scholarly journals Muti-level voltage synthetic voltage direct power flow controller

2021 ◽  
Vol 2108 (1) ◽  
pp. 012081
Author(s):  
Xinwei Cao(Cao) ◽  
Youjun Zhang(Zhang) ◽  
Zhengzheng Sun(Sun)
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Power Flow ◽  
Reactive Power ◽  
Complex Structure ◽  
Compensation Voltage ◽  
Direct Power ◽  
Storage Element ◽  
Flow Controller ◽  
Power Flow Controller

Abstract Aiming at the defects of DC energy storage elements, complex structure and large volume of unified power flow controller (UPFC), the paper combines flying capacitor multilevel technology and voltage vector synthesis technology with unified direct power flow controller. A three-level direct power flow controller (3L-DPFC) and a new control strategy are proposed. By obtaining the power parameters of the receiving end and substituting them into the derived calculation formula, the compensation voltage can be deduced to adjust the phase and amplitude, and the change relationship between the compensation voltage and the power parameters of the receiving end can be calculated through multiple groups of data, so as to adjust the active power flow and reactive power flow in the power grid. Compared with the unified direct power flow controller, it has the advantages of no DC energy storage element, small volume, simple structure, and the voltage stress of each switch is reduced by half, which reduces the failure rate and economic cost of the controller. In the paper, the topology and control strategy of three-level synthetic DPFC are described in detail, and its buck AC conversion theoretical analysis is verified by simulation.

Effect of unified power flow controller installation in dual feed induction generator (DFIG) wind turbines

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Asaad Shemshadi ◽  
Pourya Khorampour
Keyword(s):  
Power Flow ◽  
Wind Farm ◽  
Reactive Power ◽  
Wind Farms ◽  
Transient Behavior ◽  
Unified Power Flow Controller ◽  
Voltage Fluctuations ◽  
Flow Controller ◽  
Power Flow Controller ◽  
Sudden Load

Abstract In recent years, the use of wind energy to generate electricity in the world has been accelerating and growing. Wind farms are unstable when dynamic voltage fluctuations occur, especially sudden and sudden changes in load, and show oscillating performance at their output. In this paper, the Unified Power Flow Controller (UPFC) has been simulated and studied by Matlab software to improve the dynamic stability and transient behavior of the wind power plant in the event of sudden load changes. The simulation results show that by controlling the UPFC series inverter, voltage fluctuations in the PCC bus are prevented and the UPFC parallel inverter injects power after changing the load for faster recovery and stability of the PCC bus voltage and thus the stability of the wind farm. The UPFC can control the active and reactive power at the transmission line, and in fact, controls the output of the wind turbine with the generator from both sides to the fluctuations caused by sudden load changes that play a role such as sudden disturbances and oscillating errors. Also, the presence of UPFC in the system reduces power fluctuations.

scholarly journals Real and Reactive Power Control by using 48-pulse Series Connected Three-level NPC Converter for UPFC

2011 ◽  
pp. 1-5
Author(s):  
A. Naveena ◽  
M.Venkateswara Rao
Keyword(s):  
Transmission Line ◽  
Power Flow ◽  
Reactive Power ◽  
System Stability ◽  
Unified Power Flow Controller ◽  
Control Mechanisms ◽  
Active And Reactive Power ◽  
Reactive Power Flow ◽  
Flow Controller ◽  
Power Flow Controller

The equipments based on the power electronics have been improved under the name of Flexible Alternating Current Transmission Systems (FACTS) in the last years. Unified Power Flow Controller (UPFC) is the most widely used FACTS device to control the power flow and to optimize the system stability in the transmission line. UPFC is a FACTS devices that can control active and reactive power flow in transmission line by means of injection controllable series voltage to the transmission line. This paper proposes a new connection for a Unified Power Flow Controller (UPFC) to control the active and reactive power flow control in two sides of a transmission line independently and it regulates bus voltage in the same transmission line, furthermore it is possible to balance line current too. This connection of the UPFC will be called an center node UPFC (C_UPFC). It is one of the newest devices within the FACTS technology. The structure and capability of the C_UPFC is discussed and its control scheme is based on the d-q orthogonal coordinates. According to this, the performance of UPFC for several modes of operations using different control mechanisms based on Proportional-Integral (PI) and PID based controllers has been studied. The obtained simulation results from Matlab/simulink confirm the effective features.

Using Hybrid Power Flow Controller (HPFC) to Improve Performance of Old and Existing Compensators in Power System

2012 ◽  
Vol 622-623 ◽  
pp. 1048-1055 ◽  
Author(s):  
Mojtaba Hakimzadeh ◽  
Reza Sedaghati ◽  
Masoud Parhoodeh
Keyword(s):  
Power System ◽  
Power Flow ◽  
Reactive Power ◽  
Hybrid Structure ◽  
Improve Performance ◽  
Matlab Software ◽  
Hybrid Power ◽  
Flow Controller ◽  
Continuous Power ◽  
Power Flow Controller

In this paper, a hybrid topology of FACTS devices has been investigated to improve stability features of static voltage. The primary assumption is a power system which has been located under SVC parallel compensation. HPFC forms a hybrid controller using IPFC series converters as a hybrid with existing parallel and passive compensator (SVC) in power system. Thus, simultaneous and independent control of active power flow can be reached through transmission lines and the exchanged reactive power values towards sending and receiving line. Using a hybrid structure makes the use of convertors to improve performance of the old and existing compensators in the power system possible. In this study, the power injection model (PIM) has been used to model series-parallel parts of hybrid power flow controller in Newton-Raphson load flow, and all have been simulated in M-file environment of MATLAB software. In order to investigate the effect of this controller on stability properties of static voltage, P-V curve of PQ buses of a prototype system has been evaluated in a continuous power flow (CPF) in M-file environment of MATLAB software. In the section of simulation results, SVC parallel compensation and UPFC series-parallel compensation are compared in terms of the amount of losses, active and reactive power, and improvement of the system’s loading limit with the proposed hybrid structure.

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