.

scholarly journals Deep Learning-Based Power Control Scheme for Perfect Fairness in Device-to-Device Communication Systems

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1606
Author(s):  
Donghyeon Kim ◽  
In-Ho Lee
Keyword(s):  
Deep Learning ◽  
Power Control ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Data Rate ◽  
D2d Communication ◽  
Transmit Power ◽  
Transmit Power Control ◽  
Control Scheme ◽  
Control Schemes

The proximity-based device-to-device (D2D) communication allows for internet of things, public safety, and data offloading services. Because of these advantages, D2D communication has been applied to wireless communication networks. In wireless networks using D2D communication, there are challenging problems of the data rate shortage and coverage limitation due to co-channel interference in the proximity communication. To resolve the problems, transmit power control schemes that are based on deep learning have been presented in network-assisted D2D communication systems. The power control schemes have focused on enhancing spectral efficiency and energy efficiency in the presence of interference. However, the data-rate fairness performance may be a key performance metric in D2D communications, because devices in proximity can expect fair quality of service in the system. Hence, in this paper, a transmit power control scheme using a deep-learning algorithm based on convolutional neural network (CNN) is proposed to consider the data-rate fairness performance in network-assisted D2D communication systems, where the wireless channels are modelled by path loss and Nakagami fading. In the proposed scheme, the batch normalization (BN) scheme is introduced in order to further enhance the spectral efficiency of the conventional deep-learning transmit power control scheme. In addition, a loss function for the deep-learning optimization is defined in order to consider both the data-rate fairness and spectral efficiency. Through simulation, we show that the proposed scheme can achieve extremely high fairness performance while improving the spectral efficiency of the conventional schemes. It is also shown that the improvement in the fairness and spectral efficiency is achieved for different Nakagami fading conditions and sizes of area containing the devices.

Adaptive SRF-PLL Based Voltage and Frequency Control of Hybrid Standalone WECS with PMSG-BESS

2018 ◽  
Vol 19 (6) ◽  
Author(s):  
Anjana Jain ◽  
R. Saravanakumar ◽  
S. Shankar ◽  
V. Vanitha
Keyword(s):  
Reactive Power ◽  
Frequency Control ◽  
Storage System ◽  
Synchronous Generator ◽  
Energy Storage System ◽  
Voltage Regulation ◽  
Operating Conditions ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Control Scheme

Abstract The variable-speed Permanent Magnet Synchronous Generator (PMSG) based Wind Energy Conversion System (WECS) attracts the maximum power from wind, but voltage-regulation and frequency-control of the system in standalone operation is a challenging task A modern-control-based-tracking of power from wind for its best utilization is proposed in this paper for standalone PMSG based hybrid-WECS comprising Battery Energy Storage System (BESS). An Adaptive Synchronous Reference Frame Phase-Locked-Loop (SRF-PLL) based control scheme for load side bi-directional voltage source converter (VSC) is presented for the system. MATLAB/Simulink model is developed for simulation study for the proposed system and the effectiveness of the controller for bi-directional-converter is discussed under different operating conditions: like variable wind-velocity, sudden load variation, and load unbalancing. Converter control scheme enhances the power smoothening, supply-load power-matching. Also it is able to regulate the active & reactive power from PMSG-BESS hybrid system with control of fluctuations in voltage & frequency with respect to varying operating conditions. Proposed controller successfully offers reactive-power-compensation, harmonics-reduction, and power-balancing. The proposed scheme is based on proportional & integral (PI) controller. Also system is experimentally validated in the laboratory-environment and results are presented here.

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.

Comparison between an Interleaved Boost Converter and CUK Converter Fed BLDC Motor

2015 ◽  
Vol 6 (3) ◽  
pp. 594
Author(s):  
V. Ramesh ◽  
Y. Kusuma Latha
Keyword(s):  
Control Strategies ◽  
Torque Ripple ◽  
Boost Converter ◽  
Voltage Source ◽  
Motor Drive ◽  
Voltage Source Converter ◽  
Bldc Motor ◽  
Cuk Converter ◽  
Interleaved Boost Converter ◽  
Permanent Magnet Brushless Dc

There is a great concern of torque ripple and power quality of three phase voltage source converter fed Permanent Magnet Brushless DC Motor (PMBLDCM). In this paper, two control strategies for BLDC motor drive has been investigated. One of the control strategies is based on PFC - CUK converter fed PMBLDCM drive and another one is PFC- interleaved boost converter fed BLDC motor drive. Comparison has been made between the two control stragies in terms of Torque ripple, Total harmonic distortion (THD) and power factor for different operating speeds. The proposed work as been implemented under MATLAB/simulink environment. Simulation results are presented to validate proposed work. From the results, it is observed that PFC interleaved Boost converter fed BLDC motor drive is more effective compared to CUK converter fed BLDC motor drive.

PHC, Id-Iq and p-q Control Strategies for Mitigation of Current Harmonics in Three-Phase Three-Wire Shunt Active Filter with PI Controller

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
Suresh Mikkili ◽  
Adinarayana Padamati
Keyword(s):  
Control Strategy ◽  
Control Strategies ◽  
Voltage Regulation ◽  
Active Filter ◽  
Electrical Network ◽  
Voltage Source ◽  
Complex Nature ◽  
Voltage Source Converter ◽  
Shunt Active Filter ◽  
Three Phase

Abstract In this research paper, the shunt active filter (SHAF) is used to improve the power quality of electrical network by mitigating the harmonics with the help of different control strategies (p-q control strategy, Id-Iq control strategy, PHC control strategy) for three phase three wire system. It is quite difficult to optimize the performance of power system networks using conventional methods, because of complex nature of the systems that are highly non-linear and non-stationary. Three phase reference current waveforms generated by the proposed schemes are tracked by three phase voltage source converter in a hysteresis band control scheme. The performance of proposed control strategies has been evaluated in terms of harmonic mitigation and DC link voltage regulation under various source voltage conditions. The proposed SHAF with different control strategies is able to eliminate uncertainty in the system and SHAF gains outstanding compensation abilities. The detailed simulation results using MATLAB/Simulink software are presented to support the feasibility of the proposed control strategy.

scholarly journals Multiterminal Medium Voltage DC Distribution Network Hierarchical Control

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 506 ◽  
Author(s):  
Patrobers Simiyu ◽  
Ai Xin ◽  
Kunyu Wang ◽  
George Adwek ◽  
Salman Salman
Keyword(s):  
Optimal Power Flow ◽  
Distribution Network ◽  
Hierarchical Control ◽  
Active Power ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Dc Voltage ◽  
Medium Voltage ◽  
Control Scheme ◽  
Medium Voltage Dc

In this research study, a multiterminal voltage source converter (VSC) medium voltage DC (MVDC) distribution network hierarchical control scheme is proposed for renewable energy (RE) integration in a co-simulation environment of MATLAB and PSCAD/EMTDC. A DC optimal power flow (DC OPF) secondary controller is created in MATLAB. In PSCAD/EMTDC, the main circuit containing the adaptive DC voltage droop with a dead band and virtual synchronous generator (VSG) based primary controller for the VSCs is implemented. The simulation of the MVDC network under the proposed hierarchical control scheme is investigated considering variations in wind and solar photovoltaic (PV) power. The network is also connected to the standard IEEE-39 bus system and the hierarchical scheme tested by assessing the effect of tripping as well as restoration of the REs. The results show that during random variations in active power such as increasing wind and PV power generation, a sudden reduction or tripping of wind and PV power, the primary controller ensures accurate active power sharing amongst the droop-based VSCs as well as regulates DC voltage deviations within the set range of 0.98–1.02 pu with an enhanced dynamic response. The DC OPF secondary control optimizes the system’s losses by 38% regularly giving optimal droop settings to the primary controllers to ensure proper active power balance and DC voltage stability. This study demonstrates that the hierarchical control strategy is effective for RE integration in the MVDC distribution network.

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