scholarly journals Convergence Adjustment Method Based on Approximate Power Flow and Voltage Stability

2020 ◽  
pp. 53-68
Author(s):  
Nan Hu, Lin Qiao, Chao Yang, Jun Qi, Shiyan Hu
Keyword(s):  
New England ◽  
Power Flow ◽  
Voltage Stability ◽  
System Analysis ◽  
Engineering Application ◽  
Reference Value ◽  
Operating Mode ◽  
Voltage Sensitivity ◽  
Operating Personnel ◽  
Convergence Trend

Prone to problems flow calculation does not converge at the scheduled maximum power operating mode, the current operating personnel inability to visually observe the system state, convergence can only be adjusted by trial and error approach. Solving the problem of non convergence of power flow plays an important role in power system analysis. Based on the intermediate process of solving the Newton method, the concept of an approximate fashion, the relation between convergence and voltage stability is calculated by analyzing the trend of the voltage characteristics similar trend as the main basis of the judgment result in the trend does not converge, based on voltage sensitivity further, by improving the convergence of the method to boost the voltage level indirectly. Finally, after the New England 39-bus system to verify, by demonstrating the relevance and accuracy of the proposed method. When not solve the problem of the convergence trend is not impressive, it has a certain reference value for practical application. This study has a good application prospect in practical engineering application

Improvement of large power system with facts devices placement to maxim-IZE the system load ability

2018 ◽  
Vol 7 (2.28) ◽  
pp. 381
Author(s):  
O L. Bekri ◽  
F Mekri
Keyword(s):  
Power Systems ◽  
Power System ◽  
New England ◽  
Power Flow ◽  
Voltage Stability ◽  
Optimal Placement ◽  
Test Case ◽  
Static Synchronous Compensator ◽  
Large Power ◽  
Loading Parameter

Voltage instabilities and/or collapses have been recognized as one of the major causes of power system blackouts. The main objective of this paper is to provide some solutions to prevent large power systems from voltage collapse. The FACTS (Flexible AC Transmission Sys-tems) devices placement gives new opportunities for enhancing voltage stability. The calculation of the loadability point is based on the con-tinuation power flow technique (CPF) to choosing the optimal placement of STATCOM (Static Synchronous Compensator) in order to improve voltage stability by increasing the loading parameter, maintaining bus voltages at desired level and minimizing losses in a power system network.A 39-bus New England power system is chosen as test case in order to illustrate this approach. The obtained results show the efficiency of the proposed method for the planning of the Static Synchronous Compensator optimal placement and the voltage stability enhancement.  

Optimum Location of Spvg to Enhance Voltage Stability Using Static Techniques

2020 ◽  
Vol 23 (2) ◽  
pp. 49-58
Author(s):  
Melat K. Abdulla ◽  
Lokman H. Hassan
Keyword(s):  
Power Systems ◽  
New England ◽  
Power Flow ◽  
Voltage Stability ◽  
Load Condition ◽  
Vital Role ◽  
Heavy Load ◽  
The Stability ◽  
The Impact ◽  
Photovoltaic Generators

Solar Photovoltaic Generators (SPVGs) play a great and vital role in providing clean and enough energy to meet power loads. However, SPVGs integration on power systems increase power grid problems. It will lead to different problems including disturbance of the grid, instability of the voltage and swings of the power. The impact of SPVG on the voltage stability of the system is studied in this paper. The best location of SPVG is obtained using three static techniques. Power flow and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under nominal load condition respectively. On other hand, Continuation Power Flow (CPF) and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under heavy load condition respectively. The proposed techniques are apllied to the New England 39-bus standard system under various loading conditions. The results reveal that choosing a proper location for the SPVG will improve the voltage stability of the system. In addition, connecting the SPVG at the nearest bus to the weakest bus provides better performance than when it connected to the weakest bus.

Multi-Objective Optimal Power Flow with Transient Stability Constraints

2014 ◽  
Vol 556-562 ◽  
pp. 2067-2071
Author(s):  
Jin Ling Lu ◽  
Qiang Zhang
Keyword(s):  
New England ◽  
Interior Point Method ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Transient Stability ◽  
Inequality Constraints ◽  
Operating Personnel ◽  
Multi Objective ◽  
General Constraints ◽  
Generation Cost

In this paper, the deficiency of the general transient stability constrained OPF model was analyzed,on the basis of which, a multi-objective transient stability constrained OPF model was proposed. The transient stability constraints was to be as a objective function instead of the general constraints,which and power generation cost function were taken weighted sum to be converted into a single-objective optimization model. Multiple optimal solutions under different weights were given based on the original dual interior point method,which can offer a variety of options for operating personnel according to actual needs. In terms of improving the efficiency of the algorithm,The two groups of differentiated rotor equations were eliminated to be one set of equations.And the transient differential equations were dispersed to inequality constraints instead of equality constraints.the dimensions of the correction equation and the scale of the problem solved were significantly reduced. Numerical simulations on the New England 10-generator 39-bus power system, demonstrated the effectiveness and feasibility of the proposed method.

scholarly journals Enhancement of voltage stability in an interconnected network using unified power flow controller

2021 ◽  
Vol 4 (1) ◽  
pp. 65-74
Author(s):  
Idris A. Araga ◽  
A. E. Airoboman
Keyword(s):  
Power Flow ◽  
Large Scale ◽  
Voltage Stability ◽  
System Analysis ◽  
Optimal Placement ◽  
Unified Power Flow Controller ◽  
Stability Factor ◽  
Grid System ◽  
Power Injection ◽  
Bus Network

In this paper, the optimal placement of Unified Power Flow Controllers (UPFC) in a large-scale transmission network in order to improve the loadability margin was considered. In other to achieve this aim, the Line Stability Factor (LQP) as a technique for the optimal location of UPFC in the IEEE 14-bus network and 56-bus Nigerian national grid was adopted. The power injection model for the UPFC was employed to secure improvements in the loading margin of the IEEE 14-bus network and 56-bus Nigerian national grid system. Continuation power flow was used to assess the effect of UPFC on the loadability margin. Steady-state simulations using Power System Analysis Toolbox (PSAT) on MATLAB was applied to determine the effectiveness of placing UPFC between bus 13 and bus 14 in the IEEE 14-bus network and between bus 44 (Ikot-Ekpene) and bus 56 (Odukpani) in the 56-bus Nigerian national grid system. The results showed that the loadability margin increased by 8.52 % after UPFC was optimally placed in the IEEE 14-bus network and increased by 195.5 % after UPFC was optimally placed in the 56-bus Nigerian national grid system. Thus, these enhance the voltage stability of both network and utilizing the network efficiently.

Voltage Stability Assessment of Grid Connected PV Systems With FACTS Devices

2021 ◽  
Author(s):  
Melat Abdullah ◽  
Lokman Hassan ◽  
M. Moghavvemi
Keyword(s):  
New England ◽  
Power Flow ◽  
Voltage Stability ◽  
Test System ◽  
Standard Test ◽  
Operating Conditions ◽  
Loading Conditions ◽  
Heavy Load ◽  
Pv Systems ◽  
Facts Devices

Abstract Three static techniques (i.e., Power flow, Continuation Power Flow (CPF), and the Q-V curve) were used to assess the voltage stability of the power grid with a Solar Photovoltaic Generator (SPVG) and FACTS devices under nominal and heavy loading conditions. A static model is proposed for the power system that includes conventional power generation units and SPVGs with FACTS devices. Two models of SPVG were used (i.e., PV model and PQ model) to elucidate the effect of the SPVGs on the voltage stability under various operating conditions. The best location for FACTS devices was obtained under nominal and heavy load conditions using static techniques. The series and shunt FACTS devices under nominal and heavy loading conditions were compared using the abovementioned static techniques. The interaction between SPVGs and FACTS devices is detailed in this paper. The proposed approach was tested on the New England 39-bus standard test system, and the results confirmed the effectiveness of the proposed method under various operating conditions.

scholarly journals Damping forced oscillations in power system via interline power flow controller with additional repetitive control

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Shirui Feng ◽  
Xi Wu ◽  
Zhenquan Wang ◽  
Tao Niu ◽  
Qiong Chen
Keyword(s):  
Power Flow ◽  
Forced Oscillation ◽  
Control Method ◽  
Damping Ratio ◽  
Repetitive Control ◽  
Oscillation Amplitude ◽  
Reference Value ◽  
Forced Oscillations ◽  
Flow Controller ◽  
Power Flow Controller

AbstractWith the continuous expansion of power systems and the application of power electronic equipment, forced oscillation has become one of the key problems in terms of system safety and stability. In this paper, an interline power flow controller (IPFC) is used as a power suppression carrier and its mechanism is analyzed using the linearized state-space method to improve the system damping ratio. It is shown that although the IPFC can suppress forced oscillation with well-designed parameters, its capability of improving the system damping ratio is limited. Thus, combined with the repetitive control method, an additional repetitive controller (ARC) is proposed to further dampen the forced power oscillation. The ARC control scheme is characterized by outstanding tracking performance to a system steady reference value, and the main IPFC controller with the ARC can provide higher damping, and further reduce the amplitude of oscillations to zero compared with a supplementary damping controller (SDC). Simulation results show that the IPFC with an ARC can not only greatly reduce the oscillation amplitude, but also actively output the compensation power according to the reference value of the ARC tracking system.

Research on Power Flow Control of UPFC Based on PSASP/UPI

2013 ◽  
Vol 385-386 ◽  
pp. 1078-1081 ◽  
Author(s):  
Fang Zhang ◽  
Jian Ping Chen ◽  
Chuan Dong Li ◽  
Yan Juan Wu
Keyword(s):  
Power System ◽  
Flow Control ◽  
Power Flow ◽  
System Analysis ◽  
Unified Power Flow Controller ◽  
Power Flow Control ◽  
Engineering Research ◽  
Good Convergence ◽  
Practical Engineering ◽  
Bus Voltage

The main objective of power flow control for unified power flow controller (UPFC) is to increase the transmission capacity over the existing transmission corridor or line. This paper presents a practical engineering methodology of embedding the power flow control model of UPFC into the commercial software -- power system analysis software package (PSASP) based on its user program interface (UPI) function. In the proposed methodology, the interface currents of UPFC series side and UPFC shunt side between the UPFC device and the network are used to control the transmission line power flow and UPFC bus voltage, respectively. In UPFC series side, the current of UPFC series branch is calculated from the power target equation of the controlled line. In UPFC shunt side, the shunt reactive current of UPFC is used to control the bus voltage. Simulation results on a practical power system show that the proposed methodology can be efficiently applied to the engineering research and analysis of the real power grid with UPFC with good convergence and only one control parameter needed to be prescribed.

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