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 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.

Stability and Control of Tooling System for High-Speed Machining

2014 ◽  
Vol 684 ◽  
pp. 375-380
Author(s):  
Deng Sheng Zheng ◽  
Jian Chen ◽  
D.F. Tao ◽  
L. Lv ◽  
Gui Cheng Wang
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
System Stability ◽  
Finite Model ◽  
High Speed Machining ◽  
Cnc Machine ◽  
And Performance ◽  
The Stability ◽  
Tooling System ◽  
And Control

Tooling system for high-speed machining is one of the key components of high-end CNC machine , its stability and reliability directly affects the quality and performance of the machine. Based on the finite element method, developing a 3D finite model of high-speed machining tool system, studying on the stability of the high Speed machining tool from the natural frequency by the method of modal analysis. Analysis the amount of the overhang and clamping of the tooling , different shank taper interference fit and under different speed conditions, which affects the natural frequency of high-speed machining tool system. Proposed to the approach of improving system stability, which also provides a theoretical basis for the development of new high-speed machining tool system.

scholarly journals Condition-Monitoring System for Identification and Representation of the Capability Diagram Limits for Multiple Synchronous Generators in a Hydro Power-Plant

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3800
Author(s):  
Boris Glavan ◽  
Zlatko Hanić ◽  
Marinko Kovačić ◽  
Mario Vražić
Keyword(s):  
Power Plant ◽  
Monitoring System ◽  
Condition Monitoring ◽  
Synchronous Generator ◽  
Computationally Efficient ◽  
Synchronous Generators ◽  
Hydro Power ◽  
Automation And Control ◽  
Condition Monitoring System ◽  
And Control

This paper presents an experience in the design and implementation of the condition-monitoring system for the synchronous generators whose primary purpose is to record data for the identification of the capability limits of the P–Q diagram of three generators in hydro power-plant. Paper presents details about the monitoring system, the underlying theory of the identification of the synchronous generator model with a focus on the calculation of the capability limits in the P–Q diagram. Furthermore, a computationally efficient method for the representation of capability limits suitable for the implementation within the industrial automation and control system of the power-plant is described in detail. Finally, the capability diagrams for three generators were implemented in the power-plant supervisory control and data acquisition system (SCADA) system.

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 A close-loop verification approach for pedestrian stability based on machine vision

2022 ◽  
Vol 355 ◽  
pp. 03037
Author(s):  
Rongyong Zhao ◽  
Ping Jia ◽  
Yan Wang ◽  
Cuiling Li ◽  
Yunlong Ma ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Machine Vision ◽  
Lyapunov Theory ◽  
Control Measures ◽  
System Stability ◽  
Random Errors ◽  
Public Places ◽  
Crowd Management ◽  
The Stability ◽  
And Control

In public places, it is significant to analyze the stability of the crowd which can support the crowd management and control, and protect the evacuees safely and effectively. The numerical analysis method of system stability based on Lyapunov theory suffers problems that it is difficult to avoid random errors in the initialization of pedestrian density and velocity, as well as cumulative errors due to time increasing, limiting its application. This study adopts a complementary model of theoretical numerical analysis and machine vision with a parallel convolutional neural network (CNN) model. It proposes an approach of stability analysis and closed-loop verification for crowd merging systems. Thereby, this research provides theoretical and methodological support for planning of the functional layout of crowd flow in public crowd-gathering places and the control measures for stable crowd flow.

scholarly journals Adaptive Command-Filtered Backstepping Control for Virtual Synchronous Generators

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2681 ◽  
Author(s):  
Chengshun Yang ◽  
Fan Yang ◽  
Dezhi Xu ◽  
Xiaoning Huang ◽  
Dongdong Zhang
Keyword(s):  
Control Method ◽  
Controller Design ◽  
Synchronous Generator ◽  
System Stability ◽  
Synchronous Generators ◽  
Damping Control ◽  
Power Part ◽  
Transition Modes ◽  
Command Filter ◽  
Islanded Grid

Distributed energy sources are usually interfaced to the grid using power electronic converters, and lack of inertia in inverter dominated microgrids can affect the system stability. This paper presents a new method for virtual synchronous generator (VSG) control in order to solve the low system inertia and support the grid frequency problem. In this paper, the VSG based on electromagnetic transient characteristics is improved and an adaptive command filter back-stepping controller is designed. Firstly, the rotor swing equation and power part are modeled to complete the controller design for achieving system stability in the islanded, grid-connected and transition modes. In addition, a limited-amplitude command filter is used to deal with computational complexity and nonlinear saturation problems in the design process. Secondly, projection operator, and adaptive inertia and damping control are introduced to reduce the modeling error and disturbance caused by changing parameters. This ensures the boundedness of the estimated value and further improves the frequency response, especially in the transition mode. Finally, simulation results show that the proposed controller is more effective than the traditional control method for achieving power stability and frequency improvement.

Stability and Control of a Parametrically Excited Rotating Beam

1998 ◽  
Vol 120 (4) ◽  
pp. 462-470 ◽  
Author(s):  
S. C. Sinha ◽  
Dan B. Marghitu ◽  
Dan Boghiu
Keyword(s):  
Equations Of Motion ◽  
System Stability ◽  
Flexible Beam ◽  
Parametrically Excited ◽  
Stability And Control ◽  
Rotation Parameters ◽  
The Stability ◽  
And Control ◽  
Time Invariant ◽  
Time Periodic

In this paper the stability and control of a parametrically excited, rotating flexible beam is considered. The equations of motion for such a system contain time periodic coefficients. Floquet theory and a numerical integration are used to evaluate the stability of the linearized system. Stability charts for various sets of damping, parametric excitation, and rotation parameters are obtained. Several resonance conditions are found and it is shown that the system stability can be significantly changed due to the rotation. Such systems can be used as preliminary models for studying the flap dynamics and control of helicopter rotor blades and flexible mechanisms among other systems. To control the motion of the system, an observer based controller is designed via Lyapunov-Floquet transformation. In this approach the time periodic equations are transformed into a time invariant form, which are suitable for the application of standard time invariant controller design techniques. Simulations for several combinations of excitation and rotation parameters are shown.

Duffing Chaotic System Stability Control Based on Sliding Mode Control

2012 ◽  
Vol 605-607 ◽  
pp. 1639-1642
Author(s):  
Ding Ma
Keyword(s):  
Chaotic System ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure ◽  
Stability Control ◽  
System Stability ◽  
Terminal Sliding Mode ◽  
Sliding Mode Variable Structure ◽  
The Stability ◽  
And Control

Considering the Duffing chaotic system, the problem of stability control based on the terminal sliding mode variable structure is studied. A new terminal sliding mode surface and control law are designed. On this basis, the stability of closed-loop system is analyzed. Simulation results show the effectiveness of the control method.

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

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