scholarly journals State Estimation of Power System Embedded with FACTS devices and PMUs

2018 ◽  
Vol 7 (2.6) ◽  
pp. 199
Author(s):  
Balaji Venkateswaran V ◽  
Neeraj Kumar Sharma ◽  
Deepali Yadav

In recent days, the power system is incorporated with Flexible AC Transmission System (FACTS) devices for compensation of reactive power to maintain the stability of the system. The stability of the system is highly dependent on the state variables which are the outcomes of a state estimator in the power system. To improve the efficiency of a state estimator, high precision measuring devices such as Phasor Measurement Units (PMUs) are installed in the power system. Hence a state estimator embedded with these compensatory devices and PMUs is necessary for estimation of state variables. The present work has been carried out in three steps. Step 1: Considering the cost of PMUs and the availability of the communication network in the particular location, PMUs are optimally placed in the nodes of the system so that all critical measurements are transmuted into redundant ones using differential evolution (DE) algorithm to perform observability analysis. Step 2: A hybrid state estimation is performed by including the mathematical model of FACTS devices and PMUs. Step 3: It is shown that by installing optimal number of PMUs at desired location, multiple bad data detection and identification capability of residual method is considerably improved. Lastly, numerical simulation with standard IEEE 14 bus system, IEEE 118 bus system and a practical 246 bus system of northern region power grid (NRPG) is presented to confirm the effectiveness of the proposed approach in assessing the estimation of the system state variables.

2019 ◽  
Vol 4 (2) ◽  
pp. 128-136
Author(s):  
Dara Hama Amin

Voltage stability refers to maintaining the value of the voltage in all busses of the electric network at a steady level (initial operating point) during any sudden disturbance. Voltage instability may happen due to an increase in the demand of the load or in case of any change in the reactive power, thus, the system will go into uncontrollable and unstoppable decline in the voltage level. The effect of Static Var Compensator (SVC) on voltage stability is discussed in the paper, as well as the improvement of the voltage profile. Usually, SVC and FACTS devices were used for enhancing the voltage level profile and so the stability. Choosing the optimal location for the FACTS devices is essential due to its expensive costs. This paper used sensitivity factor to helpful to determine the most correct placement of FACTS devices in the system. Simulations are performed on Kurdistan Region 30-bus Power System using MATLAB-PSAT tool. As a result, the voltage of all 30 buses calculated. Based on the “voltage sensitivity factor”, the nominated weak buses has been marked which are suitable for placing the FACTS devices in order to improve the limits of the voltage stability of the system. Moreover, depending on the obtained optimal locations, a full analysis of the voltage and powers for the system has applied in two cases, before and after placing SVC respectively which is result in notable stability improvement and losses reduction.


2022 ◽  
Author(s):  
Ognjen Kundacina ◽  
Mirsad Cosovic ◽  
Dejan Vukobratovic

The goal of the state estimation (SE) algorithm is to estimate complex bus voltages as state variables based on the available set of measurements in the power system. Because phasor measurement units (PMUs) are increasingly being used in transmission power systems, there is a need for a fast SE solver that can take advantage of PMU high sampling rates. This paper proposes training a graph neural network (GNN) to learn the estimates given the PMU voltage and current measurements as inputs, with the intent of obtaining fast and accurate predictions during the evaluation phase. GNN is trained using synthetic datasets, created by randomly sampling sets of measurements in the power system and labelling them with a solution obtained using a linear SE with PMUs solver. The presented results display the accuracy of GNN predictions in various test scenarios and tackle the sensitivity of the predictions to the missing input data.


Author(s):  
Ram Gopal Sharma

Fault analysis study is the important parameter of economic, reliable and secure power system planning and operation. Power system studies are important during the planning and conceptual design stages of the project. This paper presents the fault analysis on IEEE-9 bus system. The line to ground fault is created on bus 5th and analyzed the variation in Voltage, Real power, Reactive power on different buses. The fault at 5th bus of IEEE-9 bus system is analyzed on PSCAD software.


2018 ◽  
Vol 7 (1.8) ◽  
pp. 188
Author(s):  
M Dhana Sai Sri ◽  
P Srinivasa Varma

Reliability of network is need of the hour in the present power system market and is constrained by capability of the network. The network calculations are performed using accurate and high efficient strategies. In order to perform power transactions in the system, the computation of available transfer capability is essential which a metric of capability of the system. Generally, effect wattless power is not taken into account in the methodologies for computation of linear available transfer capability. In this paper, a methodology which considers the reactive power flows for enhancement of linear ATC is presented. In order to perform analysis theoretically, a standard IEEE 3 bus system is considered. Another case study i.e., 14 bus system available in IEEE test systems is used for simulation analysis. FACTS technology is incorporated in the existing system in order to enhance capability of the network. To facilitate transfer maximum power in the system, an optimal power-flow-based ATC enhancement model is formulated and presented along with simulation results. Studies based on the IEEE 3-bus system and 14-bus systems with TCSC demonstrate the effectiveness of FACTS control on ATC enhancement.  


2016 ◽  
Vol 19 (2) ◽  
pp. 16-24
Author(s):  
Quang Huu Vinh Luu

A new algorithm simulating the impacts of the VAR supporting devices such as the static var compensators (SVCs) and the synchronous condensers (SCs) under condition of symmetrical disturbances in multi-machine power system is mentioned. Some typical numerical examples are presented in this article. The comparisons of variation of the state parameters, such as the voltage, frequency, reactive power outputs and asynchronous torques…are simulated under condition of the action of the automatic voltage regulation systems of generators and of the VAR supporting devices. The transient energy margins are calculated and compared to assess the transient stability in multi-machine power system. Basing on this algorithm, the PC program uses the elements of the eigen-image matrix to bring the specific advantages for the simulation of the transient features of state variables.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 900 ◽  
Author(s):  
Shiwei Xia ◽  
Qian Zhang ◽  
Jiangping Jing ◽  
Zhaohao Ding ◽  
Jing Yu ◽  
...  

Effective state estimation is critical to the security operation of power systems. With the rapid expansion of interconnected power grids, there are limitations of conventional centralized state estimation methods in terms of heavy and unbalanced communication and computation burdens for the control center. To address these limitations, this paper presents a multi-area state estimation model and afterwards proposes a consensus theory based distributed state estimation solution method. Firstly, considering the nonlinearity of state estimation, the original power system is divided into several non-overlapped subsystems. Correspondingly, the Lagrange multiplier method is adopted to decouple the state estimation equations into a multi-area state estimation model. Secondly, a fully distributed state estimation method based on the consensus algorithm is designed to solve the proposed model. The solution method does not need a centralized coordination system operator, but only requires a simple communication network for exchanging the limited data of boundary state variables and consensus variables among adjacent regions, thus it is quite flexible in terms of communication and computation for state estimation. In the end, the proposed method is tested by the IEEE 14-bus system and the IEEE 118-bus system, and the simulation results verify that the proposed multi-area state estimation model and the distributed solution method are effective for the state estimation of multi-area interconnected power systems.


2014 ◽  
Vol 950 ◽  
pp. 314-320 ◽  
Author(s):  
Jun Jia ◽  
Xin Xin Hu ◽  
Ping Ping Han ◽  
Yan Ping Hu

With the scale of wind farm continuously increasing, when grid fault, the influences of the wind turbines connected to the grid on the stability of the power grid can never be ignored. Therefore, there are higher standards of the wind turbines’ abilities of fault ride-through (FRT) and producing reactive power. This paper studies the direct-drive wind power system, and the main point is the fault ride-through (FRT) of the permanent magnetic synchronous generator (PMSG) with Chopper. By establishing the dynamic model of PMSG under the environment of DigSILENT, this paper simulates the fault ride-through (FRT) of the direct-drive wind power system connecting into power grid. During the research, we focus on the stability of voltage about the Chopper to the DC bus under faults. What’s more, in this paper, we analysis the data about how the Chopper help the DC bus to improve its stability. The simulation results show that: when there is a fault on the point of common coupling, the permanent magnetic synchronous generator has the capability of fault ride-through (FRT). Especially when there is a voltage dip on the grid side, the permanent magnetic synchronous generator could produce reactive power for power grid, effectively preventing the system voltage from declining seriously, so as to improve the system stability under faults.


2015 ◽  
Vol 64 (2) ◽  
pp. 237-248
Author(s):  
Piotr Kozierski ◽  
Marcin Lis ◽  
Adam Owczarkowski ◽  
Dariusz Horla

Abstract An approach to power system state estimation using a particle filter has been proposed in the paper. Two problems have been taken into account during research, namely bad measurements data and a network structure modification with rapid changes of the state variables. For each case the modification of the algorithm has been proposed. It has also been observed that anti-zero bias modification has a very positive influence on the obtained results (few orders of magnitude, in comparison to the standard particle filter), and additional calculations are quite symbolic. In the second problem, used modification also improved estimation quality of the state variables. The obtained results have been compared to the extended Kalman filter method


2020 ◽  
Vol 1 (1) ◽  
pp. 26-30
Author(s):  
Violet Kaswii ◽  
Michael Juma Saulo

The interline power flow controller (IPFC) and the unified power flow controller (UPFC) are both advanced types of flexible AC transmission systems (FACTS). These devices can provide the power system with control of voltage, and that of real and reactive power. This paper reviews the literature on UPFC and IPFC FACTS devices in voltage control and covers two main areas of research (i) voltage control using FACTS devices, and (ii) UPFCs / IPFCs and their applications in power systems. FACTs devices are applied in modern power system networks for the purpose of voltage control while at the same time providing enhanced power system stability. Research has shown that their benefits in the long run outweighs their high cost especially when they are optimally sized and located in the power network. Moreover, in the planning of power transmission systems, a Multi-Criteria Decision Making (MCDM) technique can help in the incorporation of both the costs and technical viability. This approach provides techno-economic optimization and at the same time meeting environmental criteria.


2020 ◽  
Vol 5 (2) ◽  
pp. 35-37
Author(s):  
Vipin Kumar Pandey ◽  
Dr. Malay S Das ◽  
Dr. Anula Khare

Due to increase in population and industrial growth, insufficient energy resources to generate or transmit the power in power system, increase in load causes power demand in the electrical power system. These power demand leads to voltage instability, increase the losses, reduces the power transfer capability and stability of the power system. To overcome this stability problem FACTS devices are optimally located in the power system to examine the stability of the system. To locate the FACTS devices different optimization algorithms are used in order to improve the stability of the electrical power system.


Sign in / Sign up

Export Citation Format

Share Document