scholarly journals PREDICTOR-BASED SELF TUNING CONTROL OF POWER PLANT

2006 ◽  
Vol 35 (3) ◽  
Author(s):  
Vytautas Kaminskas ◽  
Danguolė Janickienė

Design problems of predictor-based self tuning digital control systems for power plants are discussed. Investigation results for self-tuning control algorithms for a nuclear reactor are presented. These algorithms provide the minimum variance of power deviations from the given trajectory in transition and stationary regimes of operation.

2012 ◽  
Vol 58 (4) ◽  
pp. 351-356
Author(s):  
Mincho B. Hadjiski ◽  
Lyubka A. Doukovska ◽  
Stefan L. Kojnov

Abstract Present paper considers nonlinear trend analysis for diagnostics and predictive maintenance. The subject is a device from Maritsa East 2 thermal power plant a mill fan. The choice of the given power plant is not occasional. This is the largest thermal power plant on the Balkan Peninsula. Mill fans are main part of the fuel preparation in the coal fired power plants. The possibility to predict eventual damages or wear out without switching off the device is significant for providing faultless and reliable work avoiding the losses caused by planned maintenance. This paper addresses the needs of the Maritsa East 2 Complex aiming to improve the ecological parameters of the electro energy production process.


Author(s):  
Irina Anatolievna Borovikova

The article touches upon reliability issues of energy management systems (EMS) of marine power plants in emergency situations caused by disturbance of the working media consumption and their subsequent recovery. The mathematical model of processes allows to determine the nature of changes in temperature and pressure of water and lube oil in EMS systems. The requirements to the characteristics of automatic control systems of the marine power plant have been formulated. Basic provisions of the reliability theory are followed by presentation of methods of calculating reliability indices of complex technical systems. The article presents the results of the study of non-stationary modes and reliability indices. Reasonable requirements for automated control systems were obtained through the analysis of working environments and of equipment operating in non-stationary modes, non-exceedance of safety limits of marine power plant operation being taken as the admissibility criterion. Besides, there are possible special modes resulted from emergency situations caused by the power plant equipment failure. Hence, for operation and design of the analyses it is important to study changes of working media in the circulation systems, which resulted from the failure of the pumps. Basic circuit of lubrication and cooling systems of the ship diesel power plants has been approved as recommended by the company "MAN B&W" for slow speed diesel engines standard series MC. Among the recommended schemes there was approved the scheme of the main engine with an autonomous cooling circuit. Schematic diagram of energy systems of a diesel power plant has been made under recommendations of the engine developer. Specifications of the component parts of the ship diesel power plant have been taken as standard for manufactured machinery. A low running L90MC-C four-cylinder main engine manufactured by "MAN B&W" was chosen as a research sample. A mathematical model, as applied to the given problem, consists of 10 algebraic equations for nonsteady working media consumption and 18 differential equations for nonsteady heat transfer in heat exchangers, as well as equations for transport delay in the lubrication systems of internal combustion engines.


2021 ◽  
Vol 93 ◽  
pp. 01019
Author(s):  
G.A. Kilin ◽  
B.V. Kavalerov ◽  
A.I. Suslov ◽  
M.A. Kolpakova

Gas turbine units are widely used as a drive for a synchronous generator in a gas turbine power plant. The main problem here lies in the fact that the control systems of such gas turbine plants are transferred practically unchanged from their aviation counterparts. This situation leads to inefficient operation of the gas turbine power plant, which affects the quality of electricity generation. To solve this problem, it is necessary to improve the control algorithms for the automatic control systems of gas turbine plants. When solving this problem, gas turbine plants should be considered in interaction with other subsystems and units; for gas turbine power plants, this is, first of all, an electric generator and the electric power system as a whole. Setting up a control system is one of the most costly stages of their production, both in terms of finance and time. Especially time-consuming operations are non-automated manual configuration management system for developmental and operational testing. Therefore, it is proposed to use a software-modeling complex, on the basis of which it is possible to obtain a neural network mathematical model of a gas turbine power plant and conduct its tests.


2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis ◽  
Pericles Pilidis ◽  
Suresh Sampath

Abstract As demands for clean and sustainable energy renew interests in nuclear power to meet future energy demands, generation IV nuclear reactors are seen as having the potential to provide the improvements required for nuclear power generation. However, for their benefits to be fully realized, it is important to explore the performance of the reactors when coupled to different configurations of closed-cycle gas turbine power conversion systems. The configurations provide variation in performance due to different working fluids over a range of operating pressures and temperatures. The objective of this paper is to undertake analyses at the design and off-design conditions in combination with a recuperated closed-cycle gas turbine and comparing the influence of carbon dioxide and nitrogen as the working fluid in the cycle. The analysis is demonstrated using an in-house tool, which was developed by the authors. The results show that the choice of working fluid controls the range of cycle operating pressures, temperatures, and overall performance of the power plant due to the thermodynamic and heat properties of the fluids. The performance results favored the nitrogen working fluid over CO2 due to the behavior CO2 below its critical conditions. The analyses intend to aid the development of cycles for generation IV nuclear power plants (NPPs) specifically gas-cooled fast reactors (GFRs) and very high-temperature reactors (VHTRs).


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Robert A. Leishear

Abstract Explosive research proves that there is a common cause for most explosions in nuclear reactor power plants during normal operations and accident conditions. The autoignition of flammable hydrogen is a common cause for nuclear power plant explosions, where complex corrosion processes, nuclear reactions, and thermal-fluid transients autoignite explosions. Research evaluated increasingly complicated accidents. First, piping explosions occurred at Hamaoka and Brunsbuttel. Fluid transients compressed oxygen and flammable hydrogen to heat these gases to autoignition, where resultant explosions shredded steel pipes. This identical mechanism was responsible for pipe and pump damages to U.S. reactor systems since the 1950s, where water hammer alone has been assumed to cause damages. Small explosions inside the piping actually cause damages during nuclear reactor startups and flow rate changes. Second, explosions are caused by thermal-fluid transients during nuclear reactor restarts, following accidental nuclear reactor meltdowns. Disastrous explosions destroyed nuclear reactor buildings (RBs) at Fukushima Daiichi. Previously considered to be a fire, a 319 kilogram hydrogen explosion occurred at Three Mile Island (TMI). The explosion cause following each of these loss-of-coolant accidents was identical, i.e., after meltdowns, pump operations heated gases, which in turn acted as the heat source to autoignite sequential hydrogen explosions in reactor systems to ignite RBs. Third, the Chernobyl explosion followed a reactor meltdown that was complicated by a high energy nuclear criticality. The hydrogen ignition and explosion causes are more complicated as well, where two sequential hydrogen explosions were ignited by high-temperature reactor fuel.


Author(s):  
Mikhail A. Yastrebenetsky ◽  
Alexander A. Siora ◽  
Volodymyr I. Tokarev

In spite of wide expansion of digital systems for NPP control, information about realistic operating reliability measures of these systems is still lacking. The paper is a continuation of report [1] and contains results of analysis of operating reliability of digital control systems used in Ukrainian nuclear power plants. This paper contains: - reliability measures of digital instrumentation and control systems of first generation (designed in 1979–1983); - reliability measures of digital reactor control systems of second generation (designed after 2000) including reasons of failures; - analysis of the reasons of NPP violations due to digital instrumentation and control systems.


2019 ◽  
Vol 140 ◽  
pp. 02001 ◽  
Author(s):  
Roman Davydov ◽  
Valery Antonov ◽  
Sergey Makeev ◽  
Yury Batov ◽  
Valentin Dudkin ◽  
...  

The necessity of modernizing current control systems for functional units of a nuclear power plant, as well as the development of new control systems with a high degree of reliability and speed, is substantiated. The advantages of using optical sensors and fiber-optic communication lines to solve these problems are noted. Cases for which it is necessary to develop new fiber-optic sensors for monitoring parameters, for example, the flow of coolant or feed water, are considered. In some of them, it is more expedient to use standard designs of fiber-optic sensors to control the operating parameters of various blocks, for example, to control the electric field strength. A device and a control scheme for the parameters of the units and systems of a nuclear power plant using fiber-optic communication lines have been developed. The results of measuring various parameters of a nuclear reactor are presented. They showed that our proposed fiber-optic control and monitoring system for nuclear power plants operates more reliably and efficiently than systems with analogue control and measurement channels. The use of fiber-optic systems allows real-time remote control and high-speed control in terms of issuing commands to devices. This is very important when servicing a nuclear power plant while it is operating in extreme conditions.


Author(s):  
C Özsoy

This paper describes the minimum-variance parameter-adaptive (self-tuning) control algorithms for SISO and MIMO systems. The algorithms are designed on the basis of linear input-output system models by the combination of recursive-parameter estimation and control algorithms: a single-variable minimum-variance self-tuning controller and a multi-variable minimum-variance self-tuning controller. These controllers are applied to a three-input three-output single environmental space, which consists of an air heater, air humidifier and ventilator, and whose output variables are temperature, relative humidity and air velocity. The results of simulation indicate that it is possible to use the self-tuning controllers to stabilize the controlled system after a short adaption phase and to achieve at least a satisfactory control performance for time-varying set-points of the output variables.


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