scholarly journals Overview of Methods for Determining Parameters of Synchronous Generators

2020 ◽  
Vol 20 (4) ◽  
pp. 103-113
Keyword(s):  
Power Systems ◽  
Computational Models ◽  
Meta Analysis ◽  
Measurement Data ◽  
Synchronous Generator ◽  
Adaptive Model ◽  
Operational Control ◽  
Synchronous Generators ◽  
Computing Power ◽  
The Stability

A synchronous generator is one of the key elements of any power system, having a significant impact on the stability and reliability of consumers’ power supply. Nowadays, the power systems emergency and operational control issues are being solved using computational models, the parameters whereof are determined using the reference data, or the data obtained during testing. High dependence of the models’ parameters on various external factors leads to a significant decrease in the accuracy of solving the issues of emergency and operational control. Identification based on the traditional telemetry systems or synchrophasor measurements is used to improve the accuracy of parameters of the power systems’ computational models. The purpose of this research lies in a meta-analysis of the available studies aimed at developing a methodology for determining parameters of a synchronous generator on the basis of measurement data. Russian and foreign studies were analyzed and grouped to achieve this goal. After that, for each group, advantages, disadvantages, and the area of application were identified. As a result, it is shown that the existing methods for determining parameters of synchronous generators based on measurement data cannot adapt to the source dataset and also require significant computing power. As a way to overcome these shortcomings, an adaptive model of a synchronous machine is proposed.

scholarly journals Droop-free controls of inverter-based generator for use in systems that interconnected with synchronous generators

2021 ◽  
Vol 12 (2) ◽  
pp. 765
Author(s):  
Suchart Janjornmanit ◽  
Sakorn Panta ◽  
Wirat Nakkrongdee
Keyword(s):  
Synchronous Generator ◽  
Active Power ◽  
Control Technique ◽  
Voltage Source ◽  
Frequency Change ◽  
Droop Control ◽  
Synchronous Generators ◽  
Voltage Source Inverters ◽  
Autonomous Operation ◽  
The Stability

Because of its simplicity and autonomous operation, droop control technique is widely implemented for power generation control in microgrids. Despite its popularity, it has been reported that the technique has the stability problem. In this paper, the previous work of droop-free inverter-based generator designed for operating in a fix frequency islanded microgrid, is redesigned to have the ability to operate in both islanded and grid connected microgrid as well as to the main power grid where it interconnected with synchronous generators. The proposed voltage source inverters use phase locked loop(PLL) algorithm to synchronize the changing frequency due to the operation of the synchronous generator. Unlike the frequency droop control that the output frequency is varied as its active power changed, the proposed controls do not make an adjustment of the system frequency. This kind of operation reduces the chance of the system unstable due to severe frequency change and it also reduces the frequency deviation when it increases its active power output. Simulation and result of the meshed power network demonstrate the feasibility to implement the proposed controls in thereal system.

scholarly journals Modelling and Control of a Hydropower Plant in Dealing with the Speed Control Problem of Synchronous Generators

2020 ◽  
pp. 258-264
Author(s):  
Thi-Mai-Phuong Dao
Keyword(s):  
Rotational Speed ◽  
Synchronous Generator ◽  
Speed Control ◽  
System Stability ◽  
Hydropower Plant ◽  
Synchronous Generators ◽  
Output Frequency ◽  
Electric Power Grid ◽  
The Stability ◽  
And Control

Maintaining the rotational speed of synchronous generators in a hydropower plant is a vital control strategy in power system stability and operation. It is because such rotational speed is proportional to the output frequency of the synchronous generator, thereby it strongly affects the stability of the electric power grid. This paper presents a study regarding the modelling and control of a hydropower plant to maintain the generator speed. This study is divided into two main parts. A well-used model of an isolated hydropower plant is established in this study at first; then two controllers including conventional PI and intelligent fuzzy logic regulators are investigated to speed control of the generator. Simulations implemented in MATLAB/Simulink package demonstrate effectiveness and feasibility of the proposed speed controllers.

scholarly journals Effective damping of local low frequency oscillations in power systems integrated with bulk PV generation

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Ahmed Hesham Abd El-Kareem ◽  
Mohamed Abd Elhameed ◽  
Mahmoud M. Elkholy
Keyword(s):  
Power Systems ◽  
Objective Function ◽  
Damping Ratio ◽  
Low Frequency ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Local Modes ◽  
Low Frequency Oscillations ◽  
Electromechanical Modes ◽  
System Stabilizer

AbstractHigh penetration of renewable sources into conventional power systems results in reduction of system inertia and noticeable low-frequency oscillations (LFOs) in the rotor speed of synchronous generators. In this paper, we propose effective damping of LFOs by incorporating a supplementary damping controller with a photovoltaic (PV) generating station, where the parameters of this controller are coordinated optimally with those of a power system stabilizer (PSS). The proposed method is applied to damp local electromechanical modes by studying a system comprising a synchronous generator and a PV station connected to an infinite bus. The PV station is modeled following the instructions of the Western Electricity Coordinating Council. The problem is modeled as an optimization problem, where the damping ratio of the electromechanical modes is designed as the objective function. Constraints including upper and lower limits of decision parameters and damping ratio of other modes are considered by imposing penalties on the objective function. Different optimization algorithms are used to pursue the optimal design, such as political, improved gray wolves and equilibrium optimizers. The results validate the effectiveness of the proposed controller with PSS in damping local modes of oscillations.

scholarly journals Small-signal stability modeling of the microgrid with network transients taken into consideration

2021 ◽  
pp. 17-23
Author(s):  
Hung Nguyen-Van, Huy Nguyen-Duc Nguyen
Keyword(s):  
Power Systems ◽  
Frequency Control ◽  
State Space Model ◽  
Voltage Regulation ◽  
Electrical Network ◽  
Small Signal ◽  
Small Signal Stability ◽  
Synchronous Generators ◽  
Electrical Loads ◽  
The Stability

The development of a small signal model that accurately reflects dynamic processes plays an essential role in the stability analysis and control of power systems. The main components in a microgrid power system are synchronous generators, the electrical network, electrical loads, and inverters. A method to derive the microgrid state-space model is proposed in the article. This method is based on linearized models of synchronous generators, electronic power inverters, networks, and loads. This model can be further developed to account for microgrid control schemes such as frequency control and voltage regulation. A small-signal analysis of the Microgrid model is also carried out in this work.

Dynamic Performance Enhancement of Synchronous Generator Excitation via Nonlinear Backstepping Control

2017 ◽  
Vol 18 (4) ◽  
Author(s):  
Haitham Saad Mohamed Ramadan ◽  
Mohamed Becherif
Keyword(s):  
Power Systems ◽  
Transient Stability ◽  
Performance Enhancement ◽  
Dynamic Performance ◽  
Synchronous Generator ◽  
Nonlinear Character ◽  
Synchronous Generator Excitation ◽  
Single Machine Infinite Bus ◽  
The Stability ◽  
Nonlinear Backstepping Control

Abstract This paper addresses the transient stability problem in power systems of nonlinear character. A recursive nonlinear backstepping controller for improving the single machine infinite bus system’s dynamic behavior is proposed for the system global stabilization considering the network transfer conductances. Despite parameters uncertainties, nonlinear dynamics and/or disturbances, the feedback laws based on the backstepping approach are explicitly derived and the conservatism of the stability property is guaranteed for both lossy and lossless power system representations. Simulation results, via MATLAB™-Simulink, reveal that the proposed backstepping technique can be feasibly designed to ensure significant dynamic performance enhancements.

scholarly journals ANALYSIS OF OVERVOLTAGE POSSIBILITY ON THE EXCITATION WINDING OF A SYNCHRONOUS GENERATOR OF AUTONOMOUS POWER SUPPLY SYSTEM IN CASE OF EXTERNAL SYMMETRICAL SHORT CIRCUIT

2021 ◽  
pp. 112-115
Author(s):  
V.B. Beliy ◽  
Keyword(s):  
Power Systems ◽  
Power Supply ◽  
Short Circuit ◽  
Electric Energy ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Excitation System ◽  
Three Phase ◽  
Short Circuits ◽  
Analytical Expressions

Reliable supply of consumers with electric energy largely depends on the reliability of power source function-ing. In the context of this paper it depends on synchronous generators operating in autonomous power supply sys-tems. In contrast to the power plant generators which are part of power systems and are protected from the loads by sufficiently large resistances, power supply systems withautonomous generators are characterized by rather low resistances. Abrupt changes in the supply load parameters, their own transient and emergency modes, for example, short circuits at the generator terminals, forcing excitation, etc. may lead to various failures in the synchronous gener-ator operation. This paper discusses the possibility of over-voltage in the valve excitation system of a synchronous generator with external three-phase short circuits. On the basis of analytical expressions describing the physical pro-cesses occurring in the excitation system of synchronous generators, the conditions for the occurrence of overvolt-ages are identified

Synthesizing a Power System Stabilizer Using the Fuzzy Logic and Neural Network Methods

2021 ◽  
pp. 22-30
Author(s):  
Kahramon R. ALLAEV ◽  
◽  
Tokhir F. MAKHMUDOV ◽  
Keyword(s):  
Neural Network ◽  
Fuzzy Logic ◽  
Power Systems ◽  
Power System ◽  
Fuzzy Logic Controller ◽  
Power Transmission ◽  
Low Frequency ◽  
Synchronous Generator ◽  
Electromechanical Oscillations ◽  
The Stability

Power systems are large non-linear systems that are often subject to low frequency electromechanical oscillations with a frequency of 0.5–2.5 Hz. Power system stabilizers (PSS) are commonly used as effective and economically efficient means to dampen electromechanical oscillations of generators and increase the stability of power systems. PSS can increase the power transmission stability limits by adding a stabilizing signal through the channels of the automatic excitation control system. The article presents the results of training a neural network based on which a fuzzy logic PSS is obtained for increasing the stability of electric power systems. The synchronous generator rotor speed deviation and acceleration were taken as input data for the fuzzy logic controller. These variables have a significant effect on damping the rotor's electromechanical oscillations. The characteristics of the power system equipped with the proposed fuzzy logic based PSS are compared with its characteristics with a PSS with non-optimized parameters and without a PSS.

The Excitation Controller for A Synchronous Generator Based on Nonlinear Optimal Control

2011 ◽  
Vol 383-390 ◽  
pp. 5542-5547
Author(s):  
Jin Ling Yang ◽  
Ru Cheng Han
Keyword(s):  
Differential Geometry ◽  
Optimal Control ◽  
Synchronous Generator ◽  
Optimal Controller ◽  
Excitation Control ◽  
Synchronous Generators ◽  
Single Machine Infinite Bus ◽  
The Stability ◽  
Linear Controllers ◽  
Better Than

A nonlinear optimal controller for excitation control of synchronous generators is presented. Based on differential geometry theory, the controller is designed by transforming the nonlinear system to an equivalent linear system. The analysis and simulation of a single-machine infinite-bus power system indicate that the stability of the proposed controller better than the stability of conventional linear controllers

scholarly journals Synchronous Generator Model Parameter Estimation Based on Noisy Dynamic Waveforms

2016 ◽  
Vol 67 (1) ◽  
pp. 21-28
Author(s):  
Sebastian Berhausen ◽  
Stefan Paszek
Keyword(s):  
Parameter Estimation ◽  
Power Systems ◽  
Power System ◽  
Objective Function ◽  
Estimation Method ◽  
Synchronous Generator ◽  
Voltage Regulation ◽  
Operating Conditions ◽  
Synchronous Generators ◽  
Generator Voltage

Abstract In recent years, there have occurred system failures in many power systems all over the world. They have resulted in a lack of power supply to a large number of recipients. To minimize the risk of occurrence of power failures, it is necessary to perform multivariate investigations, including simulations, of power system operating conditions. To conduct reliable simulations, the current base of parameters of the models of generating units, containing the models of synchronous generators, is necessary. In the paper, there is presented a method for parameter estimation of a synchronous generator nonlinear model based on the analysis of selected transient waveforms caused by introducing a disturbance (in the form of a pseudorandom signal) in the generator voltage regulation channel. The parameter estimation was performed by minimizing the objective function defined as a mean square error for deviations between the measurement waveforms and the waveforms calculated based on the generator mathematical model. A hybrid algorithm was used for the minimization of the objective function. In the paper, there is described a filter system used for filtering the noisy measurement waveforms. The calculation results of the model of a 44 kW synchronous generator installed on a laboratory stand of the Institute of Electrical Engineering and Computer Science of the Silesian University of Technology are also given. The presented estimation method can be successfully applied to parameter estimation of different models of high-power synchronous generators operating in a power system.

scholarly journals Enhancement of Power System Transient Stability by the Coordinated Control between an Adjustable Speed Pumping Generator and Battery

2020 ◽  
Vol 10 (24) ◽  
pp. 9034
Author(s):  
Junji Tamura ◽  
Atsushi Umemura ◽  
Rion Takahashi ◽  
Atsushi Sakahara ◽  
Fumihito Tosaka ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Farm ◽  
Transient Stability ◽  
Wind Farms ◽  
System Stability ◽  
Synchronous Generators ◽  
Adjustable Speed ◽  
The Stability ◽  
Network Fault

The penetration level of large-scale wind farms into power systems has been increasing significantly, and the frequency stability and transient stability of the power systems during and after a network fault can be negatively affected. This paper proposes a new control method to improve the stability of power systems that are composed of large wind farms, as well as usual synchronous generators. The new method is a coordinated controlling method between an adjustable-speed pumping generator (ASG) and a battery. The coordinated system is designed to improve power system stability during a disconnection in a fixed-rotor-speed wind turbine with a squirrel cage-type induction generator (FSWT-SCIG)-based wind farm due to a network fault, in which a battery first responds quickly to the system frequency deviation due to a grid fault and improves the frequency nadir, and then the ASG starts to supply compensatory power to recover the grid frequency to the rated frequency. The performance of the proposed system was confirmed through simulation studies on a power system model consisting of usual synchronous generators (SGs), an ASG, a battery, and an SCIG-based wind farm. Simulation results demonstrated that the proposed control system can enhance the stability of the power system effectively.

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