A low loss modular multilevel voltage source converter for HVDC power transmission and reactive power compensation

Author(s):  
R. Feldman ◽  
M. Tomasini ◽  
J.C. Clare ◽  
P. Wheeler ◽  
D.R. Trainer ◽  
...  
Author(s):  
Damian O Dike ◽  
Satish M Mahajan

A strategy is presented for the self-tuning of a voltage source converter (VSC) based Flexible AC Transmission Systems (FACTS) according to the prevailing system condition. L-index, which is a power system voltage stability status indicator, and its associated parameters are used to automatically regulate the modulation signal of the VSC. This will lead to a proportionate adjusting of the magnitude of the current injected into, or absorbed from, the interconnected load bus by the FACTS device. This regulating scheme will enhance seamless and optimal reactive power compensation by utilizing the dynamic operational nature of present day distressed power system networks. Results obtained using this method when applied to selected load buses of the IEEE 14 bus system under varying practical scenarios showed its capability to appropriately control FACTS devices operation to accommodate system changing conditions. It is hoped that the outcome of this work will provide efficient tools for the determination of power system status, ensure optimal utilization of the dynamic reactive power compensation devices and reduce system outages.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 831 ◽  
Author(s):  
Janeth Alcalá ◽  
Víctor Cárdenas ◽  
Alejandro Aganza ◽  
Jorge Gudiño-Lau ◽  
Saida Charre

Nowadays, the use of power converters to control active and reactive power in AC–AC grid-connected systems has increased. With respect to indirect AC–AC converters, the tendency is to enable the back-to-back (BTB) voltage source converter (VSC) as an active power filter (APF) to compensate current harmonics. Most of the reported works use the BTB-VSC as an auxiliary topology that, combined with other topologies, is capable of active power regulation, reactive power compensation and current harmonic filtering. With the analysis presented in this work, the framework of the dynamics associated with the control loops is established and it is demonstrated that BTB-VSC can perform the three tasks for which, in the reviewed literature, at least two different topologies are reported. The proposed analysis works to support the performance criteria of the BTB-VSC when it executes the three control actions simultaneously and the total current harmonic distortion is reduced from 27.21% to 6.16% with the selected control strategy.


Author(s):  
Mr. L NarayanaGadupudi Et.al

 Internal Liability of power system transmission lines influenced by the turbulences owing to catastrophic disasters. In order to achieve Constant Voltage Stability at both ends of the transmission lines, Static Synchronous Compensator (STATCOM) is imperative.  Voltage source Converter mechanisms augment with switching frequency control methodologies are widely adopted to regulate the reactive power. By deliberating IEEE Standards, the minimization of Total Harmonic Distortion (THD) is conceivable with STATCOM. This paper depicts the advancement of VSC based STATCOM approaches and the methodologies to minimize the switching losses. Economical management of High-Power ratings systems is also discussed in this paper


2018 ◽  
Vol 7 (3.12) ◽  
pp. 84
Author(s):  
B Pragathi ◽  
M Suman

Along with Generation of power, distribution of power is equally important.The power produced by the solar farm are utilized only during daytime, the solar farm remain idle during night and operate below capacity in initial morning and late afternoon. A grid connected solar farm uses photovoltaic (PV) arrays for generation of DC power which is transformed to AC using inverter modeling. A FACTS family device STATCOM is centered on a voltage source converter which operates as a rectifier and an inverter is used to enhance steady power transmission limits with reactive power, voltage and damping control. A majorsection of the STATCOM is a voltage source converter which is also anessential element of PV solar module. A novel concept was proposed by which PV solar module can be operated as a STATCOM, known as PV-STATCOM in the night-time and day time. VLSI technology is used to generate the trigger pulses for three phase inverter using the VHDL programming language to generate the signal for the control of inverter section in STATCOM. The HDL compiling and FPGA implementation is done using MATLAB/SIMULINK.  


Author(s):  
Akram Qashou ◽  
Sufian Yousef ◽  
Abdallah A. Smadi ◽  
Amani A. AlOmari

AbstractThe purpose of this paper is to describe the design of a Hybrid Series Active Power Filter (HSeAPF) system to improve the quality of power on three-phase power distribution grids. The system controls are comprise of Pulse Width Modulation (PWM) based on the Synchronous Reference Frame (SRF) theory, and supported by Phase Locked Loop (PLL) for generating the switching pulses to control a Voltage Source Converter (VSC). The DC link voltage is controlled by Non-Linear Sliding Mode Control (SMC) for faster response and to ensure that it is maintained at a constant value. When this voltage is compared with Proportional Integral (PI), then the improvements made can be shown. The function of HSeAPF control is to eliminate voltage fluctuations, voltage swell/sag, and prevent voltage/current harmonics are produced by both non-linear loads and small inverters connected to the distribution network. A digital Phase Locked Loop that generates frequencies and an oscillating phase-locked output signal controls the voltage. The results from the simulation indicate that the HSeAPF can effectively suppress the dynamic and harmonic reactive power compensation system. Also, the distribution network has a low Total Harmonic Distortion (< 5%), demonstrating that the designed system is efficient, which is an essential requirement when it comes to the IEEE-519 and IEC 61,000–3-6 standards.


Author(s):  
Anjana Jain ◽  
R. Saravanakumar ◽  
S. Shankar ◽  
V. Vanitha

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.


2011 ◽  
Vol 55-57 ◽  
pp. 1361-1364
Author(s):  
Jun Li Zhang ◽  
Xiao Feng Lv ◽  
Chao Li

With the growth of industry manufacturers and population, power quality becomes more and more important issue, and is attracting significant attention due to the increase in the number of sensitive loads. A distribution static compensator (DSTATCOM) is a voltage source inverter (VS1)-based power electronic device, which is usually used to compensate reactive power and sustain the system voltage in distribution power system. Compared with the traditional STATCOM, multilevel STATCOMs exhibit faster dynamic response, smaller volume, lower cost, and higher ratings. A multilevel inverter connected to an energy storage device can control both active and reactive power flow, providing more flexible and versatile power transmission operation. SPWM is actually a kind of multi-pulse trigger mode and used to trigger the switches in DSTATCOM.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2260
Author(s):  
Fan Cheng ◽  
Lijun Xie ◽  
Zhibing Wang

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.


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