Islanded microgrids with low-inertia distributed energy resources (DERs) are prone to frequency f... more Islanded microgrids with low-inertia distributed energy resources (DERs) are prone to frequency fluctuations. With the increasing integration of DERs in microgrids, the complexity of control and stability has also increased. Moreover, the integration of DERs into microgrids may result in a power imbalance between energy supply and demand during sudden changes in load or energy generation. This can cause frequency variations in the microgrid, which could have disastrous consequences such as equipment damage or even blackouts. This paper proposes a control strategy to ensure the efficient operation of an islanded hybrid microgrid consisting of a PV generator, battery energy storage system (BESS), and emergency diesel generator. According to Energy Exchange Model proposed in this paper, the hybrid system presented operates independently without being connected to the electrical grid, where the PV system and BESS act as the main energy sources, while the emergency diesel generator provides active power backup with voltage and frequency regulation. The novel in this paper is also that DER aids in frequency regulation during active power transients by delivering and absorbing active power in accordance with the inverter's suggested P droop control strategy. In this way inverter droop control decreases system frequency nadir emulating so called "synthetic inertia". To design both the islanded hybrid system and the proposed control strategy, the MATLAB/Simulink environment is utilized. Based on the results, it can be concluded that the analyzed microgrid system is capable of maintaining stability and operating efficiently in a range of operating conditions.
A control algorithm for Parallel Connected Offshore Wind Turbines with permanent magnet synchrono... more A control algorithm for Parallel Connected Offshore Wind Turbines with permanent magnet synchronous Generators (PCOWTG) is presented in this paper. The algorithm estimates the optimal collective speed of turbines based on the estimated mechanical power of wind turbines without direct measurement of wind speed. In the proposed topology of the wind farm, direct-drive Wind Turbine Generators (WTG) is connected to variable low-frequency AC Collection Grids (ACCG) without the use of individual power converters. The ACCG is connected to a variable low-frequency offshore AC transmission grid using a step-up transformer. In order to achieve optimum wind power extraction, the collective speed of the WTGs is controlled by a single onshore Back to Back converter (B2B). The voltage control system of the B2B converter adjusts voltage by keeping a constant Volt/Hz ratio, ensuring constant magnetic flux of electromagnetic devices regardless of changing system frequency. With the use of PI pitch co...
In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeli... more In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeling of pH neutralisator. Data that has been used for training of ANFIS are obtained by performing experiments on a real pH neutralisator. The mathematical model of the pH neutralisator is strongly nonlinear so it is advisable to use ANFIS, since ANFIS is an universal approximator. Inputs of the process (control variables) are flow of acid and hydroxide. The working temperature of the process is 128 0 C, with instaled pH meter of operating range 2-12 pH with combined glass electrode in the upper part of the neutralizer, 20 cm bellow the surface. Then using Genetic Algorithms (GA) parameters of PID controller of pH value has been adjusted in optimal way. Since GA is method of search of global optimum, achieved solution is optimal according to integral criterion of performance. Simulation results show utility of the proposed methodology.
This release contains GE DFIG Wind Turbine/Generator model, network model and conventional genera... more This release contains GE DFIG Wind Turbine/Generator model, network model and conventional generator models.
A New Control Algorithm for Directly Interconnected Offshore Wind Turbine Generators
2019 54th International Universities Power Engineering Conference (UPEC), 2019
A new control algorithm for Directly Interconnected offshore Wind Turbines with permanent magnet ... more A new control algorithm for Directly Interconnected offshore Wind Turbines with permanent magnet synchronous Generators (DIWTG) is presented. In the DΓWTG offshore wind park configuration, Wind Turbines with Permanent Magnet Synchronous Generators (WTPMSG) are directly connected to the offshore AC collection grid without using a power converter. The offshore AC collection grid is then connected, via a transformer, to the offshore AC transmission grid. In order to achieve maximum power point tracking, the (collective) speed of DΓWTGs is controlled by an onshore back to back converter. By measuring the active power and speed of the permanent magnet generators, wind speed at each turbine is estimated and used for calculation of the reference speed of WTPMSGs. Voltage control at the power converter side is performed in a way which allow the DΓWTGs to be operated at a constant V/f where the maximum resultant frequency at nominal wind speed is 16.67 Hz.
This paper presents a novel control algorithm for variable speed wind generators (VSWG), designed... more This paper presents a novel control algorithm for variable speed wind generators (VSWG), designed to provide support to grid frequency regulation. The proposed control algorithm ensures that VSWG ‘’truly’’ emulates response of a conventional generating unit with non-reheat steam turbine (GUNRST) in the first several seconds after active power unbalance. A systematic method of analysis and synthesis of the new control algorithm is described in detail.
Primary Frequency Regulation in Power Systems with Large Scale Integration of Wind Farms
Povecanjem udjela proizvodnih jedinica na bazi obnovljivih izvora energije, među kojima su i vjet... more Povecanjem udjela proizvodnih jedinica na bazi obnovljivih izvora energije, među kojima su i vjetroelektrane (VE), znacajno se mijenja struktura i nacin pogona elektroenergetskog sistema (EES). U uvjetima znacajnog ucesca VE u EES, dolazi do smanjenja broja prikljucenih konvencionalnih proizvodnih jedinica, odnosno posljedicno do smanjenja vrijednosti ukupne inercije sistema i izmjena dinamickih karakteristika EES-a. U novije vrijeme je sve ucestaliji zahtjev za ucescem VE u primarnoj i sekundarnoj regulaciji frekvencije. Doprinos VE primarnoj regulaciji frekvencije može se ostvariti upravljajuci injektiranjem djelatne snage vjetrogeneratora koje je zasnovano na ''ekstrakciji'' njegove kineticke energije. Na taj nacin se postiže da VE u ovom režimu rada imaju slicne karakteristike kao i konvencionalne elektrane. U radu su, na osnovu pregleda literature, ukratko prezentirani osnovni algoritmi za upravljanje aktivnom snagom VE pri frekventnim tranzijentima. Opisane su ...
In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeli... more In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeling of pH neutralisator. Data that has been used for training of ANFIS are obtained by performing experiments on a real pH neutralisator. The mathematical model of the pH neutralisator is strongly nonlinear so it is advisable to use ANFIS, since ANFIS is an universal approximator. Inputs of the process (control variables) are flow of acid and hydroxide. The working temperature of the process is 128C, with instaled pH meter of operating range 2-12 pH with combined glass electrode in the upper part of the neutralizer, 20 cm bellow the surface. Then using Genetic Algorithms (GA) parameters of PID controller of pH value has been adjusted in optimal way. Since GA is method of search of global optimum, achieved solution is optimal according to integral criterion of performance. Simulation results show utility of the proposed methodology.
Wind Turbine Dynamics (WTD) Library features a group of Simulink blocks for simulation of dynamic... more Wind Turbine Dynamics (WTD) Library features a group of Simulink blocks for simulation of dynamic response of generic models of Wind Turbine Generators (WTG) on power system disturbances, which includes the General Electric (GE) Doubly Fed Induction Generator (DFIG) model. The WTD Library features a set of Simulink blocks that models GE DFIG as well as conventional steam and hydro generating units that are connected to a transmission grid. The Library also includes a set of Matlab m and S functions which are used for power flow calculation and initialization of state variables of the models of GE DFIG and conventional steam and hydro generating units. The WTD library is an open source simulation tool primarily aimed for educational/research purpose since it enables incorporation of user-defined Simulink models. The Library is especially suitable for development and testing of new algorithms for the control of WTG, like virtual inertia and primary frequency control algorithms. IMPORTANT NOTICE: The only difference between the WTD Library Ver 1.0 and Ver 1.1 is in the WIND_TURBINE block (which is in WTD_slx_library_ver1 folder). In order to this block works properly, please install the new version of the WTD Library Ver 1.1.
Frequency Response Metrics of an Interconnected Power System
2019 54th International Universities Power Engineering Conference (UPEC), 2019
In this paper, the frequency response metrics of interconnected electric power systems (EPS) of S... more In this paper, the frequency response metrics of interconnected electric power systems (EPS) of Slovenia, Croatia and Bosnia and Herzegovina (ENTSO-E SCB control block) is presented. In the upcoming period in this region significant integration of wind energy is expected. Increased wind integration has great impacts on EPS frequency response due to decreasing total system inertia. A frequency response metrics calculation in a short period after a disturbance occurred is essential for design of any further frequency control action. Comparison of local bus frequency and frequency of centers of inertia is in the focus of this work. The regional EPS of South East Europe (SEE) is modeled using PSS/E. Frequency response metrics calculations and plots are performed using Python simulation language.
A simple mathematical model is presented for clinker production via a pyroprocessing unit consist... more A simple mathematical model is presented for clinker production via a pyroprocessing unit consisting of serial flow preheater cyclone stages, a precalciner, a rotary kiln and a clinker cooler. The model equations are based on steady state material and energy balances for solid and gas phases around each piece of equipment. The contribution of fuel ash to raw meal, recarbonation reactions in the preheater section and temperature dependence of specific heats are included in this model. A computer program has been developed to solve the model equations via an iterative procedure, yielding raw meal, stack gas, stack dust and temperature profiles and specific fuel consumption for a given set of input variables, thus enabling the user to investigate the impact of any design or process variable on the system performance. In this study the effects of fuel type and number of preheater stages on specific fuel consumption are investigated. The results indicate that in certain cases, by changin...
TURKISH JOURNAL OF ELECTRICAL ENGINEERING & COMPUTER SCIENCES, 2016
A modified control algorithm of a variable speed wind generator (VSWG) for supporting power syste... more A modified control algorithm of a variable speed wind generator (VSWG) for supporting power system frequency stabilization is presented in this paper. A comparison of the performance of this algorithm with active power control algorithms of VSWGs for supporting power system frequency stabilization, as published in the scientific literature, is also presented. A systematic method of analysis of the modified control algorithm is described in detail. It has been shown that by using the modified control algorithm, the VSWG "truly" emulates the inertial response of a conventional steam-generating unit with synchronous generators during the initial/inertial phase of primary frequency control, following loss of active power generation when wind speed is between cut-in (i.e. 4 m/s) and rated speed (i.e. 12 m/s). By the inclusion of a signal proportional to the frequency deviation as a power reference to the torque controller feedback loop of the modified control algorithm, it is ensured that the contribution of the VSWG to frequency stabilization is independent of the initial wind speed. This independence is kept as long as the wind speed is above the cut-in wind speed and slightly below the rated wind speed (i.e. 12 m/s). One of the important features of the modified control algorithm, namely a near-proportional relationship between the initial wind turbine speed and the maximum wind turbine speed variation during the inertial response, has been identified. The results of the analysis provide a solid basis for further research in the area of VSWG contribution to frequency stabilization.
Real - time Simulation with Kalman Filter and LQ Control using Connected Signal Processing Boards
In this paper we present the control design for an unknown SISO plant with system noise and measu... more In this paper we present the control design for an unknown SISO plant with system noise and measurement noise. The control and the plant are embedded on two independent real time simulation boards. The plant is implemented on the Burr Brown board PCI-20001C-2. The board has an A/D converter on the input channel and a D/A converter on the output channel, which are connected to the D/A converter and to the A/D converter of the dSPACE board DS1104. We make use of a specially developed set of MATLAB/ Simulink blocks, which support the dSPACE board. These blocks enable easy programming of different control algorithms in the Simulink frame. After developing control algorithms and models, Ccode generated from the Simulink model, is downloaded to the dSPACE board. ControlDesk is a user-interface for the DS1104 board. It is an environment for running real-time simulations. From this environment, we are able to download applications to the DS1104 board, to configure virtual instrumentation, t...
Synthesis of Mamdani Fuzzy Logic Controller as Gain Scheduling PID Controller
In this paper, an analysis of properties of PID controller and Mamdani Fuzzy Logic Controller (FL... more In this paper, an analysis of properties of PID controller and Mamdani Fuzzy Logic Controller (FLC) according to integral criterion of performance has been performed. Equivalence among fuzzy like PID controllers and gain scheduling PID controllers has been shown. PID controllers have three degrees of freedom for their adjustment while FLC’s have much more degrees of freedom for tuning of their properties [5]. Since FLC’s under certain conditions are universal approximators [8, 12], they can approximate any nonlinear control low (as a consequence any linear control low as well) arbitrarily well on compact set. It seems that using FLC’s for cloning of fixed PID controllers is wasting of resources. In this paper a new scheme for parameters tuning of Mamdani type FLC as gain scheduling PID is proposed It has been shown, using simulation that proposed scheme has properties that are close to properties of PID controller at circumstances in which PID controller was designed for, but at the...
Analysis and Initialization of GE Wind Turbine Control Model
Applied Mechanics and Materials, 2015
In this paper the analysis of a General Electric Wind Turbine Control Model (GEWTCM) and comparis... more In this paper the analysis of a General Electric Wind Turbine Control Model (GEWTCM) and comparison with a Generic Wind Turbine Control Model (GWTCM) is presented. The analysis is performed for the GEWTCM stationary state. Based on the analysis, a systematic method for the GEWTCM initializations as well as a methodology for calculation of the GEWTCM operating point in steady state are presented. It has been shown that, due to lack of limiting of the pitch controller and pitch compensation, uniqueness of solution for initial and steady state values of all GEWTCM state variables are ensured except for the state variables of the pitch controller and pitch compensation. Conclusions from the analysis can help in the implementation of the wind turbine control model in power system dynamic simulation software packages in applications with variable wind speed.
Optimisation of mathematical model of clinker production in cement factories
A lot of industrial processes are not optimally adjusted in relation with costs of production. Co... more A lot of industrial processes are not optimally adjusted in relation with costs of production. Controllers in factories are adjusted mostly with Ziegler-Nichols method with criteria of error minimisation of controlling loops. In this paper, optimisation is based on mathematical models (quadratic regression function) which are developed for prediction of clinker production in cement industry. These models are optimised with criteria of maximum profit but with technology and quality constrains. Mathematical method used to find optimal profit is nonlinear programming with constraints. This work intends to demonstrate a cheap and efficient procedure for approaching to optimum production.
In this paper is presented Model Reference Fuzzy-Neuro Text Matching System. By using user-friend... more In this paper is presented Model Reference Fuzzy-Neuro Text Matching System. By using user-friendly interface in the form of if-then rules, syntax and semantics rule base, and English word base, the input text has been transformed to an array of potentially important terms (entities). Entities, that are characterized with their names and attributes that have been extracted from the text,
Sufficient conditions for absolute stability and optimization using Genetic Algorithms of specific class Mamdani Fuzzy Logic State Variable Controllers
2008 27th Chinese Control Conference, 2008
ABSTRACT This paper has proposed a specific class of multiple input single output (MISO) Mamdani ... more ABSTRACT This paper has proposed a specific class of multiple input single output (MISO) Mamdani fuzzy logic state variable controllers (FLSVC) with triangle input membership functions, output membership functions with the same area, product fuzzy AND operator, sum fuzzy OR operator and centroid of area defuzzifier for control of stable Single Input Multiple Output (SIMO) linear time invariant systems. The proposed FLSVC in fact represents memoryless, nonlinear, locally Lipschitz mapping between its inputs and its output. According to the multivariable circle criterion for absolute stability, nonlinear part of the system must satisfy the sector condition. In this paper necessary and sufficient conditions have been determined, which must satisfy FLSVC parameters in order for the memoryless function represented by FLSVC to satisfy the sector condition. Subsequently, using the multivariable circle criterion, the sufficient conditions for absolute stability of feedback connected linear system and FLSVC have been determined. Based on the results achieved, an optimization method for both parameters and FLSVC decision rules has been proposed using genetic algorithms (GA).
Study of two step design methodology of near optimal fuzzy logic controller
42nd IEEE International Conference on Decision and Control (IEEE Cat. No.03CH37475)
... 2003 FrAO3-2 Study of Two Step Design Methodology of Near Optimal Fuzzy Logic Controller Jaku... more ... 2003 FrAO3-2 Study of Two Step Design Methodology of Near Optimal Fuzzy Logic Controller Jakub OsmiC University Clinical Center Tuzla Tmovac bb, 75000 Tuzla Bosnia and Herzegovina e-mail: [email protected] Abstract ...
Islanded microgrids with low-inertia distributed energy resources (DERs) are prone to frequency f... more Islanded microgrids with low-inertia distributed energy resources (DERs) are prone to frequency fluctuations. With the increasing integration of DERs in microgrids, the complexity of control and stability has also increased. Moreover, the integration of DERs into microgrids may result in a power imbalance between energy supply and demand during sudden changes in load or energy generation. This can cause frequency variations in the microgrid, which could have disastrous consequences such as equipment damage or even blackouts. This paper proposes a control strategy to ensure the efficient operation of an islanded hybrid microgrid consisting of a PV generator, battery energy storage system (BESS), and emergency diesel generator. According to Energy Exchange Model proposed in this paper, the hybrid system presented operates independently without being connected to the electrical grid, where the PV system and BESS act as the main energy sources, while the emergency diesel generator provides active power backup with voltage and frequency regulation. The novel in this paper is also that DER aids in frequency regulation during active power transients by delivering and absorbing active power in accordance with the inverter's suggested P droop control strategy. In this way inverter droop control decreases system frequency nadir emulating so called "synthetic inertia". To design both the islanded hybrid system and the proposed control strategy, the MATLAB/Simulink environment is utilized. Based on the results, it can be concluded that the analyzed microgrid system is capable of maintaining stability and operating efficiently in a range of operating conditions.
A control algorithm for Parallel Connected Offshore Wind Turbines with permanent magnet synchrono... more A control algorithm for Parallel Connected Offshore Wind Turbines with permanent magnet synchronous Generators (PCOWTG) is presented in this paper. The algorithm estimates the optimal collective speed of turbines based on the estimated mechanical power of wind turbines without direct measurement of wind speed. In the proposed topology of the wind farm, direct-drive Wind Turbine Generators (WTG) is connected to variable low-frequency AC Collection Grids (ACCG) without the use of individual power converters. The ACCG is connected to a variable low-frequency offshore AC transmission grid using a step-up transformer. In order to achieve optimum wind power extraction, the collective speed of the WTGs is controlled by a single onshore Back to Back converter (B2B). The voltage control system of the B2B converter adjusts voltage by keeping a constant Volt/Hz ratio, ensuring constant magnetic flux of electromagnetic devices regardless of changing system frequency. With the use of PI pitch co...
In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeli... more In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeling of pH neutralisator. Data that has been used for training of ANFIS are obtained by performing experiments on a real pH neutralisator. The mathematical model of the pH neutralisator is strongly nonlinear so it is advisable to use ANFIS, since ANFIS is an universal approximator. Inputs of the process (control variables) are flow of acid and hydroxide. The working temperature of the process is 128 0 C, with instaled pH meter of operating range 2-12 pH with combined glass electrode in the upper part of the neutralizer, 20 cm bellow the surface. Then using Genetic Algorithms (GA) parameters of PID controller of pH value has been adjusted in optimal way. Since GA is method of search of global optimum, achieved solution is optimal according to integral criterion of performance. Simulation results show utility of the proposed methodology.
This release contains GE DFIG Wind Turbine/Generator model, network model and conventional genera... more This release contains GE DFIG Wind Turbine/Generator model, network model and conventional generator models.
A New Control Algorithm for Directly Interconnected Offshore Wind Turbine Generators
2019 54th International Universities Power Engineering Conference (UPEC), 2019
A new control algorithm for Directly Interconnected offshore Wind Turbines with permanent magnet ... more A new control algorithm for Directly Interconnected offshore Wind Turbines with permanent magnet synchronous Generators (DIWTG) is presented. In the DΓWTG offshore wind park configuration, Wind Turbines with Permanent Magnet Synchronous Generators (WTPMSG) are directly connected to the offshore AC collection grid without using a power converter. The offshore AC collection grid is then connected, via a transformer, to the offshore AC transmission grid. In order to achieve maximum power point tracking, the (collective) speed of DΓWTGs is controlled by an onshore back to back converter. By measuring the active power and speed of the permanent magnet generators, wind speed at each turbine is estimated and used for calculation of the reference speed of WTPMSGs. Voltage control at the power converter side is performed in a way which allow the DΓWTGs to be operated at a constant V/f where the maximum resultant frequency at nominal wind speed is 16.67 Hz.
This paper presents a novel control algorithm for variable speed wind generators (VSWG), designed... more This paper presents a novel control algorithm for variable speed wind generators (VSWG), designed to provide support to grid frequency regulation. The proposed control algorithm ensures that VSWG ‘’truly’’ emulates response of a conventional generating unit with non-reheat steam turbine (GUNRST) in the first several seconds after active power unbalance. A systematic method of analysis and synthesis of the new control algorithm is described in detail.
Primary Frequency Regulation in Power Systems with Large Scale Integration of Wind Farms
Povecanjem udjela proizvodnih jedinica na bazi obnovljivih izvora energije, među kojima su i vjet... more Povecanjem udjela proizvodnih jedinica na bazi obnovljivih izvora energije, među kojima su i vjetroelektrane (VE), znacajno se mijenja struktura i nacin pogona elektroenergetskog sistema (EES). U uvjetima znacajnog ucesca VE u EES, dolazi do smanjenja broja prikljucenih konvencionalnih proizvodnih jedinica, odnosno posljedicno do smanjenja vrijednosti ukupne inercije sistema i izmjena dinamickih karakteristika EES-a. U novije vrijeme je sve ucestaliji zahtjev za ucescem VE u primarnoj i sekundarnoj regulaciji frekvencije. Doprinos VE primarnoj regulaciji frekvencije može se ostvariti upravljajuci injektiranjem djelatne snage vjetrogeneratora koje je zasnovano na ''ekstrakciji'' njegove kineticke energije. Na taj nacin se postiže da VE u ovom režimu rada imaju slicne karakteristike kao i konvencionalne elektrane. U radu su, na osnovu pregleda literature, ukratko prezentirani osnovni algoritmi za upravljanje aktivnom snagom VE pri frekventnim tranzijentima. Opisane su ...
In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeli... more In this paper is presented ANFIS (Adaptive Network based Fuzzy Inference System) method of modeling of pH neutralisator. Data that has been used for training of ANFIS are obtained by performing experiments on a real pH neutralisator. The mathematical model of the pH neutralisator is strongly nonlinear so it is advisable to use ANFIS, since ANFIS is an universal approximator. Inputs of the process (control variables) are flow of acid and hydroxide. The working temperature of the process is 128C, with instaled pH meter of operating range 2-12 pH with combined glass electrode in the upper part of the neutralizer, 20 cm bellow the surface. Then using Genetic Algorithms (GA) parameters of PID controller of pH value has been adjusted in optimal way. Since GA is method of search of global optimum, achieved solution is optimal according to integral criterion of performance. Simulation results show utility of the proposed methodology.
Wind Turbine Dynamics (WTD) Library features a group of Simulink blocks for simulation of dynamic... more Wind Turbine Dynamics (WTD) Library features a group of Simulink blocks for simulation of dynamic response of generic models of Wind Turbine Generators (WTG) on power system disturbances, which includes the General Electric (GE) Doubly Fed Induction Generator (DFIG) model. The WTD Library features a set of Simulink blocks that models GE DFIG as well as conventional steam and hydro generating units that are connected to a transmission grid. The Library also includes a set of Matlab m and S functions which are used for power flow calculation and initialization of state variables of the models of GE DFIG and conventional steam and hydro generating units. The WTD library is an open source simulation tool primarily aimed for educational/research purpose since it enables incorporation of user-defined Simulink models. The Library is especially suitable for development and testing of new algorithms for the control of WTG, like virtual inertia and primary frequency control algorithms. IMPORTANT NOTICE: The only difference between the WTD Library Ver 1.0 and Ver 1.1 is in the WIND_TURBINE block (which is in WTD_slx_library_ver1 folder). In order to this block works properly, please install the new version of the WTD Library Ver 1.1.
Frequency Response Metrics of an Interconnected Power System
2019 54th International Universities Power Engineering Conference (UPEC), 2019
In this paper, the frequency response metrics of interconnected electric power systems (EPS) of S... more In this paper, the frequency response metrics of interconnected electric power systems (EPS) of Slovenia, Croatia and Bosnia and Herzegovina (ENTSO-E SCB control block) is presented. In the upcoming period in this region significant integration of wind energy is expected. Increased wind integration has great impacts on EPS frequency response due to decreasing total system inertia. A frequency response metrics calculation in a short period after a disturbance occurred is essential for design of any further frequency control action. Comparison of local bus frequency and frequency of centers of inertia is in the focus of this work. The regional EPS of South East Europe (SEE) is modeled using PSS/E. Frequency response metrics calculations and plots are performed using Python simulation language.
A simple mathematical model is presented for clinker production via a pyroprocessing unit consist... more A simple mathematical model is presented for clinker production via a pyroprocessing unit consisting of serial flow preheater cyclone stages, a precalciner, a rotary kiln and a clinker cooler. The model equations are based on steady state material and energy balances for solid and gas phases around each piece of equipment. The contribution of fuel ash to raw meal, recarbonation reactions in the preheater section and temperature dependence of specific heats are included in this model. A computer program has been developed to solve the model equations via an iterative procedure, yielding raw meal, stack gas, stack dust and temperature profiles and specific fuel consumption for a given set of input variables, thus enabling the user to investigate the impact of any design or process variable on the system performance. In this study the effects of fuel type and number of preheater stages on specific fuel consumption are investigated. The results indicate that in certain cases, by changin...
TURKISH JOURNAL OF ELECTRICAL ENGINEERING & COMPUTER SCIENCES, 2016
A modified control algorithm of a variable speed wind generator (VSWG) for supporting power syste... more A modified control algorithm of a variable speed wind generator (VSWG) for supporting power system frequency stabilization is presented in this paper. A comparison of the performance of this algorithm with active power control algorithms of VSWGs for supporting power system frequency stabilization, as published in the scientific literature, is also presented. A systematic method of analysis of the modified control algorithm is described in detail. It has been shown that by using the modified control algorithm, the VSWG "truly" emulates the inertial response of a conventional steam-generating unit with synchronous generators during the initial/inertial phase of primary frequency control, following loss of active power generation when wind speed is between cut-in (i.e. 4 m/s) and rated speed (i.e. 12 m/s). By the inclusion of a signal proportional to the frequency deviation as a power reference to the torque controller feedback loop of the modified control algorithm, it is ensured that the contribution of the VSWG to frequency stabilization is independent of the initial wind speed. This independence is kept as long as the wind speed is above the cut-in wind speed and slightly below the rated wind speed (i.e. 12 m/s). One of the important features of the modified control algorithm, namely a near-proportional relationship between the initial wind turbine speed and the maximum wind turbine speed variation during the inertial response, has been identified. The results of the analysis provide a solid basis for further research in the area of VSWG contribution to frequency stabilization.
Real - time Simulation with Kalman Filter and LQ Control using Connected Signal Processing Boards
In this paper we present the control design for an unknown SISO plant with system noise and measu... more In this paper we present the control design for an unknown SISO plant with system noise and measurement noise. The control and the plant are embedded on two independent real time simulation boards. The plant is implemented on the Burr Brown board PCI-20001C-2. The board has an A/D converter on the input channel and a D/A converter on the output channel, which are connected to the D/A converter and to the A/D converter of the dSPACE board DS1104. We make use of a specially developed set of MATLAB/ Simulink blocks, which support the dSPACE board. These blocks enable easy programming of different control algorithms in the Simulink frame. After developing control algorithms and models, Ccode generated from the Simulink model, is downloaded to the dSPACE board. ControlDesk is a user-interface for the DS1104 board. It is an environment for running real-time simulations. From this environment, we are able to download applications to the DS1104 board, to configure virtual instrumentation, t...
Synthesis of Mamdani Fuzzy Logic Controller as Gain Scheduling PID Controller
In this paper, an analysis of properties of PID controller and Mamdani Fuzzy Logic Controller (FL... more In this paper, an analysis of properties of PID controller and Mamdani Fuzzy Logic Controller (FLC) according to integral criterion of performance has been performed. Equivalence among fuzzy like PID controllers and gain scheduling PID controllers has been shown. PID controllers have three degrees of freedom for their adjustment while FLC’s have much more degrees of freedom for tuning of their properties [5]. Since FLC’s under certain conditions are universal approximators [8, 12], they can approximate any nonlinear control low (as a consequence any linear control low as well) arbitrarily well on compact set. It seems that using FLC’s for cloning of fixed PID controllers is wasting of resources. In this paper a new scheme for parameters tuning of Mamdani type FLC as gain scheduling PID is proposed It has been shown, using simulation that proposed scheme has properties that are close to properties of PID controller at circumstances in which PID controller was designed for, but at the...
Analysis and Initialization of GE Wind Turbine Control Model
Applied Mechanics and Materials, 2015
In this paper the analysis of a General Electric Wind Turbine Control Model (GEWTCM) and comparis... more In this paper the analysis of a General Electric Wind Turbine Control Model (GEWTCM) and comparison with a Generic Wind Turbine Control Model (GWTCM) is presented. The analysis is performed for the GEWTCM stationary state. Based on the analysis, a systematic method for the GEWTCM initializations as well as a methodology for calculation of the GEWTCM operating point in steady state are presented. It has been shown that, due to lack of limiting of the pitch controller and pitch compensation, uniqueness of solution for initial and steady state values of all GEWTCM state variables are ensured except for the state variables of the pitch controller and pitch compensation. Conclusions from the analysis can help in the implementation of the wind turbine control model in power system dynamic simulation software packages in applications with variable wind speed.
Optimisation of mathematical model of clinker production in cement factories
A lot of industrial processes are not optimally adjusted in relation with costs of production. Co... more A lot of industrial processes are not optimally adjusted in relation with costs of production. Controllers in factories are adjusted mostly with Ziegler-Nichols method with criteria of error minimisation of controlling loops. In this paper, optimisation is based on mathematical models (quadratic regression function) which are developed for prediction of clinker production in cement industry. These models are optimised with criteria of maximum profit but with technology and quality constrains. Mathematical method used to find optimal profit is nonlinear programming with constraints. This work intends to demonstrate a cheap and efficient procedure for approaching to optimum production.
In this paper is presented Model Reference Fuzzy-Neuro Text Matching System. By using user-friend... more In this paper is presented Model Reference Fuzzy-Neuro Text Matching System. By using user-friendly interface in the form of if-then rules, syntax and semantics rule base, and English word base, the input text has been transformed to an array of potentially important terms (entities). Entities, that are characterized with their names and attributes that have been extracted from the text,
Sufficient conditions for absolute stability and optimization using Genetic Algorithms of specific class Mamdani Fuzzy Logic State Variable Controllers
2008 27th Chinese Control Conference, 2008
ABSTRACT This paper has proposed a specific class of multiple input single output (MISO) Mamdani ... more ABSTRACT This paper has proposed a specific class of multiple input single output (MISO) Mamdani fuzzy logic state variable controllers (FLSVC) with triangle input membership functions, output membership functions with the same area, product fuzzy AND operator, sum fuzzy OR operator and centroid of area defuzzifier for control of stable Single Input Multiple Output (SIMO) linear time invariant systems. The proposed FLSVC in fact represents memoryless, nonlinear, locally Lipschitz mapping between its inputs and its output. According to the multivariable circle criterion for absolute stability, nonlinear part of the system must satisfy the sector condition. In this paper necessary and sufficient conditions have been determined, which must satisfy FLSVC parameters in order for the memoryless function represented by FLSVC to satisfy the sector condition. Subsequently, using the multivariable circle criterion, the sufficient conditions for absolute stability of feedback connected linear system and FLSVC have been determined. Based on the results achieved, an optimization method for both parameters and FLSVC decision rules has been proposed using genetic algorithms (GA).
Study of two step design methodology of near optimal fuzzy logic controller
42nd IEEE International Conference on Decision and Control (IEEE Cat. No.03CH37475)
... 2003 FrAO3-2 Study of Two Step Design Methodology of Near Optimal Fuzzy Logic Controller Jaku... more ... 2003 FrAO3-2 Study of Two Step Design Methodology of Near Optimal Fuzzy Logic Controller Jakub OsmiC University Clinical Center Tuzla Tmovac bb, 75000 Tuzla Bosnia and Herzegovina e-mail: [email protected] Abstract ...
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